Build Your Own Clone Message Board

It is currently Thu Mar 28, 2024 11:03 pm

All times are UTC - 6 hours




Post new topic Reply to topic  [ 21 posts ] 
Author Message
PostPosted: Sat Sep 17, 2016 5:16 pm 
Offline

Joined: Sat Sep 17, 2016 8:31 am
Posts: 7
Hello all!

I just finished my second BYOC pedal, a Swede, and I'm having an issue. There is a loud squeal/feedback when the pedal is plugged in. I still hear the guitar and there is distortion, but the feedback comes back the second I stop playing anything. When the distortion pot is all the way off, the feedback goes away and the guitar tone is very clear with a little distortion. The high control changes the pitch of the feedback, and will get rid of it when the pot is turned all the way off. There is also a very loud hiss when my guitar volume is off.

I tried re-flowing my solder joints and taking out IC3 since it's attached to the high pot. I found that there is still feedback, and the high control doesn't affect the feedback at all.

My V+ on each OP amp is a steady ~9.4 V and my 1/2V is a steady ~4.5V.

I'm thinking there is a bad capacitor somewhere, but I'm not sure what to look for (and I forget to check capacitance before I assembly like I did with my resistors).

My multi meter keeps reading a higher value of capacitance for all my board mounted capacitors (non mounted capacitors are reading correctly), so I may have to desolder every capacitor to find the bad one.

Any advice?

Here are a few pictures of my build, I removed the OP amps and tipped up the pots while I was poking around. Also the output jack is out of frame, but is connected.
Image
Image
Image
Image
Image


Top
 Profile  
 
PostPosted: Sat Sep 17, 2016 6:39 pm 
Offline
Moderator
User avatar

Joined: Tue Jan 02, 2007 1:24 pm
Posts: 16196
Location: Albany, NY
Have you tried swapping around the positions of the 3 IC's to see if the pedal's behavior changes?

_________________
“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 Oct 07, 2016 6:51 pm 
Offline

Joined: Sat Sep 17, 2016 8:31 am
Posts: 7
duhvoodooman wrote:
Have you tried swapping around the positions of the 3 IC's to see if the pedal's behavior changes?


It's the same no matter where I plug the IC's into.

Most of my IC rail voltages are not equal where they should be, so this is probably the source of the oscillation. IC1 has the worst voltage difference (over 0.1VDC between rails 1 & 2/3). I replaced the feedback capacitor and resistor, but I still have the same problem.

Measured voltages are below. Any other advice?

IC1
1: 4.223 VDC
2: 4.111 VDC
3: 4.109 VDC
4: 0 VDC
5: 4.592 VDC
6: 4.593 VDC
7: 4.592 VDC
8: 9.20 VDC

IC2
1: 4.591 VDC
2: 4.591 VDC
3: 4.546 VDC
4: 0 VDC
5: 4.555 VDC
6: 4.585 VDC
7: 4.584 VDC
8: 9.18 VDC

IC3
1: 4.586 VDC
2: 4.585 VDC
3: 4.541 VDC
4: 0 VDC
5: 4.544 VDC
6: 4.580 VDC
7: 4.579 VDC
8: 9.17 VDC


Top
 Profile  
 
PostPosted: Sat Oct 15, 2016 6:03 pm 
Offline

Joined: Mon Sep 05, 2016 7:18 pm
Posts: 6
Did this ever get sorted out? I'm having literally the exact same problem right now :///


Top
 Profile  
 
PostPosted: Tue Oct 18, 2016 5:49 pm 
Offline

Joined: Sat Sep 17, 2016 8:31 am
Posts: 7
Not yet, still having the same issue after replacing some capacitors, transistors, and resistors. I did notice that I get an OL reading when I test the resistance of R28 (100k resistor) in circuit, but the resistance is fine when I remove it. I soldered in a new resistor and had the same issue. I'm going to try a new switch next :|


Top
 Profile  
 
PostPosted: Wed Oct 19, 2016 11:11 am 
Offline
Site Admin
User avatar

Joined: Sun Jan 22, 2006 1:39 pm
Posts: 5984
Location: Richland, WA
Please contact sales and we'll send you a new chip set.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com


Top
 Profile  
 
PostPosted: Thu Oct 20, 2016 4:43 pm 
Offline

Joined: Sat Sep 17, 2016 8:31 am
Posts: 7
byoc wrote:
Please contact sales and we'll send you a new chip set.


Just did, thanks!

Also, I found something else I think is off. I built the signal tester on BYOC's website and found that I'm getting a distorted guitar signal when I just connect the pedal ground to the amp (the red probe was not touching anything). Is that supposed to happen? :?

Some more findings:

I'm getting a feedback sound everywhere in my circuit with the high all the way on. This goes away when I turn the high control completely off until I touch the probe to Q1's gate. I get a quiet hum from my 4.5V source, and I think my Q1 is amplifying it. I don't hear the hum when I probe my 9V source with the high control off. Any idea what could cause this?


Top
 Profile  
 
PostPosted: Sat Oct 22, 2016 7:12 am 
Offline
Moderator
User avatar

Joined: Sat Mar 04, 2006 9:15 pm
Posts: 7662
Location: Ohio
With your guitar plugged into the pedal’s input and the probe plugged into your amp with only the probe’s ground connected to the amp and pedal but with the probe’s tip not connected to anything you will get noise from your amp. Not a distorted guitar signal. The guitar is not connected to the tip of the probe so there can be no distorted guitar signal coming from the amp. As soon as you touch the probe to ground the amp will go silent. If you touch the probe to a point on the PCB that has signal you will hear your guitar thru the amp with a bit of background noise too.

_________________
"It’s your soldering."


Top
 Profile  
 
PostPosted: Sat Oct 29, 2016 1:40 pm 
Offline

Joined: Sat Sep 17, 2016 8:31 am
Posts: 7
Stephen wrote:
With your guitar plugged into the pedal’s input and the probe plugged into your amp with only the probe’s ground connected to the amp and pedal but with the probe’s tip not connected to anything you will get noise from your amp. Not a distorted guitar signal. The guitar is not connected to the tip of the probe so there can be no distorted guitar signal coming from the amp. As soon as you touch the probe to ground the amp will go silent. If you touch the probe to a point on the PCB that has signal you will hear your guitar thru the amp with a bit of background noise too.


I thought that wasn't right.

Something else I found, I'm getting a reading of -0.1 VDC on the negative terminal of my C10 (the electrolytic capacitor attached to pin 1 of the first IC) using the chassis ground as the reference. The voltage decreases to -0.072 VDC on the negative terminal of C12. Any idea why this would happen? I thought C10 and C12 block DC voltage into this section of the circuit.


Top
 Profile  
 
PostPosted: Sat Oct 29, 2016 4:02 pm 
Offline
Moderator
User avatar

Joined: Sat Mar 04, 2006 9:15 pm
Posts: 7662
Location: Ohio
Caps are not perfect devices and none of them block DC 100%. Nothing you can do about that.

_________________
"It’s your soldering."


Top
 Profile  
 
PostPosted: Sun Nov 27, 2016 10:01 am 
Offline

Joined: Mon Sep 05, 2016 7:18 pm
Posts: 6
So @JTH20 did getting new IC's actually fix the problem? My schedule hasn't given me a chance to really try to fix the issue but I'm still getting the exact same problem you're describing :/ would you suggest I go ahead and contact sales like you did?


Sent from my iPhone using Tapatalk


Top
 Profile  
 
PostPosted: Tue Dec 13, 2016 7:21 am 
Offline

Joined: Sat Sep 17, 2016 8:31 am
Posts: 7
geohewitt wrote:
So @JTH20 did getting new IC's actually fix the problem? My schedule hasn't given me a chance to really try to fix the issue but I'm still getting the exact same problem you're describing :/ would you suggest I go ahead and contact sales like you did?


Sent from my iPhone using Tapatalk


@geohewitt, unfortunately the new IC's didn't fix it. Life caused this project to fall by the wayside so I haven't tred anything else yet.


Top
 Profile  
 
PostPosted: Tue Dec 13, 2016 4:26 pm 
Offline

Joined: Mon Sep 05, 2016 7:18 pm
Posts: 6
JTH20 wrote:
geohewitt wrote:
So @JTH20 did getting new IC's actually fix the problem? My schedule hasn't given me a chance to really try to fix the issue but I'm still getting the exact same problem you're describing :/ would you suggest I go ahead and contact sales like you did?


Sent from my iPhone using Tapatalk


@geohewitt, unfortunately the new IC's didn't fix it. Life caused this project to fall by the wayside so I haven't tred anything else yet.




Damn dude :( I feel you, having already built an HM2 clone before i'm pretty disappointed with this one and have no clue what the issue is. I I tried the audio probe and for me the oscillation seams to get louder the further I go through the circuit but I still have it even if I touch it directly to the input jack. Goes away when I turn the distortion or high pot all the way down. Does yours have those same symptoms??


Top
 Profile  
 
PostPosted: Tue Dec 13, 2016 6:46 pm 
Offline

Joined: Sat Sep 17, 2016 8:31 am
Posts: 7
geohewitt wrote:
JTH20 wrote:
geohewitt wrote:
So @JTH20 did getting new IC's actually fix the problem? My schedule hasn't given me a chance to really try to fix the issue but I'm still getting the exact same problem you're describing :/ would you suggest I go ahead and contact sales like you did?


Sent from my iPhone using Tapatalk


@geohewitt, unfortunately the new IC's didn't fix it. Life caused this project to fall by the wayside so I haven't tred anything else yet.




Damn dude :( I feel you, having already built an HM2 clone before i'm pretty disappointed with this one and have no clue what the issue is. I I tried the audio probe and for me the oscillation seams to get louder the further I go through the circuit but I still have it even if I touch it directly to the input jack. Goes away when I turn the distortion or high pot all the way down. Does yours have those same symptoms??


Yep, exact same symptoms. It seems like some sort of unintentional feedback loop, but through my limited testing I didn't find any components that shouldn't be connected.


Top
 Profile  
 
PostPosted: Wed Dec 14, 2016 11:14 am 
Offline
Site Admin
User avatar

Joined: Sun Jan 22, 2006 1:39 pm
Posts: 5984
Location: Richland, WA
You both should contact keith@buildyourownclone.com

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com


Top
 Profile  
 
PostPosted: Tue Jan 03, 2017 11:45 am 
Offline
Site Admin
User avatar

Joined: Sun Jan 22, 2006 1:39 pm
Posts: 5984
Location: Richland, WA
You guys wouldn't happen to be using a 1-Spot power supply or a power supply that wasn't specifically meant to be used with guitar effects?

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com


Top
 Profile  
 
PostPosted: Tue Oct 24, 2017 2:20 pm 
Offline

Joined: Tue Oct 24, 2017 1:58 pm
Posts: 2
I just finished The Swede as my first ever DIY soldering project and am experiencing the same problem. I am trying to get the early-90's Swedish death metal sound, so I have everything pretty much dimed. I'm getting pretty good tone, but I also get the same oscillation as described here. When I roll the high off a bit, it clears up (although I lose the tone I'm looking for...which seems to kick in right before I max-out the high pot), and when I roll the distortion down to about 8:30-9:00 the oscillation disappears. TBH, I don't get a big change in tone between when I have the distortion at 9:00 and all the way maxed out, but that's with everything else dimed. I'm using a fresh 9V battery as the supply.


Top
 Profile  
 
PostPosted: Fri Oct 27, 2017 11:27 pm 
Offline

Joined: Tue May 24, 2016 11:16 am
Posts: 104
Oscillations not due to build errors are most likely due to stray capacitance in the PCB layout, or power supply decoupling issues, or maybe both. It can happen with really high gain circuits turned way up. Should be fixable though.


Top
 Profile  
 
PostPosted: Thu Nov 02, 2017 3:04 pm 
Offline

Joined: Tue Oct 24, 2017 1:58 pm
Posts: 2
Hmmm...power supply decoupling you say...how would one go about fixing that?

I did notice that the DC current draw from the battery is roughly 13mA. Surprisingly, I found that the current draw was about 11.5mA with the footswitch off but the guitar cable plugged into the output jack. Could this indicate a problem somewhere in the build? I thought the Swede was true bypass instead of buffered.


Top
 Profile  
 
PostPosted: Thu Nov 02, 2017 3:13 pm 
Offline
Moderator

Joined: Thu Nov 15, 2007 10:57 pm
Posts: 3546
Location: San Diego
True bypass routes the input directly to the output. It does not turn the effect off, and therefore the circuit is still drawing power when bypassed.


Top
 Profile  
 
PostPosted: Mon Aug 31, 2020 5:57 pm 
Offline
Site Admin
User avatar

Joined: Sun Jan 22, 2006 1:39 pm
Posts: 5984
Location: Richland, WA
Is there anyone still having feedback issues with their Swede?

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 21 posts ] 

All times are UTC - 6 hours


Who is online

Users browsing this forum: No registered users and 7 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:  
cron
Powered by phpBB® Forum Software © phpBB Group