[mgalusha]

Brad,

Not quite the same problem. Actually this one behaves very well if powered off/on. It remembers which input and volume level was last selected and comes up at that setting. It only got stupid on line spikes. Perhaps a larger cap in the logic circuit supply would provide a buffer and filter against that. The PS only runs the logic circuits and the relays, so it won't impact the sound.

Mike

[jrebman]

Mike,

How many resistors did you have to swap out?

Saw your other post on the SB and PS in the same chassis.  I would eventually like to do this with my current "enthusiast" modded SB2, and unless I can afford another Ultimate IV, some other high quality PSU -- maybe my modified Welborne (still under construction) and the buffer Wayne is working on.

-- Jim

[jules]

Paul,

you reckon the right thickness for Aluminium at 50/60 Hz is 1/2". Do you have a thickness for Copper in the same situation please?

Mike & all,

I'm using BB myself and a caps upgrade is winging it's way towards me. Jack at Burson has suggested that it could be interesting to try 100uF caps in the gain modules in place of the 47uF ones. This isn't suggested as an improvement but simply as an option that might suit some systems better than others.

jules

[Gordy]

Mike,

How many resistors did you have to swap out?
-- Jim

Jim, there are 12 resistors per channel in the stepped attenuator... link ... user's manual

[Occam]

Jules,

Defining skin depth (for purposes of attenuation of alternating magnetic fields) as the thickness required to attenuate that signal to 37% of the original level -

for copper, Cu
50 Hz...9.3mm
1 kHz...2.1mm
10 kHz...0.66mm


for aluminum, Al
60Hz .... 10.9mm
1kHz .... 2.67mm
10kHz .... 0.845mm

Sorry, I can't provide the formulas nor the 60hz value for Cu... I can't find my copy of Ott's book.

[jules]

Thanks Paul,

that's very useful and more than enough info. to work from in a practical sense. Quite thick isn't it!

jules

[jrebman]

Gordy,

Thanks for the link.  Amazingly enough, a PDF that works with my software.

Thanks,

Jim