Acoustic 150 to Acoustic 150b?

[Michael Allen]

I picked up a 150 head today for $45 at a thrift store thinking i'd read it to be a bass amp. Turns out this is the guitar version.

I've read Acoustic amps were similar between models, only slight variations and was curious if this could be modded to a 150b bass version? I can't get a hold of a 150b schematic or manual since that Acoustic wiki page seems to be dead. I read somewhere the 150b is transformer output?

Can anyone advise if this is possible with a few cap changes/tone stack mod or are they totally different beasts?

And does anyone have a copy of both the 150 and 150b schematics/manuals? I got two pages of the 150 from the Ampix site but I don't think its complete.

Thanks,
Michael

[J M Fahey]

Hi Michael. Use it as it is now, it´s already "Factory modded" for you.
¿What do I mean?: the amp is built on the same "skeleton": same power supply and power amp and basically same preamp (EQ and everything else) with reverb and tremolo added , both of which are out of the way unless you switch them on. It´s a very good SS bass amp or clean guitar amp, good reverb, quite loud amp if you load it with the suggested 4 ohms. Nice buy.

[Michael Allen]

Thanks for the information. Any idea what the footswitch is for? Mine didn't have one.

[J M Fahey]

Just switch on/off reverb and tremolo. Can be homebuilt with any suitable enclosure, a couple foot-switches, some balanced mic cable (2 hot, 1 ground) and a stereo 1/4" plug.

[Bill Moore]

Our favorite guitar used one of them with a 6-10 enclosure, really loud. We used to play outdoors a lot, (generator power), only had 1 failure when it fell backwards off a 6 foot stage, made horrible humming sounds. I opened it up and found the internal reverb tank wires were broken, I taped up the RCA plugs, and put it back together, he played it for years after.
I fixed the reverb pan, but Joe didn't use it, last year I put it in a Chinese Fender head.