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...
Boutique Stompboxes dissected... General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
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
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.
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
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
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...
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Employ the shift, no slide, and +2 instructions at...
The pedal works perfectly in 8 second mode. However, when I switch to 2 or 1/2, the effect doesn't work. When it kicks in, it basically doubles the signal overtop of the input, i.e. Just makes the sound a little warmer. There are no trails, echos, or repeats. The delay controls don't seem to change anything. The controls all work perfectly in 8 second mode however. I've recapped and swapped ICs. I get the voltages on the 4066 when sliding the selector switch. Interestingly, if I jump pins 3&4...
Hardly what i'd call a Modern Stompbox but the Schematic dates it as 3 years out on '75.
Anyway, here's a Redraw of the Factory Schematic for those of you with poorer eyesight. I think the Redraw is Correct I can't recall where I got the original Factory one from and nor can I confirm its Authenticity so if someone knows the link to that or if it's correct, that'd be handy.
I might see about converting it to 9V & V3205s as it's quite a nice simple looking Delay Project.
I checked the connections twice and also double-checked the values. The numbering doesn't follow the PCB at all because the PCB numbering is buried under the components.
Here the voltages, all measured against circuit ground (not DC adaptor ground), pedal on, switches off, knobs at 12 o'clock
Hi friends!
Is there any information on ProAnalog Fuzzes? I think they were top as for representing traditional rock / blues rock sound.
I found the layout on one of the forums and assembled it on
a pref board using old military soviet germanium transistors. It really sounds excellent.
I'm half tempted to get a Liverpool just to see what's inside, but if someone has already had a look, I'd be interested to hear it.
Supposedly, some guy on YouTube bypassed the speaker sim so he could use it with his amp - that's what I'm looking for.
I have a PDS 20/20 that is driving me crazy. The delay effect timing is right, but the effect on the note itself flanges up and down like a wave. It's like rocking a pitch shifter back and forth. I have replaced the bad caps, checked all the transistors, and swapped around several of the ICs with no change. The voltage regulator is also tested fine. I have no idea where to look next.
Here is a bare bones mic preamp project I designed based on the application notes published by THAT Corp for their THAT 1512 mic preamp chip. This was done at the behest of someone on the GroupDIY forum who was looking for a THAT chip board layout suitable for home etching, but I'm posting it here first for folks to check out and get a first look.
This design includes an option to have a switch for -6dB Line Mode, which takes advantage of a unique feature of the THAT 1512. If the switch is...
Seeing as there are only two trace side gut shots, and no one is willing to post components, I took some time to look at this.
The pictures seem clear enough to make out what might be a resistor, or a cap. Cap polarities are fairly clear as well. Even a diode symbol can be made out. Wire connections to the board seem to be bigger solder blobs. Transistor E and C letters are there. So looking at, I get this;
Two things that pop out at me, are the resistor/cap in series between B and C...
Last night I sold my MXR badass 78 distortion, so this morning put the money towards an AMT S1 legend series Soldano pedal/preamp ordered from Thomann (i'm sitting by the letter box waiting). I really want to have a look inside and work out what makes this pedal tick. If there is any info available already it would be good is someone can point me in the right direction please.
I know the designer behind it has had quite a bit to do and say on these and other forums. From the clips at the AMD...
Hello,
I have built a fuzzface clone, with some variation of my licking.
The pedal sounds good for what i want but it behaves not as i expected.
I just want to understand.
The circuit is exactly the same, i have just added a pre gain 100k pot, right before the input 2.2uf capacitor and a 10k trim pot on the second transitor collector, this is very common.
Transistors are bc108a for q1 and bc109c for q2, i have two 3pin sockets so i can easily swap them and try different combinations with other...
I don't know if there is much interest for this as it is not really a pedal but I find the circuit interesting. Also if I posted this in the wrong section please move it to where it should belong.
I've always liked the Boston guitar sound although I find these headphone amps to be a little weak in accurately producing that sound. I haven't had the chance to play one of the original headphone amps but I have read that these sound nothing like them, minus the reverb and chorus. I mainly use...
Anybody have a schematic for the MXR Omni M180 rack? I'm looking to get pot values for replacements. I'm also hoping to find the schematic for the footswitch to rebuild that. Thanks.
Does anyone know what Pro Co has done to the RAT to make it a FATRAT? I'm talking actual circuit and/or component changes not sound/features. If anyone has any gut shots or an actual verified/traced schematic that would be great. I'd like to update my comparative multi RAT schematic (below) to include this new RAT variation so I'm really curious as to what they've done.
carlsefni 
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