Paradise Builders

Use a small box inside this box to enclose the raw-psu's. Float the inside boxes and then use a 'DDRC' to connect the box to the case. Use an other 'DDRC' to connect the case to the mains ground. Keep all other circuitry isolated from the case, and use an DDRC to connect the interconnect wires to the case. That should work. See also the grounding schema in the building guide.
 
That’s Frans term from the assembly guide ;). Something like this:

An externally hosted image should be here but it was not working when we last tested it.


Frans, thanks for your tips. I've been doing some more testing, removing earth completely, floating everything, star ground etc. - I haven’t been able to change the hum at all.
Building the box inside the box is almost as much effort as building two boxes and the result is not guaranteed, I' think I'll take no risk and go for the two box approach.

Sven
 
Thanks for the additional ideas guys. Its probably easier to go for two boxes than changing the PS significantly. Changing the polarity of one transformer mains did indeed improve the situation somewhat, however the hum gets stronger the closer I get to the transformers with the cables. Even if I reduce it now somehow to an acceptable level I'd never sleep really well knowing I handle the 0.3mV signal that close to the stray field ;).

Sven
 
I'm learning Fransh. :clown: (was more interested in the 2-how, than the ddrc part)

With mc-phono stages and transformers sharing one bed, sounds more like the steel case blanket is the main trespasser.
I'd either shoot the transformers, or the box.

That is what I thought (I think :)), so I did say 'isolate them from the outer box, and (possibly) add inner boxes' (or something of that meaning :))

Flickr Search: riaa
 
How am I supposed to think what you thought, I can barely keep up with your expanding vocabulary.

Out of curiosity, with 2 amp cases, why all of 1 channel in 1 box and horizontal copper, instead of keeping power supplies well separated, but with vertical plumbing ?

(flickr search reads a bit odd)

Both cases are complete RIAA systems, the dark-texted one is MM and the light-texted one is MC. The inner boxes are, PSU(RIAA), RIAA, ADC(196/24), PSU(ADC) and Mains-Filter(Smallest box) as you may have deduced (I thought so :)). There is no (not even a hint of) hum (net related) in the RIAA's.
 
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hi berndt, you arrived at the inner sanctum of "bastling" right now! the values indicated in the schematic, which are supposed to be the end result of all parallel combinations you may want to put in there, will give you the groovy JG-MiiB house curve, a great place to start. the asse,bly guide has more proposals, looking for more neutrality, but that will all depend on your system and in particular on your loudspeakers.
keep bastling.....
 
Thank you hesener! The standard house sounds fine, would it be possible to just print a picture of what value goes where using the group buy Wilma caps? The build guide assumes that I can figure out which block on the riaa pcb coincides with the schematic, and I don't really get it. Also, for the house riaa are the pcb listed resistor values used?
Thanks in advance for your time and attention.