Hi everyone,
First, thanks for allowing me to join you here. I have done a lot of fx pedal building and recently completed the conversion of a Filmosound tube-based projector amp but a friend just asked me to look into his SS Traynor amp and it's the first time I have worked with one.
The basic issue is reduced output with a muddy tone and plenty of distortion through the speaker but loud clean output through the headphone jack. I have verified that the speaker works fine by playing my Traynor YCV40 through it and, thanks to some suggestions on a SS Facebook page, I have also confirmed that the headphone switch/jack is working and that the DC offset is about 6mV.
Last night I found several pads on the PCB that were damaged or broken so I fixed and/or jumpered those and reflowed the solder on EVERY connection. Low and behold, the speaker output was great for about 5 minutes of testing and then it abruptly switched back to the low mud and distortion.
One of the Facebook members suggested a test of the output transistors and I noticed that the 2 watt 330 ohm resistors and their adjacent diodes get very hot VERY fast and have actually discoloured/burned the PCB around them. In addition, a light tap on those resistors with a wooden stick also caused a bit of the surface to flake off.
Now, I noticed another member was having heat issues with his TBM-25 and that was another reason why I requested to join this group since I figured he must have gotten those sorted out with your help.
I can attach a copy of the Traynor schematic for this amp once I figure out how to upload a PDF and I am hoping that you might be able to help point me towards a solution to this problem. In the meantime, I *HOPE* the schematic is still available from the forum post here:
https://www.ssguitar.com/index.php?topic=4354.msg34812#msg34812
I look forward to your replies and thank you in advance!
- brad -
First, thanks for allowing me to join you here. I have done a lot of fx pedal building and recently completed the conversion of a Filmosound tube-based projector amp but a friend just asked me to look into his SS Traynor amp and it's the first time I have worked with one.
The basic issue is reduced output with a muddy tone and plenty of distortion through the speaker but loud clean output through the headphone jack. I have verified that the speaker works fine by playing my Traynor YCV40 through it and, thanks to some suggestions on a SS Facebook page, I have also confirmed that the headphone switch/jack is working and that the DC offset is about 6mV.
Last night I found several pads on the PCB that were damaged or broken so I fixed and/or jumpered those and reflowed the solder on EVERY connection. Low and behold, the speaker output was great for about 5 minutes of testing and then it abruptly switched back to the low mud and distortion.
One of the Facebook members suggested a test of the output transistors and I noticed that the 2 watt 330 ohm resistors and their adjacent diodes get very hot VERY fast and have actually discoloured/burned the PCB around them. In addition, a light tap on those resistors with a wooden stick also caused a bit of the surface to flake off.
Now, I noticed another member was having heat issues with his TBM-25 and that was another reason why I requested to join this group since I figured he must have gotten those sorted out with your help.
I can attach a copy of the Traynor schematic for this amp once I figure out how to upload a PDF and I am hoping that you might be able to help point me towards a solution to this problem. In the meantime, I *HOPE* the schematic is still available from the forum post here:
https://www.ssguitar.com/index.php?topic=4354.msg34812#msg34812
I look forward to your replies and thank you in advance!
- brad -