I recently finished my Crack build and decided to install speedball. Prior to the upgrade, the amp sounded great, no hum or any other extra noises were produced from having it on. Since installing speedball (and passing initial voltage checks) that hasn't been the case. At first everything seemed more or less okay, there was a slight hiss coming from the left channel that was only really noticeable if the volume was cranked almost to maximum. However, after 5 minutes or so there was a popping in the right channel, which then occurred regularly every 30 or so seconds after that. I unplugged my headphones and RCA cables, and left the amp on for a few hours, hoping that it was a tube issue and that a little burn-in might solve the popping and hissing. That was yesterday.
Today I turned the amp on and initially no sound was coming from the right channel. After a few minutes of playing music, the right channel crackled and music could be heard through it, although at maybe half the loudness of the left channel. The left channel is still buzzing.
I've since done a second Voltage check and all of the terminal's voltages (T1-15, 20, 21) are well within the 10-15% variance. When checking the headphone TRS jack the voltage spikes to upwards of 15 before quickly reducing to zero (this has been triple-tested). My initial check prior to playing music had the voltage cap at 7 before reducing to 0.
Other things to note.
- All LEDs light up on the board
- All transistors are in their correct place(2N2222A) and position (MJE350).
- Both tubes light up fully
- Left channel buzzes without RCA plugged in
- I have tested my Headphones (Senn HD650's), RCA cables, and DAC with my previous amp and had no issues.
Terminal Voltage Checks:
1: 81
2: 178
3: 0
4: 178
5: 83
6: 0
7: 109
8: 0
9: 109
10: 0
11: 0
12: 0
13: 180
14: 0
15: 199
20: 0
21: 220
All voltages have been double checked.
I could really use some help with this as I have no idea what to do besides re-solder. Any help is appreciated.
