• Registered: 2019-03-05
  • Posts: 84

Topic: Ref level vs input sensitivity of preamp & power amp

Hello,

just to confirm that my assumptions are correct. My sytem is streamer --> SPDIF --> ADI-2 Pro AE --> XLR --> preamp --> XLR --> power amp.

Input sensitivity of the preamp is 300 mV for 1 V output. Input sensitivity of the power amp is 1 V per XLR leg for nominal power. So if I want to achieve setting where max volume on preamp = nominal output power of the power amp, I should set the output level on my ADI-2 Pro as Ref Level +4 dBu, Volume -6 dB. It gives approx. 600 mV (RMS) = 300 mV (RMS) per XLR leg.

Is this correct?

Thank you.

2 Reply by Curt962 (edited by Curt962 2019-03-10 02:43:03)

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

Re: Ref level vs input sensitivity of preamp & power amp

Pitrs,

If your System is Sourced from a Streamer only (as is mine), simply eliminate the Pre-Amp altogether.   By so doing, you eliminate a needless layer of intrusion from a component that doesn't need to be there.  Your ADI-2 will drive your Amplifier handily.

Curt

PS:  I'm somewhat of a Simpleton. smile   Anything that doesn't need to be in my Signal Path...isn't.

Vintage 2018 ADI-2 DAC. "Classic AKM4490 Edition"
Cables:  Red, and White Ones.
Speakers:  Yes
  • Registered: 2019-03-05
  • Posts: 84

Re: Ref level vs input sensitivity of preamp & power amp

Thanks for your post although it does not answer my question. I have similar attitude nevertheless for the time being preamp is in my setup.

  • bejoro
  • S/Mux specialist
  • Offline
  • Registered: 2017-03-16
  • Posts: 300

Re: Ref level vs input sensitivity of preamp & power amp

AutoRefLevel = disabled
OUT1/2 RefLevel = 4dBu
OUT1/2 Volume = 0.0 dB

Volume control via preamp.

Also my recommendation: Eliminate the preamp, no matter how good or expensive if you have only one analog source. Connect the analog source to ADI-2 PRO, even with AD/DA conversion, the setup is better than every preamp you can buy. Of course if you need more than one analog input, you will need a preamp.

I hope this helps a bit.

bejoro's Website

  • From: Greece
  • Registered: 2018-04-14
  • Posts: 30

Re: Ref level vs input sensitivity of preamp & power amp

You will allow me to disagree. Having connected the  RME DAC2  to the final stage of my integrated amplifier and making comparative auditions, the result is much worse.

  • Registered: 2019-03-05
  • Posts: 84

Re: Ref level vs input sensitivity of preamp & power amp

Ok gentlemen, so we did cover the topic "preamp yes or no" and now let us get back to my question, if I may propose :-).

@bejoro:
Setting you suggest will give 1.2 V RMS and to me it does not correspond to my request considering the input sensitivities of preamp & poweramp. Or?

7 Reply by Curt962 (edited by Curt962 2019-03-11 22:25:34)

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

Re: Ref level vs input sensitivity of preamp & power amp

Pitrs,

Let's think about WHY your ADI-2 is "SO much better" when connected via your Pre-Amp.    That simply doesn't make sense.

Refer to the ADI User Manual, Pg.37. Fig 19.3 for an answer.

It seems quite possible that your Integrated  amp isn't really helping you.  There could be some non-standard "weirdness" going on.  "High End Mfrs" are notorious for that sort of thing.  Compliant with nothing.

A direct link between the ADI-2, and your Amplifier(s) is far, and away the better choice.   

Look into this!

Vintage 2018 ADI-2 DAC. "Classic AKM4490 Edition"
Cables:  Red, and White Ones.
Speakers:  Yes
  • Registered: 2019-03-05
  • Posts: 84

Re: Ref level vs input sensitivity of preamp & power amp

I am looking into you completelly missing the topic of this thread :-) .

I have no integrated amp :-)  and I haven't written anything about ADI-2 being "SO much better" :-) .

Let me remind what it is about:
So if I want to achieve setting where max volume on preamp = nominal output power of the power amp, I should set the output level on my ADI-2 Pro as Ref Level +4 dBu, Volume -6 dB. It gives approx. 600 mV (RMS) = 300 mV (RMS) per XLR leg.

Is this correct?

9 Reply by Curt962 (edited by Curt962 2019-03-11 22:57:22)

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

Re: Ref level vs input sensitivity of preamp & power amp

Use Auto-Ref, and let it do all the Math.  That's what it was designed for.

Pitrs, You and I are listening to Recordings.  It's not a Science Project. smile

Read the Manual, and fun things will happen! 

All the Best Mate!

Vintage 2018 ADI-2 DAC. "Classic AKM4490 Edition"
Cables:  Red, and White Ones.
Speakers:  Yes
  • Registered: 2019-03-05
  • Posts: 84

Re: Ref level vs input sensitivity of preamp & power amp

You really miss my very simple question completely. Thanks for the effort anyway.