smoothie

[1878]

Hmm. Just swapped it out for another 4.7v zener & I got the same reading. I'm pretty sure I have a couple of 5.1v somewhere.

[1878]

Just tested the voltages on the V+ rail & it's 9.06v all the way to R24 (10k). When I check the voltage at the other end of R24, I get the magical 3.67v !! Should there be such a big drop ??

[Govmnt_Lacky]

Just tested the voltages on the V+ rail & it's 9.06v all the way to R24 (10k). When I check the voltage at the other end of R24, I get the magical 3.67v !! Should there be such a big drop ??

In short... YES

One side of R24 is tied directly to the V+ input rail. Hence, the 9.06V. The other side of R24 is tied to the Zener diode rail which you are showing as 3.67V

The Zener diode side 'should' be at or pretty close to 4.7V. You are losing 1 volt somewhere which could throw off the 5952 transistors and cause no phasing.

The object now if to find out why you are only getting 3.67V on that rail. According to the document, that rail is tied to D2, R24, Bias trimmer, C11, C7... well you can see from the circuit.

If changing the zener with a KNOWN GOOD 4.7 zener did not fix it then you will need to check further down the line. Start by checking values of all the components that directly touch that rail. Maybe you put in a 47K instead of 470K. Something like that.

If nothing comes from that, try a 5.1V zener or start replacing components on that rail until your voltage pops into place.

BTW... what part number zener did you use?

[1878]

This one...

http://www.banzaimusic.com/4-7V-Zener-Diode-1-3W.html

I'm gonna spend some time on it tomorrow. Determined to get it sorted !!

[1878]

SORTED !!

I had a bit of a brainwave moment. I bought some 750K & 3.9M resistors from Ebay. Thanks to this...

http://resistor.cherryjourney.pt/

I found out the seller had labelled them incorrectly.

Thanks to everyone for your help. I was expecting a much more subtle effect to be honest, but I have been very pleasantly surprised. I am on something of a phase quest at the moment & this is a keeper !!