INFANEM the driving notion clone

[mcatano]

OK,

so there are 8 transistor/JFETs that I can see and they're all stacked in a row. I'm not sure what corresponds to what in the trace/schematic, so I'm going to just number 1-8 from top (jack side) to bottom (switch side).
I'm also assuming everything follows the SOT-23 convention of
C
B E
*or*
D
G S

For the two rotated components, measurements reference the PAD, not the component — "C" is the nominal C position on the PCB, but is connected to BASE of the component.

All knobs dimed fully CW, supply reads at 9.29v:

Q1:
C - 9.29
B - FALLS TO 1.85
E - RISES TO 2.53

Q2 (rotated 90° - B leg connects to C pad, etc):
C - 0.95
B - -0.48
E - 0.00

Q3 (rotated 90°)
C - 2.09
B - 0.52
E - 0.08

Q4
C - 8.24
B - 0.76
E - 0.21

Q5
C - 9.29
B - RISES TO 1.85
E - RISES TO 2.55

Q6
C - 9.29
B - FALLS TO 1.85
E - RISES TO 2.60

Q7
C - 0.17
B - 0.57
E - 0.00

Q8
C - 0.00
B - 4.51
E - 0.35

[imJonWain]

Sorry guys, I got tied up this weekend, I should have time tomorrow evening!

[ianmarks]

I'll compare to what I have tomorrow as well. SHould be fairly easy to line up based on the 9.29 voltages and the 0 voltages.

[imJonWain]

Sorry, I've been tied up so far this week.

[imJonWain]

Today I swear, next on my list!

[goroth]

But is it?

[imJonWain]

Sorry, too many projects and some are for people paying me lol


File is hosted here for download.
https://sndup.net/3ym2


I am running the circuit without an enclosure on my desk and I get really bad interference at my place so there's oscillation that might not normally happen boxed.

I started with clean signal and then messed around with the controls. I never raised the master volume very much as there is a ton of volume in mine.

I think low gain transistors are a key and getting the correct cap values.

[imJonWain]

thoughts? Does the pedal normally have this much volume?

[ibarakishi]

thoughts? Does the pedal normally have this much volume?

yes

[selfctrl]

Can confirm it has a ton of volume!

I have the three-knob version, so I think input is permanently at full and blend is permanently at at a 50-50 split.

This is sounding pretty close to my ears.
The oscillation sounds familiar too, I think that does tend to happen if you really crank the high/low up.
I pretty much set it how I liked it and rarely touch the settings.

Will be at the studio tomorrow night GMT and can record a couple of clips.

[imJonWain]

awesome!

[selfctrl]

Sorry for the delay! Battery was dead on the Zoom so I’m afraid it’s iPhone only.
Jazzmaster with a tele pickup (front) through a Carlsboro Stingray

https://www.dropbox.com/s/2vzxo88am7c81 ... n.m4a?dl=0

Three knob version.
Input would be full.
Blend 50-50.
Output is up a quarter.

0-6sec clean
10sec Low at quarter Hi at zero
15sec low at half hi at zero
20sec low at full hi at zero
28sec hi at quarter low at zero
34sec hi at half low at zero
38sec hi at full low at zero
46sec both at a quarter
57sec both at half
1min both at full

[oldangelmidnight]

The decay on that sounds pretty different from what I remember from my 5 knob.

[ianmarks]

Well I have spent a bit of time with mine and unfortunately have lackluster news to report. While certain transistors match up to the ones posted by mcatano (thanks BTW!) others do not. the jfET and the three transistors that get V+ check out and you could kind of make a case for a couple of the others, but none of them have a base voltage of 4.5 which he has labeled as q8. Of course given the fact that these are smt and turned around and upside down....who knows. i ended up running two more 2n2222 instead of the mpsa18 but still reversed and I can get some useable stuff going on, but it doesn't really sound like the demos. if I had to guess where a problem lays it would be on the tail end of that high section. There is always the chance that I might have messed up my layout somehow, but until I hear that someone has made one that sounds like the OG, I'm taking a break.

Anyone think Jon's samples checked out compared to the original? ...and thanks for taking one for the team, heard someone harassing you in your clip! Ha!

[mcatano]

Are you using a through-hole J201? If so, maybe swap the bias resistor for a trimmer and see if that helps at all? Or just swap a bunch of J201s?
My experience with J201 circuits has been pretty frustrating.