Chauffeur/Daily Driver OD - Too much gain?

[Joben Magooch]

Hi all,
Just wrapped up a build of the Chauffeur OD. As far as I can tell everything works as intended - the only thing is that when compared to the "real thing" (well, videos, anyways) mine seems to be breaking up a bit earlier and the breakup is a bit "woolier".

I did have to make one substitution and I'm wondering if that's the culprit: The build calls for 1N5222B for D1-D4 (2.5v Zener) and I could not find these so I used 1N5221B (2.4v Zener) instead. I'm not familiar enough with the circuit to say, but I guess that perhaps a slightly lower voltage would give it a bit less headroom and thus an earlier breakup?

Other than that, I'm not really sure. Let me know what you think!

 

[Elktronics]

I have the opposite problem. Mine feels like it doesn’t even start breaking up until just past 50% on the gain knob

 

[music6000]

Hi all,
Just wrapped up a build of the Chauffeur OD. As far as I can tell everything works as intended - the only thing is that when compared to the "real thing" (well, videos, anyways) mine seems to be breaking up a bit earlier and the breakup is a bit "woolier".

I did have to make one substitution and I'm wondering if that's the culprit: The build calls for 1N5222B for D1-D4 (2.5v Zener) and I could not find these so I used 1N5221B (2.4v Zener) instead. I'm not familiar enough with the circuit to say, but I guess that perhaps a slightly lower voltage would give it a bit less headroom and thus an earlier breakup?

Other than that, I'm not really sure. Let me know what you think!

Post Good Pictures of the PCB & COMPONENTS please!

 

[Joben Magooch]

PCB:

https://imgur.com/a/WblEr7v

Not my cleanest ever (after looking at pictures/up close, could really stand to clean off some flux...)

In case it's not legible from the pics, IC1-IC5 is NJM4558D and IC6 is ICL7660SCPAZ.

As above I *did* substitute D1-D4 (1N5222B) for 1N5221B.

Everything functions as it should, for the most part. The volume, treble, bass, and high-cut all work properly, just as you'd expect the 'real thing' to do. The only 'issue' I'm having is that it just seems a touch gainier than it ought to be - position-for-position, the other knobs match up well (i.e. 2 o'clock on the treble knob on my build sounds like 2 o'clock on the treble knob on the actual thing sounds), it's just that (again, position-for-position) the gain knob will break up a lot earlier and just get hairier/gainier in general. Like...the gain around 10 o'clock on mine sounds about as gainy as 1-2 o'clock on the real one. It's not a bad thing per se, just not quite as expected.

All pots are B10K's, though admittedly I didn't bother to take the time to check their measures beforehand.

 

[Joben Magooch]

I was able to get ahold of some 1N5222B's (as above, I had previously used 1N5221B) and swapped those in, but unfortunately didn't really make any meaningful difference to my ears. I went back and re-flowed *every* solder point and scrubbed the board down with alcohol to clean it up a bit and checked for any bridged pads or anything like that - all good. Still more of the same - more or less just feels like it has really low headroom. Breaks up really early, and the volume knob has to be 3/4ths of the way up or higher just to hit unity volume.

At this point the best I can figure is that perhaps there was a wrong component value put in somewhere, but I'm not really sure where to start. Anyone have any idea as to if there are any components in particular that could have that effect if they were an improper value? I'd rather not have to check every single thing