I've going to have to make a few changes in my system and consequently need to ask a few question. Apologies if they seem a bit basic, but everyone has to learn and I'd rather not make any mistakes.

First I'm like to move my sub to the single ended output out of my BII DAC / Legato 3.1. Then I need a way to get single ended out of the balanced Legato outputs. I've not really got enough space for the Ventus & power supply, but the chap who is fixing my amps, suggested the following (see proposed diagram):

1. Is this going to work and be OK?

2. Is it going to be better than the single ended?

3. Is this going to give half of the output on balanced e.g. 0.75v as opposed to 1.5v for single ended?

4. He also suggested I connect a 'inrush current limiter 5A/10 Ohms to ground of Placid HD (going to Legato) to the chassis. Chassis is already earthed to Mains (UK)?

5. Any cap suggestions? Thinking cheaper Obbligato Gold (http://www.hificollective.co.uk/components/obbligato_gold.html) or maybe Auricap or others?

*The resistors inside DAC are because of hum, suspect was when sub and main amp connected to same RCA splitter.*

Balanced Legato DC measurements, powered up as is, but nothing connected to Legato output:

XLR Readings

+ 1(grnd) -> 2(+) = 9.33vdc

+ 1(grnd) -> 3(-) = 9.33vdc

+ 2(+) -> 3(-) = 0.00 vdc

Using the vCap calc these numbers suggest a cap around 0.8uf caps, but I put them in the diagram as 1uf.

Proposed diagram attached

Edited by user Sunday, March 29, 2015 3:43:04 PM(UTC)  | Reason: Not specified

Thanks for your speedy reply Brian, oddly enough this is what I had been doing using a splitter, but it was prone to hum on the new amps. The engineer suggested the solution in the diagram.

Are you saying it won't work, or not work well?
If it will, what of my other questions?

My concern would be level matching your outputs. Other than that, I will defer to your builder's opinion. I would try to fix the ground loop (cause of the hum).

1) Have not tried it this way.

2) I doubt it will be "better," but it may be no worse (see #1)

3) Yes

4) I think he means adding a "ground breaker," which allows you to have your grounds connected to safety earth, but unless there is an actual fault, the grounds remain isolated. I personally keep my low-level signal and low-voltage power grounds isolated from the chassis grounds, but this can be an issue if not done correctly.

5) No. A good quality MKP cap should be fine. I don't use/recommend "boutique" caps. The ones you linked to look reasonable, though I have never used them.