preamp for aksa 55

[Melon Head]

Hi Prof
What is wrong with the B1?
Did you finish it?
Does it work?

[Professor smith]

Well it did work but I felt that the sound changed after a while and I coudln't get it back to how it sounded.

What does Hugh think about the B1 together with the AKSA?

The problem is, it has to be matched well and since Hugh designed the aksa he knows very well what will and wont work.

[AKSA]

Prof,

I have never heard the B1, so I would be doubly reluctant to condemn it.

My general feeling is that the AKSA, like most SS amps, really shines if the preamp is tube based.

Since the AKSA has a gain of 32dB, you can afford to drop a little gain, so a tube cathode follower is most effective, and the basis of my TLP, and then later, the GK1.

BUT, this is a tube circuit, the voltages are high and dangerous, and a special transformer is supplied. I do have some kits available for the TLP.

Cheers,

Hugh

[sandyK]

"My general feeling is that the AKSA, like most SS amps, really shines if the preamp is tube based."

Hi Hugh
Go wash your mouth out with hot soapy water !
Them's fighting words !
Most of us know of your soft spot for valve designs, and that AKSA 55 was designed to have a similar warmth to a good valve design.
Very many members would strongly disagree with your generalisation that most SS amps really shine if the preamp is tube based.
I heard the >AU$100,000 Ongaku valve amplifier at a Melbourne HI-FI show some years back , and it sounded very nice, with a very good soundstage when fed with a simple clasical diet. Then some wag in the audience slipped a Madonna CD recorded in Q sound into the CD player. It spat the dummy big time ! IMHO, The vast majority of valve designs do not like a lot happening at once, whether preamplifier or amplifier. I revisited a valve preamplifier a few years ago , in an effort to be more impartial with my strong views in another forum. It sounded great with DTV audio, but once again, did not perform nearly as well with complex music from CD.
Not all of us oldies need warm music to go with our hot milk and cookies just before bed time.
All in good fun, my friend !
Kind Regards
Alex

[AKSA]

Ah, Alex, aren't opinions fun? Sure, some are smelly, but they are all different......

Incidentally, valves only intermodulate badly when they are big ones, plate loaded with transformer output stages....... small tubes in CF mode are incredibly high fidelity!

Strangely, my first love is DOHC aero engines from between the wars, particularly the Napier Lion.... my second love is SS.

Hugh

[rabbitz]

My B1 (symmetrical supply / no cap version) didn't match my AKSA 55N+ but worked extremely well with the NXV200 and a LM4780. I've found the AKSA tends to thrive with a pre with a low output impedance (<75R) and my B1 is a bit highish at 330R.

Personal experience only so cannot generalise.

[Professor smith]

Hugh,

I remember you telling me that the Aksa would begin to sound muddled on more complex music, which is pretty much what Alex has just said about valve amps. It concerns me because most of the music I listen to is not solo stuff.

On modern cd pop recordings, how well would you say the aksa performs compared with simple vocal or solo recordings?

[AKSA]

Damn good, why?

It is all relative, there are few absolute standards. My comments are in comparison with the $1K+ crop of SS amps.

[sandyK]

Originally Posted by Professor smith

Hugh,

I remember you telling me that the Aksa would begin to sound muddled on more complex music, which is pretty much what Alex has just said about valve amps. It concerns me because most of the music I listen to is not solo stuff.

On modern cd pop recordings, how well would you say the aksa performs compared with simple vocal or solo recordings?

Professor smith
I have heard the AKSA55 in comparison with a Class A SS, and a fairly similar sounding 100W Class AB SS, in combination with an expensive Krell preamp, as well as a Class A preamp from 'vhfman".
It certainly didn't sound muddled on more complex music. On the day I felt that it didn't have as good a soundstage as the other highly "blueprinted" DIY amps, but it was certainly a good performer. It has to be remembered that Hugh has long since surpassed the SQ of the AKSA 55, which was in it's day, and still is, a very good amplifier. Certainly MUCH better than other DIY designs based around Hugh's implementation.

SandyK

[Professor smith]

Originally Posted by AKSA

Damn good, why?

It is all relative, there are few absolute standards. My comments are in comparison with the $1K+ crop of SS amps.

Is that a mistake? $1K?

The aksa is in that price range.