TVC Sound

Wavelet analysis is like fourier analysis but more for discrete or impulsive rather than continuous events. Signal processing is something I am a little happier with than practical electronics! Doubtless it would be of value but I am sure it wouldnt settle anything. You still need a metric.

SM - there is no competition at all - I am interested solely in improving my hifi and have invited both you and SSB to contribute but you refused. I have already stated I plan to dem multiple phonos and pres so to that extent I have already agreed with his advice.

 

Markus,

Wavelet may indeed give more info. But I cannot really do that easily.

Distortion (which is not what appears in these oscillograms in this thread BTW) is dependent directly only on the input level and the frequency below around 200Hz (typical for any transformer), distortion falls monotonic with level, though it is so close to the self noise at the kind of input levels the device is designed for (eg 2V RMS = 0dbfs) that the whole subject is rather academic.

With 5V input @ 1KHz THD is -115db (or 0.00017%) mostly 5th HD, nothing higher.

IMD at 5V input for equal measures of 19 & 20KHz is -112db (or 0.00024%).

For 2V input at 100Hz THD is -103db mainly 3rd HD, some 2nd & 5th HD.

For 5V in THD is -102db @ 100Hz, -74db @ 20Hz, again mainly 3rd HD.

Selfnoise is around 1.5uV (or -117dbV/-115dbm), unweighted, across the audio band with the volume fully up, as the output is attenuated the noise is attenuated accordingly.

Frequency response with 600 Ohm Source and 100K//330pF load @ -10db is +/-0.05db 12Hz-40KHz with a small resonance peak (+0.5db) at 54KHz and -3db at around 90KHz.

Ciao T

 

Sir!

I resemble these remarks! :MILD:

Ciao T

 

It's also (IMO) plain silly to keep saying X is better than Y, but Z is better than X and so on. Fine to say you prefer the sound of one to the other, or that one is built to a higher spec than the other, but 'better' is too subjective an epithet to generate useful discussion.

 

Hi,

What he said! :drum:

You da man Joe! :beer:

Ciao T

 

Indeed - especially if there are a large number of other undeterined variables.

I can perform wavelet analysis if given data files with little effort.

 

Hi All, new to the forum.

For what it's worth, when I moved to a TVC (Sowter) a couple of years ago, it was one of the biggest upgrades I made to my system. I now use an Intact Audio auto-former volume control made by Dave Slagle. That was another step up for me.

Cheers,
Pete

 

Shurely "resent"....eh, Thorsten?

 

no John,

If you've seen Thorsten's shirts, his comments make total sense.

 

Hi,

No, the pun was intentional....

Ciao T

 

Ah..I see.

Carry on then!

 

Cheers for that. Could you be so kind as to give an example of a particular make/model of source that would be happy driving an inductive load and one that wouldn't- just to illustrate your point, like.

- I would have thought that a very open, fast and dynamic speaker might compensate for any percieved lack of pace and drive

 

Hi,

Not easily. But in technical terms, I recently build a phono stage which had a 0.22uF output coupling capacitor wrapped into the circits feedback loop.

Into a 10K//1nF IEC load the circuit measured rulerflat. In my system, driving a TVC it was motorboating. Simulating the equivalent circuit including the TVC suggested a 28db peak at around 6 Hz, it soun ded like it too.

Adding a 100uF and 1K series resistor snubber across the 0.22uF output C not only stopped the simulations peak but also removed the motorboating.

Ciao T

 

Baudrillard,

a very fast, open and dynamic speaker unfortunately highlights such shortcomings rather than enhancing them.

 

Have you tried various speakers to have reached this conclusion?

 

Obviously though, a dynamic speaker fed with a dynamic signal is going to sound better than a dynamic speaker with compressed signal and even better than a compressed speaker with compressed signal.

 

My comment was in reply to one that had been made at the beginning of this thread about TVCs maybe lacking drive. I was merely suggesting that a fast and highly dynamic speaker might compensate for that, if indeed the phenomenon even exists. But, yes, by the same token an open speaker could also highlight shortcomings such as measured ringing at near maximum attenuation- it thats what you meant.

 

My issues with the TVC, (and I have done quite alot of further listening to it) do not relate to its lack of drive, particularly when it isn't attenuating very much. My problems with it are about its sound when it is doing a fair amount of attenuating ie more than 30dB's worth. As the output levels get lower it gets more and more obvious (and to me, offensive) Doubtless later versions than this one exhibit less of this but on the evidence of Tensons photo's it is still there. Maybe Thorsten won't lose any sleep over it but it would bother me.

A friend has just borrowed a more recent copper one. He hasn't seen this thread/forum. His findings are (unprompted) very similar to mine.

The simple fact is, this isn't for everyone. If you like it, use it, and good luck to you. If you don't, I can understand (and possibly explain) why. I'm sure there are plenty of adequate alternatives anyway.

 

It doesn't bother me at all, because I listen to CD. As my initial tests showed with a 44.1KHz sample rate the ringing is not excited in the slightest, no matter what level of attenuation or load on the output. If I had a TT I might put a 2nd order filter on the phono-stage output at about 30KHz.

As Paul (I think) said, if you use it out of bandwidth, of course it rings!

 

Hi,

I think clearly, you do not like what happens in your system context. I also think you misdiagnose the Problem.

For reference, B&W's latest diamond tweeter rings much more than the TVC.

Yup, from history, there seems to be a strong incompatibility with the TVC and systems that contain large numbers of Black Gate Capacitors (I know why, BTW), no doubt other combinations exist where also something simply goes wrong.

It might be easier to disgnose what goes wrong in your system if one had more details about the sources. If the sources have a very much above average source impedance the reason for the unfavourable interactions may lie there (didn't you use the AI P2, that certainly would not like to drive a TVC very well).

Anyway, you, in your system dislike the TVC and yes, it has some resonances, though I contend that these two are NOT causally linked.

Ciao T