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NAK 1000 ZXL (second one) in da' house!

Arrived safe & sound. I like your oak reinforcement. What jumpers did you add to the main board? Did it play at all before you replaced caps? If so, was that distortion there? I can tell you that the FET front end is overloaded for some reason, hence the distortion and pegged VU input. The only reason the meters go to "0" when Stop is hit is because the input is muted to the output and meters. I can not get the DC offset on the PB amp low enough with just the pots, and until I make/get some board extenders it will be pretty tough to troubleshoot, besides the obvious change out the op amp to just see what happens. I PRAY there is nothing wrong with those 2SK240BL FET pairs as they are like $50 each! Meanwhile, in my spare time (yeah, right) I'll build the M-9057 test unit, replace the burnt out bulbs and check all the switches. I don't think the EQ switch is switching anything. Also, did you specifically use Nichicon FG caps to something, and KL elsewhwere intentionally? I noticed that you have some KL caps (which are low leakage) where low noise (LN) caps (normally a high quality audio cap) are listed for use. I very highly doubt that is the issue, but I wanted to get an idea of what your choice of components was for.
 
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perryinva said:
Arrived safe & sound. I like your oak reinforcement. What jumpers did you add to the main board? Did it play at all before you replaced caps? If so, was that distortion there? I can tell you that the FET front end is overloaded for some reason, hence the distortion and pegged VU input. The only reason the meters go to "0" when Stop is hit is because the input is muted to the output and meters. I can not get the DC offset on the PB amp low enough with just the pots, and until I make/get some board extenders it will be pretty tough to troubleshoot, besides the obvious change out the op amp to just see what happens. I PRAY there is nothing wrong with those 2SK240BL FET pairs as they are like $50 each! Meanwhile, in my spare time (yeah, right) I'll build the M-9057 test unit, replace the burnt out bulbs and check all the switches. I don't think the EQ switch is switching anything. Also, did you specifically use Nichicon FG caps to something, and KL elsewhwere intentionally? I noticed that you have some KL caps (which are low leakage) where low noise (LN) caps (normally a high quality audio cap) are listed for use. I very highly doubt that is the issue, but I wanted to get an idea of what your choice of components was for.
Click to expand...

With everything I did, I never got the deck to work any different than when I started. Probably the good news is it did not get worse. As far as the jumpers, they were already there. I assume this was done at the factory to fix a PCB error as some of the traces are also cut. As you are probably aware from the SB, there are several updates to the PCB boards over the years. If I remember right, the KL caps were recommended for some caps where I could not find the LN caps at the time. I can send you the database I created of the cap changes if you want it. I also saved all the original caps if you also want them. I know a few of the caps were slightly different from the schematic but appeared to be factory installed. The oak brace was to reinforce the PCB that was warped from the daughter boards pressing into them. A little unorthodox but effective. The boards sure fit more secure with this brace in place.

Sure glad to see this deck in such fine hands!
 
Don't want the old caps, but the database would be great thanks! The oak was an excellent solution IMHO, BTW. Ok that helps, sleuthing has pointed to the 4066 CMOS switches as distortion sources on more than one 1000zxl, and since I detect significant cross channel signals, it may be just that or that and OP amps. All I need is time..
 
I'm not sure as I sold it to Perry. I know he was struggling but not sure if he sorted it out.
 
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