| Author | Message | ||
     Nick Bolton (slam_dunk) Username: slam_dunk Registered: 11-2009 |
i was playing my hd150 kinda loud the other day and heard a low-volume pop, followed by a complete loss of signal. but the power light still works. ive checked cables, tubes all glow, switched cabs and guitars. just trying not to dish out $100+ for a tech to tell me ive done something dumb. please any help is so totally appreciated thanks | ||
| Lars Verholt (lmv) Username: lmv Registered: 11-2009 |
Hi Nick, Some random questions: Is the volume gone on both input channels? If you turn up the master do you get a slight hiss in the speaker? Does switching the system from standby to on give you a tiny 'pop' sound? Cheers, Lars Verholt www.captain-foldback.com | ||
| Nick Bolton (slam_dunk) Username: slam_dunk Registered: 11-2009 |
hey lars yeah the volume is gone on both channels and i do get a hiss/ hum from the speakers. switching to standby doesnt really change much though. any ideas? thanks a bunch nick | ||
| Lars Verholt (lmv) Username: lmv Registered: 11-2009 |
Hmm - IC-3 or IC-8 could be the culprit here. To be sure I am looking at the right version of the schematic: Does your HD-150 have the phasor or the tremolo, and does it have reverb? -Lars Verholt www.captain-foldback.com | ||
| Nick Bolton (slam_dunk) Username: slam_dunk Registered: 11-2009 |
hmm no, doesn't have any effects, not even reverb. has 2 normal inputs and 2 bass inputs. 4 power tubes (6l6gc), no pre amp tubes. one deep and two bright switches. someone i asked said it might be that a tube's fuse is blown. and that even with a blown fuse the tube would light, but there would be no output volume. does this make any sense? or do you think its a transformer or something else? | ||
| Lars Verholt (lmv) Username: lmv Registered: 11-2009 |
Hi Nick, if you are getting a hiss in the speaker when the amp is on, your output and power transformers are probably fine. If the background hiss goes up in volume with the master volume (volume at 10 = more hiss) your driver IC is most likely fine too. If the hiss is the same no matter what, your driver IC could be faulty. Either way, you need to have it looked at by somebody who is comfortable working inside a high voltage tube amp. Sincerely, Lars Mikael Verholt www.captain-foldback.com |