Input voltage question?

Mucker · 252

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Offline Mucker

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on: July 05, 2024, 01:41:23 PM
First off, I am extremely happy with my Stereomour II. I use it near field with Klipsch RF7 II and it's quite remarkable. Currently I've been using a Pioneer BDP-05FD bluray player with a Wolfson 8740 DAC connected by RCA either directly to the Stereomour or to my Moreplay then to the Stereomour with it's volume at max (using the Moreplay to control volume). The Pio is really great for stereo playback of Bluray Pure Audio disc or CD's taking advantage of the Wolfson's which I think hold their own even today.

The Pioneer is spec'd at 200mV @ -20dB which I had read has been measured to be 2V @ 0dB.

My confusion is what is controlling the voltage out of the Pio or is it fixed?

When I use the Moreplay, it is pretty loud even at low volume, but directly into the Stereomour, the volume is set reasonably high for the same volume output (by ear). Just curious if the voltage is variable out of the Pio with from the affect of the volume control of the other units, or if the voltage is fixed.

Just trying to understand what is going on. Thanks!
« Last Edit: July 05, 2024, 01:55:45 PM by Mucker »



Offline Paul Birkeland

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Reply #1 on: July 05, 2024, 06:25:42 PM
The manuals for those components aren't always super easy to figure out.  Page 44 of the manual has some information on this, but it appears to only be variable output on the surround jacks, so I suspect the two channel dedicated jacks are simply a 2V output.  Of course if you can control the level of those jacks in any way with the remote for that player, then that assumption would be false.


Paul "PB" Birkeland

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Offline Mucker

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Reply #2 on: July 05, 2024, 07:43:47 PM
Ah, thanks for that Paul. I've been using it for so long as a CD / stereo player that I forgot about those adjustments. The 05 is a 7.1 player with 4 Wolfson stereo DAC's. It includes a separate set of stereo jacks so that a 7.1 system can be hooked up as well as a stereo system simultaneously. However, the front mains of the 7.1 and those dedicated stereo outs share one of the Wolfson DAC's.

And yes, I did set it up as full range out for the stereo jacks, 0dB. I guess that means if I drop the levels down to -20 dB, then those jacks would output 200mV according to the specs. Kind of making sense now. I definitely will keep them at 0dB. Somebody in another forum actually measured them and the were 2V at 0dB. I had completely forgotten the output was adjustable. Thanks for reminding me.

This leads me to another question. At 2V into Moreplay, is there a known voltage range for the volume knob. Does 2 volts start at min volume and then at max it's ?? volts? What would the voltage be approximately at the 10 o'clock position? And this is the voltage gain into the Stereomour? Appreciate the info.
« Last Edit: July 05, 2024, 08:01:08 PM by Mucker »



Offline Paul Joppa

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Reply #3 on: July 06, 2024, 04:18:41 AM
The stock Moreplay gain is 9dB, so a 2V input will produce about 5v output. Stereomour II wants about 1.33v input to produce its maximum linear output of 3.5 watts.

Paul Joppa


Offline Mucker

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Reply #4 on: July 06, 2024, 06:06:59 AM
Really great info! Thanks a bunch PJ!