• Registered: 2012-10-18
  • Posts: 18

Topic: Multiface II, weird noise issues

Hi,

I got Tascam 688 mixer/cassette 8-tracker connected to Multiface II (8 x group outs from mixer (RCA/phono) to inputs in Multiface II (TS)).

1:
I got this constant high pitched whining noise in Multiface. First I though that the Tascam is making it, but it turns out that changing Multiface's sample rate changes the pitch of the noise!

Is this maybe  some some kind of aliasing issue, where the unbalanced wires are gathering some ultra high noise frequencies, that even 96kHz can't handle? (Shouldn't that be low pass filtered before A/D conversion?)

The weird thing is that changing the sample buffer size affects the noise as well!

Any ideas for a treatment?

2:
With the same setup, I noticed that inputs 5-8 are very noisy, but if I connect the TS jacks only to half way in Multiface's input sockets, it gets better! The same doesn't happen with inputs 1-4.

I can see the difference in S/N ratio in HDSP Mixer's decibel meters, it's not just in my head!

Is there a logical explanation for this...???

2 Reply by MC

  • MC
  • MC
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  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 25,565

Re: Multiface II, weird noise issues

1. Standard ground loop. Check your ground/earth connections on all equipment connected to your computer. This also relates to devices for example connected to the Tascam and not directly to the computer.

2. That sounds like these inputs are broken. The unit will most probably need service to fix this. Is the Analog Level switch still working for all inputs?

Regards
Matthias Carstens
RME

MC's Website

  • Registered: 2012-10-18
  • Posts: 18

Re: Multiface II, weird noise issues

MC wrote:

1. Standard ground loop. Check your ground/earth connections on all equipment connected to your computer. This also relates to devices for example connected to the Tascam and not directly to the computer.

Darn. Okay I'll check them.

2. That sounds like these inputs are broken. The unit will most probably need service to fix this. Is the Analog Level switch still working for all inputs?

Yes, I think the level switch is working for all channels. I'll check that as well when I get back to studio.

Cheers!