Salas hotrodded blue DCB1 build

[Disme]

Hi.

I got 2 PCB´s (one for each channel) from Thea-Bag because I want my DCB1 to be balanced. I'm pretty new at DIY amplifiers.

So I got a question about the wiring at the inputs, I can't find the answer anywhere, searched this forum and google a lot.

I will have most XLR inputs and only XLR as output, but I would like to have one or two RCA inputs but don't know how to wire them, hopefully one of you help me???

 

[Salas]

I found this in my files. Surely from older posts of a balanced builder in the Hypno DCB1 threads. RCA can be paralleled to hot and ground single phase on each.

 

[Disme]

Thanks Salas. The XLR looks very easy to wire, but still can't figure out how to wire the RCA connector when I have two boards?

 

[Salas]

Between XLR pin2 and signal return points on boards (R+/GND board pins).

 

[Disme]

So L- points will be left unused?

Sorry for All the newbie questions.

 

[Salas]

For RCA yes, L- points will be left unused. RCA is single phase.

 

[RKH]

For RCA yes, L- points will be left unused. RCA is single phase.

So to have the option of an RCA (unbalanced) output, one would apply the same logic to the output side?

Thanks,
RKH

 

[Salas]

Yes.

 

[mantha3]

RCA to XLR
DBRC-2A

 

[mantha3]

DIY Audio Electronics from Zynsonix.com: Balanced XLR to RCA Cable

 

[RKH]

Is the DCB1, as configured in Salas' post above, able to drive BOTH Balanced and SE outputs simultaneously?

Thanks,
Ryan

 

[Salas]

Yes if they don't fall below 5K as a combined load.

 

[RKH]

Is it correct to determine the combined load as follows?:

(1/Zin1 + 1/Zin2)^(-1)

Where Zin is the input impedence. (I realize that balanced inputs may/will have different Zin than the SE inputs)

Sorry for the naive questions. Thanks for your patience.

Ryan

 

[Salas]

Exactly like when paralleling resistors. Rtotal=(R1*R2)/(R1+R2).

 

[johnwmclean]

FYI if anyones interested...

http://www.diyaudio.com/forums/swap-meet/237823-diy-salas-hot-rodded-balanced-dcb1-buffer-fs.html

 

[Salas]

That was one of the most spectacular DCB1 balanced builds here. Sad to see it on sale... Has no function in your current setup? It would need a volume control and a selector for most guys though.

 

[johnwmclean]

Hi Salas,

Just running into some financial difficulties.
I used digital volume and only one source...

Many thanks,
John

 

[mantha3]

John,

Nice DIY Audio Equipment sells well on AudiogoN - The High-end Audio Community... Just another place to post this.

A work of art I'd say.

 

[harmolodics]

Powering Multiple DCB1

With multiple DCB1 circuits, is it recommended that each has its own PSU and transformer? Or can additional DCB1 circuits be adequately powered from the SalasDCB1 board?

I'm looking into a buffered 2-way crossover that would use 3 DCB1.

 

[Salas]

Use 30VA separate trafos and 200mA CCS setting each in own regs populated for best separation config. Using 3mm floor of a medium size box for sinking can avoid separate sinks bulk and cost and it will suffice. Use silpads.