Hello everybody, I just picked up this amplifier as a side project to the HP 1727a scope that I am working on, I don't think it will be finished anytime soon.
![Tongue :P](https://www.eevblog.com/forum/Smileys/default/xtongue.gif.pagespeed.ic.J5mTe0A2NA.png)
The amplifier in question is a Marantz Model 4070 console amplifier. I picked it up for what I would usually say is a rather high price but I have seen that these Marantz amps can sell for a lot on the used market, which is my intent once I am done.
It was sold to me as not working, which is kind of true. Everything seems to work fine(after cleaning some stuff), the only issue is that overall the volume is kind of low on all channels and all inputs (as far as I can tell). I don't know exactly what the volume should be but compared to most other amps I have messed with this one is quiet.
This unit has rear preamp to main amp jumpers so of course I put my signal in there and the volume+quality is great (on the crap speakers I have anyways). This narrows the possibilities down some.
So now that you have the background does anybody have any suggestions on what to test/look for?