The Tube Distinctions AOS classic series valve amp - the verdict

[anthonyTD]

I cannot help but feeling that an amp which depends so much on which brand of valve is used is badly designed.

a valve must be classed as a circuit in its own right,with its own capacitance and reactance values,to name a few of its characteristic traits, hence the reason they all sound different, but there are recognised types that definitely sound more "right" than most others, these are invariably old stock versions, coming from an era when valves were pretty much all there was, so, it would seem logical to some that they were made more "right" than most modern equivalents!
anthony...

[anthonyTD]

If I'd known it was going to be used for Celine Dion I'd never have gone along with this. I'm sure Anthony wouldn't either






Nice write up Steve

my heart will go on, and on, and on....

[Marco]

Iain,

Hmmm. To me, the write-up highlights some of the problems with 'subjective' reviewing*, as well as throwing a glaring spotlight on Steve's musical taste.

I don't know what Steve was doing digging out Celine Dion albums to highlight the amp's musical prowess but trust me that's not all he listens to

In retrospect perhaps he'd have been better digging out some Keb Mo, Stacey Kent, Mary Chapin Carpenter, Tiesto, Newton Faulkner and tons of other stuff that I know he's got in his collection.

And I was positively shocked by the statement that 'My wife Tasha was also beginning to actually sit down and listen to music for the first time in her life'!

LOL. I realise that's how it reads but he didn't mean it that way. Tasha loves music but she, like many women in my experience, prefers to listen to music whilst doing something else rather than just sitting there in front of the hi-fi. The fact that the TD/AOS amp (and copper amp) was so good made her for the first time want to sit down and listen.

My wife's the same - now and again she'll sit for an hour or so and listen to music with me but after that she gets bored and will go off and watch TV or something, whereas when I have mates round we'll sit for hours on end listening to music. However she'll quite happily go to concerts/gigs with me and sit or stand listening to bands/orchestras for as long as is necessary and loves every minute of it.

*Most obviously, in the statement on the lines of 'this sounded harsh, but now it's burned-in it sounds wonderful'. Or maybe Steve's ears have just made the necessary allowances for the perceived harshness?

Hi-fi equipment in my experience does take a while to burn-in and perform optimally from new and his TD/AOS amp, which has recently had a lot of new components added, is no different. This is hardly a new phenomenon. I also know exactly what happened regarding the harshness Steve mentioned and it was simply a case of getting new valves (and the amp) to burn-in and perform as designed.

Marco.

[Steve Toy]

I cannot help but feeling that an amp which depends so much on which brand of valve is used is badly designed.

I cannot help but be encouraged by the more transparent designs that show up the differences.

The amp works regardless of the valves used but getting it to sound just right does require the right choice of valves. If my amp after burning in rejected the better, more vibrant valves in place of the duller ones I'd be worried.

I guess your choice of amp would be sufficiently opaque so as not to make a difference.

[Steve Toy]

Or maybe Steve's ears have just made the necessary allowances for the perceived harshness?

No allowances could be made given that the harshness wasn't apparent straight away.

Such glib comments overlook the fact that we dont listen to music constantly. We turn it off and on and come back repeatedly over time.

You never get used to harshness, quite the opposite in fact.

[Togil]

I guess your choice of amp would be sufficiently opaque so as not to make a difference.

No, but it should be optimally designed for the stock valve , I once got a very curt reply from EAR when I asked whether there were any "better" KT90s for their designs

However I do realise this may not be possible at the given price point.

[Marco]

I once got a very curt reply from EAR when I asked whether there were any "better" KT90s for their designs

Haha, I can relate to that! That'll be the famous/infamous (delete as you feel applicable) Mr Tim de Paravicini

He's actually different face-to-face. I was at his factory recently with a friend to have his 509s serviced and he is a charming, though somewhat eccentric, chap. Interesting set-up at the factory, too. He has a great rapport with his staff. I learned quite a few things.

Hans, Steve's amp *was* optimally designed for the stock valve - that's the point, and why the Electro-harmonix valves Steve tried didn't work. The amp (and the stock valves) just needed to burn-in to lose the initial slightly forward presentation. All is now well.

Marco.

[Steve Toy]

Hans, Steve's amp *was* optimally designed for the stock valve - that's the point, and why the Electro-harmonix valves Steve tried didn't work. The amp (and the stock valves) just needed to burn-in to lose the initial slightly forward presentation. All is now well.

Indeed the amp was designed (having been modified) to work with the Svetlana KT88s, Mullard GZ34s and Philips JAN 6SN7s fitted. The alternative EH 6SN7s and Mullard GZ 32s didn't work as well.

LOL. I realise that's how it reads but he didn't mean it that way. Tasha loves music but she, like many women in my experience, prefers to listen to music whilst doing something else rather than just sitting there in front of the hi-fi. The fact that the TD/AOS amp (and copper amp) was so good made her for the first time want to sit down and listen.

Well put Marco. The process of her beginning to listen more actively to music in the home began with the unmodified Puresound A30 which she described in her own words as being "involving" in its portrayal of music. I guess the involvement factor is the key to getting people to actually sit down to listen rather than just have the music "on" while attending to other things like housework or reading a magazine.

Tasha is a music lover but until recently the recorded music in the home experience was never like attending a concert, probably still isn't (she goes to two or three a year including V Festival) but I think we are close enough now for her to just do the sitting, listening and enjoying.

[Steve Toy]

So if you want good quality valve amplification without spending 5k here are your options in summary:

1) Buy a direct-import Chinese amp like the Yaqin or Bewitch for under £400. Use a step-down transformer for safety or your music may be smokin' (this has actually happened btw as Richard is conveniently overlooking so be warned!) Get used to it first before sending it to Anthony of Tube Distinctions or someone else doing a similar job. You can then fully appreciate the improvements when your amp comes back. You will need to pay for new mains transformer(s) that work with UK voltages which may well cost you as much again as the other mods and valves.

2) Buy the above and don't even switch it on. Instead send direct it to Anthony for modification. You'll need to replace the mains transformers as above. The amp will be great when it comes back but you won't know how it sounded to begin with.

3) Buy an amp that has been adapted for use in the UK and is certified. You'll pay more for it but the price difference will be about the same or less than replacing mains transformers. You'll get the chance to audition it before you buy it and appreciate the improvements when it comes back from being modified.

There, I've outlined my experiences and reasoning wrt this amp. What anyone else may decide to do if it is of interest to them is of their own choosing. Hopefully their choices are now informed ones.

Isn't this what forums like this are supposed to be about?

[Iain Sinclair]

And/or

4) Buy a good second-hand amplifier at a fraction of the 'new' price.