http://diystompboxes.com/analogalchemy/pedals/antiquity.html
have fun
Hello Hello Joe--
Great...thanks for the circuit! I love FF circuits.....I can always learn new "stuff" with 'em.
Why adjust the bias with Q1 instead of Q2's collector?? Any tonal advantages?
Thanks again--
Brian.
Hello Hello Joe--
Great...thanks for the circuit! I love FF circuits.....I can always learn new "stuff" with 'em.
Why adjust the bias with Q1 instead of Q2's collector?? Any tonal advantages?
Thanks again--
Brian.
Great... another fuzz I would be able to sleep until I build... thnx a bunch, JOE!
I'm kidding, it sure looks interesting...gotta build it!!!!
Thnx Joe, really
:)
P.S.
QuoteWhy adjust the bias with Q1 instead of Q2's collector?? Any tonal advantages?
I think it's a typeO
Quote from: Phorhas
P.S.
QuoteWhy adjust the bias with Q1 instead of Q2's collector?? Any tonal advantages?
I think it's a typeO
No, it's correct. Biasing a fuzz with Q1's collector resistor works really well. Most people bias with Q2 only, and pay no mind to Q1's voltages. As long as Q1's emitter is at zero, they are happy. Biasing by Q1 is also how Joe's got his Fuzz Calculator set up. Now that he's tweaked it some more for Ge's, I'll have to test it again. Before, the Ge tranny voltages were spot on except for Q2's collector being a bit high. For Si, it's completely on.
The way Q1 is biased, it is very sensitive to changes in beta value (hfe). Q2 is much less sensitive. Q1's collector resistor either raises or lowers the gain to the appropriate level. Compare these two pedals:
1. Q1 beta = 500, Rc1 = 5.6k
2. Q1 beta = 100, Rc1 = 28k
The gain of both stages is approximately the same. Now compare differences in Q2's beta value and it's effect on the calculated resistor value:
1. Q2's beta = 700, Rc1 = 5.67k
2. Q2's beta = 300, Rc1 = 5.63k
3. Q2's beta = 100, Rc1 = 5.49k
4. Q2's beta = 50, Rc1 = 5.29k
Not much difference at all. I chose to do it this way so that the pedal compensates for gain, but changing both resistor values is certainly valid as well.
Hey Joe,the easydrives great!
http://www.soundclick.com/bands/1/indigomono_music.htm
I'll have to try this one out!
Hi Joe and all.
Hey Joe (he he), could you tell us what difference the input diode makes? I presume that it provides some compression. How much?
Also, these Si fuzz pedals sound better (IMO) with some of the high-frequency whistle and hash taken out. This is easily achieved by placing a small capacitor (0.047uF or try from .022 to 0.1) in parallel with the 470 ohm resistor. That makes for rolling off frequencies above about 6kHz. It makes for a less nasty, slightly vintage sound.
thanks for the inspiration!!
Quote from: brettAlso, these Si fuzz pedals sound better (IMO) with some of the high-frequency whistle and hash taken out. This is easily achieved by placing a small capacitor (0.047uF or try from .022 to 0.1) in parallel with the 470 ohm resistor. That makes for rolling off frequencies above about 6kHz. It makes for a less nasty, slightly vintage sound.
I was expecting to see a 100pf (or so) cap across Q1 & Q2's collectors. Brett, that cap across the 470ohm gives a pretty good Ge type sound with low gain Si's, right? I usually ran just enough pf across the collectors to kill the real harsh bite, which also depends on the Si's being used. Until I run out of Ge's, I like my Si's to sound like Si's. Sometimes, the classic Si sound is harder to get than the Ge sound. Decent sustain, biting treble without killing dogs, and no oscillations.
I'll have to give Joe's ckt a try. :)
Hello Hello--
Hey Brett, howare you??
So, if I biased the collector of Q2 to get 4.5 would it sound any different then if I changed the value of Q1's collector resistor to get a 4.5 reading off of Q2's collector??
B.
I can answer that one Brian. Yes, I can hear a difference most of the time. Try biasing your next fuzz three ways:
1. Adjusting Q2 only.
2. Adjusting Q1 only.
3. Combo of both.
Especially with Ge's, I find that one biasing method usually sounds better than the other two. Take note of all the voltages each different way. The best sounding biasing will usually have the most uniform voltages.
At least that's what I've found in all my messing around.
I went ahead and built one, and put it in a box I had.
High Gain FF circuit, to be certain, and the diode, Si, Ge, or jumper all decidedly sound different.
I think it can probably use some HF rolloff sometimes, I may use a cap to pot to ground or somethng like that, so the high end content can be tuned.
First impression is that the circuit is low noise...HG/LN transistors...go figure !! NTE47 is Q1 and MPSA18 is Q2 in mine.
I used trimpots for collector resistors, 10k for Q1 and 18k for Q2, set the for shown resistances...wha 'la, biased very nicely...the calcualtions born out in real life...!!!
Very Cool !!!
You're the man Joe! I'm about to build your Blackfire, and I thank you for the awesome variety of circuits that you've put online... I'll have to add this sucker to my "list".
That little diode in there does some magic, I ponder the size of the resistors or the HG/LN transistors role in the Low Noise Floor...the circuit with shown transistors exhibits high gain / low noise. Nice.
I was doing some A/Bing, like I do, this is one potent FF. Quite the dynamic punch on pick attacks, single notes, it follows that sustain is 'there' as the gain and output are strong.
Thanks Again To Joe Davisson !!! 8)
Hell Hello--
Fretwire-- Thanks. I've spent some time biasing FF's all those different ways and still haven't come up with any hard-and-fast conclusions as to which way sounds "warmer" or more "GE-like" etc....
Wotta you think??
Anybody?
Brian.
Hi Brian, compare the biasing methods to the voltages. See any patterns yet? Q1's emitter is zero, we all agree on that. Q2's collector sounds good between 4.5v and 5.5v. When I get these voltages, I also usually get the best sound:
Q1 base: .1v
Q1 collector: .5v
Q1 emitter: 0v
Q2 base: .5v
Q2 emitter: .4v
Q2 collector: 4.5v - 5v
Btw, this data is with the standard Dallas ckt, not with some of "mods" and "fixes" that some use to make Si's sound like Ge's.
Hello Hello--
Right, I understand the relationship of biasing within the given circuit. My question is --"Will there be a difference in sound based on WHERE the biasing is done?" IF I get 5.5v on Q2's collector using Joe's resistor values [5.6k for Q1 collector etc....] and then I switch Q1's collector resistor to 33k and bias Q2's collector to 5.5v [just for the sake of my question], will there be a difference in sound? I think that there will be a difference.....just not sure what it is!
Brian.
Quote from: brian wenzMy question is --"Will there be a difference in sound based on WHERE the biasing is done?"
Yes, I thought that was what I was saying...sorry for the confusion. But, it's not like better eq or anything like that. It sounds..... better biased. Better sustain, better clean-up with the guitar volume, better touch response and dynamics. Using stable, low leakage trannies of the proper gain, and the best optimum biasing is what gets the best sound. So that's what it sounds like...just optimum biasing for your given set of q's.
Hello Hello--
AH HHaA!! I always wondered about biasing from Q1 as opposed to the old tried-and-true "Q2 collector" method. [Then there's adjusting the emitter resistor of Q2..... I remember Joe Gagan talking about his preference for a 2k instead of 1K.]
I keep running into Fuzz Face - type circuits [some of them are English, too] that have much lower resistor values on the collector of Q1. Actually, I seem to remember one called a "SRS Fuzz" that had a 5.6K on Q1's collector. I'll have to dig up the schematic for that one.
Thanks again--
Brian.
Hello Again-
Wonder what sounds could be had with a lower-gain Q1????
Here I go again.............
B.
Hello Joe--
What about tranny substitutes? Would any BC 184c or the like be as good sounding and low noise as your 2N's ?
Thanks-
Brian.
QuoteWonder what sounds could be had with a lower-gain Q1????
This is a good question (and the only thing better than a good answer is a good question.
One of the advantages (and it's a BIG one) of low hFE trannies for Q1 is that the base of Q1 is biased closer to ground. If a high hFE transistor is used, a resistor is placed on the emitter to reduce gain (Gain = Rcollector/Remitter). For low hFE transistors, there's no emitter resistor, and the base is at 0.7V. With an emitter resistor, the base sits at a higher voltage. The low base voltage of the low hFE transistor gives more assymetric clipping (it hits the ground more easily), which is one of the key features of the fuzzface (see RG's article Tech of the FuzzFace for details). A significant part of the magic of Ge transistors is that the base is at only 0.3 volts, which means the fuzz they produce is very assymetric.
So for that classic tubey sound, low hFE Si transistors (such as the 2N/PN2369A) will be the next best thing after a Ge transistor.
That's not to say that symetric, high-gain fuzz doesn't have a place. It's just not going to be a tubey, soft fuzzface kind of sound.
PS I only *think* these idea are right. Any experts out there? RG?
Golly guys...some of that tech-talk is tryin to lean me sumthin!
Alls I knows is: I just built the sucker...found a sweet spot by ear trimming Q1...and damn does this clean up nice & smooth & keeps all of my strat (into a twin) harmonics nicely in my face. Maybe I got lucky...but I'm hearin magic and thankin you for the circuit! Tis a yummy controllable fuzz!!
What's the Squidster been up to lately besides building fuzz pedals? Oh, by the way, if you haven't built the Tripple Fuzz yet, I believe you're going to like it. It's not a vintage JBT mind you, but really handy in it's own way.
Yo Jeff,
Just played in Vegas...was worshipped by thousands...haha! Then was a poker player in a pretend casino for a movie...surrounded by babes...then a guy walkin out of a grocery store for a TV show...and lots of time off to discover that...this Antique FF into a Sparkle Boost (w/the gain down) sounds REAL nice...lots of gain variation w/my v-knob.
Still must pass the acid test...next weekend's rehearsal...which will be recorded.....hoping the magic comes thru.
There's a tiny spot in the bias where my sound becomes super hi-fi.
I be lovin it.
Oh...and I'll get to the *Triple* one day when I order the proper trannys.
Powerful and Smooth !!!
I did the Axis trick, a .1uf across the 470...
Squid, I put a Sparkle Boost in front...
The circuit performs very well, passing the initial tryouts and a/b tests [against other FF's] easily, showing great potential with the powerful sound and smoothness, pick attack juice'...I think we'll be hearing more about this one...I'll let you know in a about a week...[seems to be enough time for thoroughly field testing a Fuzz, in my camp]...
It saturates really well and cleans up cool......it's like higher gain for the guitar volume control settingS [source input level] comparitively.
I just put this one together, I had a few free hours today, sounds real nice :D
I changed the output cap to a .047 as it seemed a bit "thin" with the .01
in there. ( .1uf was too "thick" )
Thanks Joe, much appreciated :D
Marty.
EDIT: I just tried this at 18 volts, using a recent build with a MAX1044
chip...... AHEM ! SOUNDS FANTASTIC !!!
Louder/cleaner and "fuller" sounding distortion......
Should we be running more "FX" at 18volts perhaps..??
PS: My "Fuzz" collection has now just passed the 20 mark... !! :oops:
I remember way back when I used to just have a fuzz collection of 20, but it'll get better and bigger with time. Try not to let it get you down. :lol: I think thats a good question you posed there Marty. There are only specific circuits that use something higher than 9 volts. Is there a whole lot more to get out of certain pedals by upping the +V? I take it that your girl friend was taking a nap or at the grocerie store at the time of this fuzz building?
Does the diode change the input impedance i.e. increase it so the circuit is less woofy? Would increasing the 100K drop down resistor increase the impedance?
Also, does this work when using MOSFET's for Q1 or Q2? 8)
Hi.
I'm planning on building this tonight and will measure the input impedance. (You can do this yourself - increase the output impedance from a signal generator until it reduces the signal by half and you've matched the input impedance of the device under test). I use a 100k linear pot as a variable resistor in-line with a 1kHz 100mV peak-peak sine wave.
Fuzzfaces usually have 10 kohms or so of input impedance (which also matches the theoretical values calculated from the emitter current and Q1's hFE).
Hello Brett--
Are you going to try a lower gain tranny for Q1 or stick with the high gain one??
B.
Quote
Does the diode change the input impedance i.e. increase it so the circuit is less woofy? Would increasing the 100K drop down resistor increase the impedance? Also, does this work when using MOSFET's for Q1 or Q2? Cool
The diode increases input resistance in proportion to the signal strength. The 100k can be changed, but I don't think it will have as much effect as in a typical transistor stage. It's only there to keep the diode slightly biased. Q2 can be anything, I would think.
It's important to note that the gain of Q1 is effectively lowered during a signal peak. So although the 2N5089 is a high-gain transistor, the effect is not the same as in a regular silicon Fuzz-Face circuit.
Interesting. As the signal level increases so does the impedance. I assume that results in a "brighter" tone at high levels than at lower levels. As the attack decays, it becomes "darker" :shock:
It's like a series resistor that sizes itself based on the input power. Seems to have more of an effect on distortion than tone, though. Kinda wierd...
Seems to be the same idea used in the Vulcan...right?
Would this work in other circuits...tonebender....tube reamer....mosfet boost?
It's the same trick. The diode needs to be within the opamp circuit itself (between the differential stage and output stage). Where the diode fits in otherwise depends on the circuit.
It's the same trick. The diode needs to be within the opamp circuit itself (between the differential stage and output stage). Where the diode fits in otherwise depends on the circuit.
WoW, great stuff Joe, I can't wait to try this thing.
z-zero
Hey Squid, I too am being worshiped as a God. I'm building framed lattice panels to put under our wrap around porch. Of course the "crowd" is a little smaller than yours. :wink: I got out the Simple Square Wave Shaper last night. It's just about as versitile as the Tripple Fuzz, but different one all together. Out of the pedals I've built recently, I'll usually ene up going back to that one. I love the sustain, and the different types and tembres of tone you can get out of it. It can go from very sweet, to very nasty, and not too many pedals can do that. I love Tim's stuff. They're usually always amazing, highly variable, and and noisless. What more could you ask for? Now, I going to go put the SSWS back on the alter with the rest of his effects :shock:
VERY cool circuit....
I've been going over this thing with the signal generator and 'scope and there's some really interesting things here. One is that not only is the input signal compressed, the compression happens at the cost of significant gain. That might explain the apparent success of Q1s with high hFE, set up for more gain than would normally be considered good in a fuzz face.
With a sine wave of 100mV (p-p) at 1kHz on the input side of the diode, only 8mV appeared on the other side of the diode. That's a loss of 12x or a little over 10 dB. With 10mV input, almost 2mV gets through (5x loss), indicating good compression. I used 100mV and 10mV because they represent a firmly, freshly picked note and a soft or decayed note, respectively.
The other thing that is noticable in the scope trace is how asymetric the signal becomes after the diode. Kinda like what you'd get from a tubescreamer or bluesbreaker with a mild amount of drive. Looks really interesting.
Actually, I'm dying to use this pedal, but it's 11pm and the missus is in bed, so I guess it'll have to wait until morning.
For the record, these measurements were done with a Q1 = 2N2369A with hFE= 75 and a 33k collector resistor and Q2 = BD139 with hFE=100 and a 1k fuzz pot.
cheers
Hi. Built it using regular FF-style transistors (hFE=70 and 120). Fuzz was modest unless turned way up. That loss of gain of about 5 x across the diode makes me think that maybe a Q1 transistor with hFE about 5x70 might be best in this circuit. Interestingly, the input impedance of this fuzz is very high (50k for a large signal, 100k with a small signal). This probably explains some of its differences in tone from a regular fuzz face.
This circuit is definately worth experimenting on.
cheers