• Registered: 2022-01-12
  • Posts: 6

Topic: Volume setting on ADI-2 DAC when connected with tube-amp?

Hi guys, I was wondering if anybody had raised this question before, but if so, pls forgive me for the repetition.

I am currently linking my RME ADI-2 DAC fs (9028 version) with a Marantz ND8006 as resources (CD, or AirPlay steaming via Apple Music or Qobuz, or USB line linking iPhone/iPad/laptop either to Marantz ND8006 or to ADI-2 DAC directly), and a Marantz PM8006 for a pair of  speakers and a tube-amp for my headphones.

The tube-amp has volume control, so is the PM8006. So what is the volume that I should set on DAC?

If I run the volume on DAC to -3.0 dBr, which is 9 dBr to the maximum, I need only to turn the volume knob on tube-amp a little bit from zero position, which is around 6 o’clock, to make it loud enough.

If I run the DAC volume to -20 dBr, the volume position on the tube-amp is at 9 o’clock for same effect, or -40 dBr on DAC and 12 o’clock on tube-amp.

Maybe you will say just let the ears decide which one to choose, but I can hardly tell the sound quality difference between these setting.

Should I bother to worry about this? Or is there a better choice, for sound effect or for the best functions or proper use of the machines?

Any suggestions will be appreciated. Thx

2 Reply by ramses (edited by ramses 2022-01-28 17:45:37)

  • ramses
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Re: Volume setting on ADI-2 DAC when connected with tube-amp?

> but I can hardly tell the sound quality difference between these setting
> Should I bother to worry about this?

What to worry about if you hear no difference ..?!

Simply do not overlad the analog inputs of your (integrated?) amps preamp and let autoreflevel do the rest.

If you want to optimize it further for least noise (although you do not seem to hear any) use attenuators to be able to use ouput levels close to 0dB at the dac. https://forum.rme-audio.de/viewtopic.php?id=25399
and then use autoreflevel which chooses the optimum reflevel to optimize for least SNR/highest dynamic.

But if you hear no noise .. if you are satisfied you can do but there is no must.

BTW, meanwhile the forum is full of such questions and answers.

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

3 Reply by KaiS (edited by KaiS 2022-01-28 21:08:04)

  • KaiS
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Re: Volume setting on ADI-2 DAC when connected with tube-amp?

PatrickS wrote:

I am currently linking my RME ADI-2 DAC fs (9028 version) with a Marantz ND8006 as resources (CD, or AirPlay steaming via Apple Music or Qobuz, or USB line linking iPhone/iPad/laptop either to Marantz ND8006 or to ADI-2 DAC directly), and a Marantz PM8006 for a pair of  speakers and a tube-amp for my headphones.

The tube-amp has volume control, so is the PM8006. So what is the volume that I should set on DAC?
...
Should I bother to worry about this? Or is there a better choice, for sound effect or for the best functions or proper use of the machines?

I can’t say anything about the unknown tube amp.

I suggest to use the Power Amp Direct on the Marantz PM8006.
It’s even switchable from the front, hold the button 3 seconds.

Here’s how to set it up, Case2 is for you:
https://forum.rme-audio.de/viewtopic.ph … 21#p161721


https://manuals.marantz.com/PM8006/EU/DE/fig/Conne%20amplifier%20PM8006_OBAOILbrpyeqlc.png

KaiS's Website

  • Registered: 2022-01-12
  • Posts: 6

Re: Volume setting on ADI-2 DAC when connected with tube-amp?

ramses wrote:

> but I can hardly tell the sound quality difference between these setting
> Should I bother to worry about this?

What to worry about if you hear no difference ..?!

Simply do not overlad the analog inputs of your (integrated?) amps preamp and let autoreflevel do the rest.

If you want to optimize it further for least noise (although you do not seem to hear any) use attenuators to be able to use ouput levels close to 0dB at the dac. https://forum.rme-audio.de/viewtopic.php?id=25399
and then use autoreflevel which chooses the optimum reflevel to optimize for least SNR/highest dynamic.

But if you hear no noise .. if you are satisfied you can do but there is no must.

BTW, meanwhile the forum is full of such questions and answers.

Thanks a lot for your kind reply, Ramses.
It seems there isn’t much to be worried about, as I don’t hear any audible noise other than the floor noise that comes with the headphone tube- amp, which is an integrated one.
Attenuator is totally a new stuff I never heard of before, and this is already too much and sort of overwhelming for a newbie both for hifi and for RME. Let me just stay put for a while here and figure out all these complicated functions and jargons and specifications etc before moving another step.
Thanks again!

5 Reply by ramses (edited by ramses 2022-01-30 18:17:24)

  • ramses
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Re: Volume setting on ADI-2 DAC when connected with tube-amp?

Hi Patrick, indeed, take your time.

BTW .. here an overview how flexible ADI-2 DAC/Pro can be used in different setup. There you can see the position of such an attenuator:

https://www.tonstudio-forum.de/index.php/Attachment/2842-RME-ADI-2-DAC-Pro-Connection-Diagrams-etc-v001-jpg/

See manual chapter 19.3 about the benefit of 4 different reflevels and the auto reflevel feature, with an easy example calculation:
https://www.rme-audio.de/downloads/adi2dacr_d.pdf
https://www.rme-audio.de/downloads/adi2dacr_e.pdf

This sticky gives you some information about solving level mismatches with attenuators:
https://forum.rme-audio.de/viewtopic.php?id=25399

These two attenuators are switchable:
https://www.thomann.de/gb/jts_ma_123.htm (-10, -20, -30 dB 22-20kHz)                     €22)
https://www.thomann.de/de/shure_a15as.htm (-15/-20/-25 dB 20-20kHz +/- 0.5dB      €67)
For XLR (balanced) and you place them best in front of the connected pre/power amp.

The 2nd one is a recommendation from KaiS that I saw last recently in a thread.
Seems to be that the frequency range is a little bit higher in the bass and the Shure gives the info within +/- 0.5dB, this is missing with the less expensive product. If I would need or have to buy a new one then I would get the Shure as the specs are a little better, but I doubt that there will be a noticebly / audible difference.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14
  • Registered: 2022-01-12
  • Posts: 6

Re: Volume setting on ADI-2 DAC when connected with tube-amp?

KaiS wrote:
PatrickS wrote:

I am currently linking my RME ADI-2 DAC fs (9028 version) with a Marantz ND8006 as resources (CD, or AirPlay steaming via Apple Music or Qobuz, or USB line linking iPhone/iPad/laptop either to Marantz ND8006 or to ADI-2 DAC directly), and a Marantz PM8006 for a pair of  speakers and a tube-amp for my headphones.

The tube-amp has volume control, so is the PM8006. So what is the volume that I should set on DAC?
...
Should I bother to worry about this? Or is there a better choice, for sound effect or for the best functions or proper use of the machines?

I can’t say anything about the unknown tube amp.

I suggest to use the Power Amp Direct on the Marantz PM8006.
It’s even switchable from the front, hold the button 3 seconds.

Here’s how to set it up, Case2 is for you:
https://forum.rme-audio.de/viewtopic.ph … 21#p161721


https://manuals.marantz.com/PM8006/EU/DE/fig/Conne%20amplifier%20PM8006_OBAOILbrpyeqlc.png


Thanks very much KaiS for your link and suggestion, which is very helpful.

I now have plugged the RCA cable from ADI-2 to the Power  Amp Direct end of PM8006. And YES! The sound is more solid with much clarity, and more enjoyable. (I believe this is not because I turned on my “brain-amp”, if you see what I mean, hoho)

Is it true that with this connection, the pre-amp function of PM8006 is disabled and replaced by ADI-2, which functions both as a DAC and as a pre-am?

Since the volume control is disabled at PM8006, now the volume level on ADI-2 is between 30-40 dB for normal loudness.

BTW, the tube-amp I am using is a Chinese-brand headphone one, Original OPA-3A, which is rather well recognized here in China  among many tube lovers but I don’t think it is as popular in other countries.

It is a 300B tube amp which can also drive a pair of bookshelf speakers with its 8W output. I tried to use it on my B&W706S for a while but now returned to use PM8006 for the speakers, and tube-amp only for my HD800S.

The reason I bought this ADI-2 DAC is because a friend told me the DAC chip of ND8006 is ESS9016 which is rather old and sort of out of date. Also, ND8006 has no balanced output, but ADI-2 does, so I can now make full use of the balanced HD800S with XLR link between ADI-2 and tube- amp.  Do you have any suggestion for volume setting on this pair — ADI-2 and tube-amp?

I have even copied an EQ setting which is said to be for adjustment for 800S, but actually the change is not very clear compared with EQ disabled.

Guess this is too long a reply.
Thanks again for your time, and wish you a Happy Lunar New Year ( Xin Nian Kuai Le) if it is also celebrated where you live.

  • Registered: 2022-01-12
  • Posts: 6

Re: Volume setting on ADI-2 DAC when connected with tube-amp?

ramses wrote:

Hi Patrick, indeed, take your time.

BTW .. here an overview how flexible ADI-2 DAC/Pro can be used in different setup. There you can see the position of such an attenuator:

Wow, you are always quick to respond Ramses.
Thanks again, guess I need to spend a while before I can figure out what is what.
A question is raised, then comes an answer, but with many more questions at the same time, and more and more….oh my! LOL
Anyway, guess that is where the fun is — to learn, to try, to share, and to have fun.
All the best!

8 Reply by MC

  • MC
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Re: Volume setting on ADI-2 DAC when connected with tube-amp?

ramses wrote:

These two attenuators are switchable:
https://www.thomann.de/gb/jts_ma_123.htm (-10, -20, -30 dB 22-20kHz)                     €22)
https://www.thomann.de/de/shure_a15as.htm (-15/-20/-25 dB 20-20kHz +/- 0.5dB      €67)
For XLR (balanced) and you place them best in front of the connected pre/power amp.

The 2nd one is a recommendation from KaiS that I saw last recently in a thread.
Seems to be that the frequency range is a little bit higher in the bass and the Shure gives the info within +/- 0.5dB, this is missing with the less expensive product.

It's not really missing. Gving a frequency response for a simple 3 resistor switch is bollocks. Frequency range starts at 0 Hz with 0 dB deviation, and ends far above 100 kHz. On both.

Regards
Matthias Carstens
RME

MC's Website

  • ramses
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Re: Volume setting on ADI-2 DAC when connected with tube-amp?

MC wrote:
ramses wrote:

These two attenuators are switchable:
https://www.thomann.de/gb/jts_ma_123.htm (-10, -20, -30 dB 22-20kHz)                     €22)
https://www.thomann.de/de/shure_a15as.htm (-15/-20/-25 dB 20-20kHz +/- 0.5dB      €67)
For XLR (balanced) and you place them best in front of the connected pre/power amp.

The 2nd one is a recommendation from KaiS that I saw last recently in a thread.
Seems to be that the frequency range is a little bit higher in the bass and the Shure gives the info within +/- 0.5dB, this is missing with the less expensive product.

It's not really missing. Gving a frequency response for a simple 3 resistor switch is bollocks. Frequency range starts at 0 Hz with 0 dB deviation, and ends far above 100 kHz. On both.

Thanks, good to know, saves some money.

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

10 Reply by Curt962 (edited by Curt962 2022-02-01 19:20:46)

  • Registered: 2019-01-07
  • Posts: 1,463

Re: Volume setting on ADI-2 DAC when connected with tube-amp?

"Bollocks"   Now THERE'S a word that is far under-utilized!  smile

FWIW:  I use a pair of fixed attenuators in my apparatus, and life is good!  If they rolled off at 50Khz...ehh..I could probably muddle through somehow nonetheless.  It's Audiophile Cables that roll off at 10khz that astonish me.

Pads can be your friend, and they needn't cost a fortune.

Best to all,

Curt

Vintage 2018 ADI-2 DAC. "Classic AKM4490 Edition"
Cables:  Red, and White Ones.
Speakers:  Yes