=========================================================================== 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: 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 Mon May 16 17:52:42 1994 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 Distribution: world NNTP-Posting-Host: zeus.tamu.edu News-Software: OpenVMS/VAX VNEWS 1.41 [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