RD160: Significant overdrive distortion using streaming

#1

My system for reference;

RS130 connected to network via fiber, connected to RD160 via fiber
RD160 (fw 1.51)
ML 52 preamp
Constellation Audio monos
Magico S5 speakers

when playing any music from my RS130 embedded ssd, through the RD160, all is ok. The 52 takes up to 12Vrms input, I have the RD160 set to 9V balanced out.

When I switch the music to streaming through the RS130 using say Qobuz, i hear obvious distortion (overdrive type). While this distorted music is playing, I lower the RD160 output to 5Vrms balanced, and the distortion is gone. I don’t get any such distortion playing any music that is local from the RS130 to the RD160 while the output on the RD160 is set to 9Vrms balanced.

Am i doing something wrong?

#2

In audio it is better to follow standard practices. For balanced output voltage around 4 V is considered good practice. 9 V seems to be too demanding for upstream overload. Why you were setting 9 V in your system? Was there a noise problem?

1 Like
#3

Thanks Serge, I only set it higher after reading that my previous Dac (UD701n) had a higher output voltage. I didn’t know 4V is the right starting point. I’ll keep it at 4V for now.

#4

What is the input sensitivity of your preamp? That spec should give you an idea about where to start when setting the output voltage of your source.

#5

I found that my preamp has max input limits based on gain settings, which I adjusted and that fixed the distortion I heard when streaming (with my preamp gain set to 0, RD160 set to 9V output, no distortion). Basically I had my gain set too high for the RD160 when using the 9V output setting on the RD160.

I’m still unsure why there’s a difference when streaming vs. using any files I played from the SSD.

From the Levinson 52 manual (sorry about the format, this was a table):

Input Overload (line-level): Gain
+18dB
+12dB
+6dB
0dB
XLR Inputs
2V
4V
8V
16V
RCA Inputs
1V
2V
4V
8V

#6

Is there a nominal value setting for the output of the RD160? (unsure how the non-nominal values are achieved, such as amplification or attenuation)

#7

At the current settings (I still think 9V is too high even at 0 Gain), does streaming Qobuz sound louder than playing the same song at the same volume from the SSD? Better yet than relying on your ears, does the SPL measure differently between Qobuz and the SSD?

So there is no indication in the manual of what the input sensitivity of the preamp is? That number will tell you the minimum output voltage setting from the 160 you need for the preamp to output full power. It is a good place to start. You can always bump it up a little within the limits you described above.

#8

In your case, the output voltage should be set to 5V. To be precise, around 4.5V would be ideal, but since that option isn’t available in your settings, 5V is the closest match.

At 5V, the soundstage tends to move slightly forward, and the low frequencies tighten up into a more controlled, punchy core. At 4V, on your setup, the presentation may come across as a bit too relaxed in the bass.

That said, as always, it ultimately comes down to personal preference.

1 Like
#9

Hi Eleven, I did not find any guidance in the manual for input sensitivity. I only found this information via google;

The Mark Levinson No. 52 Reference Dual-Monaural Preamplifier does not have a single fixed input sensitivity; instead, it features a highly configurable gain structure to accommodate various source components.

  • Line-Level Gain Settings: The user can select from four primary gain steps: 0dB, +6dB, +12dB, or +18dB.
  • According to technical measurements, the input sensitivity for the +6dB gain setting is approximately 500mV.
  • Fine-Tuning (Offset): In addition to the primary gain steps, the No. 52 offers an Offset parameter that allows for fine-tuning in 0.1dB increments over a range of –20.0dB to +20.0dB. This is used to balance levels between different source devices.
  • Phono Stage Sensitivity: The dedicated phono input is also configurable based on the cartridge type:
  • Moving Magnet (MM): Selectable gain of +40dB.
  • Moving Coil (MC): Selectable gain of +60dB.
  • Input Overload: The preamplifier can handle high-output sources with an input overload margin of greater than 100mV at 1kHz for the 40dB phono gain setting and greater than 10mV for the 60dB setting.
#10

Thank you VIK, I’ll work with those values and evaluate what I hear.

#11

Write later about the impressions you experienced.

#12

Hi Fhindi,

Unfortunately, I can’t answer your questions directly.
But I noticed that you mentioned firmware version 1.51 for the RD 160. I thought the latest version was 1.46…

Do you have an earlier version?

Best regards

#13

My RD160 spontaneously shuts off after two hours with the latest firmware 1.51, even when music is playing? I know you can turn this off, but surely this should only happen if it hasn’t been used for two hours? I think i roll back to 1.43.

#14

I fortunately have not had any functional issues with my Rd160 using 1.51. The display is still quite dimly lit compared with my RS130

#15

@fhindi Which output voltage did you settle on? Were you able to avoid overloading the input stages?

#16

Thus far, I’ve been using 5V as the setting for my preamp. I’ve not had any issues with distortion since using this setting. however, i’ve not evaluated other settings. I’ve not had the time in the past week, due to work overload. I have to travel overseas for the next couple weeks, so more delays coming. I’ll post more after I get a chance to have some critical listening. Thus far, I’m enjoying what I hear, but the display…ugh it’s too dim