Hello all,
I am new to this forum and an avid pedal collector. With the recent passing of the great Richard Kaplan, I decided to try and take up a project that he recently revealed before he died. That is his legendary Bigger Muff pedal. This is used extensively on Sepultura's Roots album as well as Korn, Slipknot etc.. The best way to hear the pedal soloed is to listen to Roots Bloody Roots and go to 1:50 into the song. It gives two soloed guitar parts. This is undoubtedly the pedal. I spoke with Richard a long time ago and stated it was a DIY project, but being he named it the "Bigger Muff" I had ahunch he used some sort of schematic to get started. AfTER SEACRHING FOR A WHILE, I FEEL I HAVE FOUND THIS SCHEMATIC. Now the only mystery is to figure how he incorporated a transformer and tube into the mix. Here is the original:
(https://www.gearslutz.com/board/attachments/so-many-guitars-so-little-time/379941d1389587331-guitarists-show-me-your-pedalboard-bigger-muff-jpg.jpg)
Notice to the left you see "Vol" written. The top switch(which I thought was true bypass), is labeled "Tone". Look closely its faded. Then on the bottom right you see another black pot labled "sustain". Alll notice the 4 transistors going across the bottom. After seeing this I knew he had to copy a schematic. I came up on this one:
(http://www.kitrae.net/music/Images_Secret_Music_Page/V2_WITH_'76_POTS_SECTION_OVERLAY.jpg)
The resistor and transistor layout seem to be a match. The big mystery seems to be the right side of the original pedal. It has a transformer, a tube and some capaictors. I am wondering how those were incorporated. IF ANY OF YOU GUYS CAN HELP OUT IT WOULD BE GREAT. I THINK THIS WOULD BE A HELL OF A PEDAL TO CLONE. THANKS. NICK 9548021969
Notice the power plug: this thing is meant to be plugged into the mains. I imagine the transformer is part of the high voltage AC to low voltage DC conversion circuit. I guess that would make sense if you wanted to use higher voltages for the tube and lower voltages for the transistor, but I'm just guessing now.
No clue about the rest.
The tube could be a rectifier.
ahhhh. Makes sense. The 2 silver wires seem to go where a 9v battery would go on this same schematic. Then there is a red wire going scross. on top. Do you think the schematic for the board matches up??
The tube seems to be a regular 12ax7 type tube. However the big question is where does it fit into the schematic.
Its difficult to read the values or colors, the tropical fish caps on the board are 100nF, some of the resistors match up, can't tell with the others. Can't read the transistors. Better photo? Did you check what the tube designation is- 6x4?
Unfortunately its the only picture that exists. This pedal was kinda kept secret for a while.
oh wow I saw this in a guitar magazine in article with korn whilst they were working on the Life is Peachy album. It got me interested in tinkering with guitar effects
Love these kind of mysteries!
A quick google search didn't turn up that particular transformer, but judging from size and what appears to be a rectifier tube (6CA4 / EZ81; 6X4WA ; 35W4), the 3 huge caps, resistor, smaller electros and tropical fish cap (39nF?), I'm guessing its 12V. I'm not a power systems guy, hopefully someone will chime in and correct any mistakes here. According to this reference (http://www.hammondmfg.com/pdf/5c007.pdf), if half wave rectified with cap load it would yield a max of 0.9x12V = 10.8V , after rectifier loss and smoothing probably closer to 9V to the board.
There is a You Tube video of this: https://www.youtube.com/watch?v=VKv8tmLPZEE
the 2 "silver" wires look like coax for input and output...
maybe 12ax additional stage(s)... 220k might be anode resistor...
Interesting stuff. Also I wonder where the red wire coming across from the tube ties in. I agree with the two silver wires being for In and Out. Makes sense. Do you guys think there is enough info here to try and build one???? I'm looking for some who will take this on for the right price.
This is reply #11 from a May 2010 thread: "Big Muff version to get Korn tone" « on: May 21, 2010, 06:59:30 PM »
Quote from: jmasciswannabe on August 03, 2010, 07:51:38 PM
Well, I thought it might be fun and worth a try to send Mr. Kaplan an email. He was kind enough to respond. Check it out!
Hi,
I built the 'Bigger Muff' for Korn and then another one for Sepultura to use on the road.
They were a hybrid of discrete transistors and a single high gain tube distortion stage.
I have no schematic - they were built as a 'breadboard' experimental circuit that worked
so well that everyone wanted to use it for years to follow. I closed and sold the studio a few
years ago.
The original plywood pedal that was used on all the Indigo studio albums went to David Lyons at Sonic Circus.
Yes I have read that email. What is a "discrete" transistor. At least we know the tube is an actual distortion stage. What do you think cozybuilder?? enough info to build or do we need more.
I would have to study this some more, not enough there right now. Its intriguing.
Quote from: illuminatiNPS on April 22, 2015, 02:36:08 PM
Interesting stuff. Also I wonder where the red wire coming across from the tube ties in.
My guess is the red wire is power, unless the left hand board gets power from a separate supply.
I'm afraid there isn't enough information in the photo to clone it. You could make an educated guess that the left hand side is some sort of big muff and possibly figure out the component values but there's no chance of working out what the right hand board does.
i'm kinda bored at the moment and wanna help even though i have zero experience with the Big Muff or this rare variant.
i doubt you could get in touch with Korn (not capitalising the "R" must be a sign of age...) or the likes, but maybe you could try to get in touch with others associated with the pedal, such as that David Lyons guy or maybe some former road techs for Korn or Sepultura? maybe you've already tried that. worth a shot maybe!
made in tawain
A few guesses
I would place the tube stage between the fourth transistor stage and volume control and switch it in and out with a DPDT maybe the slide switch is a DPDT I think I read harmo(harmonics?) to the left of it maybe the tube stage switched in? grey wires are in and out of the tube stage
As slacker posted the red wire is most likely the transistor section power supply lead
Can't read what is by the red handle toggle switch
I don't see any rectifier diodes on the tube stage board they must be blocked by other parts in the picture
I would guess the heater is DC and is also used for powering the BMP transistor section 6.3VDC or 12.6 VDC or maybe another voltage. Maybe 12 volts and the bigger brown resistor at an angle above the BMP like circuit is to drop the 12 to 9VDC?
I only see one 100K possible plate resistor so maybe only one tube gain stage.
The tube could be single triode or a dual triode one side used or a dual triode both sides in parallel or a pentode as a triode or ...
For more dirt maybe a lower voltage B+ around 100VDC and a grounded cathode contact bias( I do not see a cathode resistor in the picture)
The black electro and what is connected in the clear sleeving would be a part of the B+ note they both connect to what I would guess is the 100K plate resistor
Can anyone read the writing on the perf board
eh ... I see there's four transistors on that board, so most likely the gain recovery stage is standard.
I'd say, if you have the equipment, build the first three stages of a muff and then use a 12AX7 triode as the gain recovery stage with 100 or so volts at the anode and see what it sounds like. Don't forget to tune your guitar down to A or whatever they used to do ... you know, till the strings flap.
Hell, make the first stage of the muff the first triode and the last stage the 2nd triode. Bias and bypass to taste.
Correct me if i'm wrong but just below the red switch i can make out an "ECC" and above it a word ending in "DE". Maybe it had the ability to switch between tube and silicon diode, like the Mesa amps. Remember Korn used triple recs. Maybe thats what Kaplan was thinking. Definitly an ECC under that red switch. The "E Harmo" on the left side of the board is probably a joke. It is a Big muff afterall.
OK my number is 954-802-1969. Would any of you be interested in building this for me?? If so call me so we can work out details (parts/ labor). Amazing how much experience on this forum. I think we are close.
Just a quick update guys. Traced down the pedal to its current owner, Rich Costey. Yeah I know, major producer. Shot him over an email to see if we can get a picture of the reverse side of the board. Fingers crossed.
Also contacted a few boutique pedal companies, and the feedback was mostly negative, due to no "full" schematic. That and its probably a copyright thing because they are selling an EHX circuit. No biggie, Its up to us. Without the schematic of the tube stage, we are stuck with propabilities. No harm in solderless breadboard for the circuit and then experimenting with the addition of a tube gain stage from their. This pedal was built on trial and error anyway. In the meantime, I successfully created a patch on my PODHD 500 that nails the sound almost 95% to my ears. Its basically a Chandler Tube driver going in series to a big Muff and adjusting the blends. That is ran into a plexi model with V30 speakers with a parametric EQ post amp. Pretty close and noisy as hell without a noise gate, just like he original.
Hey guys,
I noticed this topic has gone cold but have some new developments for the possibility of cloning this "Bigger Muff"
1) Listening to the StudioRatHQ interview about the pedal, Richard stated that the pedal has 2 power supplies. After talking with an experienced pedal designer (he cloned a mutron biphase), he thinks the tube section is plugged in, maybe even 250v, and the board is powered by a 9v battery.
2) Also being that the tube gain stage is classified as high gain, its possible the tube gain stage is inserted before the 1st transistor stage. Or even in between the clipping stages. The pedal designer i spoke to beleives the silver cables are carrying audio to and from the tube stage, which maybe means it leaves a transistor stage goes to the tube and back.
3) The pedal designer I spoke to also sparked an interest in this Bigger Muff pedal enough to consider it for a new product. Keep your fingers crossed
4) This isn't the only time a tube Big Muff has been produced. Check out this schematic.
(http://img11.hostingpics.net/pics/739836TBMPproto020811.jpg)
Give me your thoughts fellas. probably gonna start ordering parts. Never soldered anything in my life, but this has me curious enough
would the diodes be necessary/desired in that design?
illuminatiNPS
The picture posted shows a dangerous build. Two wire AC cord no fuse that I can see no power switch no enclosure etc.
Of course it will need two supply voltages as a minimum. One for the tube heater and one for the tube B+. The heater could also be used for the BMP supply as well.
The pictures tube stage and BMP build looks crude.
I would guess it is standard stuff stuck together in an unsafe way
I am surprised a studio would let something like this be used would the insurance cover the studio if there was a fire or someone got shocked?
This is not a 9VDC effect. The picture looks like the person who built it did not care or maybe did not know how to build a line powered device.
Yeah anything exposed would be unsafe. I too wonder if the diodes would be necessary. Kinda of reminds me of the Dual rectifier switch in the back where you can choose between tube or diodes. I wonder what transistor stage he introduced the Tube into.
Quote from: illuminatiNPS on May 05, 2015, 06:36:17 AM
Kinda of reminds me of the Dual rectifier switch in the back where you can choose between tube or diodes.
Totally different thing - the rectifiers that many an over-excited metal guitarist has boasted about having two or three of are actually the part of the power supply that converts AC to DC, and the quantity depends on how many watts the amp puts out. They don't provide amplification or clipping, just a change in "feel" for those that notice such things.
My contributions to the guesswork:
From what can be made out of the writing, it does look like one of the switches selected between "Diode" and "ECC???" - I'm assuming the tube hadn't been set up in a "triodes-as-diodes" configuration as Kaplan referred to "high gain". The pair of shielded wires from the tube board look like they end up before and after the first clipper stage (working right to left to end up with the volume control). What if...the switch swapped Q2 for a ECC83-or-whatever dual gain stage - meaning the input of Q3 gets slammed with a >100Vp-p guitar signal that is then diode-clipped on top by the feedback loop?
Remember, this is somthing deemed worthy of the name "Bigger Muff", so it's not going to be a case of just sticking a cathode follower somewhere! ;)
...though I'm not sure if there's a transistor with the ability to withstand that input swing. Still, my hunch is that the tube had to provide something "more" than a stock Muff does.
Quote from: anchovie on May 05, 2015, 08:03:13 AM
Quote from: illuminatiNPS on May 05, 2015, 06:36:17 AM
Kinda of reminds me of the Dual rectifier switch in the back where you can choose between tube or diodes.
Totally different thing - the rectifiers that many an over-excited metal guitarist has boasted about having two or three of are actually the part of the power supply that converts AC to DC, and the quantity depends on how many watts the amp puts out. They don't provide amplification or clipping, just a change in "feel" for those that notice such things.
My contributions to the guesswork:
From what can be made out of the writing, it does look like one of the switches selected between "Diode" and "ECC???" - I'm assuming the tube hadn't been set up in a "triodes-as-diodes" configuration as Kaplan referred to "high gain". The pair of shielded wires from the tube board look like they end up before and after the first clipper stage (working right to left to end up with the volume control). What if...the switch swapped Q2 for a ECC83-or-whatever dual gain stage - meaning the input of Q3 gets slammed with a >100Vp-p guitar signal that is then diode-clipped on top by the feedback loop?
Remember, this is somthing deemed worthy of the name "Bigger Muff", so it's not going to be a case of just sticking a cathode follower somewhere! ;)
I agree that the red switch is a Diode/ECC switch. Also if you look at the "Bigger Muff" pic, you can see the same 2 diodes above Q3. I think they match the diodes in other pic I posted. The 2 diodes that are supposed to be above Q2 maybe be hidden by a disc capacitor in the pic. So if the diodes are visible above Q3, then your 2nd dual gain stage theory would be correct, but that would also mean the switch is a "tube on/off" switch and not a "diode/tube swap" switch. Also if this is a 250v tube gain stage, he must
have stepped down the voltage at the heater and then sent power to the board via the red wire. Here is a trace of the 76' BMP so you can see where he may have introduced the tube gain stage. Its ver 2 on the right:
(http://www.kitrae.net/music/Images_Secret_Music_Page/CIRCUIT%20TRACE%20COMPONENT%20LIST.jpg)
If this is a dual gain stage at Q3, how would that be any different than running lets say a tube overdrive pedal in series into a big muff??? Ive done it and it sounds alot like Roots Bloody Roots. Anchovie, do you live in the states??
I'm in the UK.
Looking at the photo again, I'm now not convinced that it says DIODE above the switch. There's a blob above the ECC8?? though that could be a +. Your experiment with the POD is promising, so I think we should certainly give consideration to the idea of the tube acting as a switchable boost before a regular Big Muff. It won't be a Tube Driver though, as that's a hybrid design with low plate voltage and an opamp providing most of the gain. But however it's set up, there's not so much voltage swing that it destroys Q1 of the Muff.
The transformer markings include PREM - Prem Magnetics is a manufacturer, but the numbers on the transformer look nothing like the product codes they currently use. I'm taking a real guess here - in the 0102024 code the 024 denotes 24V. I don't believe that's a proper tube amp transformer, it looks salvaged from something else, and if the 24V is two 12V secondaries in series then you've got your 12VAC heater voltage right there and 24VAC to rectify into DC for a starved-plate tube booster.
Anchovie,
Taking your advice I modified the patch and used a dual rectifier pre(high gain tube), into a big muff and it sounds more accurate once te IR EQ curve is added. I am currently trying to bid this project to some boutique pedal builders. Basically asking for a big muff witha high gain tube boost in the q3 section, or even the ability to switch between tube and transistor. Let's see who has the balls.to take it on. Everyone has there price I guess
I can't believe no one has mentioned the word Valvecaster yet in this thread, that is all ;)
That's because I don't believe it's a 12AU7 - 12AX7/ECC83 would have been seen as the go-to choice for anything intended for metal bands.
That's not to say that you wouldn't get a decent approximation by putting a Valvecaster in front of a Muff, and it's certainly worth trying in order to get rid of the need for the chunky transformer.
IlluminatiNPS: Your experiments are indicating that tube-before-Muff gives good results. My gut feeling, given the lashed-together look of the unit, is that this may well be all it is rather than a tube/transistor-swapping switch.
Quote from: anchovie on May 07, 2015, 04:52:13 PM
That's because I don't believe it's a 12AU7 - 12AX7/ECC83 would have been seen as the go-to choice for anything intended for metal bands.
That's not to say that you wouldn't get a decent approximation by putting a Valvecaster in front of a Muff, and it's certainly worth trying in order to get rid of the need for the chunky transformer.
IlluminatiNPS: Your experiments are indicating that tube-before-Muff gives good results. My gut feeling, given the lashed-together look of the unit, is that this may well be all it is rather than a tube/transistor-swapping switch.
I agree totally. The only two questions I would have is 1) does the voltage going to the tube section effect gain. I ask because if it's buildable, then is a transformer necessary,. The transformer makes me think it's a preamp more then a "gain stage". 2) do you think there would be a difference in tone whether it is introduced in q1(vol) or q3(clipping).
I've been kicking around the idea of building this circuit for a couple months now...
The tone "switch" at the top of the board is actually a pot with the knob missing.
The tube stage is a typical high gain 12AX7 triode stage, similar to the one pictured here.
(http://www.ampbooks.com/mobile/classic-circuits/soldano-slo-preamp-2/soldano-preamp-2.gif)
The power transformer on the right is supplying the B+, you will definitely need high voltage for this circuit to operate properly. This is not a beginners first build!
It should be possible to use a nixie power supply or charge pump circuit to produce enough high voltage to safely run from a 9 or 12VDC supply.
You could substitute the triode stage for a valvecaster or fetzer valve, but where's the fun in that?
You've sparked my interest in this project again.... Stay tuned, I'll report back shortly. ;)
Quote from: BuGG on May 08, 2015, 07:11:54 AM
I've been kicking around the idea of building this circuit for a couple months now...
The tone "switch" at the top of the board is actually a pot with the knob missing.
The tube stage is a typical high gain 12AX7 triode stage, similar to the one pictured here.
(http://www.ampbooks.com/mobile/classic-circuits/soldano-slo-preamp-2/soldano-preamp-2.gif)
The power transformer on the right is supplying the B+, you will definitely need high voltage for this circuit to operate properly. This is not a beginners first build!
It should be possible to use a nixie power supply or charge pump circuit to produce enough high voltage to safely run from a 9 or 12VDC supply.
You could substitute the triode stage for a valvecaster or fetzer valve, but where's the fun in that?
You've sparked my interest in this project again.... Stay tuned, I'll report back shortly. ;)
Bugg,
Thanks for joining the talk. Yes the tone knob is definitly a pot and the board is most likely a Rams Head BMP layout.
There are still a couple of mysteries though. The purpose of the red switch, and where does he introduce the tube gain stage. A few of us think at the q3 transistor clipping stage, this way it become a dual gain stage. Not a beginners build, and I am the detective in this whole thread. I've spoken to Richard and Ross Robinson before to get bits and pieces of info. There is one other person who has been in front of the pedal that may still be of help as well.
Bugg, do you live in the states?? If so we should swap numbers and if you want to take this on, I will
Help with parts cost.
Anything more information on where the tube stage is?
If the tube gain stage is before the BMP you could use a transistor gain stage instead and run it from 9VDC. 9VDC is safer.
If a 12ax7 was used you need to think aboout the Rp and how it adds to the input resistor of the BMP and gain of the first stage of the BMP
Gus,
No concrete info on where the tube gain stage "actually" goes. Ross robinson has confirmed though that the red switch is to switch from "regular muff" to "overblown". It has feed back even when a guitar is not plugged in. Which makes sense because a lot of the sepulture tones sounds like the notes are on the verge of feedback when they are played.
The layout could be helping with getting feedback, long wires etc. built on a wood board.
It could be a simple tube stage before the muff. Something like reply 21 first tube stage with a cathode bypass cap something like 22uf.
I am still thinking the brown resistor on the perf board at a small angle could be dropping 12VDC to about 9VDC.
A good link for you http://www.aikenamps.com/index.php/designing-common-cathode-triode-amplifiers (http://www.aikenamps.com/index.php/designing-common-cathode-triode-amplifiers)
An issue is the low input resistance of a BMP it is the about the 27K to 39K series input resistor you see on BMP schematics this loads the stage before and reduces the gain
So maybe both triodes are used in a 12a_7 or maybe plate out to cathode follower
You could try a fet input opamp set to a gain of 10 with a 1meg input resistance before a BMP as a test, this might sound better.
I did sim a nice BJT stage to use before a BMP
Can anyone tell the directions of the electros and what number the transistor are?
The electro direction will help figure out the powering
is this a NPN or PNP build
could this be PNP being powered by +9VDC
I got in touch with PREM, the transformer manufacturer and they said the Prem8732 means it was built in the 32nd week of 1987. After clean up the pic a bit and looking at the resisotrs along the bottom, it looks like the 430k in Q1 is missing. Also the solid colored white resistors are matching as oh, value resistors.
A closer look at the writing under the red switch makes me think it says : ECCFaT. The Mallory Electro looks like it says 650k. The Black one above just says CC. The birds nest of wires near Q2 seem to be the wires of the Q2 diodes. the more I look at the tube gain stage, the more I think it was just pulled from an amp and stuck on the plywood.
Still waiting on possible back of board pics. Fingers crossed ???
Another set of GUESSES
Looked at the Prem web site it might be a 20VA transformer. I measured a tube and did a fast scaling of the picture and got close to the dimensions in the link.
http://www.premmagnetics.com/Products/Details/SPW-611-D (http://www.premmagnetics.com/Products/Details/SPW-611-D)
Note it has a dual primary. Maybe one primary winding is used to power the transformer and the other for the B+ supply, not the best thing to do. It is not something I would build
PRR might want to post about this
Not many parts on the PS PCB
A crude 9vdc power supply was a 6.3VDC full wave rectified 6.3VAC X 1.414= 8.9VDC with ripple maybe it is a 12.6V tube heater at about 9VDC or a 6.3V at 9VDC
OR it could be 12.6VAC powers the heater and a diode(s) is used to the two smaller caps to filter the DC. Problem is I can see any diodes in the picture One diode, 12.6 x .7 = about 9VDC
From the picture the output electro looks like it does not have the - band pointing at the last transistor stage if the + is pointing to the transistor I would guess a NPN version HOWEVER if they are not polarized it is still a 50 50 guess to NPN or PNP build
If the 430K is missing base to +9VDC the last stage might be a crude noise gate distortion stage. If the signal is big enough it will turn the transistor on in a distorted way
The input 39K? body might be under the sustain control shaft
Prem the transformer company confirmed the transformer:
0102024-002
prem8732
Input 115v in paralell 230v series
output:
3 secondary windings.
2 are same at 12vac at 50ma
3rd 200vac at 100ma
.1amp x 200V = 20VA
12V x .05amp = .6VA
21.2VA. I was close with the 20VA rating guess
200VAC at 100ma is way more then needed B+ current for a small signal tube
Now this is a puzzle 100ma(50ma + 50ma) at 12VAC.
A 12ax7 is rated 150ma at 12.6V
Maybe the transformer is being used beyond it current rating at 12VAC
The 200V winding should not be stressed I would guess about 1ma
R.G. would this allow more current to be drawn from the 12VAC without overheating the transformer?
BMP like circuits without a led should be under 2ma
I wonder what tube it is?
EDIT one could use a "Real Mctube" type power supply with a voltage doubler instead of a full wave bridge
Gus,
I know we have been kind of ignoring that "Harmo" word on the left side of the board. But part of me is starting to think it has to do with the tube. That is not an E next to the "Harmo", its a dash. Part of what comes before it is covered by duct tape. I'm think the word stands for Harmonic Distortion/Even Order Harmonic provided by the tube. This makes sense because 1) Wes Borland said the pedal "was always on" and 2) Kaplan said when he made the 2nd one for Andreas he included a "hard on/off" switch. Also evenb order harmonic distortion includes octaves which essential would make the Big Muff sound 'fatter/bigger". I am starting to believe the middle switch on the board activates the tube stage.
Also if you looking closely at the volume pot, you see a pink wire attached. If you follow it under the perfboard, you can see that the wire travels underneath the brown resistor to the switch. Coincidentally, there is another pink wire coming from that switch heading towards the sustain Pot. Maybe the pink wires represent Input and output. Good possibility the tube is the first think the signal hits. And with that pink wire traveling from Vol to the switch, that could be the feedback loop that creates feedback/oscillation with only the pedal being plugged into an amp without a guitar, which is activated by the red switch
Still doesn't explain the rogue brown resistor traveling from left to right, unless of course that is the missing 430k from Q1. :o
Very confident that the word below the red switch says "EFFECT" not ECCFat. Thanks to my buddy with graffiti experience.
Bump
I am surprised by the small amount of posts in this thread.
A number of things have been figured out, still a few unknowns
I think it's just difficult for most of us to test out the ideas being tossed around because, I assume, most of us don't have the supplies lying around to easily wire up a 12AX? with 100+ plate volts.
I have been keeping tabs on this thread though .. just don't have anything to add really.
The subject title is enough to scare anyone.
Anyone know what the power supply PCB might have been from?
It looks like it might have three caps on it stock the two small electros(I see PCB traces to the two in the picture) and the blue Mallory, looks like it has print on the PCB under the bigger blue cap.
The reason I ask is this will give a hint to how the circuit is powered and how the circuit reacts.
I don't see any diodes, could it be the two 12VAC windings are rectified(two small blue caps)so the PCB has two about 12DC outputs with another output somewhere around 200VDC
Quote from: Derringer on June 27, 2015, 04:20:31 PM
I think it's just difficult for most of us to test out the ideas being tossed around because, I assume, most of us don't have the supplies lying around to easily wire up a 12AX? with 100+ plate volts.
I'm using a little Nixie SMPS to bump 12VDC up to around 190VDC (unloaded)....
cool BuGG, any cool results mucking around with permutations of this circuit?
Almost done....
(http://i673.photobucket.com/albums/vv95/Orven/Pedal%20Builds/Bigger%20Muff.jpg)
Quote from: BuGG on July 12, 2015, 01:59:15 PM
Almost done....
Me right now ↓
(http://sd.keepcalm-o-matic.co.uk/i/overly-excited.png)
Sorry, nothing to add. Just want to know what BuGG's results are.
Oh yeah, it's up and going like it should. ;)
Just have to apply graphics to the enclosure then this one will be on it's way to Nick (illuminatiNPS).
Looks awesome BuGG!
a sound sample would be awesome if possible!
what design did you go with ? where do the triodes sit in the signal path?
bugg what schem are you working from?
Is there ever going to be a layout/schematic for this? Or at least some pointers such as: What BMP version was used (russian, triangle, ram´s head, etc)? Transistors? Values of coupling caps (since is intended for lower tunings)? Where in the circuit are the tube triode stages applied? Man I friggin´love that sick over-the-top guitar tones from Sepultura and early Korn records, the mystery is eating me inside!!!!
Yes, of course I'll give some pointers. It follows a ram's head layout/schematic. The mods done to the muff board are mostly in the capacitors. The input cap and ouput cap is 10uf. the coupling cap that is at the end of Q2 is also 10uf. This can be seen by the 3 grey electrolytics in the original image. The feedback caps which are normally around 470pf are dropped down to 47pf for extra buzz(these are the 3 big lollipop looking caps on the board). the 12ax7 gain stage sits between the 2 diode clipping stage. Being that its high voltage, the transformer powers the anode, the heater, and the muff board itself. The original schematic calls for 125vdc at the plate, so you will need 200+vdc for b+ or more if you use an SMPS instead. Its is single triode and heaters are in series. The brown resistor running across the board is most likely a 2ns feedback path that caused extra fuzz as well s as feedback and ooscillation when the strings are muted, much like a Fuzz factory. This can be heard on Life is Peachy and Roots.
I apologize for not responding to the hungry requests on the pedal. I have since built one for Ross Robinson himself as well as building for an indigo Ranch engineer and one for Soulfly. If you wish to attempt to build one just contact me at nickspera@hotmail.com or 954-802-1969 for notes/layout etc.. merry Xmas everyone
This interview?
https://www.youtube.com/watch?v=VKv8tmLPZEE
Hello guys,
This pedal caught my attention, looks like a very-very-very interesting thing to build.
Couple of questions:
- the component values for the tube stage are those from BuGG's schematic? (Post #33).
- The plate voltage is 125-200V?
Thanks!
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Quote from: edy_wheazel on January 25, 2017, 04:11:53 AM
This pedal caught my attention, looks like a very-very-very interesting thing to build.
Caught my attention too. :icon_eek:
Hi guys, I'am very happy for work you have mad, I'am very interesting in recreating this pedal. I saw a few people has manage to build this pedal olso I can't find any circuit online... so I asking if somebody can send me a link of it or maybe where i can purhase it.