Strauss Bass-174 transistor Amp

[TechiRick]

Have this wonderful old Amp, probably built in the 70's, to restore. Several transistors blown and a couple of resistors I can't identify. Anybody have or know where I can get a circuit?

[Roly]

Oh yeah.  Built in Melbourne Australia in the late 70's to early 80's.  Where are you?

You'll find the Strauss story here.

Circuit?  Very little chance I'm afraid but I will ask around - HOWEVER I can be sure that it won't be brain rocketry, it will be quite straight forward (with the possible exception of the tonestack area).

Some crisp pix of the internals and the damaged section, transistor type numbers, would help a lot.

[Roly]

Sorry it took a while, but here's the power amp circuit.

[TechiRick]

"Some crisp pix of the internals and the damaged section, transistor type numbers, would help a lot."

Thanks for your help Roly (I am in Warooka,SA) the transistor line-up is different with the last being 2N5680/5682 feeding MJ15003's. I will see how closely your diagram matches what I have and it may give me a clue as to the burned-out resistor and what I can use as substitutes for the other transistors.

[Roly]

Find a camera that has "tulip" macro mode, flash off, pour a bunch of light in, and post pix of the dubious area.  Given good pix it's often the case that the offending bits can be quickly identified (but it's always a pretty fair guess with one of these that it is the power stage emitter resistors that have fried.)  Generally speaking when I've needed a transistor to substitute for something unknown up to the driver stages the BD139/140 pair seem to do the job.

[Roly]

Keeping all the junk in one place...