Circuit Analysis

The research folders: please contribute whatever little piece of information you might have on stompbox circuits new or old. Discussion should be civil and to the point.

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Vintage Stompbox Corner ( ... - 1975)
Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
Topics: 676

676 Topics

15293 Posts

Last post Re: EXH - Big Muff Rams Head…
Cub
04 dec 2024, 07:52
Modern Stompbox Effects (1975 - ...)
All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
Topics: 1714

1714 Topics

24956 Posts

Last post Re: Behringer's Boutique Bona…
modman
yesterday, 21:26
Boutique Stompboxes dissected...
General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
Topics: 1880

1880 Topics

58800 Posts

Last post Re: Pete Cornish - NG-2
palelight
30 nov 2024, 23:09
DIY Projects
Original effects with schematics, layouts and instructions, freely contributed by members or found in publications. Cannot be used for commercial purposes without the consent of the owners of the copyright.
Subforums: Printed/Published Online Designs, Original Tracer Layouts
Topics: 1615

1615 Topics

28897 Posts

Last post Re: Buffer/Splitter with dire…
asbestosaurus
today, 08:16
Electric Guitar/Bass Wiring
Pickups, wiring schemes, switch techniques and onboard active electronics for guitars and basses
Topics: 290

290 Topics

2658 Posts

Last post Re: Fishman Universal Recharg…
ABtheBassPlayer
21 oct 2024, 21:34
Analysis Requests Folder
Before you launch a request, please a) search the forum; b) search the web and c) share whatever you did find and where you searched.
Topics: 885

885 Topics

3963 Posts

Last post Manfred
05 dec 2024, 17:10

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Last post

Original tracer layouts for classic pedals

Last post by andregarcia57 « 30 May 2023, 14:03
Replies: 61
by peps1 » 26 Apr 2010, 18:16
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Rating: 2.2%

(Hope this is in the right place, as it n0ot really a technical question and didn't want to post a request in the vintage section)

Hi Guys,

Trying to gather a collection of Original tracer layouts for classic pedals like the Tycobrahe Octavia, Dallas Rangemaster, ToneBender, Muffs & so on.

Got a couple so far....but would love more!
61 Replies

72326 Views

View the latest post Re: Original tracer layouts …
Last post andregarcia57
30 May 2023, 14:03
BOSS Book (pdf & mp3's)

Last post by The G « 15 Dec 2020, 15:28
Replies: 3
by The G » 15 Dec 2020, 15:02

Rating: 4.1%

Discussion is here

--------
Did a compressed version. Didn't noticed visual differences compared to the original.

The Boss Book.pdf

And the audio files:

01-AudioTrack 01.mp3
02-AudioTrack 02.mp3
03-AudioTrack 03.mp3
04-AudioTrack 04.mp3
05-AudioTrack 05.mp3
06-AudioTrack 06.mp3
07-AudioTrack 07.mp3
08-AudioTrack 08.mp3
09-AudioTrack 09.mp3
10-AudioTrack 10.mp3
11-AudioTrack 11.mp3
12-AudioTrack 12.mp3
13-AudioTrack 13.mp3
14-AudioTrack 14.mp3
15-AudioTrack...

3 Replies

24622 Views

View the latest post Re: The BOSS Book
Last post The G
15 Dec 2020, 15:28
Tim Escobedo's "Folkurban" circuits. Zipped.

Last post by modman « 26 Jan 2020, 03:10
Replies: 24
by culturejam » 17 Mar 2012, 15:41
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Rating: 11.2%

I've recently noticed that Tim's great site at is coming up as a virus, trojan horse, or other bad things in my browser. So I thought I'd grab all the circuit images and zip them up for safe keeping. I have emailed him in the recent past, but there has been no reply. :hmmm:

Attached is a zip file of ALL of the effects circuits from his site.

Rock on, and may the creative spirit of the Great Escobedo be with you always. :thumbsup
24 Replies

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View the latest post Re: Tim Escobedo's "Fol …
Last post modman
26 Jan 2020, 03:10
THE ENGINEER'S THUMB... At last, a better compressor!

Last post by jhergonz « 20 May 2018, 18:09
Replies: 101
by merlinb » 21 Apr 2012, 14:23
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Rating: 14.3%

For a long time I've felt guilty that my pedal board didn't include a compressor. Finally, after about a year of breadboarding, I have produced a circuit that can take on a Dynacomp and win , boasting:

Up to five times more headroom than a Dynacomp
Less noise than a Dynacomp
Same available sustain as a Dynacomp
Fewer parts than a Dynacomp
Cheaper than a Dynacomp
Feedforward side chain
Possibility for all five controls
Fits in 1590B
Millennium bypass

Despite its final simplicity, I went though...
101 Replies

220243 Views

View the latest post Re: THE ENGINEER'S THUMB... …
Last post jhergonz
20 May 2018, 18:09
READ THIS before posting!!

Last post by modman « 11 Sep 2011, 13:52

by modman » 11 Sep 2011, 13:52

Rating: 1.7%

This section is devoted to circuit analysis . This means...

requests for schematics or layouts will be moved the the Request section
messages about your sick puppy or your new Android powered phone should go into the FSB Café
debugging questions will be moved to the Workbench
useless post (containing no extra information) may get deleted to preserve the readability of the thread.
you should check whether a thread exists about the unit in question, and add your info in that thread.
you...

0 Replies

55621 Views

View the latest post READ THIS before posting!!
Last post modman
11 Sep 2011, 13:52
DO NOT post requests in this forum. Pretty please.

Last post by modman « 19 Mar 2010, 09:41
Replies: 2
by culturejam » 22 Nov 2009, 21:18

Pretty please, with sugar on top.

Don't post in this forum asking is there is a schematic or layout or info on XXX pedal.

There is a subforum setup for requests already. It is located here:
REQUESTS FORUM

Any requests posted here will be moved to proper sub forum, and I'll also make nasty remarks about your mother. :mrgreen:

2 Replies

55453 Views

View the latest post Re: DO NOT post requests in …
Last post modman
19 Mar 2010, 09:41
DO NOT post requests in this forum. Pretty please.

Last post by lolbou « 22 Nov 2009, 21:23
Replies: 1
by culturejam » 22 Nov 2009, 21:18

Pretty please, with sugar on top.

Don't post in this forum asking is there is a schematic or layout or info on XXX pedal.

There is a subforum setup for requests already. It is located here:
REQUESTS FORUM

Any requests posted here will be moved to proper sub forum, and I'll also make nasty remarks about your mother. :mrgreen:

1 Replies

57090 Views

View the latest post Re: DO NOT post requests in …
Last post lolbou
22 Nov 2009, 21:23
The Goose, the Middleman, the Idolmaker and Gomer Pyle

Last post by noelgrassy « 01 Feb 2008, 19:42
Replies: 91
by CS Jones » 07 Dec 2007, 21:41
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Clay, I would really love to hear the full story on this one. It seems like you have lots to tell!

Thanks LPD. How much do you want to hear? The Reader's Digest version or the pull up a chair, get comfortable because it'll be a while version ?

I'll try to finish something up this weekend. Long and short versions, if you're still interested. :)
91 Replies

251203 Views

View the latest post
Last post noelgrassy
01 Feb 2008, 19:42
Buffer/Splitter with direct output and balanced output

Last post by asbestosaurus « Today, 08:16
Replies: 1
by cocnut » Today, 02:33

Rating: 0.2%

Hi, I'm working on a project of simple DI Box with splitter/buffer functionalities.
The idea is to have a direct unbuffered output and some buffered outputs and ballanced output to send the signal directly to the mixer/audio interface. I want to plug it in somewhere at the beginning of my pedal chain using an input and a direct output, to affect the tone as little as possible, then use buffered output for some other purposes like recording clean signal on my laptop and an XLR output to send...

1 Replies

42 Views

View the latest post Re: Buffer/Splitter with dir …
Last post asbestosaurus
Today, 08:16
Behringer's Boutique Bonanza...

Last post by modman « Yesterday, 21:26
Replies: 8
by modman » 23 Nov 2024, 15:01

Rating: 0.9%

You gotta be kidding me...

8 Replies

1156 Views

View the latest post Re: Behringer's Boutique Bon …
Last post modman
Yesterday, 21:26
MXR - M-118 Analog Delay SAD1024

Last post by Fernando JFET « Yesterday, 19:59
Replies: 17
by musopaul » 12 Oct 2013, 13:51

Rating: 1.3%

Hi there,

I have a green box MXR 118 Analogue delay that i have brought back from the dead and am trying to align but cannot find the alignment procedures for clock frequency and location of trim pots anywhere...

It is the SAD1024 version with 118-3001 102 board.

I have found a couple of alignment sheets on here but they are for the PT2399 modded version and refer to trim at point A with no reference to what point A is.

Thanks,

17 Replies

65817 Views

View the latest post Re: MXR - M-118 Analog Delay …
Last post Fernando JFET
Yesterday, 19:59
Rowin Comp Nano Gutshot

Last post by FernandoGarcia « Yesterday, 14:48
Replies: 3
by accompanist » 17 Nov 2024, 03:56

Rating: 1.3%

Searches didn't clear up whether this was an optical compressor or not, so I had a look. I am guessing the big black cylinder with a triangle on the board next to it is the LED and photoresistor--does that seem right?

To save some squints, I observed a TL072 opamp, LM358 opamp, and a OP275G JFET. Seems to be some tantalum caps too. Transistors labelled 1AM (MMBT3904 from my searches).

Sorry for the lack of additional details, I just had it open and wanted to check it out....

3 Replies

791 Views

View the latest post Re: Rowin Comp Nano Gutshot
Last post FernandoGarcia
Yesterday, 14:48
Boss - OD-2 Turbo Overdrive

Last post by Gila_Crisis « Yesterday, 07:47
Replies: 4
by gambitpawn1 » 29 Jul 2014, 17:12

Rating: 0.4%

i have a boss od-2r and i am concidering moding a blend pot into it verses just buying a boss ls-2. i found this pedals sounds good with my bass but i would like a wet/dry mix.

this is the page that i am using the schematic from for the pedal, i was hoping for a little guidence on where i should try to make my connections/breaks for a blend pot if possible. i have not opened the pedal yet to see if there is any room in it for the pot, but worse case i can put it in a different box and maybe a...

4 Replies

6367 Views

View the latest post Re: Boss - OD-2 Turbo Overdr …
Last post Gila_Crisis
Yesterday, 07:47
MXR M114 Stereo 10 Band EQ

Last post by GermánMoreno « Yesterday, 00:38
Replies: 5
by CheapPedalCollector » 07 Jun 2023, 22:09

Rating: 0.4%

Recently got a commission to convert this EQ to 1/4 jacks, new power supply caps and NE5532 upgrade to make it less noisy. I took a bunch of photos to post here for tracing if someone wants to have a go. I have one of these of my own too if I need to check any part values. MXR 10 Band EQ 01 .jpg MXR 10 Band EQ 02.jpg MXR 10 Band EQ 03.jpg MXR 10 Band EQ 04.jpg MXR 10 Band EQ 05.jpg MXR 10 Band EQ 06.jpg MXR 10 Band EQ 07.jpg MXR 10 Band EQ 08.jpg MXR 10 Band EQ 09.jpg MXR 10 Band EQ 10.jpg MXR...

5 Replies

1560 Views

View the latest post Re: MXR M114 Stereo 10 Band …
Last post GermánMoreno
Yesterday, 00:38
Engl e530 Fet

Last post by lutor « 05 Dec 2024, 15:31
Replies: 30
by armkon » 16 Mar 2014, 13:52
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Rating: 1.5%

i'm sending layout + schematics of orginal tube version still need a bat85 on fet legs, same like in AMT designs
If someone have time to check or have any ideas please help :)

Layout is made for Fets not for tubes !!!
30 Replies

15142 Views

View the latest post Re: Engl e530 Fet
Last post lutor
05 Dec 2024, 15:31
EXH - Big Muff Rams Head 2N5133, FS36999 hFE notes

Last post by Cub « 04 Dec 2024, 07:52
Replies: 24
by solderman79 » 02 Jan 2019, 01:26
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Rating: 6.5%

A few years ago I posted the actual hfe of Q1-Q4 from a 1974 Rams Bead Big Muff with FS36999 transistors as measured using a Peak DCA55. They were: Q4: 163, Q3: 214, Q2: 171, Q1: 160.

Since that time I've worked on three more pre-1975 Rams Head Big muffs. Two had FS36999 trannys and one had 2N5133 trannys. Guess what...they all measured less than 200 hfe, lol. The one with 2N5133 trannys were as follows: Q4: 132, Q3: 117, Q2: 145, Q1: 128. I also noticed Kit Rae posted some of his own...
24 Replies

22276 Views

View the latest post Re: EXH - Big Muff Rams Hea …
Last post Cub
04 Dec 2024, 07:52
Germanium and Silicon diodes comparison

Last post by Cub « 03 Dec 2024, 19:00
Replies: 44
by thomasbe861 » 13 Oct 2023, 10:01
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Rating: 11%

Long story short, I ended up testing and measuring a good part of all odd diodes I have had accumulated over the decades of tinkering.
Some are modern, widely available, some are more rare and not produced anymore, germanium, silicon, including Schottky, silicon carbide, Zener, LEDs, IR, etc.
Here are the graphs, showing the forward voltage drop for a given current (I-V curve) for different types of diodes. Hope this is helpful to anyone. All were measured using a Peak Atlas DCA75 Pro.

The...
44 Replies

30548 Views

View the latest post Re: Germanium and Silicon di …
Last post Cub
03 Dec 2024, 19:00
Digitech - PDS 8000 Echo Plus 8

Last post by Stevenrb718 « 02 Dec 2024, 22:59
Replies: 12
by Stevenrb718 » 21 Feb 2024, 22:55

Rating: 0.6%

Anybody have a schematic for the Digitech PDS 8000? I have one that produces no effect and the infinite loop is locked on. I will at times get a digital squeal when the effect is engaged (and the infinite loop is too obviously) until I go back to bypass.

12 Replies

41468 Views

View the latest post Re: Digitech - PDS 8000 Echo …
Last post Stevenrb718
02 Dec 2024, 22:59
Ibanez - FP-777 Flying Pan

Last post by BMS1971 « 02 Dec 2024, 16:03
Replies: 56
by bradb » 13 Jan 2008, 21:11
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Rating: 2.6%

Hello all,

I've been hearing wonderful things about this pedal. They go for like $1000 on ebay generally. I found some really neato sound samples at

Unfortunately, the guy there isn't building these anymore, nor offering any secrets so I'm stuck with building one from scratch. I love a challenge.

Bajaman gave me 2 schematics to work from, let's see how i can post them, they're PDFs. Here's a sendspace.com link

If there is trouble, PM me.
56 Replies

34501 Views

View the latest post Re: Ibanez - FP-777 Flying P …
Last post BMS1971
02 Dec 2024, 16:03
Pete Cornish - NG-2

Last post by palelight « 30 Nov 2024, 23:09
Replies: 169
by Fuzzer » 17 Dec 2008, 11:44
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Rating: 2.8%

All right my friends, thanks to an unidentified mysterious cool guy;

mr_x.gif

Here we have some Cornsih pedal guts, you can't get to trace shit, but at least you can look at some good pedal porn.

Enjoy;
169 Replies

68293 Views

View the latest post Re: Pete Cornish - NG-2
Last post palelight
30 Nov 2024, 23:09
Pelota 2: PT2399 delay

Last post by chip- « 30 Nov 2024, 17:49
Replies: 12
by dylan159 » 21 Jan 2023, 11:51

Rating: 6.3%

It’s been a couple of years since I’ve made the first Pelota delay: from the very name, it was a circuit inspired by a few popular PT2399 delays, such as the Rebote series, the Deep Blue Delay, and many others that aren’t that different to be worth mentioning.

Even then, with my more limited experience and knowledge, I knew I could try to do better, starting from the awful, noisy, high resistance inverting input stage you find in the vast majority of them that makes you wonder who did it first...

12 Replies

5798 Views

View the latest post Re: Pelota 2: PT2399 delay
Last post chip-
30 Nov 2024, 17:49
Fred Briggs - Super OCD

Last post by blackboarcult « 30 Nov 2024, 11:09
Replies: 67
by briggs » 28 Feb 2012, 16:39
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From my blog:

The Fulltone OCD has been an overdrive favourite for many years now. It's got a really nice tone when your amp is set right (I prefer it with Marshalls I must say). Well, I've always thought about modifiying the basic circuit (which itself is based around the old Voodoo Labs Overdrive) to give it a little more variety and use over a wider spectrum of tones.

As you can see the Super OCD has a few extra controls:

- Firstly the Bass control - it's nicked from Paul C's Timmy pedal...
67 Replies

27775 Views

View the latest post Re: Fred Briggs - Super OCD
Last post blackboarcult
30 Nov 2024, 11:09
BJFE - Dyna Red Distortion

Last post by jawacan « 30 Nov 2024, 08:21
Replies: 86
by culturejam » 05 May 2009, 19:51
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Okay guys, here's a fun one to play around with.

I was merely tapped to post this, and I was in no way involved with the reversing or drawing the schem. I don't want it to seem like I am trying to take credit here. I'm just the messenger. :mrgreen:

This has been played around with a bit on the breadboard, and it is believed that the schematic below is in fact an accurate rendering of the BJFE Dyna Red Distortion. The schematic was donated to FSB anonymously. Apparently this version was...
86 Replies

52895 Views

View the latest post Re: BJFE - Dyna Red Distorti …
Last post jawacan
30 Nov 2024, 08:21
Xotic Effects - Super Clean Buffer (SCB)

Last post by aion « 29 Nov 2024, 21:34
Replies: 9
by matoni » 18 Jul 2024, 21:55

Rating: 2.4%

Hello,
I haven't seen anyone do this yet, so I thought I'd get one and trace it! Please let me know if there's anything that you see that looks obnoxiously wrong, or if there's anything that you think I may have missed.

9 Replies

2741 Views

View the latest post Re: Xotic Effects - Super Cl …
Last post aion
29 Nov 2024, 21:34
Behringer - VD400 Analog Delay

Last post by bc108 « 29 Nov 2024, 10:18
Replies: 14
by culturejam » 03 Oct 2010, 05:23

Rating: 0.6%

No, the VD does not stand for venereal disease . It stands for vintage delay .

There's a Cool Audio V3205 under the hood. The clock chip is marked CD3102GP, which is NOT made by Cool Audio. Does anyone recognize the manufacturer logo on it?

Bottom side has a shit-ton of SMD, as expected.

I managed to eek out a bit more than 300ms out of it by dicking with clock trimmer. But it's a very tight range that sounds good (to me).

For the money, it's a pretty good short analog delay. The filtering...

14 Replies

14163 Views

View the latest post Re: Behringer - VD400 Analog …
Last post bc108
29 Nov 2024, 10:18

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