Using Power Amps without a Pre Amp

All things NVA
Bill hart
Posts: 2
Joined: Thu May 06, 2021 10:56 pm
Has thanked: 9 times
Been thanked: 0
Great Britain

Using Power Amps without a Pre Amp

Unread post by Bill hart »

I am looking to purchase either the M300 or M600 monoblock amplifiers. I only stream music from a NAS drive or listen to internet radio stations through a RME ADI 2 FS dac which can control volume and balance etc. so don’t really see the need for a pre amp. I am not an expert so would welcome people’s thoughts on if this is a good solution, or do I really need to get a pre amp in this situation. All thoughts welcome, thanks.

User avatar
karatestu
Posts: 5945
Joined: Sun Jan 08, 2017 4:40 pm
Location: North Yorkshire
Has thanked: 1865 times
Been thanked: 1378 times
Great Britain

Re: Using Power Amps without a Pre Amp

Unread post by karatestu »

I would get a passive pre. Depends on the quality of the volume control in the dac though I suppose

NVA make rather good passive pre amps :dance:
These users thanked the author karatestu for the post:
Bill hart (Sat May 15, 2021 9:01 pm)
DIY FREE ZONE

User avatar
karatestu
Posts: 5945
Joined: Sun Jan 08, 2017 4:40 pm
Location: North Yorkshire
Has thanked: 1865 times
Been thanked: 1378 times
Great Britain

Re: Using Power Amps without a Pre Amp

Unread post by karatestu »

Oh, and welcome to the forum and world of nva Bill.
These users thanked the author karatestu for the post:
Bill hart (Sat May 15, 2021 9:01 pm)
DIY FREE ZONE

User avatar
savvypaul
Posts: 8635
Joined: Tue Oct 11, 2016 7:14 pm
Location: Durham
Has thanked: 1657 times
Been thanked: 2978 times
Contact:
Great Britain

Re: Using Power Amps without a Pre Amp

Unread post by savvypaul »

It will be safe unless there is a fatal failure of the RME's volume control - e.g. a short that causes the DAC to output excessive voltage - very, very unlikely.

We like our passive pre-amps for sound quality and additional protection but we know of at least a couple of NVA users who are using a high quality digital volume control straight to our power amps, with no ill effects.
These users thanked the author savvypaul for the post:
Bill hart (Sat May 15, 2021 9:01 pm)
I am in the hi-fi trade
Status: Manufacturer
Company Name: NVA Hi-Fi
https://nvahifi.co.uk/

Geoff.R.G
Posts: 1562
Joined: Thu Aug 11, 2016 2:46 pm
Location: Denham UK
Has thanked: 132 times
Been thanked: 476 times
Great Britain

Re: Using Power Amps without a Pre Amp

Unread post by Geoff.R.G »

Despite what you may think, many an “active” pre-amp does little more than control the volume with high level inputs. Phono input needs to add some gain and many FM tuners don’t have enough output to drive a modern power amp fully. Older CD players and tape recorders may be OK.

All of which is academic if you only use digital sources through a DAC but I am aware that search engines will find this thread so the above is more for those who find us by that means.

Of course if you have an older power amp with higher sensitivity, the output from a DAC may need to be attenuated, as your intention is NVA power amps that won’t be an issue either.
These users thanked the author Geoff.R.G for the post:
Bill hart (Sun May 16, 2021 1:45 pm)

User avatar
karatestu
Posts: 5945
Joined: Sun Jan 08, 2017 4:40 pm
Location: North Yorkshire
Has thanked: 1865 times
Been thanked: 1378 times
Great Britain

Re: Using Power Amps without a Pre Amp

Unread post by karatestu »

Geoff, in my experience active pre amps all take away something from the music, usually detail and emotion. Personally I can't live with that. They generally remove some of the music. Remember keep it simple stupid.
These users thanked the author karatestu for the post:
Bill hart (Sun May 16, 2021 1:45 pm)
DIY FREE ZONE

User avatar
Fretless
Posts: 9290
Joined: Wed Nov 12, 2014 12:15 pm
Location: Somewhere in Holland
Has thanked: 1487 times
Been thanked: 2280 times
Netherlands

Re: Using Power Amps without a Pre Amp

Unread post by Fretless »

I had troubles with my NVA A40 monoblocks when I ran them direct from a DAC with variable output.

There was a lot of ground-buzz and it seemed that the amps were a bit unstable. Putting a passive pre in place sorted that out and improved the overall SQ.
These users thanked the author Fretless for the post (total 2):
karatestu (Sun May 16, 2021 9:34 am) • Bill hart (Sun May 16, 2021 1:44 pm)

Upstairs:
Vinyl
Pro-Ject 1.2 + Grado Sig Jr + Cambridge Alva Duo
DigiVolumio PC + Kiss DP-500 + Sabaj A20d
NVA: P50sa - Cube2 - SSP - LS6+ Sabaj A10a (x2)
Downstairs:
Vinyl
Logic DM101 + Syrinx LE1 + Grado Sig MCX
DigiDenafrips Ares II + Volumio PC + Cambridge CXC
NVA: P50 - BMU+ Aiyima A07 MAX (x2) + Arcam One
HP: HifiBerry Digi+ PRO + Sabaj A10d
Office:
Allo DigiOne SIG + SMSL M300se + Douk G4 (x2)
Mission 760 + Monolith THX AAA 887
Headphones: German Maestro, Monolith & AQ

antonio66
Posts: 1006
Joined: Mon Jul 29, 2019 8:16 am
Location: Grimsby/Phnom Penh
Has thanked: 1449 times
Been thanked: 408 times
Great Britain

Re: Using Power Amps without a Pre Amp

Unread post by antonio66 »

From my experience, the best sound comes with no pre-amp, although I will say the dac used had a good volume control, so I think it is a case of try it with and without a pre, see which you prefer. I do believe many are using the RME dac as the pre amp so I would assume it to be decent.
These users thanked the author antonio66 for the post:
Bill hart (Sun May 16, 2021 1:44 pm)

valvesRus
Posts: 562
Joined: Sat Feb 24, 2018 2:34 pm
Has thanked: 25 times
Been thanked: 63 times
Great Britain

Re: Using Power Amps without a Pre Amp

Unread post by valvesRus »

karatestu wrote: Sat May 15, 2021 9:23 pm Geoff, in my experience active pre amps all take away something from the music, usually detail and emotion. Personally I can't live with that. They generally remove some of the music. Remember keep it simple stupid.
Just remember that NVA power amps don't need an active pre amp because they have an extra gain stage to work with passive pre amps.

Using an active pre amp with most "other" power amps can give one better drive, but it's not 100% guaranteed. ;)
These users thanked the author valvesRus for the post:
Bill hart (Sun May 16, 2021 1:44 pm)

Geoff.R.G
Posts: 1562
Joined: Thu Aug 11, 2016 2:46 pm
Location: Denham UK
Has thanked: 132 times
Been thanked: 476 times
Great Britain

Re: Using Power Amps without a Pre Amp

Unread post by Geoff.R.G »

In my experience the best sound is achieved when there is sufficient gain across the amplification stages to drive the output stage correctly. Whether that gain is achieved in the source component (CD player, DAC etc.), a Pre-amplifier or in the power amplifier is, to some extent immaterial. Obviously the more interconnects and power supplies involved the greater the chance of an electrical mismatch and the introduction of noise etc.

It needs to be remembered that 60 years ago components had much lower output levels. The Leak Troughline tuner has a very low audio output but the contemporary Varislope pre-amp had gain stages in the Tuner input to ensure that it could drive a power amp properly. Try using a Troughline with an NVA passive pre and power combination and you will need pretty much full volume and even then might not be able to get it loud enough. On the other hand take a 2020 CD player and put it through a Leak Varislope pre-amp and it will clip on every input because the output is so high.

In both cases the overall gain is probably about the same but where the gain components are situated has changed from the pre-amp to the CD player. Clearly, using an active pre-amp with a modern CD player into a low sensitivity power amp makes no sense. A low output tuner with a passive pre-amp and the same low sensitivity power amp is far from ideal. Throw a tape recorder into the equation and we have a whole new set of problems.

In the 1970s a Hi-Fi system might have consisted of a Tuner, Turntable and Tape machine with either an integrated amplifier or a Pre/Power combination, passive pre amps were some way off. One of the jobs of the pre-amp, or pre-amp stage, was to match the levels of the sources such that the volume control didn't have to be adjusted when the listener changed the source. Hence the Turner input had more gain than the tape input and the phono input may have had selectable gain for moving coil or moving magnet cartridges.

Today a Hi-Fi system consists of a CD player, streamer and/or a computer. Recording on to tape is pretty much unknown, FM tuners are all but unavailable new and turntables are the preserve of the enthusiast. Some cheaper turntables have a phono stage built in. The 2020s components all have high output levels and passive pre-amps are common. Also common are combined CD player. DAC pre-amps.

If you are into such things, look at upgrades for Quad power amps, you will find that almost all of the available DIY or dealer upgrades start by reducing the sensitivity of the amp. This is done because the designer makes the assumption that a modern pre-amp will be used and the output will be too high for the original sensitivity of the power amp.

Simply, it isn't a case of active pre-amp = bad, passive pre-amp = good but one of use the pre-amp that is most appropriate to the power amp and source components you are using. There is no "one size fits all" solution.
These users thanked the author Geoff.R.G for the post:
Bill hart (Sun May 16, 2021 1:44 pm)

Post Reply