Topic: Output voltage

Hello! I have been searching in the manual for an answer to the following question, but I have not found any info.
Anyway.
I just simply wonder what the output voltage is from the ADI-2 DAC. I have the first version/generation.

Regards

2 (edited by KaiS 2024-05-30 06:15:14)

Re: Output voltage

See manual page 21 and 52.

dBu is referenced to 0.775V.

XLR, balanced connection:
+19 dBu, +13 dBu, +7 dBu, +1 dBu @ 0 dBFS
6,91V,      3,46V,      1,73V,     0,87V.

Cinch unbalanced, all 6dB lower:
+13 dBu, +7 dBu, +1 dBu, -5 dBu @ 0 dBFS
3,46V,     1,73V,    0,87V,    0,43V.

To better confuse people the Reference Level in the display, opposed to the manual page 52, is referenced to the RCA output and shows:
DISPLAY values: +13 dBu, +7 dBu, +1 dBu, -5 dBu.
+19dBu is NOT shown.
In fact XLR balanced is 6dB higher than the values shown in the display.

I guess the next version manual will change this inconsistency in manual page 52.
Manual page 21 describes the behavior correctly.


If you want to know more I suggest to read this posting and maybe the whole thread:
https://forum.rme-audio.de/viewtopic.ph … 80#p157880

3 (edited by par.linden 2020-08-14 09:03:09)

Re: Output voltage

Thanks KaiS.

Re: Output voltage

When I read page 21 or 52, I can´t find any info about the dBu referenced to 0.775V.

5 (edited by KaiS 2020-08-15 02:22:08)

Re: Output voltage

No, because this is a common technical unit like mph.

dBu is the voltage equivalent of dBm, which is the power of 1mW into 600Ω.
The exact value of 0dBu is: 0.7745966692V, or square root of 0.6.

The value origins from early telephone systems, which had lines with  approximately 600Ω.
Analog telephony works with power matching to avoid echoes, so every input, output, line, device had to have 600Ω.


Do you want to know more ... smile

This is the reason why we have this crooked number as reference.
I prefer dBV BTW, 0dBV = 1V.

Re: Output voltage

http://www.sengpielaudio.com/Rechner-db-volt.htm

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14

Re: Output voltage

Hi! I have an old Naim amplifier that says input sensitivity 0,75 on the Aux input. What is the correct setting for the RME output? +1 dbu on unbalanced?

Old Naim gear tend to have a very steep incline on the volume potentiometer with modern sources with fixed output.

8 (edited by KaiS 2024-05-04 23:00:20)

Re: Output voltage

Naim indeed is special.
+1 dBu reference level seems reasonable.

Re: Output voltage

Thank you KaiS! Setting it to +1 and decreasing it by the volume knob is the correct procedure?

10 (edited by KaiS 2024-05-04 20:25:18)

Re: Output voltage

• Set ADI-2’s VOLUME to -5 dB
• Set Naim’s volume for about your “normal” listening loudness.
Put a little sticker or a pencil mark on the front-plate to mark that position.

• Now control listening level with ADI-2’s VOLUME dial.
You now should typically move in the range from -20 to +3 dB on ADI-2.


BTW: it’s always a good practice to exactly name the models of the devices involved if you’re out for detailed advice.
I often can find specs in the net that provide necessary information.

Re: Output voltage

Thank you again! Its a Naim Nait1 red diode.

12 (edited by KaiS 2024-05-04 22:58:14)

Re: Output voltage

I couldn’t find any further specs or a schematic of the NAIT 1.

But, I found a good resolution photo of the circuit board that clearly shows:
The Aux / Tape inputs are running through a discrete buffer amp before going to the volume pot.

This confirms the above:
Run ADI-2 on +1 dBu Ref Level to avoid overdriving this buffer.

Seems this little amp can be a nice beast sound-wise, have fun!

13 (edited by Kjetil200 2024-05-04 21:24:38)

Re: Output voltage

So - 5 dbu and then + 4 on volume?

And yes, it beats most of the high end amps I’ve tried in terms of musical joy.

14 (edited by KaiS 2024-05-06 08:15:27)

Re: Output voltage

Kjetil200 wrote:

So - 5 dbu and then + 4 on volume?

And yes, it beats most of the high end amps I’ve tried in terms of musical joy.

Sorry, my bad, I mixed up a sign, must be +1 dBu.
Corrected my postings above.

Don’t go above +3 dB on ADI-2’s VOLUME dial or you get distortions.
The range above +3 dB is a reserve only for weak sources like a TV set or quiet classical music.


As mentioned:
• Set ADI-2’s Reference Level +1 dBu
• For adjustment purpose, temporarily set ADI-2’s Volume dial to -5 dB
• Set a comfortable loudness on NAIT 1, then don’t touch it again.
• Use ADI-2’s VOLUME dial in the range up to max. +3 dB to dial the listening loudness in daily usage.
• If you find you need more over the time, you can of course bring up NAIT1.

That’s it.


Note the difference between:
dBu = a fixed voltage unit, referenced to 0.775 Volt.
dB = a relative level, in this case related to your chosen ADI-2 Reference Level.

Re: Output voltage

Again, thank you very much! I bought the RME because of the DAC alone, but I got so much more. Besides this forum ads to the value av the ADI-2. Never seen a sound product supported this way smile

Re: Output voltage

Trying to get close to an amps input voltage at 75mV. Is there any difference between +4dbu and -4db on the volume vs +1dbu and -1 on the volume?

17 (edited by KaiS 2024-05-29 21:19:22)

Re: Output voltage

Kjetil200 wrote:

Trying to get close to an amps input voltage at 75mV. Is there any difference between +4dbu and -4db on the volume vs +1dbu and -1 on the volume?

I‘m not clear why you‘re hanging so slavishly to this 0 dBu / 0.775 V figure.

You probably will never drive your power amp that high, almost full scale.

Auto Ref Level is your friend for best match of levels.

18 (edited by Kjetil200 2024-05-29 21:59:34)

Re: Output voltage

KaiS wrote:
Kjetil200 wrote:

Trying to get close to an amps input voltage at 75mV. Is there any difference between +4dbu and -4db on the volume vs +1dbu and -1 on the volume?

I‘m not clear why you‘re hanging so slavishly to this 0 dBu / 0.775 V figure.

You probably will never drive your power amp that high, almost full scale.

Auto Ref Level is your friend for best match of levels.

It’s not a power amp, I’m using the amps volume control and I’m trying to match the input voltage spec.

19 (edited by KaiS 2024-05-30 09:37:01)

Re: Output voltage

Kjetil200 wrote:
KaiS wrote:
Kjetil200 wrote:

Trying to get close to an amps input voltage at 75mV. Is there any difference between +4dbu and -4db on the volume vs +1dbu and -1 on the volume?

I‘m not clear why you‘re hanging so slavishly to this 0 dBu / 0.775 V figure.

You probably will never drive your power amp that high, almost full scale.

Auto Ref Level is your friend for best match of levels.

It’s not a power amp, I’m using the amps volume control and I’m trying to match the input voltage spec.

It has no advantage to exactly “fit” these figures.
Naim themselves doesn’t do that, e.g. their CD player CD5SI puts out the typical 2.1 Volt, that is +8.7 dBu.


Choose one of ADI-2 DAC’s available reference levels and set ADI-2’s volume to 0 dB for best DAC quality.

The +1 dBu reference level should be the best fit, while making the amplifier’s volume dial range comfortable.


Choose not too high reference level, because in general it’s better to use an analog volume dial (like on the Naim amp) in a range not too close to zero.
In the lowest range most analog dials have increased balance errors.


This is one of the reasons why RME built into ADI-2 the sophisticated combination of digital volume control, mated with automatic analog reference level switching.

Read manual page 65, 66:


In summary:

RME's digital volume control in 42 bit TotalMix technology avoids all the disadvantages of analog level control via pots, is easy to use, offers reproducible settings, and the highest sound quality.

Re: Output voltage

My amp isn’t from the redbook era so it does not well with the 2v input.
Reason I’m trying to match the input level is that the alps volume pot has a noticeable imbalance at low volumes. I’m experimenting and trying to find the set and forget level on the ADI-2. The ADI-2 is set inside the cabinet and the amp is on top ☺️

Re: Output voltage

Kjetil200 wrote:

My amp isn’t from the redbook era so it does not well with the 2v input.
Reason I’m trying to match the input level is that the alps volume pot has a noticeable imbalance at low volumes. I’m experimenting and trying to find the set and forget level on the ADI-2. The ADI-2 is set inside the cabinet and the amp is on top ☺️

That‘s what I say: use +1 dBu - or even -5 dBu for more dial range.

It‘s the result that counts, not some abstract figures (within reasonable range).

Re: Output voltage

KaiS wrote:
Kjetil200 wrote:

My amp isn’t from the redbook era so it does not well with the 2v input.
Reason I’m trying to match the input level is that the alps volume pot has a noticeable imbalance at low volumes. I’m experimenting and trying to find the set and forget level on the ADI-2. The ADI-2 is set inside the cabinet and the amp is on top ☺️

That‘s what I say: use +1 dBu - or even -5 dBu for more dial range.

It‘s the result that counts, not some abstract figures (within reasonable range).