Paradise Builders

[hesener]

https://flic.kr/p/2mb83XA

Simon your builds are beautiful!

 

[stephan-schulz]

looking like noise, not oscillation.

I agree.

what would be an acceptably low value for the R43 resistors?
the measurings were taken when the Input was shortened with 10ohm. Will retry with 10k

 

[jamie123]

Simon your builds are beautiful!

they sound pretty darn good too!

 

[Simon1972]

Thanks Hesener, I've had enough practice at this little project of yours, Joachim's and FDW's.

If your going to build something it's worth while doing it right.

https://live.staticflickr.com/7848/33434148568_3fe86dcd5b_k.jpg

 

[Simon1972]

Stick a10k across input and ground them adjust the central trimpot until you measure 0.0mv across the input. Then measure the rest of it.

I have a known good, separate, shunt reg pcb that I wire up for all my builds so I can check the riaa section. It means I can rule out any faults in the shunt.

I also put the last transistor on each side of the input stage on header pins, then you can swap them easily to adjust the offset before soldering them in.

 

[stephan-schulz]

Ok, reduced the R43s to some k below 100k, bridged the input with 10k and ajusted to close than 0V on the output.

Check!

Now connected both boards with 300R cross the input to the MC and measured output voltages just to play safe before connecting to the Amp.
16V - what??

 

[stephan-schulz]

Seems to be a grounding problem when the boards are fitted into the enclosure as board is ok w/o enclosure.
Will further check tomorrow.

 

[Simon1972]

Plastic stand offs, always.

A mate mounted his calvin boards by drilling through the board, using brass stand offs, you can guess the rest.

 

[Calvin]

Yeah, miserable!
I prefer my standoffs from plain true gold

jauu
Calvin

 

[stephan-schulz]

Wrong direction, guys!
It was an issue with the RCA connectors .

So if all is fine tonite, I'll have a first listening session.

Cheers
Stephan