Advice on how to get rid of fizz

[Jay Strange]

Hello, I just got a Carr Vinnie two weeks ago and have noticed some irritating fizz-swirllyness at the decaying of the note. Its horrible with the boost and bad with my OCD. It does it also when the amp is cranked with no boost. I switched preamp tubes one at a time as well as power tubes and no luck:mad: I also ran it through a 4X12 with V-30s( about 40-50 hours on them) and still fizz. Its especially bad with the neck pickup on a Paul or Strat. Any help is much appreciated and thanks for reading the post.

[skylabfilmpop]

Have you tried this in different rooms. I have an el-84 amp that does a raspy thing on g12 alnicos, only in a small hardwood room. 84's have a little of that naturally but at home it sounds like a sleestack. But not under a mic and not live and not with greenbacks. I chalk it up to phasing. Is this a master volume amp. Yo might also be hearing some bright cap interaction as the volume is not up enough to find the amps sweet spot. Ever run a boss distortion into a marshall on 2? Yuck, thats BC it hits the bright cap on the volume pot the emphasis of which is more subtle at higher volumes.

[soulsonic]

I would consider the amp defective. I would maybe try some lower gain preamp tubes just to see if it does anything to change it, but it sounds like you should contact Carr about repair/replacement.

[donnyjaguar]

You get this sound when its a solid state amp with inadequate bias on the output section. That wouldn't explain your situation though. Gotta admit I'm scratching my head a little here! Check for a mechanical problem, ie: loose chassis screw, bolt or jack, speaker wire, plug, tube socket.

[Jay Strange]

I'm patiently trouble shootin', its hard though because the amp still sounds unbelievable clean. Much appreciation for the imput guys anymore keep it comin'.

[VacuumVoodoo]

Hello, I just got a Carr Vinnie two weeks ago and have noticed some irritating fizz-swirllyness at the decaying of the note. Its horrible with the boost and bad with my OCD. It does it also when the amp is cranked with no boost.

If it happens when the note transitions from power tube distortion to clean but the clean decay to fade out does not swirl the problem could be in the phase inverter.

I'm guessing it's a rather new amp so a chat with the builder can't hurt.

[evacuated]

If it happens when the note transitions from power tube distortion to clean but the clean decay to fade out does not swirl the problem could be in the phase inverter.

I'm guessing it's a rather new amp so a chat with the builder can't hurt.

Recently I observed the exact same condition on an amp I built. The sound you described, during the time the amp transitions from distortion to clean. On the scope it showed a distinct point on the top of the waveform on the anode half of the phase splitter when driven into saturation. The cathode half was clean. I attributed it to layout, since it was an eyelet board I made myself with a different layout than usual. I couldn't get rid of it, so I ripped out the board and built another one using Leo's original layout. The peak is much less than before but still there a little. Changing PI tube made no difference. I'm beginning to wonder if it's got anything to do with a power tube maybe drawing grid current on one half. I used a Fender replacement tranny, instead of a Heyboer or Hammond, which I usually use, and it's smaller physically, and I'm wondering about core saturation too. . I'm still looking at this, because I hear it and want to get rid of it.

[Jay Strange]

Here's what I've discovered, With a Tim pedal it does not do this even with the boost on the Tim engaged. However, with it at lower volumes it does it with the OCD and doesn't do it at all with the OCD through the Tim even at lower volumes. It does have a split load Concertina phase inverter. Its the worst when in 33watt mode with the boost engaged and the amp cranked. It doesn't do it in 7watt mode. I'll post back after more hunting/experimenting and thank you for the replies:)

[Jay Strange]

Here's what I've discovered, With a Tim pedal it does not do this even with the boost on the Tim engaged. However, with it at lower volumes it does it with the OCD and doesn't do it at all with the OCD through the Tim even at lower volumes. It does have a split load Concertina phase inverter. Its the worst when in 33watt mode with the boost engaged and the amp cranked. It doesn't do it in 7watt mode. I'll post back after more hunting/experimenting and thank you for the replies:)