I just breadboarded this and it sounds (and responds) pretty nice, if not a tad shrill. Having trouble with freq dials (not changing much) but I’ll have to play with it more tomorrow (at proper volume). I’m late to the game on Exar, but the few ODs of theirs that I have built have all performed wel...

Since this one was mentioned in the Poltava topic, here is the schematic for Ltava (credits https://sovietguitars.com forum)

Googling this pedal brought me to a auction selling a later version of this pedal. There were pics of a schematic too. Also retitled this thread, but kept the Ukraine credit... Lltava has a bit different circuit inside, even controls are different - I have both and they do sound quite different, ha...

I recently got this vintage pedal "PUE Sustain Filter" (Poles are really creative at naming stuff), and it was described as Polish Big Muff, so I decided to check out the circuit. PUE was producing guitar pedals in the 80s in Lodz, Poland. PXL_20240303_202929008.jpg It has a plastic enclos...

I've opened Exar OD-3 recently, and it appeared to be the same circuit - they changed transistors (probably just what was available at the time) and improved power supply filtering a bit. Schematic is in the attachments.

Neurobasher wrote: ↑20 Jun 2023, 15:01 This looks like an discrete Timmy

Timmy didn't exist when this thing was released

I created a GitHub repo with KiCad files, Gerbers, schematic, and Interactive BOM for a modified version I did as a part of the Pedal Drop series: https://github.com/vitaliy-bobrov/kropy ... -overdrive

It has additional clipping options on the toggle and Fat switch.

CheapPedalCollector wrote: ↑02 May 2023, 04:38 Are they the same as the XR chip manufacturer? I always wondered.

No they never made ICs.

CheapPedalCollector wrote: ↑01 May 2023, 20:21 Neat, thank you. Interesting design choices in this one for sure.

They definitely had a lot of interesting stuff, but unfortunately those pedals were underrated locally in Poland and unexplored globally

I'm back with a new Exar circuit traced :D , unfortunately, I was a bit busy all the time. I traced Exar HV-03 Hoover, and it appeared to be quite interesting inside. Here is what it looks like with a box. PXL_20230501_082954962.jpg The translation of a pedal description from the user manual: "...

I continue to trace my Exar pedals - today, it's Exar KM-03 Kamikaze. That particular model seems to be quite popular in Poland back in time because I've seen some good mentions about it. I had two units; both had the same components inside, so I traced the one in a slightly worse condition. For ano...

I got a chance to check another OD-1 unit, slightly earlier production circa 1990. It has exactly the same PCB, but black color textolite, components values are the same. The only difference that that unit uses JRC4558D IC instead of Panasonic one, initially I thought that all of them should have AN...

I analyzed EQ a bit. So we have a 3rd order Sallen-Key lowpass filter (I just drew it a bit unusual, you could play with it here http://sim.okawa-denshi.jp/en/Sallenkey3Lowkeisan.htm ) for Low; it cuts everything higher than 90 Hz. For High we have a bunch of highpass filters at 1.5kHz and 15kHz. Th...

I'm back to Exar pedals tracing, I was a bit busy during the last weeks, and it took me almost a month to finish HM-02 Heavy Metal tracing. According to the pots and warranty card dates, the unit I have seems to be produced and sold in 1999. PXL_20230204_113433180.jpg PXL_20230204_113459549.jpg It w...

Updated schematic version with fixed tone stack values:

hi VitaliiBobrov, thanks for schematic, in past (like 15 years ago) i tried to reverse engineer this pedal but i failed :( I compared shematic with my own superfuzz and it seems that you got error with R27 and R13 (on schematic those are marked as 2k3) i got 12k there sf3.jpg for mods i liked opa26...

I was lucky to get Exar OD-1 in good condition for a reasonable price, so I thought I must trace it. Many legends are around that pedal, and pricing on the used market went too far, significantly after JHS added it as one of the modes in Bonsai pedal. I hope my trace will help reduce insane prices o...

Another Exar pedals tracing, this time it is not one but two effects at once - MT-02 Metal and BM-02 Bad Metal. I traced both at once, as it appeared that they shared a single PCB. PXL_20221231_150236846.MP.jpg PXL_20221231_151241700.jpg Both units seem to be manufactured same year - 1995 according ...

Another Exar pedal trace, Exar SF-02 Super Fuzz. I was lucky to have a friend in Austria who helped to get this one for a reasonable price. The unit seems to be produced in 1997 or later, as the latest date on the potentiometer was '97. PXL_20221227_125404729.jpeg PCB is standard for series 2 Exars ...

I traced Exar FL-1 Flanger from my collection 🎉. The unit should have been made in 1989 or later due to the dates on the pots (09-89). I even have the box 😅. PXL_20221219_211836112.jpg This trace was quite challenging due to amount of components on the small single-sided PCB. PXL_20221217_195623135....