Ask Amp Tech Expert Skip Simmons

Howzit Skip, i was checking out the electric components in my old pa head (1953) the other day and noticed that one of the red tiny chief capacitors looked wet, looked like when you dip a piece of cardboard in water. does this mean the cap is on the way out and going to explode? last time i took it to the tech he replaced all of the out of speck stuff, there are 2 more tiny chief caps should i just replace those too before those start sweating also?

Well, I'm going to pick up the Blackface this week. I hope that this is not to much amp for my situation. What kind of tube swap out in the preamp do you recommend to make this amp more friendly for harp. Thanks

Hi Skip, first of all thanks for your advice on the Vibrolux, I think I will just run it as it is. I actually haven't really had any complaints. I play in a five piece and as long as the amp is mic'd I haven't had any problems on the bandstand, the band is loud but I never have problems getting thru the mix or experiencing feedback. continue reading...

i'm a beginner and a i would like to start with a mini amp, even because i don´t have money to buy a pro amp.

I was looking this two models, Pignose 7-100 and Vox Mini 3.

Which one is better to play with a harmonica?

Both, none, or there is another one?

Thank you.

I have a few amps(more than i really need). Should i turn the ones on that I havent been using and let them warm up? My question is will the caps and resistors get crusty or out of spec if i dont run them and should the amps be turned on every week or month ect.? Thanks

The pots on my '73 Princeton Reverb have gotten "scratchy". Can they be cleaned up without removing them from the chassis? Contact cleaner spray or something like that?

Thanks!

Hi skip,
I purchased a Holland custom amp many years ago. It has two twelve inch speakers It has volume normal, volume bright, treble, bass, middle and presence nobs. To be honest I have hardly ever used it because it screeches even at low volume. I have worked on dialing it in to no avail. I have tried numerous microphones. It's been sitting for years. Any ideas? Tim

Hi, Skip.

Can you explain the differences between inputs 1 and 2 on the normal channel of a Bassman 59 RI? Input 1 definitely sounds louder, but it also seems like there are other tone quality differences...or is that my imagination?

And if the input circuits are different, how does it affect bridging options from the normal channel to the bright channel, if at all?

Thanks.

Mark H.

Hey, Skip.

What do you think about using a 12DW7 in the V3 position of, say, a Bassman RI?

I have read that this is a "hybrid" tube, like a 12ax7 on one side and a 12au7 on the other, that causes the power tubes to be driven "out of synch" and gives more/different distortion in the power amp stage. Sounds magical to me.

Okay, so you drop the input V1 from 12AX7 to 12AU7/ECC802S, or something like that? I've done this and my amp is lust quieter throughout the volume range. The 6L6's don't go into overdrive until the volume knob is up around 8-10. Used to be 4-5 with the 12AX7's. The amp is still at the same SPL when breakup occurs. So really what is the purpose of this mod?

Thanks!