| Author | Message | ||
| Christian Johnson |
RD112 100, EL34s. JJ tubes replaced and re-biased by a pro in 1999. Low hours on new tubes. When playing clean, there's a bad crackle/clip/distort with a hard signal input (hit the strings hard). Sounds almost like a blown speaker (EV). Any ideas? Bad tube? This amp has had it's share of issues over the years, mainly total loss of output (goes to sleep). | ||
| FlatRacer |
I have an RD100 head that had the same symptoms. First time it was repaired, they said it was a crack in the foil (solder) on the PC board. Five months later, same problem. This time they replaced two chips. That seems to have fixed the "fitzzing out" when hitting hard on the low notes. Two months later I had a bunch of capacitors replaced (they can sound like a blown speaker when they go bad). It could be any one or a combination of these, but that should give your amp tech a place to start anyway. Good luck! Eric | ||
| Langley |
You need to get your amp to an oscilloscope. I've seen a few amps that have just one side of the wave being amplified by the output section. because diodes and resistors soldered to the tube sockets succumbing (is that a word?) to the heat. The symptom is often distortion when clean, due to a tube or (tubes) not functioning. This may or may not be your issue. And of course, as Roseanne Roseannadanna said: "Its always something. If its not transformer rust then it's an open rectifier, or a voice coil rub." | ||
| Christian Johsnon |
Thanks, guys. I've spent a lot of money on this amp relative to value over the last 4 years, so I'm not sure what I'll do. I own a guitar shop, so I have access to lots of amps. www.adrianguitars.com |
Tue, 03/25/2014 - 09:57
#1