ratty sounds coming off standby

[morningstar]

Carvin VL100 head "Legacy"

It has always sounded like crap form about 30 seconds after coming off of standby. Real ratty, almost like that ratty crap you sometimes get with amps after putting them on standby then shutting the power off. Yuk.

The amp sounds incredibly good once it gets over this case of the ratties.

Any ideas on what could cause an amp with great mojo to behave like this?

Thanks

morningstar

[gtone]

After giving ya' a bum steer on your "barky" Belair, I'm gonna STF up on this one. You sure like your Carvins, huh?

[silentman]

Try swapping out some tubes?

[morningstar]

I like Carvins a lot. Between the studios and my personal amps I have about twenty or so, V3's mostly, the BelAir, Legacy and a bunch of bass amps. I like the lack of "compression" in the sound. Carvins come biased cold, so they used to impress me as brittle sounding. A little fiddling and wham-o you got a fat sounding amp. I guess Carvin worries more about tube life than hot-footing the sound. I'd rather toast the tubes than sound stiff.

Coming off standby is like EMGs with a dead battery and a loose connection. Very ratty. Why it sounds so bad and then so good has always stumped me.

morningstar

[FrankieIII]

Hey Tommy,

Hope all is well. For what it's worth, I never even use the standby switch on any tube amps. I turn on the power switch to play, and off when not playing.

[Moose]

Wild ass guess? Bad capacitor in the power supply.

I don't have one here, and if swapping tubes doesn't change behavior you need to take it to a qualified tech to check it out, but when you flip the standby switch it charges all the capacitors for the high voltage supply. On standby, these don't get voltage, only the filament supply for the tube heaters. Caps that are good will self-heal under voltage in very short order. But if it takes 30 seconds, every time, and the amp doesn't sit for a long time between uses, something's not 100%.

This is NOT something easy to diagnose without the amp in the shop and open, though.