Balanced connections from dspMusik to amps

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HAL

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Balanced connections from dspMusik to amps
« on: 19 May 2016, 02:08 am »
It is interesting that I have been told by some to make sure I twist all my cabling to minimize hum problems. This is a problem that plagues single ended analog systems. The dspMusik and modified ChipAmp/Gainclone amps have fully balanced connections as seen in this picture. The cables are Mogami Neglex Star Quad 10' balanced mic cables as used in recording studios. The Neutrik XLR connectors are wired balanced to the amps. No twisting in the Neutrik XLR wires, yet the system is dead quiet, no hum or buzz.

With a balanced connection you get 3dB better signal to noise ratio and common mode rejection of hum and buzz from the environment. 



richidoo

Re: Balanced connections from dspMusik to amps
« Reply #1 on: 19 May 2016, 02:56 am »
Rich, dspMusik has true differential signal outputs?

Thanks

HAL

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Re: Balanced connections from dspMusik to amps
« Reply #2 on: 19 May 2016, 09:12 am »
Rich,
Yes, the dspMusik has fully balanced differential analog inputs and outputs.  Uses TRS style connectors on the chassis. 

The Mogami Gold cables I use are TRS to XLR connectors for fully balanced inputs and outputs.

You can also use dual RCA to TRS adaptors for single ended signals, but loose the benefit of the balanced connections.  The system was designed for fully balanced analog signals.

HAL

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Re: Balanced connections from dspMusik to amps
« Reply #3 on: 19 May 2016, 10:39 am »
When using the dspMusik with the Audio Weaver software development system on the MS-3 PC, you have access in realtime to the 8 channel WM8742 DAC 32bit volume controls.  This allows volume adjustment of all 8 channels simultaneously for direct connection of the dspMusik to the power amps.  This is via a volume slider, or direct number volume keyboard input. 

For digital file replay, the amps and speakers are all that is needed to have a digital music playback system.  For analog sources, they get connected directly to the ADC module.  If more than one analog source, that can be a stereo preamp output.  Now volume control can be either the preamp or the dspMusik digital volume control.

Speedskater

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Re: Balanced connections from dspMusik to amps
« Reply #4 on: 19 May 2016, 01:12 pm »
Good balanced outputs can be active, passive or transformer.
"true balanced' sounds like a marketing department tool.

HAL

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Re: Balanced connections from dspMusik to amps
« Reply #5 on: 19 May 2016, 01:14 pm »
The dspMusik has fully active balanced analog inputs and outputs. 

Any other questions?

richidoo

Re: Balanced connections from dspMusik to amps
« Reply #6 on: 19 May 2016, 03:24 pm »
Unfortunately, the word "balanced" itself is an often abused marketing tool. Fake balanced is ubiquitous in the marketplace now. It is fine for budget gear, but dspMusik purports to extreme sound quality so it should have true balanced differential i/o. Thanks for confirming, Rich. 

Differential has two signals of equal amplitude but opposite polarity, and ground is not necessary. With fake balanced the "negative" signal leg is connected to ground usually with a 50ohm resistor. The line driver and receiver electronics are simpler and cheaper and still maintain compatibility with differential equipment. Performance compared to differential signal is lower but acceptable for budget applications. Parts quality suffers too because cost reduction is critical in the budget market. It has its place and the market has accepted it to the point that if you want real differential you have to ask by name.

Speedskater

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Re: Balanced connections from dspMusik to amps
« Reply #7 on: 19 May 2016, 04:54 pm »
While I was aware of a lot of audiophile & boutique equipment with pin 1 problem, it's not hard to do a passive/impedance balanced output stage correctly.

HAL

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Re: Balanced connections from dspMusik to amps
« Reply #8 on: 19 May 2016, 10:23 pm »
For more info, here is the dspMusik webpage, including Audio Weaver software development package that comes with the system preinstalled on the MS-3.

http://www.danvillesignal.com/high-performance-audio/dspmusik-2-8-multichannel-dac