TVC Sound

Heard a TVC (mine) with an Audio note 300B amp stuffed full of Black Gates and it sounded excellent.

 

Hi Thorsten,

The P2 has a gain control, not thankfully on the output but before the final stage so I wouldn't need to use the TVC with that anyway (and I haven't yet)

My reservations about the TVC have related to its behaviour with 3 different CD players (well 2 and a DAC) and now 4 different power amplifiers. Only one of these has any Black Gates in it and then only as cathode bypass on a couple of stages.

I have 3 other linestages (each very different, 2 valve, 1 SS) here. None of them exhibit the noticeable (and in my view incorrect) characteristics of the TVC.

I find what you say about the BG caps interesting though. They are another thing that strongly divides opinion. I don't think they work in every application by any means, but they can give good results in some places. Why do you think these caps and the TVC don't get on (or is it a trade secret?)

 

Murray, would you care to try using your CD source as the signal generator for the 4KHz or 1KHz test tone and doing another comparison?

If it is anything like the two (admittedly cheap) 44.1KHz source's I tried, it won't excite the ringing in the slightest. Thus if this is also the case with your system I would suggest Thorsten is right that the ringing and what you don't like about them are not linked.

 

Hi,

Interesting. Using CD as Source (not even non-os BTW) will not excite the resonances in the TVC.

They would not, as they all use some form of resistive volume control.

I agree. They have their applications.

I think they do not get on because of the strong sonic signature of the BG's, which opposes some of the (sonic) losses you have with resistive volume controls (and other things). Remove these losses using a TVC and suggenly the BG's sonic effect becomes a liability. I had this very thing happen in two systems of friends, who are all "BG'ed up" and I mean all the way (PSU, anything).

In one system where we tried a lot neither direct connections nor S&B TVC's sounded right, but a sowter TVC with over 1db attenuation at 20KHz did sound right in this system, adding a simple lowpass to the S&B TVC fixed the sonic problem, but the owner quite sensibly argued that the much cheaper Sowter TVC with it's build in treble choking (in my system) lowpass behaviour already did all he wanted and much cheaper than the S&B one....

As said, the issues are complex and rarely make themselves noted with good quality commercial gear, which was the target ancillary of the TVC....

Ciao T

 

Hi,

I am not sure that this is "true" in the subjective sense.

I could note two specific kinds of setups which are always claimed to have great PRAT and/or Dynamics by their owners, when in fact what they hear is compression.

One such system is a typhical late 70's...early 80's Linn Naim Setup, Linn Kan Speakers (sorta like LS3/5), Naim Amp's & Preamp, Linn LP-12 loaded up with Linn Arm and Linn cartridge.

Another is the "HK Audiophile Special", which has some form of High End CD-Player, a Marantz M7 or M7 derivate Preamplifier allied to a high gain very soft clipping SE Amp and a pair of LS3/5.

Both systems must invariably compress severely when played at any level above late night listening, for a variety of reasons and on top of that these systems have basically no bass. Nevertheless, they invariably are claimed by their afficados to offer "good dynamics" suggesting that "good dynamics" to them actually means high compression.

So, the issues are again complex and obvious ideas end up misleading.

Ciao T

 

Hi Thorsten,

Let me get this straight. Are you suggesting that any pre-amp that uses some form of resistive attenuation loses something that the TVC doesn't?
If that is the case do we have to redesign our power amps and loudspeakers to compensate for what normally sounds correct but which, with the full picture delivered by the TVC now sounds wrong? Which particular aspect of the signal do you suggest an 'in circuit' resistive attenuator loses? It isn't dynamic range (or at least not a significant amount) because that wouldn't explain why the choke loaded linestage I have here sounds much more dynamically capable. It isn't bandwidth as the same linestage (and the SS one) both have greater bandwidth. Distortion, maybe the TVC measures better but it doesn't sound better particularly at low levels. Let me reiterate that the TVC I have here doesn't sound bad. I wouldn't be paying it so much attention if it did. I certainly wouldn't be wasting time engaging in this sort of discussion either. I like transformer coupling. The best power amp I have here is fully transformer coupled with Tango IT's and OPT's and I think it sounds lovely. The TVC has a little of that likeable character. But too little. I can conceive that the performance of a TVC is inevitably going to be worse the more attenuation is applied. I suppose I'm just wondering whether the transformers could be made any better than they are. I'll have to try some Mk3 ones as I said before.

 

Ah well there is an interesting one. With these open baffle speakers I was using them at the start with the room EQ from my PMC's which made them bass light. The dynamics sounded amazing. Once I adjusted the room EQ to give smooth bass response the dynamics seemed to disappear a little bit (I don't think it was due to pushing the driver harder for various reasons). So it seems that subjectively, if there is not much bass you hear more dynamics.

On closer listening I think the dynamics are all still there, you just don't pay as much attention too them when you are rocking away to the bass line in your chest!

 

<coughs and splutters coffee into keyboard>

You think the LS3/5 and Linn Kan sound similar! ?

Interesting

In all seriousness Thorsten I do understand what you mean about compressed systems giving a false sense of PRaT. In the example given, the 'fault' is almost entirely with the Linn Kan. Heavy 5 inch bextrene woofer with limited power handling and excursion placed in a small sealed enclosure giving little useable output below 70hz. In addition to the compression we have enhanced 'leading edges' caused through raised upper mid levels which combined with the reduced low bass and 'dry' loading give the impression of enhanced speed. Upper bass harmonics are eccentuated and the expense of the fundamentals. It works very well on some music but is poor on others but no one should be under any illusion that the 'Kan sound' is anything other than very contrived to give a particular effect.

I rather like it on rock and jazz/fussion but on other stuff - ?. Pass.

 

Interesting developments, A client brought round a TVC for comparison with a simlar priced active unit. The Music first was comprenhensive beaten in ALL areas and at ALL volume levels by an active pre costing £2.2K.
The vocal region especially been exposed as average at best, also detail and dynamics some what lacking along with real presence, bass perfomance and overall 'palpability'
Very interesting afternoon I might add

 

Music First

This is just via the ears - but this is the best preamp I have ever heard - period - and I have heard a few. Been suggested I listen to a Shindo and wil report back if intersted in my findings - but value for money - these amps are amazing.

 

Murray,

the problem you will have is that the TVC is seen as neither adding nor taking anything away from the signal by it's creator and some advocates.

Despite your objective evidence, and much subjective testimony, the TVC brigade will not stray from their path and will remain convinced of superior accuracy. It's such a common stance on hifi forums, untterly unproveable in most instances, and when disproved, will lead to more and more outrageous claims to counter. I suspect the creator is only just warming up ;-)

 

Why so much heat on the subject?

I have some reservations about them but given that you can DIY a TVC pre amp for about £250 the criticisms surely have to take cost into consideration?

All present at Dev's recent bake-off, including two posters here critiacal of the TVC, thought the Django clearly superior to a perfectly respectable Glasshouse passive attenuator.

Mike, from my reading on this thread Thorsten is not claiming that the TVC is universally superior in all circumstances. Look at the comments re matching with BGs for example.

 

SM

I shall look forward to visiting the 3D Sonics room at the next HiFi Show and hearing for myself the startling performance that my own amplifiers and speakers are obviously incapable of revealing.

As for the remainder of the TVC owners club, many of them seem to be using PMC speakers! FFS!

I shall say no more for fear of upsetting anyone.
Each to their own.

 

Calm down dear, it's only an attenuator :MILD:

 

Hi Rob,

I'm calm. It's the implication that this thing is above criticism and that the fault lies with my CD player, amplifiers, speakers or ears which I find surprising.


rgds,

Murray

 

name that pre tony!

I beleive only one pmc owner has a tvc and thats me. Perhaps you would care to put up your own system for discussion murray?

 

The thing I find interesting about the TVC is how we get such different views on them. In my system, which has changed quite a bit around them, they sound very, very good indeed. In fact I can't hear them! Yet people like WM and Murray obviously don't find the same.

Because of my own experience of them and the way they should (at least theoretically) measure better than most pre-amps it is all too easy and nice to think that the reason for this is just that some people don't like hearing what is actually there. I guess thats why there is quite a bit of heat.

So lets keep the fire going! Thus far there are no measurements to show that the TVC is not superior, as long as the source is CD. I’d like to see some measurements to show this in the positive. Anybody got time to do some comparisons with other pre-amps. Thorsten were the distortion specs you quoted measured or derived from theory?

 

Oi, I'm not being critical of TVCs, just of one of the owners

The Django into Dev's Rogue was clearly better than the Glasshouse, but it would have been interesting to in turn compare that to a good active pre, something we didn't get a chance to do.

I'm still on for The Great Kan Test btw, if you are.

-- Ian

 

Its easy to be as critical as you like of my system SSB - without having actually heard it or the majority of its components you can expound at great length unconstrained by any bothersome facts. As I know you love to do.

 

I'm not being critical of your system, I've repeatedly said I suspect that your TT is probably excellent. I really don't like PMCs, and I think you ought to investigate active preamps and better phono stages, but mostly my critical comments are aimed at you rather than at your gear - the silly competitiveness and unwillingness to consider that you may be wrong on occasion, and that others may know about how to build good systems even if they don't choose any of the components you like. I couldn't give a fart about your system, if you like it that's just dandy.

-- Ian