Chauffeur (Daily Driver) Troubleshooting

[rgoodman]

Hello everyone, I built the daily driver clone and wow! I totally love this drive. It really suprised me by how good it sounded! I'm having an issue. Probably nothing to do with the circuit but my own mistake(s) somewhere. The pedal is making a high pitched squealing noise that is dynamic. I wonder if anyone can tell whats going on by the noise (maybe its a common noise for a particular issue). The noise occurs when powering on (engaging the footswitch) and fades away. The noise corresponds to the "gain" knob position it is not present or inaudible around 50% and below. It become apparent above 50%, increasing with the gain knob and occurs dynamically as I play. The harder I play, the noise is louder and also similarly fades away. Here is a link to my google drive folder housing 3 pictures and 2 videos (one video is audio only) demonstrating the issue. If you need anything else please let me know!

Shnobel Daily Driver Build Troubleshooting - Google Drive

drive.google.com

Thank you so much!

Bob

 

[music6000]

Okay, interesting stuff. This is all new to me so I youtubed how to do the reading. Also, I'm not sure how to communicate the measurements. Q1,2, 3 correspond to the pedalpcb build docs. E = emitter, C = collector. Here's what I've found:

Q1:
E = .649 V
C = .633 V

Q2:
E= 0 V
C = .593 V

Q3:
E = .643 V
C = .630 V

https://docs.pedalpcb.com/project/Chauffeur-PedalPCB.pdf

The back of your PCB needs a good clean, there's bits of Solder & Flux residue that needs to be removed!

 

[rgoodman]

The back of your PCB needs a good clean, there's bits of Solder & Flux residue that needs to be removed!

Just cleaned off all of the remaining flux from the board very well with IPA and the problem is still occuring. I've also inspected every solder joint to make sure no leads are touching, except for under the IC sockets.

Hey yes, thank you. I did this with IPA and it all cleaned off very well the problem still occurred after the cleaning

 

[rgoodman]

Hey all, this pedal has now been fixed. The issue was the Q2 2N4401 transistor was bad. Robert (reverse engineer) thank you for your support. One of the main helpful ways I located the issue was by continually using steel tweezers and poking around to see what changed the sound or caused normal sound. I discovered that when the tweezers connected one of the transistor legs with one of the diodes, the sound was normal. I took out Q2 and jumped the outer legs (as Robert had previously shown me how to do for the other transistor which may have also been bad btw) to bypass this transistor in the circuit and it worked! I then ordered a new 2N4401 and replaced it. Thanks for everyone's support.

 

[devanbumstead]

Hey all, this pedal has now been fixed. The issue was the Q2 2N4401 transistor was bad. Robert (reverse engineer) thank you for your support. One of the main helpful ways I located the issue was by continually using steel tweezers and poking around to see what changed the sound or caused normal sound. I discovered that when the tweezers connected one of the transistor legs with one of the diodes, the sound was normal. I took out Q2 and jumped the outer legs (as Robert had previously shown me how to do for the other transistor which may have also been bad btw) to bypass this transistor in the circuit and it worked! I then ordered a new 2N4401 and replaced it. Thanks for everyone's support.

Glad it got resolved! Now…the real question is, now that it’s fixed, how close is the tone to the actual Daily Driver?

 

[Robert]

Glad it got resolved! Now…the real question is, now that it’s fixed, how close is the tone to the actual Daily Driver?

Taking component tolerances into consideration, and the fact that the overloaded power supply voltages seem to vary from one unit to the next (including the originals) it should be pretty dang close.

 

[rgoodman]

Glad it got resolved! Now…the real question is, now that it’s fixed, how close is the tone to the actual Daily Driver?

The tone is exact with one exception. There was a slight high end presence that the original had (not what the treble knob does, but a high end presence similar to what the high end switch does) that the clone could not match at any setting. Most likely component tolerances I suppose! It was slight and would not be noticable to most players IMO. Like I said, other than that the tone is exact. The original did not socket the op amps which was a big draw back for me as well. I sold the original and kept the clone!

 

[MichaelW]

The tone is exact with one exception. There was a slight high end presence that the original had (not what the treble knob does, but a high end presence similar to what the high end switch does) that the clone could not match at any setting. Most likely component tolerances I suppose! It was slight and would not be noticable to most players IMO. Like I said, other than that the tone is exact. The original did not socket the op amps which was a big draw back for me as well. I sold the original and kept the clone!

What did you use for the 2.5v Zeners? As I recall these are part of the clipping circuit. I had a devil of a time finding 2.5v's but eventually found some on Ebay. I think I originally built it with 2.6v's which according to @Robert "should" be pretty close but eventually swapped them out for 2.5's.

 

[rgoodman]

What did you use for the 2.5v Zeners? As I recall these are part of the clipping circuit. I had a devil of a time finding 2.5v's but eventually found some on Ebay. I think I originally built it with 2.6v's which according to @Robert "should" be pretty close but eventually swapped them out for 2.5's.

I used Vishay 1N5222B 2.5 V from mouser electronics found here: https://www.mouser.com/ProductDetail/78-1N5222B