Installed bulk foil resistors in phono amp

But how high can you go? You can’t keep increasing the value hoping for more and more rejection! Maybe the designer deemed 1k enough.
The amp uses 2 diodes in series to bias the cathode. Can you suggest a better way to do this? I’ve seen NiCads and LEDs used.

@gs5556 Good to hear. 
The only manufacturer I know of that uses bulk foil resistors is VAC in their ref or sig series at $80k!

Oscillation is a nasty beast, as it can be inaudible and fry downstream components.

@noromance
VAC offers an "SE" upgrade for their standalone Renaissance phono stage that adds some 30+ of those Z-foil resistors and Jupiter copper/beeswax coupling caps. Still not a cheap stage by any means, but $14.4K is a hell of lot less than 60 - 80! Unfortunately a lot of those Z-foils are allocated for the MC loading, and I bypass it all to come into MM because I prefer other SUT's to the built-in Lundahls. 

I’ve had both the SE and non-SE versions of this Renaissance phono in my system, currently own the SE. Both sound amazing. The SE does have extra clarity and detail but honestly the extra warmth of the non-SE ($10K) can be appealing too. Can’t go wrong either way if you have a high-end upstream to take advantage of it; they both make magic.

But how high can you go? You can’t keep increasing the value hoping for more and more rejection! Maybe the designer deemed 1k enough.

@noromance 

That's right. With a 12AX7 10K still gives you plenty of bandwidth. In guitar amps that value is a lot higher, as the intent is to roll off the input considerably more.


LEDs can work quite well to set up the bias.