Alpha Vs Beta - Slave Amp Differences

[EarthRumbles]

Title pretty much says it all. What are the differences between the alpha series and beta series slave amps? Are they all based off of the concert slave? As much info as you got would be great, both technical and tonal characteristics. Thanks again

[loudthud]

The Concert Slave is a much more primitive design than the Alpha, Beta or even Coliseum amps. It's transformer coupled much like the Thomas/Vox amps of the mid 60's. The Concert amps have no short circuit protection so they can die suddenly. The other amps have short circuit protection circuits but they are not "fail safe". The protection circuits can sometimes interact with some speakers to create "transistor sound", a not so pleasant distortion that you don't get from tube amps.

The 100W@4ohm Alpha Slave is same circuit as the Beta series amps and Beta Power Plus.

[EarthRumbles]

Thanks for the info Loudthud, is there any difference between the beta and the beta plus other than one has a volume knob?

[loudthud]

As far as I can tell they used the same circuit board and just added a pair of input jacks and a volume pot.

[John Matrix]

I always see these things on ebay but I have no idea what they are really for. Are they just power amps? When would I want to use one of these things?

[loudthud]

Checkout this: http://sunn.ampage.org/site/catalogs/1979/1979catp6.jpg

At the top of the page, note that each speaker configuration is offered as a normal combo amp and also with the suffix P+. This is the Power Plus version with only the power amp and no preamp. Since the Beta series combo amps can't accommodate an extension speaker, this is how you would make a bigger amp. Note in the picture, it's kind of fuzzy, the 4-10 amp is a 410P+. If the Power Plus module was offered by itself, it wasn't in the catalog. It looks suspiciously like the Alpha Slave but the Alpha Slave is 26 inches wide while all the Beta amps are 24 1/2 inches wide.