Ask Amp Tech Expert Skip Simmons

I am managing the musical entertainment for an outdoor festival at work. One responsibility is working with the sound guy we have hired to provide audio. In addition to hosting the show I will also be playing a few tunes. I will be bringing my Fender Super Champ X2 with a wireless Ulitmate SM57 mic. I am used to having my amp mic to the PA. However the sound guy prefers to use the line out function. I have never used it and do not know what it will sound like. Any recommendations or things to watch for.

Thanks

Brian

Hi Skip, I want to play live gigs (loud 5 piece band) with two amps linked so as to get the benefits of each different amp in the overall mix. I'm using a Sonny Jnr 4x10 and a Princeton reverb. If I use an AB-Y splitter box to get one amp or the other amp as well as getting the two combined when I want to - will there be any issues with the AB-Y such as mic signal supression or circuit hum? Is there any alternative way of linking two amps I should consider?

Hi Skip, I posted this in general discussons but it's probably better to ask an expert!

So I'm having the age old problem of not getting enough volume when playing with a loud band.  I would say the band is about as loud as an average bar-band....maybe a bit louder than most.    I prefer playing through a Bassman but even when miced through the PA I am not getting the volume I need. continue reading...

Hi. I have done some mods on my Fender pro jr:

1. speaker - Weber 10A125-O 

2. power tubes - 2pair of el84s 

3. preamp tubes -  V1 -  12au7 and  V2 -  12ay7

I can play it on volym 6 - 7 depending on the mic, and  I´m using a feedback killer.I have Non-Adjustable Fixed Bias, and the tubs are running hot.

Is it possible  to reduse the gain even more but not so much that the tone gets bad,Suggestions?

And the power tubes are a bit bright, suggestions on a good pair of power tubes?

Thanks J.A

Hey Skip,

  continue reading...

Hey Skip, continue reading...

Hello Skip, 

I was wondering why the two input jacks on my Kalamazoo 2 sound different.  Jack 1 gets a lot louder and more sensitive and jack 2 is not as loud?  what would be the difference?  

Thank you.  

David Saccucci

Hey Skip. I am entering the market for a used amp, probably a Fender Hot Rod Deville or 59 Bassman reissue. What sorts of things should I look for when buying used to protect against getting ripped off?

Hi, Skip!

I have a Masco MU-17 that looks beautiful, but has an unacceptable 60 Hz hum. After replacing caps with original value caps, the hum persisted. Increasing values of caps didn't make a notceable difference.

 It doesn't get louder with volume knob changes.

It is NOT present if the the PI tube (12AX7) is REMOVED, but replacing the PI tube did not help either (except that it might have been a little less loud when I tried a 12AT7 in there). continue reading...

hi Skip

on newer amps I guess it's fairly common to see speaker out ohm ratings of 4, 8 and 16. but on the older pa amp heads I am seeing some of those values like 4 and 8 but often higher ones like 30,60,125 even 500. 

are these still in use today or are these obsolete or maybe related to the original use of these heads which were PA purposes and not rocking out? 

Andrew