Amp hiss / fizz issue

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jeremyb
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Re: Amp hiss / fizz issue

Post by jeremyb »

jhyang549 wrote: Fri Aug 26, 2022 5:50 pm Are the tubes in the ac10 okay? Have you checked whether if any of them are microphonic?
They’re all new and remember the amp is perfectly fine unless I’m going thru the Ampero.

Going to try a hum isolate and see if that helps :-)
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Re: Amp hiss / fizz issue

Post by RectifiedAmps »

Is it an AC10c1? They have a FET as the 1st gain stage that may be responsible for the weird interaction. They also have a large input capacitor right after the input jack that could create nasty blocking distortion if you’re pushing a large amplitude signal into the front of the amp.

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Re: Amp hiss / fizz issue

Post by jeremyb »

RectifiedAmps wrote: Sat Aug 27, 2022 12:18 am Is it an AC10c1? They have a FET as the 1st gain stage that may be responsible for the weird interaction. They also have a large input capacitor right after the input jack that could create nasty blocking distortion if you’re pushing a large amplitude signal into the front of the amp.
It certainly is, I wonder if there’s some mods I can do if the hum isolator doesn’t fix it :-)

The weird thing is the noise doesn’t change in volume with the volume control on the Ampero, it’s the same at zero volume :-(
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Re: Amp hiss / fizz issue

Post by sizzlingbadger »

If you put a pedal with a buffer between them does it go away ? As RA said above, the FET on the input could be the issue if it has a very high input impedance, I don't have an AC10 schematic to check stuff out.
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Re: Amp hiss / fizz issue

Post by jeremyb »

sizzlingbadger wrote: Sat Aug 27, 2022 10:41 am If you put a pedal with a buffer between them does it go away ? As RA said above, the FET on the input could be the issue if it has a very high input impedance, I don't have an AC10 schematic to check stuff out.
I was thinking about chucking a pedal between the ampero and the amp too, only things I have sitting around don't have buffers in them, but maybe the mooer chorus being on might be a good test? hmmmm...
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Re: Amp hiss / fizz issue

Post by jeremyb »

Update! Tried a behringer hum debugger (dual isolating transformers) and a mild improvement, thought maybe there was something in the app for the ampero around the output jack settings, switched it from inst level to line level and BOOM huge improvement, add the hum debugger in and its very tolerable noise wise, hoorah!
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Re: Amp hiss / fizz issue

Post by sty »

jeremyb wrote: Tue Aug 30, 2022 1:35 pm Update! Tried a behringer hum debugger (dual isolating transformers) and a mild improvement, thought maybe there was something in the app for the ampero around the output jack settings, switched it from inst level to line level and BOOM huge improvement, add the hum debugger in and its very tolerable noise wise, hoorah!
Is your problem now solved?

if not, or only temporary, I have a Lehle Sunday Driver SW and I think I have a dedicated line buffer in a small box that you're welcome to borrow for a while and see if they tell you anything
Last edited by sty on Tue Aug 30, 2022 2:13 pm, edited 1 time in total.

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Re: Amp hiss / fizz issue

Post by jeremyb »

sty wrote: Tue Aug 30, 2022 2:07 pm
jeremyb wrote: Tue Aug 30, 2022 1:35 pm Update! Tried a behringer hum debugger (dual isolating transformers) and a mild improvement, thought maybe there was something in the app for the ampero around the output jack settings, switched it from inst level to line level and BOOM huge improvement, add the hum debugger in and its very tolerable noise wise, hoorah!
Is your problem now solved?

if not, or only temporary, I have a Lehle Sunday Driver and I think I have a dedicated line buffer in a small box that you're welcome to borrow for a while and see if they tell you anything
Yeah tis solved, quite a lot of faffing but happy enough with the outcome now :)
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Re: Amp hiss / fizz issue

Post by MikeC »

Great that the problem was solved with a workaround. I'd still like to know if that FET is the issue...
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Re: Amp hiss / fizz issue

Post by jeremyb »

MikeC wrote: Tue Aug 30, 2022 3:35 pm Great that the problem was solved with a workaround. I'd still like to know if that FET is the issue...
I'd say its amplifying the issue, I turned up the Laney too and it had a bit of it but nothing like as loud as the AC10 :-(
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Re: Amp hiss / fizz issue

Post by MikeC »

jeremyb wrote: Tue Aug 30, 2022 3:36 pm
MikeC wrote: Tue Aug 30, 2022 3:35 pm Great that the problem was solved with a workaround. I'd still like to know if that FET is the issue...
I'd say its amplifying the issue, I turned up the Laney too and it had a bit of it but nothing like as loud as the AC10 :-(
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