Bogen Acoustic Master

[CJ]

somebody wanted to plug there guitar into this mixer/amp, so we spliced in a 1/4 inch jack on the back, how did it sound? like you expect only there was some grit available with the gain up and the master down,

there are 4 mic input transformers in these things, they have limited response, beware of people selling them on evilbay as moving coil transformers at 500 a pair,

 

[CJ]

there is an option to wire the inputs for hi z just by moving some jumpers which is pretty cool,

note tropical fish caps and BC series transistors,

those black cans are the plug in transformers,

 

[CJ]

how does the compressor sound?  lots of thumps with 10 second recovery time, other than that, it is pretty good,

notice the 3300 cap output into an output transformer, double protection, never seen that before,

im out...

 

[PRR]

> notice the 3300 cap output into an output transformer, double protection

Transformer is "mandatory" because the market needs 4 ohm to 80 ohm taps, and sometimes floating.

Cap is in any case needed because the amp is single-supply and the audio output has +29VDC at it.

Yes, they could have used a CT OT and reduced rail voltage. But the plan not relying on an OT to merge phases was very common in OTL transistors and maybe was more comfortable to their designer.

 

[Rocinante]

I just uninstalled and replaced these at a restaurant (2nd place I have done that had these in them) as they used them for their sound system (that maybe had bingo night on Sundays)  I'll just say the used Yamaha system I installed was way better.