Ask Amp Tech Expert Skip Simmons

Hey Skip,

I found an Alamo Model 5 at a guitar shop for $300 that works.  My amp repair guy says it's going to take some work fixing it up.  What should be my cap for dumping $ into this?  I can't find anything about these anywhere online.  Just the Model 3.  What's the difference?  What can you tell me about this amp?

-Taylor

Hi Skip,

  continue reading...

Hi Skip,

I just purchased a Sonny Jr "Four Ten".  When it arrived, it didn't have the tubes in it.  inside the amp it says 5U4 6L6 6L6 12AY7/12AU7 12AU7 12AT7/12AX7.  I'm playing through a CR JT-30 and not sure what combo to put in or what tubes to get.  Any advice about what combo to put in or what sound effect the different combonations will have?

-Taylor

Be VERY careful when installing or removing preamp tubes. The tube sockets on many new amps are fragile, AND it is very easy to bend the pins of the tube. Be sure to check the pins of the tube before installing to make sure they are not bent. They can be carefully straightened with needle-nose pliers if they are bent. continue reading...

Hi, Skip,

Would you mind sharing your thinking, in general, on the importance of brands and types of resistors and capacitors?

I know that some "old amp" guys (not to be confused with "old" amp guys) like to keep everything as close to old technology as possible, using carbon comp resistors everywhere, for example. But I think it's also true that using quieter types (wire-wound?) in early amplification stages is preferred by others. continue reading...

Hi, Skip.

Can you direct me to a source for a power lamp bulb for my MA-17?

Also, are the resistor values for the speaker-driven line out circuit dependent on the amp output, or can one use, for example, a 220 ohm and a 2200 ohm 1/2 watt just as well for a 5 Watt as for a 30 watt tube amp? continue reading...

Hi Skip, I was looking at my bogen he10 the other day and the cap can for the main filtering section is 80uf,30,10. Its original but the schematic shows a 10uf,10 cap can. The other cap can  is same as schematic 5uf,5,5,5. when time comes to replace the main one should I use the same values as the can rather than follow the schematic. It sounds and runs great but i was just thought it was strange that the values were so different and wondered why  Bogen did that.

I have decided its time to get my first tube amp to play primarily at the local jam. As this is a new venture for me I realize there a lot of very different choices and completely opposite ends of the afforadable scale. With affordability in mind, I have come across a used Epihone Valve Special at the music store that I believe I should purchase. The price is totally right for me. After reading many reviews, I see that many harp players do or have played this amp. Also I notice that some modify it slightly for better Tone and/ or volume. continue reading...

Hi!

Im new to playing harmonica and have never played amplified before. I got myself a good deal on a Hohner Hoodoo box 5W tube amp and got it home the other day. It sounds pretty good to me, but to make it sound good with a nice distorted sound I need to crank it up quite loudly. The problem is that I live in a flat and can't play it too loudly for obvious reasons. continue reading...

Hi, Skip.

The Kalamazoo and the MA17 you did for me are treasures. People ask me about them all the time, and I would like to sound smarter when I answer some of their questions.

I know that (tube)  amps that are designed for guitar and as PA heads are often "modded" when they are to be used for harmonica. But could you explain, generally and in terms that harp players might understand (and without giving away any trade secrets, unless you are so inclined), what the main goals of "voicing the amp for harp" are? continue reading...