hey guys, first feel free to move to the correct location of this post.

I'm thinking of making a buffered volume pedal, is it correct to do it this way?

I put the 250k potentiometer between the buffers. which potentiometer ideal for this circuit?
thanks

Behringer DC9

PCB photos
Top Layer top_layer.JPG
Bottom Layer bottom_layer.JPG
Circuitry close up bl_close up.JPG

It is using surface mount BC846 transistors, CoolAudio V13700 absolutelly identical to LM13700.

I will post the schematic tomorow.

Here are the guts to a cool volume pedal that can simulate a backwards guitar. Sorry about the picture quality my camera refuses to focuswhen i use the zoom.

the IC chips say: U5: too small to read.
U3 and U4: HCF4016BE
W990A9735
Malaysia
U2: 4558D
JRC
7398B
U1: MC14013BCP
FOL9806

Hello, Is there anyone who has the Keeley Compressor Pro and can send me high-quality and high-resolution photos of its PCB ? I want to design a compressor with THAT4320 and I want to get help from this pedal. :D

Hi guys,
I was just reading a lot of topics and I'm looking for clues to repair my EHX Memory Boy.
It was stored for some years, and now i can't get any effect out of the pedal, i already tried battery, and AC, and the behavior its the same, i can turn it on and off, i have sound, but no effect...
Delay and Depht doesn't affect the sound and blend and feedback just do some type off modulation turning the sound imperceptible.

Anyone can help me with this one?

This topic on MXR ISO brick includes some mentions of Ojai & includes a gut shot:

Schematic or IC datasheet for Ojai???

More gut shots of the Ojai here:

24V connector is EIAJ-05 (
24V input/loop board appears to just hold a Nichicon filter cap & (common mode, given 2 colours of wire?) inductor.

16 pin chip marked AJE BAC is probably a buck converter. Possibly controller only? Figuring out what this is should lead to a datasheet explaining 90% of the rest of it.
3 pin SOT connected to...

Guys

I have an Blackstar HT Dual pedal Im trying to fix. I purchased from eBay. Shortly after I noticed a problem in the switching. Negotiated a 50% reduction on the basis I would fix. Im not a pro but have built fx and fixed amp problems before so am confident in tackling this.

Wanted some advice before I open the box though.

Symptoms are...
Unit always works in Bypass
Sometimes either green, red (or both) channels are silent.
Sometimes the volume of green or red channel will dip randomly....

Intro

Hi everyone! I had the chance to get my hands on the MXR Doubleshot for a little while, and found out there are no available schematics anywhere. It's nice to do some selfless circuit tracing once in a while, in the true spirit of FSB.
Starting from what was known already, the Doubleshot is usually described as the dual channel version of the Dime, and we'll see this is accurate. That circuit already has something interesting in its own right, but this one builds upon it with the...

Would anyone have a schematic or service notes for the Boss DD-6.
I bought one over the weekend. Totally dead as described.
No light or sound at all.

Hoping it's just a power problem. Found a post on another forum that suggests it could be the IC6 5v regulator. Will check that first. As well as checking all the power rails are correct.

There are some similarities to the dd7 but feel like im flying on the dark without a schematic.
Can find the dd3, 5 and 7 but not 6.
Does anyone have it?

I found a video with a few pics of the PCB and managed to trace cabinet sim section.

When I compare the frequency response of the circuit as drawn it doesn't seem to match up with the response plots of the GI100 I've seen. It's not bad but it looks a little bottom heavy and the mid dip frequency looks a little high. Having said that the impulse responses I've seen all seem to disagree in the low end. I don't know what to believe.

I'm sure the part values that matter are correct on the...

Doesn’t sound like a rat too me. Has more mids.

When I was in highschool in the mid-1990's, one of my bandmates got a brand new Turbo Rat. I was surprised to see that it didn't have the same kind of footswitch as my Rat 2 (also bought new around the same period, probably 1994). His Turbo Rat had a plastic soft touch footswitch like this:

I later saw this same style footswitch on my Roadkill. We now all know that the Brat/Roadkill used electronic FET switching like a Boss/DOD pedal. Now I'm very curious if there was a short-lived version of...

Does anyonr have a service manual for the Tech21 Sansamp bass driver di pedal?

Screen Shot 2020-02-12 at 23.37.54.png

Figured I’d take a few pics of this before I let it to. Not a bad sounding unit at all. Darker than most pt2399s based delays I’ve used but it has a darker vintage analog delay tone “think dod FX90 or any old Reticon units pushed to their max. Modulation was also nice. Just have too many delays. Only changed I noticed with the chips is a tl072 used instead of a burr brown. Even has voltage regulator and preamp trim.

Nothing much to see here with all the smd components. But I know others have been curious as well is this is just a crushing orange , bb pre, clone. It doesn’t sound like the bb preamp. Or, atleast the taper on the gain and level react differently. Isn’t near as loud as the crushing orange or bb pre either. All I could make out were the 2 TL072 op amps and 2 diodes d1 and d2. Maybe 1n914 or 4148s? Anyways I figured @cheapedalcollector may enjoy it.

Here should be a schematic of the Sansamp (Tech 21) Tri-A.C.:

scroll down a bit.

analogguru

Hi Guys,

Been looking at this schematic and wondering why they have biased the opamp this way using the non-inverting configuration. Could someone please explain this for me ?

madbean.PNG