=========================================================================== Digest of fuzz box building and other fuzzy articles =========================================================================== From: dam@dcs.glasgow.ac.uk (David Morning) Newsgroups: alt.guitar Subject: Fuzz Box From Hell (corrected version) Date: 30 Sep 92 09:24:37 GMT Organization: Glasgow University Computing Science Dept. I knew I shouldn't have posted something which had been collecting dust for years in my files. Oh well. My original version used 2 batteries to provide a split rail supply. In my rush to post it, I bodged the battery supply splitter. I wasn't convinced I'd got it right after I'd posted it so a built it from scratch at the week-end. There are 2 connection errors in the original, both the input resistor and the 680 ohm feedback resistor should go to the V/2 rail and NOT the battery -ve. Sorry folks. This one does the trick. Oh..and it's a 9 volt battery (small type) Battery is 9 volts. Op-amp is anything. 741 is noisy, TLO71/72 is less noisy, NE5534 is least noisy but drains the battery. --- Op-Amp | \ | \ Inputo----||----------| + \ 0.47u | | \ 0.47uF | | >-----------------||------ | | / | | | | ---| - / | ---\ - - | | / - / \ ZD1 | | | | | | / | | - | |100k 68k | | | | / 330k| | | - - | --- - - |-------o Output | | | \ / ZD2 | | | | ---/ - | | | | | | | -------------------|------- | |2k2** | | - | - | | | | | | 680ohm | | | | - | | | | ------------------------------> V/2* | | Input | Output Gnd o----------------------------------------------------------------o Gnd Battery rail splitter ===================== Batt +ve-----------------------------------------> To Op-Amp +Vs | | - | |220k | | - | -------|------------> To V/2* | | --- ++ - 100uF --- | | 200k | | | | - | | | | Batt -ve -----o\o-------------------------------> To op-amp -Vs Jack socket switch | | ------> To Gnd Jack socket switch wiring:- ========================= ------------------- | Sleeve Ring Tip | Jack plug ---> | - - - | goes in here | | | | | | | | | | | | | | | | --| |---| |---| |-- From battery -----| | | | | | -ve terminal - - - | -------------> To battery rail splitter Inserting mono plug shorts sleeve and ring together and activates the battery. --------------------------------------------------------------------------- This it? +9v---|1meg|----|1meg|----> Gnd | | |----||--- - + 1uf 1meg | | | | - | 10nf | | \ 741 In ----||---|10k|----|+ \ + 1uF | | >-------||----|10k|----- - -|- / | | - 1nf | | / - | | | | | 1meg | | | - - | -----------| | | | | 10k| |<----- Out | - 47nF | | | - - | | | | - | | | |4k7 | | - | | ----------| | | | | | | -------- - 500k | | | | | |<- | | 1N270 - 1N270--- | | | | | \ / / \ - | | | --- - |--- | | | | | | ------------------------------------------------------------------Gnd Dave --------------------------------------------------------------------------- Newsgroups: alt.guitar From: META000 Subject: MXR Distortion + Organization: The University of New Brunswick Date: Fri, 2 Oct 1992 22:03:34 GMT Ok, folks... I found my schematic, and since, for some zany reason, lots of people are interested, here is the schematic for what I gather is the original MXR Distortion + (circa 1978). This schematic was traced out from one I borrowed. Given the simplicity of the circuit, I am pretty confident of its accuracy. Unfortunately, the system here tends to screw up the spacing of characters, adding and deleting spaces here and there, so I'll have to verbally describe the circuit, step by step. 1) The circuit employs a 741-opamp, 4 x 1meg resistors, 2 x 10k resistors, 1 x 4.7k resistor, 2 x 1.0uf electrolytic caps, 1 x .01uf cap, 1 x .05uf cap, 1 x .001 uf cap, 2 x 1n270 diodes, a 500k pot, and a 10k pot. 2) The input goes to a .01 cap then to a 10k res, then to pin 3 on the opamp (the noninverting or + input). A .001uf cap also goes >from the input (i.e. before the .01 cap) to ground (to shunt off high end so you don't end up fuzzing high frequencies). 3) Pin 3 also connects to a 1meg res and 1.0uf cap (in series, with the + end of the cap connected to the resistor), with the - end of the cap going to ground. 4) Pin 2 (the - or inverting input) on the op amp connects to a series of components, first a .05ufcap, then a 4.7k resistor, then to a 500k pot, used as a variable resistor going to ground (i.e., the 4.7k res connects to the center terminal on the pot, and one of the side lugs goes to ground). 5) a 1meg resistor joins pins 2 and 6 on the opamp 6) Pin 4 on the opamp goes to ground. 7) Pin 7 is connected to two 1meg resistors in series, then to ground. 8) The point where the two 1meg resistors are joined is connected to the point where the 1meg resistor coming from pin 3 meets the + side of the 1uf cap. 9) Pin 6 of the opamp connects to the + side of a 1.0uf cap. The - sideof the cap connect to a 10k res, then to a 10k pot wired as a standard volume control, then finally to the output jack/switch. 10) Two 1N270 diodes, wired in parallel, one the reverse orientation of the other (i.e., the stripe is on the other end), are connected between the input to the volume control and ground. 11) This is the entire original circuit. As those of you more technically inclined can tell, its a standard non-inverting amp, with a variable gain of 3 to about 200 or so, using standard clipping diodes at the output. You can substitute a quieter op amp forthe 741, use metal film resistors, and plastic caps (for all those below 1.0uf) for a "mil spec" box. I reduced the noise on a friends' using a .001uf cap in parallel with the diodes to shunt high frequencies to ground. My guess is that the 1N270 diodes are critical, however, you can probably use a numberof substitutes in your circuit for some of the other parts. The 1.0uf cap going to ground can probably be replaced with a higher value one such as 2.2uf or 10uf, perhaps even improving the sound. If you have a very "hot" signal going into it, you might consider replacing the 4.7k res with, say, a 22k or 47k, and a 1meg pot. This will reduce the maximum gain, and allow you to achieve gains < 3. This will let you dial in softer sounds. If you want, you can stick a cap in parallel with the feedback resistor (the 1meg joining pins 2 and 6) to reduce the high end and shape the tone. You probably don't want to go much higher than 220pf on this. If you want, you can stick in a 3-position toggle switch and alternate between no cap, 47pf and 220pf for different voicings. There you go. I realize this is a fairly low-level description, but I'm hoping some of those entry-level do-it-yourself-ers may be inspired to take up soldering pencil and create. It's amazing how many classic sounds were created by very simple means. While I remember, the .05 cap can probably be replaced with something higher, like a 0.1uf, without any noticeable change in the sound, perhaps a wee bit more bass. Indeed, bass players may find this circuit sounds better with the .05cap increased and the capacitor in the feedback path. Finally, I highly recommend Hammond 1590B or BB boxes. These may be sold as Eddystone radio boxes in the US. They are cast aluminum, and the original MXR chassis. They are very easy to machine, and extremely rugged. Expect to pay about $10 from an electronic supply house. Mark Hammer --------------------------------------------------------------------------- Newsgroups: alt.guitar From: META000 Subject: Re: MXR Distortion + Organization: The University of New Brunswick Date: Tue, 6 Oct 1992 22:30:15 GMT In article dam@dcs.glasgow.ac.uk (David Morning) writes: > >This it? > > +9v---|1meg|----|1meg|----> Gnd > | | > |----||--- > - + 1uf > 1meg | | > | | > - > | > 10nf | | \ 741 >In ----||---|10k|----|+ \ + 1uF > | | >-------||----|10k|----- > - -|- / | | > - 1nf | | / - | > | | | | 1meg | > | | - - > | -----------| | | > | | 10k| |<----- Out > | - 47nF | | > | - - > | | | > | - | > | | |4k7 | > | - | > | ----------| | > | | | | > | -------- - 500k | > | | | | |<- | > | 1N270 - 1N270--- | | | | > | \ / / \ - | | > | --- - |--- | > | | | | | > ------------------------------------------------------------------Gnd > >Dave > >-- >. >. Just about. The diodes are connected between the input to the "OUTPUT" volume control, not the input to the "DRIVE/DISTORTION" control, and ground. In response to queries sent to me, let me note that the + terminal of the battery (i.e., +9vdc) is connected to pin 7 on the op-amp, and the - terminal of the battery goes to pin 4 and ground. Not all readers are aware of these implicit details. My apology for ommitting them. Mark Hammer --------------------------------------------------------------------------- Newsgroups: alt.guitar From: dnj@kauai.verity.com (Dave Johansen) Subject: Re: Tube sound fuzz Organization: Verity, Inc. 1550 Plymouth Ave, Mt. View, CA 94043 Date: Mon, 25 Jan 93 19:09:49 GMT A word of note: Hendrix' Purple Haze was done with a Fuzz Face, and a Roger Mayer Octavia (on the solo, and outro solo) thru of course a Marshall 100w Super Lead.... PS you can buy all the Roger Mayer products from North Star Audio, in Charlotte NC.... -dnj --------------------------------------------------------------------------- Newsgroups: alt.guitar From: s0477311@let.rug.nl (M. Verhoef) Subject: RAT schematics Date: Wed, 6 Apr 1994 08:55:52 GMT Organization: Faculteit der Letteren, Rijksuniversiteit Groningen, NL Hi All, it took a long time but here it is......... -------------------------------------------------------------------------------- ****************************** PROCO RAT *************************************** -------------------------------------------------------------------------------- this should be connected to 'distortion' (part below) (+) (+/2) | | | | __|d | | R7 |\ + / C3 o----+- C1 - R2 -->|g FET | |3 \| / / | |__ s | | 7 \ /1 / o R1 |__ (+)C2 __ R4 __|___| \ /8 | | | | | >---------- + C11 - --- R11 ------------- A | | | | | 6/ | | | | R3 C5 | 4 /| | | V V | | |-|2 / V | ------- V V | |/ | | | | | D1 D2 |----- - C8 + ---- | | | distortionpot | --------- |------150k log--- | | \ | | ----------------- \__| V | | R5 R6 | | + + C6 C7 - - | | V V (+) ____ | / \ ____d / | | A----- -100k log+ ------ R12 ------ C12 -------|g FET filterpot | | |____s | | |____ + C14 - ___________ C13 R13 | | | ___________o | | R14 R15 + / OUT | | | | 10k log o V +/2 V V - levelpot | | | V V The distortion part: (+)------ R10 ------------------------------------------------------(+) | | | | + --- R8 | C10 D3 |________ C4 - | | + | | | R9 C9 | | | | | | (-)---------------------------------------------------------------|-() | V C1 : 22n R1 : 1 M FETS: 2x BF 245A C2 : 1m * R2 : 1 K _____________ C3 : 30p R3 : 1 K \ . . . / C4 : 100n R4 : 1 K \ G S D / C5 : 1n R5 : 47 Ohm \___/ C6 : 2m2 * R6 : 560 Ohm gate source drain C7 : 4m7 * R7 : 100 K C8 : 100p R8 : 33 K C9 : 47m * R9 : 33 K IC: LM 308 C10: 100m * R10: 47 Ohm + nc C11: 4m7 * R11: 1 K __|__|__|__|__ C12: 22n R12: 1 K 5 | 8 7 6 5 | C13: 3n3 R13: 1 M |\ | C14: 10m * R14: 1 K |/ | R15: 10 K | 1 2 3 4 | --|--|--|--|-- (-) Diodes: 2x 1N4007 2x 1N4148 * watch the +/- connection!!!!!! elco's!!!!!!! Pots: Distortion: 150 K log Level : 10 K log Filter : 100 K log This version of the RAT has been modified since it was intended to be used in a rack mounting. It has no 'battery saving', though you could easily do that yourself (check out 'electronic projects fo musicians' by Graig Anderton). It works very well, just like a 'real' RAT. Experiment with the resistance of the distortion pot, you might find a 220 K sounding a bit more fuzzier (like I did). The more resistance the more fuzz you get. Good Luck! Btw, officially this schematics shouldn't be on the net so just use it for your own purposes, don't let me be responsible for PROCO going bankrupt :-). Mike --------------------------------------------------------------------------- From: bew4568@zeus.tamu.edu (Bruce E.) Newsgroups: rec.music.makers.builders Subject: Simple Distortion circuit schematic Date: 14 May 1994 13:18 CDT Organization: Texas A&M University OpenVMScluster Here is a little distortion circuit that I kinda like. It's very easy to build and sounds amazingly like an Ibanez tube screamer. With the exception of the diodes it is the circuit for the Electra Power Overdrive module (the one that went inside the guitar--another relic of the '70's). It's important to use Germanium diodes to get the right sound. The voltage out is .4 volts. If you need more power and less distortion use Silicon diodes, for 1.4 volts output (you can change the values of the 4.7K and 470 ohm resistors to get more distortion if you need. Just tell your electronics friend that it's an emitter follower and you need more gain). B+= 9v | | / \ / 4.7K \ / 2.3M | | | /\/\/\/\-o | | | o-------| |--------o-------o---> Out | / | | | | | | /C | | | | | | | | / ----- ----- | | | |/ 0.1 mfd /^\ \./ Both Ge-type In >-----| |------o----| 2N3904 ----- ----- | | B |\ | | | | | \ | | 0.1 mfd | \E |---o---| \| | | | | ---------- | ------- / --- \ - / \ 470 / \ | | | --------- ----- - Now for all you electronics types who just said, "Heck, that just hard-clips the signal. It'll sound horrible", you should realize that the gain of the transistor is changing with the signal level, and has the effect of rounding out the upper lobes of the undistorted wave. If you don't believe me just put it in your PCSPICE program and watch what it does. I don't claim credit for the circuit--the Electra people came up with the amp, and I was just fiddling with it and found that this worked well--later on I figured out why. If you want an uninverted signal (if you think there is a difference) take the signal off the emitter instead of the collector. It might not sound the same, however. I didn't test it. Have fun with it. Should cost about $10 from Radio Shack components, including jacks. Ask me about it if you really really really need to. Bruce bew4568@zeus.tamu.edu --------------------------------------------------------------------------- From: bernards@ecnsun.ECN.NL (Marcel Bernards) Subject: Re: Schemata - speaker load boxes, Fuzz; re: tube screamer posts Date: 29 Apr 1994 09:18:19 +0200 Organization: Netherlands Energy Research Foundation (ECN) I have the service manual of the original TS-9, it's nothing special really.. just a 4558 OpAmp with two antiparallel MA150 Diodes and a small tone circuit. and a input and output transistor buffer (emittor followers) It's too complex for making an ASCII drawing :-) I am surprised that this thing is causing such a hype on r.m.m.g. It is really a very common schematic of a signal clipper published in several electronic magazines etc. I have made such circuits many times, and I could not hear very much difference between them and an original TS9. Cheers, -- Marcel Bernards, UNIX & Net sysadm ECN - Netherlands Energy Research Foundation Facilities Dept. - Group Computer & Network Management: E-Mail: Bernards@ECN.NL SnailMail: P.O. Box 1, 1755 ZG Petten Phone: (+31 /0)2246 4579 Fax: (+31 /0)2246 1864 SCREAMNet : AAAAAARGHH!HUH?? : Disclaimer: "The AntiChrist is the Computer !" --------------------------------------------------------------------------- From: bew4568@zeus.tamu.edu (Bruce E.) Newsgroups: rec.music.makers.guitar Subject: Simple Distortion Circuit v0.2 Date: 16 May 1994 14:29 CDT Organization: Texas A&M University OpenVMScluster [Ed. Note: This is properly attributed to Bruce, but the header and date may be wrong. TJS] Here's the new, improved file. The circuit is correct. I've included some of the voltages and currents you should be seeing. The only difference I've seen between the parts list and mine is the value of Cc (which I've changed to 1.0 mfd to give better bass response with low-impeadance amps) and the use of Radio Shack's MPS3904 transistor rather than my National 2N3904. The transistor difference shouldn't matter, though. They both have the same specs. Here is a little distortion circuit that I kinda like. It's very easy to build and sounds amazingly like an Ibanez TubeScreamer. With the exception of the diodes it is the circuit for the Electra Power Overdrive module (the one that went inside the guitar--another relic of the '70's). It's important to use Germanium diodes to get the right sound. The voltage out is .4 volts. If you need more power and less distortion use Silicon diodes, for 1.4 volts output (to get more distortion use the mod listed below, use Ra = 100 and Ca = 8 mfd for a gain of 45). By the way, this is a common-emitter amplifier. For those of you needing an exact duplicate of the TubeScreamer, you'll need to add 2 more parts, indicated as Ra and Ca. These are added to lower the A.C. gain below the cutoff frequency (f = 1/(2*pi*Ca*Ra)) to duplicate the TubeScreamer bass roll-off. Ra should be 270 to 330 ohm, and Ca selected to give the proper cutoff frequency, I guess around 200 Hz. I'll try to find it exactly. I haven't tried this mod. Good luck. Vcc=9v | | / \ / Rc=4.7K \ / Rb=2.3M | (Xout=5K) /\/\/\/\-o | | | o-------| |--------o-------o---> Out | | | | | | | /C | | (Xin=50K) | | / Cc=1.0 mfd -----D1 ----- | | | |/ /^\ \./ Both Ge-type In >-----| |------o----| 2N3904 ----- D2----- | | B |\ (NPN:gen. purps, | | | \ small signl.) | | Cb=0.1 mfd \E |---o---| \| | | | o---------. ----- R S # | | --- Q: 2N3904 276-2016 / \ - D1,D2: 1N34A 276-1123 \ / Ra Cb: 0.1 mfd 272-1069 / \ Cc: 1.0 mfd 272-1434 \ Re=470 / Vb = 0.8 - 0.9V Re: 470 271-019 / | Vc = 7.0V Rc: 4.7K 271-030 \ ----- Ve = 0.1 - 0.2V Rb: 2.2M 271-061 | ----- Ca Ic = 0.5mA 9V jack 270-325 | | Perfboard 276-149? ----- ----- Box 270-235? --- --- Jacks(2) 274-252? - - Switch 275-011? Now for all you electronics types who just said, "Heck, that just hard-clips the signal. It'll sound horrible", you should realize that the gain of the transistor is changing with the signal level, and has the effect of rounding out the upper lobes of the undistorted wave. If you don't believe me just put it in your PCSPICE program and watch what it does. I don't claim credit for the circuit--the Electra people came up with the amp, and I was just fiddling with it and found that this worked well--later on I figured out why. If you want an uninverted signal (if you think there is a difference) take the signal off the emitter instead of the collector. It might not sound the same, however. I didn't test it. Connect the left-hand side of Cc to the emitter to do this. I've noted that the Screamer mixes some of the original signal in with the distorted signal, and the mix seems constant mo matter how distored the signal gets--the setting of the distortion knob effects only the distorted signal drive. This may be wrong, but that's what it sounds like to me. If you want to do this, you'll need to take the signal off the collector, otherwise you'll get some wicked bass phase cancellation when you mix the signal with the original. Have fun with it. Should cost about $20 from Radio Shack components, including jacks, box and a footswitch. Ask me about it if you need to. Bruce bew4568@zeus.tamu.edu From: Arsenio.Novo@mba.org (Arsenio Novo) Date: 04 Jul 95 23:04:50 Newsgroups: rec.music.makers.guitar Subject: New Overdrive Circuit Organization: MtlNet (MBA.org) MBA [514-465-8524] Brossard, QC Hi, I've noted that talk on this echo always comes back to the subject of overdrive distortion. Whether generated by a vacuum tube amplifier or a transistor amplifier there seems to be undeniable differences to me as well. Lately, I was tinkering with an unusual transistor circuit configuration I had come upon a few years ago and made a few modifications to the circuit that turned it into one beautiful screaming "tube-like" overdrive but without the wall of noise these things usually make. When pushed it even makes that distintive "zoo-zoo" sound...!!! The original circuit was simply a complementary matched pair of transistors connected so that all the terminals overlapped. i.e. both bases tied together, emitter of the PNP connected to the collector of the NPN, and the collector of the PNP connected to the emitter of the NPN. Thus: ___________o 2N3906 | | b |< e |/ c o---|------| 2N3904 |\ c |> e |______|____o This transistor pair is then biased by 2 equal value resistors in each of the compound legs, one to the positive supply and the other to ground common. The signal is coupled to the base pair leg and the output is picked off either of the other 2 legs. The result is that the above circuit exhibits the behaviour of a multiplier over a range of signal values. It basically performs a sin function: in other words a frequency doubler. This doesn't have a very good distortion sound though because it is rather "burpy and buzzy". However, lately I was toying with the circuit when I offhandedly decided to try doing something to it just to see what would result. After adding a large cap from the NPN's emitter to ground the thing went wild on me... WANGO ZE TANGO! SUPREMO DISTORTION! I then proceeded to refine the circuit a little more and got a better understanding of what it was doing. The final schematic follows but first a couple of notes on the circuit. The "bias balance" trimmer should be adjusted for a symetrical clipping threshold of the output signal as viewed on a scope. Short of this it can be easily set by "ear" for the most sensitivity somewhere around mid-turn. The input should be driven by a lo-z stage if your electric guitar doesn't have a built-in pre-amp. You can alter the emitter capacitor value in a range from 0.1uF to 1uF in order to obtain various basement characteristics but I found the indicated value is a good compromise. The input capacitor should not vary much either though because if it is made too large the circuit goes balistic and cuts out on the tutti. "Tube-sound" Distortion Overdrive Circuit: _____________________________o + 9volt battery | | < bias balance < 20K < <--. set < 10K trimmer < | < _|_ < 220K | 0.1uF /// < ___________o----||----o output < | | c 0.0047uF | b |< e |/ c 2N3904 input o----||---o---|------| |\ c |> e |______|____o----- 2N3906 | | < --- 0.22uF 10K < --- NB: 2N3906's gain matched < | with 2N3904's |------ _|_ /// gnd common The operation of the circuit more closely resembles a vacuum tube than a diode clipper does because of the strong square law characteristic. This is due to the negative feedback around both base-emitter pairs. This feedback accentuates the junction non-linear behaviour manyfold. Thus each transitor drives the other even harder so that the transfer curve ends up more logarithmic than is typical of a single transistor. In other words: the clipping is gradual and not abrupt like it is in the case of a silicon diode. Typically a lot more 2nd harmonic is produced as well. As a bonus the waveform folds over on itself when the circuit is overdriven! Now in the interest of the common good I donate this design to the public domain for personal use but retain copyright and reserve all rights for any commercial purpose. In other words build one for you and your friend but if you have it massed produced for profit I only ask a fair share. Please, do try the circuit and leave any comments in private at my e-mail address: arsenio.novo@mba.org Arsenio arsenio.novo@mba.org ... Accordion: A bagpipe you can't fold quietly. ~~~ ReneWave v1.00.wb2 (unregistered) -- | InterNet: Arsenio.Novo@mba.org | Standard disclaimer: The views of this user are strictly their own. From: Michael Kent Newsgroups: rec.music.makers.guitar Subject: Re: New Overdrive Circuit Date: 12 Jul 1995 17:53:49 GMT Organization: MIND LINK! - British Columbia, Canada On the subject of novel use of bipolar transistors to get 'musical' distortion, take a look at the distortion circuit that's in the August 1995 issue of Popular Electronics (I haven't built this yet). The author used a long-tailed pair of transistors in a configuration which he claims gives gradual cut-off at saturation, and which is further configured to emphasize the even harmonics. Please check this out. --Mike. From: michael_kent@mindlink.bc.ca (Mike Kent) Newsgroups: rec.music.makers.builders Subject: Re: FuzzFace transistors Date: Wed, 15 Nov 1995 03:18:10 GMT Organization: MIND LINK! - British Columbia, Canada If you are looking for germanium transistors, buy any one of those old surplus military boards from the 1960's--many of the transistors which are in a silver can are often of the germanium type. Less chance that any of the small black ones are. You might have to look them up in an older transistor manual to check, because those particular part numbers might no longer be made. I bought a surplus board for $1 and it had no less than 8 germanium transistors on it. I still haven't tried them out yet. --Mike. jorman@aol.com (J Orman) wrote: >Germanium transistors are in limited supply. See the data sheet and info' >posted on my Web page at: >http://users.aol.com/jorman/ >If you are interested in building a duplicate of the original FuzzFace >distortion unit, a germanium transistor is the only way to go... >JACK From: keen@austin.ibm.com () Newsgroups: rec.music.makers.builders Subject: Re: FuzzFace transistors Date: 15 Nov 1995 21:43:22 GMT In article <48bm5n$ltd@fountain.mindlink.net>, michael_kent@mindlink.bc.ca (Mike Kent) writes: > If you are looking for germanium transistors, buy any one of those old surplus > military boards from the 1960's--many of the transistors which are in a silver > can are often of the germanium type. Less chance that any of the small black > ones are. You might have to look them up in an older transistor manual to > check, because those particular part numbers might no longer be made. I > bought a surplus board for $1 and it had no less than 8 germanium transistors > on it. I still haven't tried them out yet. > > jorman@aol.com (J Orman) wrote: > > >Germanium transistors are in limited supply. See the data sheet and info' > >posted on my Web page at: > > >http://users.aol.com/jorman/ > > >If you are interested in building a duplicate of the original FuzzFace > >distortion unit, a germanium transistor is the only way to go... > I have used 2N404's (lots of those on 60's mil surplus boards). They work well. I found a cache of 2N527's, which appear to work EXTREMELY well. Very nice ranges of distortion. My guitarist friends are beating me to death to get these. Test the transistors for gain. Supposedly, the first transistor should have Hfe of 90-100, and the second 130 to 250, with a range of clipping sounds being available as the second transistor gain varies. Who knows? Your mileage may vary. R.G. Newsgroups: rec.music.makers.guitar Organization: AOL http://www.aol.com From: fulltone@aol.com (Fulltone) Subject: Re: Fulldrive2 REVIEW Part 4 (final) Date: 27 Jan 1997 00:45:03 GMT The effect a Buffered output has may be sonically indistinguishable to some..but the way it can destroy the performance of other pedals in the chain (Fuzzes, especially PNP) is what keeps most pros away from buffered devices.Try your own experiment, put an Ibanez or Boss pedal before a Germanium Fuzz and see how it squashes the fuzz when the Ibanez/Boss is "off". ------------------------------------------------------------------------------ For more information on Tube Screamers, see http://users.aol.com/AnalogMike/ts9.htm More Fuzz Face info: http://users.aol.com/AnalogMike/fuzzface.txt ------------------------------------------------------------------------------