Hi,
You know the standard Fuzz Face with 2 transistor (Q1 and Q2).
Can I replace them with pre-amp tubes?
(http://www.geofex.com/Article_Folders/fuzzface/fftech1.gif)
I've been searching the Internet for a solution, cannot find one.
Some of these tubes have like 8 pins and transistor 3 (emitter, base and collector)
(http://www.mclink.it/com/audiomatica/tubes/img/12at7pin.gif)
and I've seen pre-amp schematics using pins 1,2,3 then 6,7,8 ...etc
What am I trying to say is:
I want to know how the fuzz face schematic would be like using tubes in place of the transistors.
Thanks,
Jon
Has anyone build a tube fuzz face ???
i think the answer would be don't bother. i've never built anything with tubes, but....one your only dealing with 9v power, which i think wouldn't come close to the requirement of a tube. you' need to step the voltage up by heaps. two, i believe some of those pins will be for the tube's heater. you need to keep those suckers hot to operate.
find a good tube project on the web and try not to electrocute yourself/gear i guess. there's be so much adaption to get the fuzz face to work with tubes that you would have designed a completely original circuit.
I think that a triode fuzz face would be a fun project. It would have to operate way differently from the real thing, of course. It would need high voltages, and would probably have a high input impedance (unless the circuit was designed to waste that high input impedance). It wouldn't sound like a fuzz face, but it'd be fun as heck to try out, and some super bragging rights would go to the person who designed it.
DANGEROUS TERRITORY!
Listen to what the guys have told you.
Just off hand I didn't think this was all that likely to work out. But I popped it into the simulator to see if there was any promise. Yes, I know that circuit simulators are not perfect. But they are good indicators.
1. The original power supply won't work, as was mentioned. 9V is really not enough for the commonly available tubes. I upped the power supply to 75V, then 150V (which you can get by rectifying the primary voltage of a back to back transformer setup. I could get that to bias up and amplify at least.
2. The original resistors won't work. They're in general too low.
3. The original biasing setup won't work, as tubes are depletion mode devices; they are naturally "on" and you have to do something to the input to turn them off. Bipolars are enhancement mode devices which are naturally off, and you have to do something to them to turn them on. So I diddled with the biasing setup.
By this time, there was none of the original circuit left, except that there was a first gain stage, directly coupled second stage, and feedback biasing to the first stage input. But it did amplify. The amplification made for a really sharp clip on the top side of the output and no clipping at all on the bottom side. There would be a prominent fuzzy octave effect, pretty harsh. Very little soft smooth tube distortion.
It's possible that more tinkering would produce something usable, but it would be an entirely new circuit.
Back when I was in school, they taught some stuff about generalized three terminal devices. This covered bipolars, triodes, pentodes, JFETs, and MOSFETs. All of these have an input pin (base, grid, grid, gate, and gate respectively) an output pin (collector, anode, anode,drain, drain) and an input/output pin (emitter, cathode, cathode, source, source) and can be used in generalized circuits of the same format except for the biasing and supply voltage provisions.
Sometimes you can make easy and simple substitutions, sometimes you can't.
Beyond that, you have some very good advice from the other guys. Tube power supplies can be as low as 12V, as they did in old car radio circuits, but the only tubes in current production are not like those specialized ones. The 12AX7 that we can actually get has a very hard time working that low, and sounds distinctly starved and astringent when you do it. It really needs over 50V and better yet over 100V. These voltages are downright dangerous.
So - good inspiration. But the actual execution of the idea will be long, difficult, and possibly dangerous if you don't have experience with high voltages.
I don't know about a tube Fuzz Face, but you could do a low voltage tube fuzz.
Check out the following patent, lots of detail in that one:
http://www.freepatentsonline.com/5022305.pdf (http://www.freepatentsonline.com/5022305.pdf)
IMHO total waste of tubes. I mean, fuzz is meant to sound harsh and ugly. The reason everyone likes tubes is their warmer and smoother overdrive. Why would you want to do that when you can get the lowest quality transistor and get the same effect?
Simulators, bah. I actually built one quite awhile back. I ran it at a higher voltages and had to mess with the circuit quite a bit just to make it work most of which R.G. has covered. When it did work it was very much unlike the FF and was unimpressive in itself. To get anything interesting I has break the core FF design principals.
I would say unless you want to try it for a learning experience I wouldn't bother.
Andrew
...i know daniel at dinosaural is building a "tube-bender"...what it has in common with the original tonebender, i have no idea....
...also...for low voltage applications there *are* tubes such as 6088 and ck512ax submini's....here a link to some info....
http://members.aol.com/sbench101/BatteryPoweredAmps/submin.html (http://members.aol.com/sbench101/BatteryPoweredAmps/submin.html)
http://members.aol.com/sbench101/ (http://members.aol.com/sbench101/)
i doubt you'd have good results as a "fuzz face" style circuit, but heck....if youre gonna experiment, its much safer with these low voltage ones...and you may very well come up with something cool !
hope this helps,
AC
ha! stay tuned......
Don't leave us hanging, give us a few hints. Space charge tubes? 12ae7?
Quote from: pinkjimiphoton on April 23, 2020, 01:19:37 PM
ha! stay tuned......
Should we also stay tremendously scared, Jimi..?? :icon_cool: :icon_eek:
if it works, and it should, well..... lets just say its gonna run on 9 volts. i figured out a couple weird little tricks i'm currently playing with. i mean...
a fuzz face ya want around hfe's of 70-100. that's easy to do with a 12ax7 with a gain of 100... make the first stage less gain . easy breezy.
the trick is getting enough current to run the tubes, and also to run the heaters for the tube cathodes.
matsumin did most of the heavy lifting, really. compare a fuzz face and a valve caster. if ya think of the plate grid and cathode as collector, base and emitter, well... you can most certainly wire up a fuzzface using much of the standard ff circuit, and matsumin's power supply ideas for running it on dc.
dc runs about 130ma of current with a 12ax7 heater circuit if ya run it at 12 volts instead of 12.6. it will still light up the heaters. if ya can light the heaters, you can make the tube work.
the one i'm working on uses charge pump circuitry and voltage regulation to get enough juice and current to take care of the heater supply, then uses a simple diode bridge to run the plates off a 9vac 2000ma supply. i'm not supposed to really mention this shit cuz its gonna be coming out commercially, so i can't give all the details, but i think most of you brethren are savvy enough to figure out what i did.
remember, you don't need to worry about linearity in this, its a @#$%in' fuzzface ;) you don't need much headroom, and low plate voltages with a decent supply of current will help you fuzz. the big thing is setting the gain for each triode right, and then biasing correctly.
think of the support circuitry for the tubes as being completely separate, yet simple. think valvecaster and the couple clues i gave... think of plate grid and cathode as collector base emitter and wango...
you too can make a tube fuzzface. it's semi working on my bench already. i just gotta dial it in a bit more. standard fuzzface values for most parts, too, cuz a lot of the tone of the ff circuit comes from the passives, imho.
i'm gonna get murderlyzed for posting this shit lmao
but down the road a mite, if i can do it ethically/legally, i'll post the project here. technically its gonna belong to mla.
Have you been winding the transformer for the last 14 years?
hahaha well, ya know.....
<pink draws hard on his herbal jazz cigarette....>
no transformer necessary ;) if all goes according to plan, shit , ya could probably run it on a 9v battery, at least for a few minutes ;)
i've got a semi working tube fuzzface on my breadboard right now, passing signal. i used the stock topography of the fuzzface so far, have indeed had to mess with values some. it sounds like a fuzzface with a very dead battery at this point... but its working, and fuzzing. sounds decent driving an overdriven amp.
the fuzz control at the moment is back down to 1k, with a 220u bypass cap. big input cap helped some, too.
obviously its gonna likely need some work to develop into something useful, but it DOES pass signal and does it at 9v. sounds a bit better at 18v, so... gotta play with it a bit.
who knows what will happen. ;)
.......ahem
https://www.youtube.com/watch?v=1QTMZFAJC2o&feature=youtu.be
values of resistors and caps a bit different. 470r resistor still the same value ;) you'll have to play with values a bit and make some things much bigger. but the topography of the circuit is the same other than using the valvecaster bit to run on 9volts.
its not as fuzzy <yet> as a transistor fuzzface. but it still reacts and sounds quite a bit like what you'd expect a tube one to sound like.
this is running on a 9 volt adapter. i can't post the schematic and values at this time, but they were easy enough for me to figure out, and i hope someone tries it. its kinda cool. into a dirty amp it screams.
(https://i.postimg.cc/G4cSzRQD/tff1.jpg) (https://postimg.cc/G4cSzRQD)
(https://i.postimg.cc/N9T4BCDY/tff2.jpg) (https://postimg.cc/N9T4BCDY)
i can say this...its still the same number of parts other than the heater supply.
when i can, i'll post the whole thing up. may be a while. hopefully i've posted enough clues for peeps to figure out what i did.
think big on the caps ;)
i think it sounds fairly good. the quick video is just into a pos ibanez 5 watt el84 toob skreemer amp with the volume and tone about 3 o'clock.
peas
A year or so ago, I built an overdrive pedal with one preamp tube. This one works well at 9V, but it is even better at 12V. There are schematics for this at the net. The 12AX7 wont work very well, due to the low voltage. I think I used 12AU7 tube for this one (might have been 12AT7, I dont remember as we speak). Remember that all the tubes mentioned are dual stage tubes. That means you only need one to replace two transistors.
When that is said, the tube in my overdrive got voltage far out of it specs. But it did work!
Be careful, thought that you don't use higher voltage than 12V, since this is the maximum for the heater of the tube. If you have higher voltage, then you need to lower it to max 12,6V for the heater.
If I was you, I would try to replace the transistors, and off course set the bias and gain accordingly to what a tube needs. Maybe the tube will not make this pedal act as a "fuzz", but it will at least clip in some way.
I will try to dig up my schematics for this pedal (I think I stole it from somewhere on the net. Perhaps on this forum?)
Also found 12au7 works much better than a 12ax7. I was running a transformer with dual 12.6 vac secondaries. 12v to heaters and 20 vdc to the plate.
That sounds like even a better solution. But it runs good on a single 12V or even 9V supply also. Its, as I said, far out of spec, but it works😉
Cant find my schematics, but google matsumin valve caster. I think that was the base for it (I always modify those schematics after my own taste)...
This sounds like you will have a Fuzz Face that is independent of ambient temperature. All you need is a power supply regulator and you will be rid of the worst characteristics of a Fuzz Face - temperature dependence, supply voltage dependence and tone sucking from low input impedance.
BTW it may be difficult to find, but a 20EZ7 is a 12AX7 with a 20 volt 100 mA heater but the pinout is not the same and there is no centre tap for the heater. I have an old tube AM/FM/FM stereo radio that uses them. You could build a fuzz that runs off a 19 volt laptop battery, so it would be rechargeable. The fuzz control could be the voltage adjust on an LM317.
12au7 draws way more current than a 12ax7.
for a fuzzface, it won't work better at a higher voltage. you guys are thinking like ee's, linearly. you cannot use that kind of thinking with a fuzz. the higher the voltage, the CLEANER the tube will get. that's not what ya want in this kind of circuit.
the point of the example was it was claimed early on in this thread that to do this would be impossible. that's not true. this is running on 9 volts. it distorts. it sounds like what you'd expect soft clipping tubes to do in a fuzzface circuit.
you need to look at the current draw of the tubes as well. at 9 volts, a 12ax7 draws less than at 12v, and uses about 1/10th current of what it would draw at 6.3vac. a 12au7 draws close to 10x more current. the 12ax7 is the way to go.
with a fuzzface, you need gains of around 70 to 100 for the two transistors. a 12ax7 has a gain of 100 for each side of the bottle. works perfect..... well... not perfect, but as expected.
we're not talking a tube overdrive here, we're talking fuzz.... lol the older guys will probably get the humor of this all. ;)
the actual circuit i have i'm working with uses some tricks for a proper power supply. the fuzz will work on a damn 9 volt battery, for a while, anyways. that was also important. the actual units use a little simple wizardry to do a proper supply for the heaters. its regulated to and clamped at the proper voltage, tho still run in series, not parallel.
yes, the matsumin valvecaster answers most of the question of how to do it. it really comes down to adjusting the passives to adapt to the tube circuitry. the topography of the circuit/number of parts remains the same as the original circuit. that i can say ;)
amptramp, that's all stuff i love about fuzzfaces, bro...lol... the key to this is i want the ultimate product to run on a standard 9 volt supply. i can easily do this with a 12ax7, and most of the specs work out right.
any of you watch the video? its only about 20 seconds long lol
mozz, higher voltages work fine for preamps and overdrives, but this is a fuzz. ya gotta think the other way for this one, or it .... sounds like a tube preamp. ;) ya gotta starve that bottle to find the fuzz ;) there's definite sweet spots, but the matsumin values for the valvecaster for the plate resistors are pretty much close enough for rock and roll.
i have hundreds of variants for the fuzz face circuit designed and built at this point. its insane. ;)
banjan, thanks for the advice. i used to "pop" weak tubes with my tube tester by turning up the voltage to the heater supply. most tubes can take almost twice their rated voltage without damaging them. i had this thing running at 24 volts yesterday at one point for a few minutes. 9 volts worked much better. lower voltage is the way to go with this kind of circuit. you do NOT want headroom! ;)
btw, for all my secrecy <hah> the entire freekin thing is laid out on the breadboard... you can see EXACTLY what i did in the pics lol
but i still didn't post the schematic :icon_mrgreen:
Quote from: pinkjimiphoton on April 25, 2020, 11:48:01 AM
btw, for all my secrecy <hah> the entire freekin thing is laid out on the breadboard... you can see EXACTLY what i did in the pics lol
but i still didn't post the schematic :icon_mrgreen:
If anyone could build tube fuzz, that would be Mr PJP!
brother ranko, how ya been, mate?
hahah... thanks for the vote of confidence. i am still working on it. its not too hard to figure out, ya just gotta decade thru some resistors til ya find what works best... of course, every change re-biases the dang tube, so ya gotta wait for it to settle in, etc...
but now i've gotten it to where i think the volume is adequate, and it's fuzzing about where a good ge will sound with the guitar volume just barely rolled back.
into a clean amp, its almost in the vein of say, a kay fuzz... lotta upper harmonic, as RG and others cautioned it would have. but into a barely overdriven amp, it freeking SCREAMS. will try n get more video in a bit.
obviously, ya gotta go with pots to dial in the plate voltages... ya gotta bias it to a point where it fuzzes, but doesn't velcro. but the two resistors remaining, well.... the little one gotta go wayyyyyyyyyyyyyyyyyyyyy down, and the big one has to go wayyyyyyyyyyyyyyyyy up.
bigger caps for in/out/fuzz are definitely in order. think huge. go up and down in decades til ya find what ya like.
there's a bit of a compromise between output volume and fuzz at this low voltage. exploit it. find the sweet spot where ya get a fair amount of distortion, and still enough to be well above unity gain.
a lot of the "flavor" of the fuzz face comes thru, cuz the circuit remains largely the same with the connections... identical, in fact... other than the +/- connections to the heater of the tube. its NOT gonna clip as hard, tubes clip much softer... but it will still fuzz when ya find the sweet spots, which are seriously starved down with the biasing pots most of the way up. before you hit cutoff, is where you'll find the fuzz. in the middle regions, it will sound more like a tube preamp that's fairly clean. exploit the un-linearity and ya can make it fuzz.
so far, for the first attempt, i'm fairly satisfied. since the video last nite, i've changed the values of the two remaining resistors and gotten good result.
think of it as an npn fuzzface. think of the two halves of the 12ax7 as two transistors. think of plate as collector, think of grid as base, and think of cathode as emitter. other than running the heaters in series, and changing the values to account for the tubes and the way they work, the circuit is still the circuit.
with transistors, gain goes up with bigger resistances. with tubes, think the opposite, as reported 14 years ago.... its weird ;)
but it works. not necessarily RIGHT.... yet.... but its passing signal, loud, and relatively fuzzy.
Are you talking a 12au7 draws more fil current or plate? Filament current is the same 150 ma. Plate current is really small and shouldn't make much of a difference in the very short life you would possibly get out of a 9v battery. I can measure the 12au7 plate current and compare to a 12ax7 just for my own curiosity. Preamp and fuzz is the same thing, just direct coupled.
Mr PJP.
Love you language😉 😅
This looks to be SO COOOOL, Jimi. Getting FF like cleanup/sparkle in a not-so-fuzzy circuit would, I think, be incredibly useful.
i was just chatting with petey twofinger about this thing.. lol
the biggest bitch is that the tubes don't saturate and STAY saturated like transistors do, so its not as phat sounding as you'd think. a 12 volt supply to the heaters will likely help, but this things at 9 volts.
tubes, as the decay begins, lose distortion quickly. they're completely misbiased in this application, so you can get a fair amount of distortion... if ya tag in the valvecaster tone control it helps to warm it up some, its fairly bright ... i mean a fuzzface is a treble booster in some ways. dialing back the treble makes it a bit warmer.
i tried adding various clippers, and found one i liked at a highly improbable place in the circuit.
think of each triode half of the 12ax7 as an npn transistor.
for the 470r resistor, think REALLY tiny. gigantically smaller. its really only there to decouple the two stages anyways, right?
for the 100k resistor, do the opposite. there's a definite sweet spot you'll have to find. think big.
for the first stage, use a 500k pot to find your bias. second, use a 1 meg. there's compromises to be had that you'll have to find.... ya gotta find spots with each stage where its distorting without going all fizzy, and where ya have a decent amount of gain. like most such things, its all compromise.
you'll get it eventually where it sounds and acts like a fuzzface pretty much. it responds to the guitar knobs almost the same, and at max distortion, will give a nice decent if slightly gated overdrivey sound into a clean amp, and will scream into an overdrive pedal or overdriven tube amp... in which case, it acts much like a normal fuzzface, but without the mud.... like having a bass cut.
make the fuzz control freeking huge, too. gigantic.
every time ya make a component swap, give the circuit a couple seconds to stabilize.
it sounds REAL nice into my 80's solid state marshalls. warm, phat, really makes 'em sing.
and STILL the same basic circuit layout as the actual fuzz face. same four resistors, same three caps, just different values...
i used a huge 2200uf cap for the power supply rails, hoping to keep it quiet and reasonably stable, this isn't the actual product i'm working on, but it will get ya in the ballpark of it if ya take the time to read this crud crap stuff i spew... and look at the pix. beware, there's components there from me tinkering that aren't actually in the circuit.
for the rest of the caps, multiply by decades to find what you like. again, think big.
not gonna tip my whole hand yet ;)
tried a simple gain stage driving it... not super exciting. it definitely will make it more fuzz face (tonebender?) like, but it gates in a fairly ungraceful way as the transistor and tubes decay at different rates and in different ways. a slight boost into the front, however, WILL help the tubes saturate and sustain better... but then it's no longer, well, a fuzzface.
the other way to go is to seriously starve the tubes much more, and then add a recovery stage...
BUT...
tube preamp distortion at this voltage level... and face it, the design needs to run on 9 volts to keep guitar players happy... is fairly fizzy. if ya crank it up to where it truly fuzzes, it gets REAL fizzy as predicted 14 years ago. its not as pleasant as germanium or low gain silicon in this circuit. but ya can get it to where it sounds and reacts fairly well, and sounds with the guitar dimed about where a dimed fuzz face with your guitar rolled back to about 8 sounds for distortion level, which is still fairly useful.
add in the valvecaster tone control, and when ya roll off some of the treble, it sounds much better.
output pot 500k at least.
damn. giving away all mah secrets agin. sumbeech.
for the clipper... look in the circuit for the only couple places you can add one... will add a tiny bit of compression and a bit more wood to the tone, and help the tubes stay saturated a little longer. again, transistors when saturated, stay saturated til they're off... tubes the distortion fades in and out depending on attack, decay and to a certain degree, envelope.... it doesn't stay saturated as easily as the transistors do.
but... you can exploit that, and the way it acts like a fuzz face, into a marshall pretty effectively.. when ya turn down, you can get a phat brassy crystaline clean that is really cool, even into a dimed marshall with this thing dimed as well. it just kinda adds overtones and sustain.... and ya get back the rest of the missing gain from the voltage being so low ;)
consider researching how to get yourself a 12v supply for the heaters off a 9 v power rail ;)
ok... done. stick a fork in me. i'll try n get a little more video as i get this thing done. i'm about done molesting this circuit's poor electrons for now...
think of it as a building block. maybe build a fuzzface around it, with the first stage of the transistor fuzz face part driving the tube part and the second stage of the transistor part amplifying the tube part output.
the world's your oyster, lol... get your breadboard, crack a beverage, load your favorite smoking utensil, if you partake of such with your trusty pair of xircon encrusted tweezers, and mess around with it. just remember, its tubes... so every time ya change something, it gotta recover.
at 9 volts, its safe enough even for my re-intarnated arse to mess with, ya can't really hurt tubes like ya can transistors ... well, ya CAN, but... the point is, i think if ya tackle this as a circuit snippet, there may be something cool you'll find to call your own. ;)
peas
here's a schematic for how it goes together. since its gonna be a commercial product ultimately, i'm not posting the values, but with a breadboard, you'll figure it out. notice the similarities in hooking up the triodes to how transistors would hook up. this does not include the entire circuit, this is just the fuzzface part of it. it DOES work. and doesn't sound as bad as you'd think it would ;)
(https://i.postimg.cc/cgyGqdc0/12-AX7-FUZZ-FACE.jpg) (https://postimg.cc/cgyGqdc0)
ok... enough secret handshake stuff for one day. if ya follow me down this rabbit hole, have fun... if not... well, another day... another fuzzface.
moz, the filament current changes depending on whether you run it on ac or dc. on ac at 6.3v, a 12ax7 draws about 150ma, but at 12vdc, i believe its more like 10 or 15ma instead. i suck at math, so that part, yer on your own ;) at 9v, its different still, but the au draws more than the ax in this application... there's another ancient thread comparing them somewhere here on the forum.
Filament current doesn't change. 6.3v draws 300ma, wired in series at 12v draws 150 ma. Watts is watts. AC or DC does not matter. If you're running at 9v on the series arrangement it's just going to be dim.
300 and 150 are the same ? ;)
works for me. i don't really care one way or the other, the point was to see if it would work. that's all i really gave a shit about. ;)
there's definitely a thread around here about it. i just read it a day or two ago when i first started messing with it.
got it almost to the point of boxworthyness last nite. gonna need some support circuitry to get it "right" i imagine, ain't worried about it. may take this monkey 10,000 years and 10,000 trashed components, but eventually i'll get something i figure is worth keeping.
ya'll rock on and have fun. lates.
Quote from: Ben N on April 25, 2020, 04:23:07 PM
This looks to be SO COOOOL, Jimi. Getting FF like cleanup/sparkle in a not-so-fuzzy circuit would, I think, be incredibly useful.
hi ben!! how's the weather over there? hopefully this pesky covid crap isn't as bad as it is here in new england.
its an interesting circuit bro... obviously! worth a play with, you may find it useful! ;) rock on, bro
Quote from: pinkjimiphoton on April 25, 2020, 10:31:30 PM
gigantically smaller.
And there's my new sig line. Better than a tube fuzz. :icon_cool:
<3
its now fairly dialed in and almost ready to box. sounds great after a
ready?
an actual fuzz face. ;)
Any pot with voltage on it is going to be scratchy. Best off to use resistance on the second triode grid to ground.
Not continuing to nitpick but i said "6.3v draws 300ma, wired in series at 12v draws 150 ma." Filament current does not change if it is AC or DC. I said filament current doesn't change due to you saying it is different from AC/DC. It's the same. Same as a light bulb. It doesn't care if it's AC or DC, if you run lower filament voltage, the gain of the tube will be less. I'm sure all the other tube parameters are also thrown out the window.
Filament current is going to be much larger than any draw from the plate, whether it is 1ma from a 12ax7 or 10ma from a 12au7. You would be best to run a 9v voltage doubler or tripler for the plate if using a large enough external power supply.
I can only see a 9v battery lasting 1 hour, maybe 2 hours. I spent many a day and hour tweaking a valvecaster running 12v fil and 20v plate. No such thing as a separate fuzz circuit, as i said, it's a direct coupled amplifier.
(https://i.postimg.cc/f3Xppq0J/amp.jpg) (https://postimg.cc/f3Xppq0J)
hahaha.... dude, you're trying to explain theory to an ape. ;)
and missing the point. it works, even tho it shouldn't. raising the voltage will make it fuzz less. do you think i didn't already go there? ;) the higher the voltage, the less fuzz. 9 volts actually FUZZES. above that, its a ...as you said... direct coupled preamp.
no worries, rock on, man! all good. ;)
adding series resistance to v2 isn't necessary, as it already has a bypassed resistance to ground. the cathode isn't very much voltage even on a high voltage circuit, pretty negligible here. 'sides, its for the fuzz pot... which generally is left dimed, anyways. ;)
6.3vac is parallel wiring at 300ma. 12.6vdc is 150ma. i understand what you are saying, but 300 and 150 are NOT the same, 300 is double 150. the tube will run either way, but at 12vdc it draws less current than it would with an ac 6.3v supply. how can 150 and 300 be the same? they are, but they aren't. the tube's the same, the circuit's the same.... mostly. but the differences in current draw make a big difference when designing the supply for it.
but its all good. remember, you're talking to an ape with opposable thumbs ;)
i don't know nothing about electronics engineering. all i know is that which fuzzes is fuzzy. ;) they don't teach fuzz in electronics class i don't think. i don't know the rules, so i don't know not to break them. ;)
and again, its a guitar pedal. gotta be able to run it on 9 volts. i'm not looking for any ideals. just experimenting with YAFF. when i saw it said it couldn't be done, i decided to see if that was accurate.
peace ;)
Hey, Jimi. Weather's nice. It's a good thing we have a nice little garden, otherwise I might not get to appreciate it, hiding in the house. Spring temps are running a littler later this year than usual, which is great for the electric bill, too. We're starting, ever so gingerly, to de-isolate. We'll see how that goes.
I may give this a breadboard go with some of my Russian submini stash and trying higher voltages. It just seems like it could be such a "character" pedal.
higher voltages just won't fuzz, bro. they'll overdrive or do clean... higher ya go, the less fuzz ya get.
but good luck! it's just a goof that it works at all, ben. have fun, bro!
glad to hear stuff is getting better there. we're not even peaked here... and the orange one wants to rock and roll.
i'll lay out with.... history shows again and again how nature points out the folly of man. stay safe bro. shalom!
here ya go, worst video ever. great new pc. ughhh
https://www.youtube.com/watch?v=-5JKPk5yMLU&feature=youtu.be
if u make it to the whole thing, god bless ya. audio is really weird. sorry.
rock on! :icon_mrgreen:
I don't know about the circuit but
Jimi you're defo the dude that keeps on giving for sure
Your posts are the absolute best they always put a smile on my face and that takes a lot for a miserable b@$€@?) like me, just hilariously brilliant in the nicest possible way
Great circuits, good banter what more d'ya want?
Keep em coming Sir
lol hi billy ;)
i'd post more stuff, but the company i work with sucks up every dang new thing i come up with. i'm grateful for that, but it seriously kinks the flow of my experiments being distributed for free. i'm hoping once mla is more established i can release some of the other stuff i've come up with which is being developed.
its all about the stupid, bro ;) one love, stay safe!!
Jimi
If we ever get this gpcb fam meet up going when all this madness is over
You'll need to take a day off come get a few beers, I'll be buyin!
i'll bring the left handed herbal jazz cigarettes ;)
Oh yeah!
i mean, 'twould be a joyous celebration for all us electron addled deviants to get to hang out ;)
Quote from: pinkjimiphoton on April 27, 2020, 03:53:21 PM
'twould be a joyous celebration for all us electron addled deviants to get to hang out
Cool circuits and poetry too! What a neat place this is. :icon_cool:
Pjp:
Wattage is the same.
P=U*I
P is power (W)
U is voltage
I is current
A Garnet amps stinger schematic looks interesting
thanks bro,
but i know nothing of any of that stuff ;)
i think my point is the current draw is different depending on the voltage being run at, and whether ac or dc.
messed with it more last nite a little, finally added bypass... at 9v i can just barely hit unity gain, which of course is unacceptable. i'll be messing with it more at some point, one of these days. really better to be thought of as a circuit snippet than a standalone.
the point was really just to see if it would "work". it does. well? no. ;)
hi gus
it kinda sounds like a garnet amp.... very "american woman" rhythm guitar, kinda
That math is actually not diffucult.
You get the same wattage with
12,6V*0.15A=1.9W
6.3V*0.3A=1.9W
As mentioned earlier, it does not matter if it is AC or DC. The heater draws equal amount of current. If you don't believe that, experiment with an AC source and measure, and do the same with a DC source. Should be the same.
oh, i believe ya ;)
but pink don' be knowin' nothin' bouts none of that stuff ;)
i boxed it today. still tinkering tho. used a f'd up pea%^&* enclosure to stuff it in, cuz all i stock for me is 1590a's and b's
(https://i.postimg.cc/MvFRWnsX/tube-face.png) (https://postimg.cc/MvFRWnsX)
i finally gave up on trying to make it fuzz like a fuzzface. the circuit is the same still as a stock face other than the part values, the valvecaster tone control and adding in a "voice" control in the feedback loop. finally settled on running the plates with a charge pump at around 30 volts, and the heaters at 9. tried running the heaters at 12v with a chargepump bumping it up to 18v and then regulating it to 12, but it just wouldn't fly. i, as always, take great pride in letting the magick smoke out of obscure and pricey components.
in the end, its a nice sounding tube preamp, the voicing and fuzz controls let ya dial in everything from clean and kinda compressed to ripping velcro. the super saturation and woolyness of the fuzzface isn't gonna happen with this circuit. that said, it doesn't sound bad now that i'm not trying to just make it fuzz. maxxed fuzz pot is about where a ge fuzzface sounds with your volume on about 8... kinda clearish overdrive that will crackle when ya punch it hard, and is very sensitive to playing dynamics. but below that, with the voicing control, you can dial in a pretty good range of overdrive sounds. it SOUNDS like a fender amp breaking up, pretty much... the ones with master volumes.
i'm still messing with it... may add a ge tonebender stage to the front end, and a few other things, but as a standalone, it very much sounds and acts like a fuzzface now, minus most of the distortion. i'm hoping MLA turns it down so i can just release the dang thing ;)
Hey dude.
Might be nice to write proper english so that us foreigners can follow you😉
So this is going to be a commercial product? Have you considered some of the standards that the authoraties need for releasing it? I used to work at one of these electrical safety companies, and I know that even tough were talking about 9V, it may be some rules. (perhaps not since this is a audio product. I used to work with medical products and there 9V is potentially lethal)..
sorry mate, i'm american, proper english??? ;)
the actual product, if it happens, will be the problem of the company to deal with. my gig is just creating weird noisemakers for them. not too worried about the standards thing. perhaps if mass producing them, but not at the entry level stuff we're doing.
yes, this will likely be a commercial product. i was asked about developing the idea by them, was their concept. my gig was to see if it was feasible and worth doing. i was researching to see if others had done this already and found the thread. i was amused by it, and decided to see what would happen. i am no EE. i don't claim to know anything about electronics. i take a cookbook approach based on years and years of experimentation and breadboarding. not afraid to let the magick smoke out of expensive vintage rare components.
my focus is and has been on fuzz almost since the beginning. they don't teach that stuff in electronics. its more about bending and breaking the rules than following them. ee's are taught linearity and to minimize distortion. i seek to maximize it thru exploiting il-linearities i come across.
i'm literally the guy that will sit there for days swapping out different value passives and listening intently to what the audio result will be... and fine tuning stuff from there til i'm happy with it, or can accept it as about as good as i can get it.
so when i saw this thread, and the claims in it that it couldn't be done, i was like.... not that much dif in function between an npn transistor and a triode, really. and i was right..... and wrong.
the circuit works as what it is. the differences come down to the behaviour of the semiconductors/tubes. transistors saturate and stay saturated and clip hard. tubes saturate but don't STAY saturated and clip soft. that's the biggest hurdle with this kind of circuit.
i'm hoping when i send the prototype to MLA they reject it. then i can just release what i did, which ended up a relatively useful and toneful box. its a tube face, but not quite a fuzz face. they sound very similar, but very different.
i usually release all my projects here. since i been working with them, most of the stuff i come up with gets picked up by them. frankly, being able to pay my expenses for a change as i pass thru this life is kinda liberating, after being a completely broke ass musician living off tapeworm food for 5 decades ;)
peace!
ps, will try n get a stupid pedal trick video of it when done. right now, its up to 4 knobs and a peculiarly placed diode clipper; trying to decide if i want to make that part switchable.
the two main knobs are fuzz and volume. the other two are matsumin's tone control from the valvecaster verbatim, and i made part of the feedback resistance variable as a voicing control. the basic circuit retains the fuzz face topography, which was a big part of the concept to me... so i can live with it. i'd like more fuzz out of it, but .... that would require a voltage drop substantial enough to kill the output.
like everything, its all compromises. ;)
Quote from: Banjan73 on May 01, 2020, 07:09:30 PMHey dude. Might be nice to write proper english so that us foreigners can follow you😉
Why should you have all the fun? I comprehend Missouri, California, New Jersey, and now some Maine, and I mostly have no idea what the Jim is going on about.
what, paul, u don't speak connecticut swamp yankee flatlander hipster musician baloney?
damn, dude, you ain't lived ;)
I speak all sorts of baloney! Gulden's Mustard helps when I get stuck.
Interesting enough, I can clearly understand Jimi, even english it's not my main language. In fact, I got my "formal english classes" by being a member of this forum on early days (using google translator's help) and by playing Final Fantasy 7 on ps1.
Maybe it's because we're both apes on theory. Or because I'm drinking a glass of a good beer rn while I'm reading Jimi's posts. That's probably the secret: have a nice beer. If you still don't understand Jimi, drink another one and try again :icon_wink:.
My favourite Americanism is "it don't make no nevermind". And it don't that's true.
When you wire the filaments in series, it's 12.6v, 150ma.(pins 4 and 5) When you wire the filaments in parallel it's 6.3v 300ma. So i guess you are wiring it in series and running at reduced voltage. Cathode poisoning, probably not in a small audio tube though.
or herbal jazz cigarettes will help. i actually talk like i write, so people must be sufferin' all over.
still in this thing. still messing with it. still running on 9v input. plenty of volume, finding where to tweak to get fuzz. the BITCH IS, every @#$%ing time you adjust anything at all, you need to @#$%ing wait for the @#$%ing bias to @#$%ing settle in again on the mother@#$%ing tube, which can be really super @#$%ing annoying, wayyyyyy more @#$%ing annoying than @#$%ing transistors are, which are really @#$%ing easy to @#$%ing work with.
extra points if ya figure out what @#$%ing word just got censored above 35 times. ;)
and of course, at this point, the prototype has been molested so much that it is literally falling apart just about constantly, which is always my FAVORITE part of the whole damned process.
in the meantime, if anyone is dumb enough wants to follow me down this rabbit hole, take a peak at the wolf computer schematic for potential mods... many of them will work with this, as well.
i've committed to different resistances than originally used. typical scaling ya need to do up or down to find the sweet spots.
right now its volume, fuzz <gain,really> tone <valvecaster> and voice. voice is adjusting part of the feedback resistance between v1 grid and v2 cathode. lets ya go from cleanish compressed to a fairly decent distortion, to ripping velcro at min settings.
voltages are @#$%ing crucial. and they change with everything. this is even more of a pia than a ge fuzzface is. you can get lost with the biasing for literally days... i've been messing with it more than a week!! insane shit.
i am also committing to not worrying about keeping the circuit as identical as i had... seems to be subtle improvements made by changing fixed resistances or even variable ones with a combo of the two.
anyways... onwards n upwards.
i'll try and make this easier.
see jimi.
see jimi build.
see jimi build fuzzface.
see jimi use a tube instead of trans sisters.
see jimi work on it.
work, jimi, work.
jimi is very stupid to waste his time on this.
waste, waste, waste.
but jimi is crazy,
SO jimi makes fuzzy goodness possible.
be like jimi. make the world fuzzier.
gotchem go bye-bye.
:icon_mrgreen:
Quote from: mozz on May 03, 2020, 04:37:45 PM
When you wire the filaments in series, it's 12.6v, 150ma.(pins 4 and 5) When you wire the filaments in parallel it's 6.3v 300ma. So i guess you are wiring it in series and running at reduced voltage. Cathode poisoning, probably not in a small audio tube though.
yep. series, but running the heaters on 9volts instead of 12. pins 4 and 5, yep. cathode poisoning. i like it. ;)
i don't see cathode being damaged run at 9v. reduces emission slightly, tube lasts longer, slightly less transconductance possible.
https://www.diyaudio.com/forums/tubes-valves/31770-heater-voltage-range-hi-low.html
https://el34world.com/Forum/index.php?topic=20238.0
"
QuoteHere's the straight-poop on this topic:
The tube was designed to be operated at its rated heater voltage (6.3vac) and will deliver "most satisfactory service" (the common term in old texts), meaning "best chance of meeting/exceeding claimed specs, for as long as possible" when you apply 6.3vac.
"If your running at a lower voltage, I would assume you would have a slight rise in current." The unstated assumption for this assertion is that heater-power stays constant. In fact, it doesn't, but rather follows Ohm's Law. So, if you drop the 6.3vac to some lower voltage, less current flows through the same-resistance of the heater, and the heater consumes less power (volts*amps) from the winding.
The cathode was designed with a certain planned power consumption by the heater, which then heats the cathode. Less power consumption then means less cathode-heating. The possible effect has two facets:
- Normally, a new cathode has an excess of electron emitting capability in its cathode coating. So under-powering results in no real change of actual electron emission, and the tube operates as it would with less heater power, though the tube envelope may be very slightly cooler.
- A tube which has already had a long period of use may have partially depleted some of its cathode coating, and under-powering the heater results in less emission than the tube would have under normal operating conditions.
If your tube falls in the latter category, then for the same operating point, transconductance (Gm) will be reduced by some amount. That might translate to a measurable reduction in gain. Whether the measurably-reduced gain is audibly-obvious in use depends on the amp and how severe the gain reduction (or really, tube age/wear) is.
"
With heater power, there is something to do with the Getter element inside the tube. Most of us know there is a thing called a Getter in there and can recognise it, but because it doesn't have a schematic connection, we may not know what it's for.
As I understand it...
The Getter is coated with something that really likes bonding with oxygen. Everything else in the tube must not be allowed to react with oxygen since obviously, oxidising will be bad for reliability.
The idea is that any oxygen left in the tube will get stuck in the Getter.
Nothing is perfect, so there is still oxygen hanging around, some of it hiding in the materials but releasing over time.
Unless the heater is running at its designed temperature, the stray oxygen particles may not have enough energy to reach the Getter and may react with the heater itself or other elements. I think the tube is treated to a dose of microwave or induction energy at manufacture to heat things up so that the Getter can sweep up most the looser stray oxygen before use.
So underrun heaters can reduce tube life.
That we don't notice a reliability problem due to underrun is probably because we don't run tubes 24/7 like Military/Scientific/Industrial users did/do.
Quote from: pinkjimiphoton on May 03, 2020, 07:48:12 PMextra points if ya figure out what @#$%ing word just got censored above 35 times. ;)
Well, Jimi, it helps that you @#$%ing spelled it the same @#$%ing way every @#$%ing time, all 35 @#$%ing times.
@#$%!
You're the man.
Well, I had no idea that the getter kept on working. Always thought it to be a single use element activated during manufacture. Goes some way to explain why I see getter descriptions in some tube ads.
Hi Jimi /pjp or whatever.
I do understand mostly of the stuff you are saying. Have been watching some U.S. movies during the years, ya know! But when you really start to freak out, it could be hard to follow, hehe.
Actually, I find Jimi's writings quite eloquent, conveying both meaning and intention without giving secrets away. Of course, my understanding of it may have been tainted with fermented grape juice but nonetheless, down the rabbit hole I went. Trouble is, there's more than one rabbit hole and mine apparently went in a different direction and I got to thinking.
Submini, military tubes are meant to withstand extremes for a short time - maybe minutes. How extreme is extreme? Filaments as bright as my light bulb, sparks, arcs and banishment to the shed for blowing the circuit breakers while the missus was working is what I've found out so far.
Must have sounded good at some point cause the wife asked "what the @*$%ing hell is that noise?"
Must have sounded good at some point cause the wife asked "what the @*$%ing hell is that noise?"
[/quote]
:icon_lol: :icon_lol: :icon_lol:
There is an interesting blurb on the Steve Bench audio site here:
http://diyaudioprojects.com/mirror/members.aol.com/sbench102/dht.html
on directly heated triodes showing a reduction in harmonic content when the tube filaments are run at reduced voltage. He shows that with reduced heater voltage, the µ, transconductance and plate resistance remain constant over a large range of plate voltage and the results are shown for voltages from 10 to 50 in ten-volt steps. I would assume the same thing applies to indirectly heated cathodes like those on a 12AX7.
This may be why your attempts to get fuzz from an underheated cathode seem to stubbornly stay in the linear region with a minimum of distortion. It seems reasonable that a little more cathode emission may get you out of the range where the THD is low. He measures the THD and operation at 10 volts on the plate seems to give the lowest distortion with reduced filament voltage.
He has several other pages showing harmonic content at various voltages and it seems to be minimized at low filament voltages. This one on the 6B4:
http://diyaudioprojects.com/mirror/members.aol.com/sbench102/6b4.gif
shows minimum distortion on a 6.3 volt filament operating at 3.2 volts. Maybe if you want a fuzz to fuzz properly, you need to run the cathode at the design temperature.
hi guys ;)
its definitely working and boxed and even fuzzing, tho tube fuzz is much more transparent that transistors. its a "clean" fuzz, for lack of a better word.
the "getter" is the silver shit inside the glass. its purpose is, indeed, to take care of any oxygen in the tube. but the key here is in the term vacuum tube. there's videos on youtube of how to make your own.
when a tube is manufactured, the elements are placed in a glass tube and heated over a flame. this eventually drives out most of the air, and the end of the tube will be pinched and twisted... thats where the little nippile at the top of a 12ax7 comes from, in fact.
the getter's ONLY job, as i recall from back when i actually was doing tubes all the time and reading everything i could, is to remove any residual ATMOSPHERE from the tube. atmosphere will make the elements burn up; so if any air is left in there, its the getter's job to burn it off. this is the "sound of static" that tubes sometimes make while warming up. a tube that develops a leak, you'll actually see the getter oxidize, and turn from silver/black to white and milky.
generally, the only time you need to worry about the cathode being hot enough are with nixie tubes, or tubes nearing the general end of their life cycle. while emissions and transconductance <what we call hFE> are slightly reduced, the overall life of the tube is largely unaffected.
remember, line voltage. when most stuff for tubes was invented, line voltage was significantly lower than it is today, used to be 110, but usually more like 100 when i was younger. now its usually closer to 125-130 coming out of the wall. now, this shouldn't matter, with transformers... they're gonna still produce that 6.3vac for the heaters just fine. but the rest of the circuit will still be affected somewhat. voltage could be high, could be low. hell, you could run your heaters at 5 volts, running off a rectifier tap, and they'll still work.
lowered heater voltage will make a weak tube die slightly quicker. but a normal tube will often last much longer, and they tend to distort MORE slightly low. i did set up a 12v heater supply <dc>and tried it to see if it were worth messing with... was thinking an lt1054 to bump it up to 18v and then regulate it back to 12 to run just the heaters on... i know, too much current requirement... well, almost. i looked at the data sheet, and that jellybean can handle up to 150ma current, so it would work at least for a while... but the 12v supply i used didn't really make much difference tonally. no more fuzz. somewhat less, in fact. can't think linear when making fuzz. shit don't work!!
so anyways, when all's said and done, i DID use a charge pump. the heaters run straight off the 9v supply. the charge pump is set up to deliver ludicrous and possibly dangerous voltage levels to run the plate. get a mess of 5817's and 10uF caps and have at it til ya find the sweet spot ;) its there for the taking with some experimentation. don't try a 7660 or 1044, all it will do is whine.
the hardest part, again, is the goddamned biasing. the "sweet spot" to dial in v2 is ridiculously tight. and every miniscule, picayune adjustment made means you have to wait 2-3 minutes for the bias to settle and the tube to operate. it wants to see very specific voltages... all quite doable, i mean, my dumb ass figured it out.... but if ya go above or below, the tube will go into cutoff... cuz its being run in a VERY unlinear region. but once its right... you get fuzz. and tone. together, ya get fuzztone!
at this point, the only thing left i'm likely gonna do is add a hi pass filter to the input; it can get quite woofy like a real ff does. rolling off the bass from my guitar makes a huge impact on the tone.
its a fair bit above unity gain, not as much as the average transistor ff, but enough to drive your amp.
to get ample volume out of it required a slight modification. look up my "fuzzface +" circuit and you'll see what to do. moving ONE component to a different node gains an easy 6db output or so. if ya think about it, you'll figure it out. you'll be like... @#$%! this can't work! and then ya try and go...cool!
so its got volume, fuzz, tone, and a "voice" control. all the way up on that last one is fairly "clean"... as ya turn it down, it gets more gated til ya get the classic velcro ripping sound of a misbiased 60's fuzz. incense and peppermints ? we got it. spirit in the sky? nope. nothing sounds that crappy ;)
for the voice, add a variable resistance to the feedback loop between v1 and v2. again, wolf computer mods work pretty well.
i DID add a diode clipper, as well. i wasn't gonna say where, but @#$% it. there's two places in the circuit where you can put an antiparallel to ground diode clipper. one is off the output cap. there's only one other place in the circuit you can do it. you gonna make me say where?
you're thinking... pink, that won't work, its improbable, its not done. but it DOES work. old radio trick. increase compression a little, and removes some noise by clipping the signal. make it assym. i'd reccomend led's cuz they have the highest "compression" in this circumstance <for the newbies, yes, i am indeed talking about the clipper going to ground being located off the circuit side of the INPUT cap.>..... weird trick, but works. and ya don't lose the output volume you'd get at the end of the circuit. brings a little of the "woodiness" of the ge sound back to the circuit, and helps drive it a little better.
still sustains like a fuzzface.. almost like a compressor
LOTTA second harmonic. you can starve it into a bit of an octave up with the voicing.
cleans up like a fuzzface.
my advice, if ya follow me down this rabbit hole, is to do the biasing with knobs full up, and guitar rolled down to where you want it to sound "clean" or "cleanish" ...say, 2-3 on the guitar knob. bias to get max volume and best tone, and ya can't go wrong when ya crank the guitar up.
again, its not as saturate as a fuzzface. more like an improbable cross between a boogie, fender, and marshall kinda tube saturation. all the way up, is a nice compressy brown tube preamp sound. start starving it with the voice, and the distortion goes up. its kinda cool. the fuzz control and voice interact quite a bit, letting ya get a lot of different fuzz tones.
is it perfect? hell NO. was it a pain in the ass? well, i worked on it for a freeking week, lol... but was it worth it? hard to tell. ymmv. i like it.
can it be done?
hell yes.
Quote from: pinkjimiphoton on May 04, 2020, 11:35:12 AM
so anyways, when all's said and done, i DID use a charge pump.
Ha! I knew it!
Quotestill sustains like a fuzzface.. almost like a compressor
LOTTA second harmonic. you can starve it into a bit of an octave up with the voicing.
cleans up like a fuzzface.
my advice, if ya follow me down this rabbit hole, is to do the biasing with knobs full up, and guitar rolled down to where you want it to sound "clean" or "cleanish" ...say, 2-3 on the guitar knob. bias to get max volume and best tone, and ya can't go wrong when ya crank the guitar up.
again, its not as saturate as a fuzzface. more like an improbable cross between a boogie, fender, and marshall kinda tube saturation. all the way up, is a nice compressy brown tube preamp sound. start starving it with the voice, and the distortion goes up. its kinda cool. the fuzz control and voice interact quite a bit, letting ya get a lot of different fuzz tones.
Yeah, I'm psyched to get going on this. Just gotta clear some stuff off the bench. (You know how that goes.)
> something to do with the Getter element
Tantalum and a few other Transmitter Tube getters must be run hot to absorb gas.
Receiving Tube getters, the micro-thin silvery flash inside the glass, do not have to run hot. However if they were assembled in air they would be used-up before they got to the vacuum pump. They are made in a lump so most of the getter-stuff does not get contaminated. Yes they commonly use a burst of RF to vaporize the lump into a flash. Making the getter-stuff holder ring-shape helps the RF heat.
thanks, paul!
ok, after @#$%ing with this thing for wayyyyyyyyyyyyyyyyyyy too long, and playing thru it for mark at mla last nite, we decided its simply not worth @#$%ing with. too much of a pain in the ass to deal with.
in true fuzz face fashion, literally EVERYTIME ya plug it in, it sounds DIFFERENT. @#$%ING MADDENING!!
input audio? changes the biasing. move a knob? change the bias. unlike transistors, ya gotta wait for the bias to settle. again. its insanely interactive, just like the real deal. but to get a decent fuzztone out of it is crazy hard. and its unreliable. and it sounds different everytime. and its @#$%in' impossible to bias.
but it was still kinda fun to take on, and may well be a worthy "circuit snippet" to add to a fuzz or dirt pedal project, but on its own its just not really worth it imho. your mileage may vary.
anyways, since we're NOT gonna pursue it, i can release it to you guys. too @#$%in lazy to scan the schematic at this time, but i can tell ya what i did.
go to tagboardeffects and check IvIark's layout for a charge pump power supply. ya wanna shoot for around 30v output. i used an lt1054 and 5817's to ultimately get about 26v to the plates of the 12ax7
run the heaters on straight 9v. pin 4 to ground, pin 5 to +
input cap bump up to 22uF. you MAY wanna add a hi pass filter inline with the input to roll off some bass. it NEEDS the big cap to get enough bass to fuzz that first stage. you can use other caps, obviously.
on the other side of the input cap, the circuit side, make a diode clipper to ground off the circuit side of the input cap... this adds a little compression and smooths the circuit out a little bit. i used a white 5mm led, band to ground on one side, and a red 5mm and 1n270ge in series for the other side, bands pointing to the signal.
v1 plate load resistor i used an a500k 9mm pot as a trimmer, you're gonna wanna shoot for about 15v on the plate.
v2 plate load resistor, i used an a1m 9mm pot as a trimmer <the actual unit i just used little blue n white trimmers like they sell at tayda...> shoot for about 21v on this plate.
decoupling resistor between the plate loads goes down from 470r to 47r.
feedback resistor between grid of v1 and cathode of v2 wants to see roughly 1.5meg. i used a 470k fixed resistor off the v1 grid, and an a1m pot to vary the resistance. i call this a "voice" control... all the way clockwise, ya gotta fairly standard fuzzfaceish sound... as ya rotate it left, it will get more distorted, jagged, and gated. in fact, it makes a fairly decent noise gate at some settings. go figure. ;)
for the fuzz control, a1m again, cathode bypass cap taken from 22u to 220u.
v1 cathode directly to ground.
output cap moved from plate/plate load resistance to node of 47r and plate load resistor of v2. this gets ya enough output to be able to use the circuit... hooked up normal, just plain not enough output. this MAY be a little noisy. a smallish cap, say 1000p-3300p to ground should eradicate it. i didn't bother.
output cap, i went ultimately 3.3uF. output pot, i went a1m again.
for power supply, i used 2200uF electro with standard 1n400x protection, and a 3.3n snubber cap to nuke noise. ya need the big cap so ya have enough reserve to stop the tube from sagging too much under brutal abuse. brutally abusing the input can rebias it to the point it goes completely unlinear and freaks out. then it will gate real bad and kinda swell back in. neat. not super useful, but neat, and definitely exploitable.
you can get a lot of standard fuzz face weirdness with this. everything but the full-on fuzz.
if ya dare follow down the rabbit hole and @#$% around with this piece of shit, let me know how ya make out!!
at some settings, ya can get a decent octave up fuzz, too. in fact, the thing it reminds me most of is an anemic version of gus smalley's OUSB or tim escobedo's jawari.
anyways... i DO have a vero and schematic for it, if ya REALLY need it, let me know and i'll post it... but odds are its unnecessary if ya read this here post.
so that's it. no more cloak and dagger. i may still use it as a snippet in another circuit <it sounds @#$%ing great being driven by, or driving, a wide assortment of dirt pedals> but standalone, its just not good enough to @#$% with anymore imho.
hope this helps some future daredevil out.
love to all... wash your hands, please... despite the @#$%in morons claiming this is a liberal hoax going on, yeah, @#$% that, my @#$%ing BROTHER is currently in an icu with it, and is likely gonna @#$%ing die.
Have you considered a hybrid face? A tube in the 1st spot seems to work just about in simulation with some fiddling.
too lazy ;)
If you had been able to use p-channel tubes, it might have worked like a PNP germanium Fuzz Face and been the new darling of the industry. I could picture one using a 6D4 gas triode (thyratron or noise generator) and offering a great new sound. Somebody should do this. Somebody who is not me.
Quote from: pinkjimiphoton on May 07, 2020, 02:37:57 PM
love to all... wash your hands, please... despite the @#$%in morons claiming this is a liberal hoax going on, yeah, @#$% that, my @#$%ing BROTHER is currently in an icu with it, and is likely gonna @#$%ing die.
Love right back at ya, Pink One, and your bro.
thanks marc. my brother survived the nite. covid 19 positive. severe double fibrotic pneumonia. he's conscious and aware. but complications from it are costing him a leg tomorrow. @#$% this shit. @#$% it in its neck.
My best wishes to your brother, Jimi. Hope he make thru this.
Oh, man, brothers and legs are pretty damned serious. I pray your brother has a quick recovery, and I'm terribly sorry about what this is costing him.
We had a scare when my sister and brother in law were hospitalized and on the hi-octane O2 for about a week before they pulled through, thank God. But a friend of mine lost his sister. I hope I never hear anyone say this thing is a joke to my face; too many sick people and worse for that.
Sending the love your way, Jimi.
thanks bros. @#$%ing hating on what's happening to so many good people. hope it evolves into something less nefarious soon.
just wash your hands. stay away from dicey peeps and situations. and hope for the best.
next mother@#$%er with the stupidity to say hoax to me is gonna be swallowing blood and chiklets.
I'm really sorry to hear your brother's ill, I hope he will get through that. :(
Sending positive vibes Jimi
All the best to your brother big chap I hope he gets through it
I posted this in 2008, a FET-NPN FF. I can't find an all FET FF in my notes, but with minor tweaks can be done.
I hope it helps with subminis.
(https://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=41304&g2_serialNumber=1)
mac
Quote from: Scruffie on May 07, 2020, 03:17:57 PM
Have you considered a hybrid face? A tube in the 1st spot seems to work just about in simulation with some fiddling.
thinkin i'm a gonna try it. just take a couple wires swapping around. i DID try a couple real simple amp states after/before it, too... so v1, npn ge/si, and make v2 a buffer, or use it to drive a more sophisticated tone stack or something. or, more gain. tonebender ;)
no rabbit hole for me tonite.... thanks, scruff.... see you guys in a week...lol
Quote from: pinkjimiphoton on May 08, 2020, 08:35:34 PM
thinkin i'm a gonna try it.
(https://assets.econsultancy.com/images/0007/1227/destiny.gif)
https://www.tubecad.com/2020/04/blog0499.htm (https://www.tubecad.com/2020/04/blog0499.htm)
Look around the middle of the link