Build Your Own Clone Message Board

It is currently Sun May 18, 2025 8:51 pm

All times are UTC - 6 hours




Post new topic Reply to topic  [ 9 posts ] 
Author Message
PostPosted: Mon Apr 14, 2025 5:42 pm 
Offline

Joined: Sat Jun 05, 2021 9:13 pm
Posts: 4
Hello! I built this classic compressor a few months ago and never quite got it working

The sound I am getting out of it is VERY soft, like I have the guitar volume cranked, the level on the pedal turned up, and the gain on the amp pretty hot and it's still relatively low volume. Without the pedal this is too loud to listen to.

This happens both with the pedal engaged and bypassed.

LED does come on when I engage the pedal.

I think it sounds different with the pedal engage, but honestly it's too quiet to really tell.

Here are the voltages from the IC with a test tone going through the pedal:

1: 0v
2: 4.5v
3: 4.5v
4: 0v
5: .694v
6: 3.9v
7: 9.18v
8: 0v


Attachments:
Circuit Board top.jpg
Circuit Board top.jpg [ 455.36 KiB | Viewed 1088 times ]
Circuit board back.jpg
Circuit board back.jpg [ 426.87 KiB | Viewed 1088 times ]
Top
 Profile  
 
PostPosted: Tue Apr 15, 2025 9:22 am 
Offline
Moderator
User avatar

Joined: Tue Jan 02, 2007 1:24 pm
Posts: 16338
Location: Albany, NY
Maybe it's a trick of the camera angle, but in your first photo, it looks like there's no wire connection to lug 7 of the footswitch. Am I just seeing things (or NOT seeing things)?

The IC voltages you posted look very reasonable.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2


Top
 Profile  
 
PostPosted: Tue Apr 15, 2025 1:26 pm 
Offline

Joined: Mon Aug 03, 2020 6:10 pm
Posts: 36
2nding voodoo’s comment


Top
 Profile  
 
PostPosted: Wed Apr 16, 2025 11:21 am 
Offline

Joined: Sat Jun 05, 2021 9:13 pm
Posts: 4
Holy crap how did I miss that? Just looked at it and it is indeed not connected. maybe it broke with all the shuffling around.

I'll fix it tonight and see if that solves the issue. Thank you!!


Top
 Profile  
 
PostPosted: Wed Apr 16, 2025 2:08 pm 
Offline
Moderator
User avatar

Joined: Tue Jan 02, 2007 1:24 pm
Posts: 16338
Location: Albany, NY
mungu wrote:
Holy crap how did I miss that? Just looked at it and it is indeed not connected.

Exactly why we always ask to see photos, and the ones you provided were excellent. A fresh pair of eyes (or two!) often are able to spot something that gets overlooked.

Since that wire connects the output of the effect circuit on the PCB to the footswitch path leading to the output jack, it certainly explains your lack of audible signal.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2


Top
 Profile  
 
PostPosted: Fri Apr 25, 2025 5:19 pm 
Offline

Joined: Sat Jun 05, 2021 9:13 pm
Posts: 4
Alright, it took me a while to get back to this.

I re-did the connection to footswitch. And I re-flowed/re-attached a few other joints that looked questionable.

Good news - with the unit bypassed, it seems like everything works fine. No loss in volume. Checked voltages going in and out of the pedal and everything looks right.

I'm using a simple cable tester which can generate tons at 3 different levels (+4dBu/-10dBv/-50-mic level). It sends about 1.4v out. When bypassed, I see 1.4v on the other side too.

Bad news - with the unit enabled, LED comes on, but the signal is very suppressed. Only seeing about .7v coming out the other side. And when I plug a guitar in it just sounds MUCH quieter. I understand a compressor is going to make the guitar quieter, but even with the level and the trim cranked all the way up it is super super quiet.

Any ideas how to diagnose further?


Attachments:
20250425_152942.JPG
20250425_152942.JPG [ 841.07 KiB | Viewed 924 times ]
20250425_153009.JPG
20250425_153009.JPG [ 862.69 KiB | Viewed 924 times ]
Top
 Profile  
 
PostPosted: Fri Apr 25, 2025 8:12 pm 
Offline
Moderator
User avatar

Joined: Tue Feb 09, 2010 4:45 pm
Posts: 4740
Location: Rochester, NY
You mention having the trim cranked, but I just want to verify that you've dialed the trimpot in according to the instructions, because "cranked" is most likely not the right place for it to end up.

Have you done this step?

Quote:
If you don't get any sound at first, don't worry. You will need probably need to adjust the trimpot. If your trimpot isn't already set at the middle of its rotation, do so. This may or may not be the optimal setting for the trimpot, but it should definitely produce sound and be a good starting point for fine tuning.

You should adjust the trimpot to the position where you get the least amount of distortion when playing your guitar and where you get the longest smoothest decay. This may take a few minutes and several adjustments. You should still get a very small amount of pleasing distortion. It's just the nature of the circuit. It is not perfectly clean, but the distortion does give it some warmth and is part of the pedals character. If you have an 18v adapter, we recommend using it while adjusting your trimpot. It makes the trimpot much more sensitive and easier to dial in. 18v will also increase headroom and reduce distortion.

_________________
Scott

My band, Austin Hollow


Top
 Profile  
 
PostPosted: Fri Apr 25, 2025 11:35 pm 
Offline

Joined: Sat Jun 05, 2021 9:13 pm
Posts: 4
Most of my testing has been with the trim pot set to middle.

But I never actually tried to adjust it to tune it because I was worried that there was no sound even with it set to the mid point.

So I just tried it again and as soon as I touched the trim pot I started to get sound! Must have just been stuck. I twisted it back and forth a few times all the way and everything seems to be working smoothly now!

Thank you for the suggestion! I should have just messed with it more!


Top
 Profile  
 
PostPosted: Sat Apr 26, 2025 8:14 am 
Offline
Moderator
User avatar

Joined: Tue Feb 09, 2010 4:45 pm
Posts: 4740
Location: Rochester, NY
Glad to hear it got you working! Enjoy the pedal.

_________________
Scott

My band, Austin Hollow


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 9 posts ] 

All times are UTC - 6 hours


Who is online

Users browsing this forum: No registered users and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group