Hey everyone, found this great thread today.
I'm having a similar, possibly the same issue with a '63 Black Face AB763 Tremolux. Not sure if it's the same problem, but listen for yourselves and tell me what the proper nomenclature is for this problem. I would describe it more as "glass crushing" or "tube rattle" than "Fizz". I have an Audio sample of it.
<https://soundcloud.com/blondeorphan/196 ... ux-problem>
It sounds like a tube rattle, or glass vibrating when pushed with an overdrive. Thought it was a preamp or PI or Power Tube or Rectifier tube issue but all the tubes have been replaced and the problem still persists. Caps that were out of spec were just replaced.
Output Transformer was bypassed on the bench by a tech friend of mine, and he said the amp sounded the same as the one that's in the amp although he was not ever able to duplicate the problem, which is why I recorded the problem, now that the amp is on a second techs bench.
Any insight would be greatly appreciated. I love this amp but can't use it till it's fixed, and it's proving to be tough to diagnose.
Audio sample on Soundcloud link was recorded with a Unidyne III 57 > Pro Tools Mbox 3 Pro > Pro Tools 11 > No Plugins.
Tremolux Amp repair FINISHED
Moderators: pompeiisneaks, Colossal
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blondeorphan
- Posts: 2
- Joined: Sat Mar 15, 2014 1:00 am
- Location: Vancouver WA
Fizz? Glass Rattle? HarmonicDistortion? Hear for yourself...
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Re: Tremolux Amp repair FINISHED
Tough to tell from the recording. Have you already tried different speakers? I mean play the amp thru another cabinet?
I build and repair tube amps. http://amps.monkeymatic.com
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blondeorphan
- Posts: 2
- Joined: Sat Mar 15, 2014 1:00 am
- Location: Vancouver WA
Same issue with more than one speaker
xtian - Great question and thanks for your help. I have tried it thru a 4ohm 2x15 cab and the issue was still there, same as with the 2012 C12n Jensen. The soundcloud conversion rate seems to low-fi the audio enough that it is harder to hear the issue than the attached mp3. I'm hoping the ampgarage community can maybe recognize and help identify the sound of the issue with the amp. Please let me know if it's hard to hear in the attached mp3, the glass rattle/fizzy sound.
Re: Same issue with more than one speaker
Hi, did you resolve your problem? I just repaired a 1964 Tremolux with a similar issue, among others. If you haven't I'd be happy to let you know what I did.blondeorphan wrote:xtian - Great question and thanks for your help. I have tried it thru a 4ohm 2x15 cab and the issue was still there, same as with the 2012 C12n Jensen. The soundcloud conversion rate seems to low-fi the audio enough that it is harder to hear the issue than the attached mp3. I'm hoping the ampgarage community can maybe recognize and help identify the sound of the issue with the amp. Please let me know if it's hard to hear in the attached mp3, the glass rattle/fizzy sound.
Re: Same issue with more than one speaker
Don't keep us in suspense!stump wrote:Hi, did you resolve your problem? I just repaired a 1964 Tremolux with a similar issue, among others. If you haven't I'd be happy to let you know what I did.blondeorphan wrote:xtian - Great question and thanks for your help. I have tried it thru a 4ohm 2x15 cab and the issue was still there, same as with the 2012 C12n Jensen. The soundcloud conversion rate seems to low-fi the audio enough that it is harder to hear the issue than the attached mp3. I'm hoping the ampgarage community can maybe recognize and help identify the sound of the issue with the amp. Please let me know if it's hard to hear in the attached mp3, the glass rattle/fizzy sound.
Re: Tremolux Amp repair FINISHED
I replaced all of the 25mF/25V cathode caps, 25mF/50V bias cap, .02mF cap and LDR in the Trem section, Both had one leg broken. I also replaced the treble cap in each channel as someone had installed .01mF caps previously, so I installed the correct value 250pF SM caps, replaced the bright switch and 120pF cap in the normal channel as the switch was broken and an incorrect .01mF cap was across it. Re biased the power tubes. Problem solved after the cathode cap and treble cap replacement, I figured that I may as well reflow all of the 40 year old solder joints too while it was open. The amp was even quieter after doing so.
That's the whole job. Amp sounds great and the owner was so happy that he's bringing me his Silverface Twin and early Blues Jr. to get sounding as they should. I do this as a hobby, not a business, but I'm starting to getting about 4-8 amps per month, I only take personal referrals from others I've done work for.
That's the whole job. Amp sounds great and the owner was so happy that he's bringing me his Silverface Twin and early Blues Jr. to get sounding as they should. I do this as a hobby, not a business, but I'm starting to getting about 4-8 amps per month, I only take personal referrals from others I've done work for.
Re: Tremolux Amp repair FINISHED
That's how it starts, man.stump wrote:I do this as a hobby, not a business, but I'm starting to getting about 4-8 amps per month, I only take personal referrals from others I've done work for.
I build and repair tube amps. http://amps.monkeymatic.com
Re: Tremolux Amp repair FINISHED
xtian wrote:That's how it starts, man.stump wrote:I do this as a hobby, not a business, but I'm starting to getting about 4-8 amps per month, I only take personal referrals from others I've done work for.
Since that last post I've repaired three more amps, made one road worthy, modded one of mine and have another, from a repeat customer, to do, but she's in no rush for it because it seems to have some major trouble. It's a Kitty Hawk, just to give you an idea. I also went through my ancient Dynaco/Dynakit ST 70 and PAS Preamp, and now have them set up, pumping out some righteous tunes. When it rains, it pours. I'm kinda hoping for a lull right now.
