PIMETA V1 not behaving

[Jam_Master_J]

I've just built up a PIMETA here (v1) that is not working at all. It's Class-A biased, BUF 634P, AD843 and OPA 2132 based. Chips seem to be getting the right voltages, nothing is getting extremely warm, but I get nothing but noise on the output. I've left out R11 L/R which I didn't think should be a problem, do I need to jumper this instead?

I'm also using the RK27 pot but I'm using the input pads over by the Alps Blue spot which I thought was correct.

Any ideas what to check?

 

[FallenAngel]

DC offset?
PSU?
Input/Output wiring?

 

[Jam_Master_J]

Only a few mV.
Supply is 9v battery for testing, will be 20V TREAD setup after that
Input wiring is some panel mount RCAs, output is 1/4" output jack, neither are in a case right now so that grounding should not be an issue.

 

[FallenAngel]

Photos

 

[MisterX]

Did you install or jumper the R8 positions?

Regarding the R11s, you could jumper them if you wish but there was a post a long time ago that showed some resistance is actually a good thing there.

 

[Jam_Master_J]

R8s are jumpered. I'll dig around and see if I have any resistors good for R11s.

 

[Jam_Master_J]

Quote:

Originally Posted by MisterX /img/forum/go_quote.gif Did you install or jumper the R8 positions? Regarding the R11s, you could jumper them if you wish but there was a post a long time ago that showed some resistance is actually a good thing there.

Would leaving them open be bad then? Resistance=infinity

 

[Jam_Master_J]

I just jumpered R11s, no difference. I can faintly hear the signal only at max volume and the noise is much louder than the signal.

 

[Jam_Master_J]

I'm confused by something:

Quote:

Originally Posted by Tangent's Website IL, IR, IG: Signal input, if you’re using the ALPS RK27 or Panasonic EVJ pots. Left, right, and ground, respectively. IL2, IR2, IG2: Same as above, but only for the ALPS RK097 pot.

But when I look at the board layout:

It seems like this doesn't add up.


Edit: Wait a minute.... I got the names of the Alps pots backwards. I have the RK097 and therefore I need to use the second input pads, doh!

Edit 2: Wired it up the right way this time and it lives