Ampeg V4B question

[raytsmith]

This amp seems to work great and sounds great, but has an annoying pop when the standby switch is engaged (to silence the speaker).

It is annoying in that I have to turn the volume down so it won't make the speaker pop too bad when I switch it to standby, then when I take it off standby I have to adjust the volume back up.

Is this normal ?

Its not a big deal for practice, but I don't really want to gig it this way.

[will33]

No, it's not normal, shouldn't make any noise when switching. Possible fixes, other than it turning out to be a bad switch, I'll leave to the experts.

[JimmyM]

it's not a big deal imho. it's got something to do with the inrush of current into and out of the caps and it happens in a lot of tube amps. i don't know the ins and outs of it, but i've had tube amps last years with no problems while making that thump.

[rust_preacher]

A "pop" could mean there is a direct voltage level engaged when the HV is turned on. A "thump" is the normal sound you get with many tube amps. (If possible, take a look at the speaker movement. In the normal case, the speaker cone should settle to the same rest position as in the zero volt case, if there is a direct voltage level present, the cone settles a bit off.)

[pgk]

replace the standby switch. they're always underrated compared to a power switch because of penny pinching, yet they have to take the same pounding as a power switch. a bad standby has the same symptoms of other much more expensive repairs, and the head scratching that ensues, 'cause you can't get rid of the damn thump! you'll never lose it entirely because a quiet pop is normal, but if it's a loud thump that's not good. a good quality Carling standby switch costs under $10 and is a five minute job for a good tech. if it still does'nt go away significantly it's a sure sign of old dried out power supply caps that need to be replaced. regardless, in my "learned the hard way" opinion Every 30/40 year old needs a new standby switch, it's the very first thing you replace. it's the cheapest insurance you can buy

[raytsmith]

Thanks for the replies, I should probably start looking around for a good tech to have everything checked out anyway, and have him replace the switch while he's in there.

[michael_atw]

My V4B does the same thing. I just turn the volume down when I turn it off. If you get it serviced, it won't do it anymore.

[Dave44]

Hey! nice to know there are still a few V4B's playin' on stage. Mine has been around since the early 70's. I bought it off an old friend before he became famous. Alex Sklarevski from the Slap Bass Program. This little baby is a heavy weight but she can sound sweet.