split output

[Rickard]

Is there a good way to split the output on one of these preamps? or is there a good splitter that can be purchased. This is for direct monitoring.

Thanks

Dean Rickard

[tpryan]

We use a patchbay to mult the outputs to our converters and monitoring console, but there are other ways to do it. If you need isolation, check out the Cinemag and Jensen splitter transformers. The simplest is to make up some Y cables.

[Rickard]

What do you mean by isolation? Is there a sonic hit to using a Y cable?

Thanks

Dean

[Rickard]

Anyone know about this?

Dean

[KevinL]

I split my preamp output signals to my board and my converters with a balanced Y cable and don't hear any problems with it at all. You may run into problems trying to split a mic signal going in but that's another story.

[JackofallTrades]

OK. Gonna dig up this old thread.

I split the outputs of all my SCA pres with a patchbay. One signal path eventually goes to the A/D, the other signal path is for 0 latency monitoring.

I was explaining this monitoring setup to someone else and they mentioned that they tried this in the past and it resulted in a ~3 db reduction in output going to the converters.

I tested this today with a signal generator and found 0 difference in the signal level. By moving the waveforms around I got an almost total null when flipping phase of 1 channel.

This leads me to believe that sonically or level-wise, I am not changing anything by multing the output in the patchbay.

Does anyone know of any other reasons I would not want to do this? I saw Tim's comment about isolation. I assume his is taking about ground loops and such.

Thanks.

[Randyman...]

Isolation would kill any hum or ground issues between connected units (common for broadcast type splits where you are feeding a main mix console, a monitor console, and the broadcast truck - all with wildly different ground potentials and silly long cable runs).

The only other issue would be excessive loading of the preamp's output transformer with 2 loads connected in parallel. Most input impedances are high enough not to matter (staying at or above 600 Ohms is recommended - and that's with the internal 603 Ohm termination jumper removed).

[Randyman...]

Looks like I'll be doing this myself soon enough I'm planning on multing my Kick and Snare preamps - One feed direct from Preamp>AD - the other feed to some compressors for some analog parallel compression - maybe some analog EQ - then into a seperate AD channel. Should be interesting. I'm planning on using simple XLR "Y" cables for the mult. I've got a Dyna-Mite on the way for Snare Spanking, and I'll probably DIY some 1176 clones soon for other uses. Woo hoo!

Quick Q for Tim - What is the lowest combined load you'd recommend for the A12 and N72? Since I'll be paralleling 2 units off the Preamps' outputs - I'm thinking I might want to raise the internal 604 Ohm termination resistor a little so when it is paralleled with the other 2 loads (2x 10K loads in parallel, or 5K) it will still end up around 600 Ohms.

It would seem that currently with 2x 10K loads plus the 604 Ohm Termination in parallel I'd be around 538 Ohms. So I'm pondering replacing the 604 Ohm resistor with a 681 Ohm resistor for a net 599 Ohm load on the transformer. Is this nit-picking? It might be easier to simply pull the module's termination jumer, and add the 681 resistor in the XLR Splitter.

Then output pads might also come into the equation - further complicating the actual load placed on the transformer. It never ends :p

Thoughts?

[Randyman...]

Bump for Tim - Mainly curious about the N72/A12/J99 output loading. Is 538 Ohms too low with 2x 10K loads plus the internal 604 Ohm Term resistor in parallel?

Thanks!

[tpryan]

I wouldn't even think about it until the total load drops to 300 ohms or so.

[Randyman...]

Thanks, Tim!

On a similar tangent - is there a way to sum 2 preamps together into a mono compressor while still recording each preamp output seperately to the AD's? EG: Snare Top & Snare Bottom - Top and Bottom summed into Compressor into the ADC, and also have Top goto the ADC and Bottom goto the ADC simultaneoulsy (3 input channels)? I don't have the luxury of an isolated control room for monitoring whle tracking, and I'd prefer to have a safety backup in case my compressor settings or top/bottom mix just didn't work for the tune. I obviously don't have a console to handle the bussing, either

I made an 8-Channel passive summing device which works, but obviously needs make-up gain (approx 30dB worth). Is there any way around that for a simple 2x1 summing device?

Thanks for any insight. I think I'll be filling up my 2nd SCA rack VERY soon!