More on: Tubes for Naimies

Posted by: uem on 26 January 2004

Some time back there was a thread (started by Kuma) asking about the use of tube power amps with NAIM gear – some replies were rather encouraging for my problem.
I’d like to expand on this “tubey thing” a bit further:

My chain is: CDS 2, 252, currently AYRE V3 (the one item being “negotiable”, as I guess, this may be the weakest link by now) running into Wilson Benesch ACT 2. – And frankly, it all sounds great - BUT: The WBs reportedly have a very good synergy with tube amps, so I’d like to try this option.

Without any doubt, the logical “NAIM-fidelity” choice would be the NAP 300 (or higher - !$!£ !)
However, I want a power amp, that can be switched into stand-by mode (or switched off altogether), since I also run a headphone amp (Stax) from the 252 line-out signal; and during headphone listening, the power amp must be muted.

Now my question:
Which tube power amps are used by fellow Naimies with success, which would play in the league of a NAP 300 (or 135’s for that matter)?

I have recently heard of the Balanced Audio Technologies VK-75, but none is available at the local Swiss rep/ dealer for demo. Anyone with experience of BAT with NAIM ?

Thanks for any suggestions

Urs, Switzerland

Posted on: 26 January 2004 by Andrew Randle

If your loudspeakers are an easy-enough load, then I would go for Audio Note. Audio Note's about the most musical valve manufacturer I've heard.

Andrew

Andrew Randle
Linn Binn Sinner

Posted on: 26 January 2004 by kuma

quote:
Originally posted by uem:
However, I want a power amp, that can be switched into stand-by mode (or switched off altogether), since I also run a headphone amp (Stax) from the 252 line-out signal; and during headphone listening, the power amp must be muted.

I have recently heard of the Balanced Audio Technologies VK-75, but none is available at the local Swiss rep/ dealer for demo. Anyone with experience of BAT with NAIM ?

Urs,

I've never seen a valve amplifier with a stand-by mode unless you go hybrid types? ( the ones that use tube for driver stages and solid state for output power )

ACT2 needs powerful amps and good ones, either solid state or valve, won't be any cheaper than NAP300.

I would be very surprised if BAT amps, whilst they can drive WB, sound anything like Naim amps...

Posted on: 26 January 2004 by uem

Andrew, Kuma,

thanks for your input.
Yes, WBs are not an easy load - they do need powerful amps (I did try some 15 watt tube amps with an earlier set-up incl. WB ACT 1s - without success, as there was simply no bass and musical foundation; mind you, female (soprano) voices were a dream !!

- and exactly this is the reason why I would like to have another try with tubes !

I would go for a NAP 300 anytime, but what I mean with "I need stand-by mode", is you can't switch off a NAIM unit without lengthy re-warming periods, AFAIK. Muting the preamp output is not feasible, as I want to drive the headphone amp from it.

OR: Is there a way around this problem ? Keep the power on, but somehow mute the signal in the power amp internally ?
Any technical expert to answer to this ?

Urs

Posted on: 27 January 2004 by kuma

quote:
Originally posted by uem:
I did try some 15 watt tube amps with an earlier set-up incl. WB ACT 1s - without success, as there was simply no bass and musical foundation; mind you, female (soprano) voices were a dream !! - and exactly this is the reason why I would like to have another try with tubes !

Funny Urs. Just this weekend, I've tried your preamp with my SET amps ( 30 watts buy my speakers are easier to drive than yours ). Do I dare say it was tube like? I got the midrange back from krell preamp I have been using. The bass was respectable and whilst did not put out the Krell bass ( I've a feeling 552 would ) , whatever down there was tuneful. How ironic is that soild state pre that can emulate valve's sonic strength without none of the extra baggage.
I am beginning to believe that Naimies are closet tube lovers?

FYI, if you are serious about valve amps, you might want to consider changing speakers. You really can't isolate between speakers and power amps with valves. ( almost like a package deal )
A sort of valve amplifications that can drive your spearkers with a respectable frequency extension up and down would cost a fortune, impractical to operarate and more than likely to be an eye sore.

Posted on: 27 January 2004 by David C

I have a BAT pre-amp that I have used very successfully with a nap 250, it works a treat. I am now using it with a Linn Klimax power amp and even better success.

The Vk-75 is really really good, I am surprised that you cannot get a home dem of it though. Try contacting BAT direct and explaining your predicament, they may put pressure on the dealer to be more helpful!

They are the only company I have come across whose customer service is as good as Naim.

David

Posted on: 27 January 2004 by kuma

quote:
Originally posted by David C:
I have a BAT pre-amp that I have used very successfully with a nap 250, it works a treat. I am now using it with a Linn Klimax power amp and even better success.

David,

Which BAT preamp do you use? and what is the difference between 252?

Posted on: 27 January 2004 by Top Cat

I was very impressed with the Rogue Audio M150 monoblocks - they're not cheap at around £4k, but they do offer 150wpc of Valve Power, a standby mode, easy bias adjustment, and switchable Triode/Ultra-Linear modes.

Sonically very quiet at idle, very powerful without too much of a valve signature. I tried them with the Magnum 99 preamp but it wasn't so great and let the side down, suffering as it did from noticable tube rush, NOS microphony and the weirdest and clunkiest remote control action I have *ever* come across. However, the monoblocks are delightful, if a little bit too big for my room (22" deep x 14" wide x 10" high each) - my dear wife took one look and just said "No Way!" even though she agreed they sounded nice.

John

Posted on: 27 January 2004 by Jean-Marc

quote:
Muting the preamp output is not feasible, as I want to drive the headphone amp from it

Urs,
correct me if I'm wrong, but you can mute only the preamp line output, leaving the recording loop switch on (and vice-versa).
If you connect your headphone amp to one of the record output, you then would be able to mute only the power amp output??

Jean-Marc

Posted on: 27 January 2004 by uem

Kuma,
Changing the ACT-2s is rather not an option - they do sound (and look !!) nice; I did hear them with high-class tubes (forgot which ones) - just fantastic !

Jean-Marc,
Yes, you can use the record-out only - I'm using this option as well, and I built a "DIY cable-remote-control" for the volume of my Stax driver (using LEGO toy mini-electic motors and a rubber string-system - rather basic, but it sort of works...)

Top Cat - Thanks for the tip:
Rogue Audio - I'll follow this up

Urs

Posted on: 27 January 2004 by David C

Kuma,
I have a VK-40, I have not compared it to a 252. It replaced a late model 52 in my system. I think that it was a significant improvement, although true disciples at the alter of naim would hang me for saying so. I have no desire to move to change it for anything else, even a VK51 SE.
I might have gone for a Vk-75 power if they were smaller. However, they seem to have a footprint the size of a rugby pitch. Far too intrusive in my small room.
David

Posted on: 27 January 2004 by kuma

quote:
Originally posted by David C:
Kuma,
I have a VK-40, I have not compared it to a 252. It replaced a late model 52 in my system. I think that it was a significant improvement, although true disciples at the alter of naim would hang me for saying so. I have no desire to move to change it for anything else, even a VK51 SE.

David,

Perhaps their preamps might fair better than their CD player. I've tried thier SE version of CD player few years back and it reminded me of a fat babushka.

Posted on: 27 January 2004 by David C

Kuma,
I have not heard the VK D5-se, I know that there are quite a few variations of the player, different transports and different dacs, then factor in different output tubes and it becomes a nightmare. I have been really impressed with their amplification, I have not tried the CD. I keep wavering between linn and naim for cd. All I can say is that it replaced a 52 and I don't look back, but as is always the case it is a very personal thing.
David

Posted on: 28 January 2004 by kuma

quote:
I have not heard the VK D5-se, I know that there are quite a few variations of the player, different transports and different dacs, then factor in different output tubes and it becomes a nightmare.

AFAIK, it uses Phillips transport, Burr Brown DAC and you can't tube roll D5SE as it uses 6H30 valves which unlike 6922 varieties, very difficult to find NOS or replacements.

Posted on: 29 January 2004 by Peter Stockwell

quote:
Originally posted by uem:

Muting the preamp output is not feasible, as I want to drive the headphone amp from it.

OR: Is there a way around this problem ? Keep the power on, but somehow mute the signal in the power amp internally ?
Any technical expert to answer to this ?

Urs

Headline ? Or am I being stupid ?

Peter

Posted on: 29 January 2004 by uem

Peter,

Sorry - confusion on my side - could you please explain further ?

Urs

Posted on: 29 January 2004 by Peter Stockwell

quote:
Originally posted by uem:
could you please explain further ?

What about this:

naim Headphone Stage

Peter

Posted on: 29 January 2004 by uem

Peter, I sent you a private mail (PT)

Posted on: 29 January 2004 by kuma

quote:
Originally posted by Peter Stockwell:
What about this:

http://216.149.62.210/products/headline.html

I'll be very surprised if Headline can run Stax.
For one thing, you need an adaptor. ( I don't think they come with 1/4 plug )

They need a real amp.

Posted on: 29 January 2004 by uem

Kuma,

of course your right it's all clear.
Stax has it's very own line of power amps; mine is the 007 T - attached is a PIC of my DYI -cable remote; the red little thingy is the LEGO-motor, which is operated by a battery-box allowing foreward and reverse.

Urs