TVC Sound

Hi,

Need to see what can be done, HOWEVER, based on my auditioning the MKI & MKIII are very close sonically, with the MKIII possibly having a little more "transparency" and "air", but it's darn close to call.

Actually, there have only two iterations.

But Music First has often made "custom" units, specials (such as I suspect you have), depending on customers needs/requests. Typical examples are fully seperated outputs and/or fully isolated tape loops which involves additional transformers and I think maybe the first two or three silver versions (after which the "silver" PMP became an official product version).

Such custom units obviously perform somewhat different.

BTW, again, all the UK reviews (HiFi World, HiFi News Andrew Harrison) where of MKII.5 equipped PMP's, while the US reviews (6moons & Stereophile) had MKIII versions. A MKIII silver unit has been for ages over at HiFi News and is aparently regulary used in the reviewers system, but has not been written up....

Ciao T

 

I bought one from walrus about a year ago. It has a volume control that starts (no volume, maximum attenuation) 4 notches BEFORE the first marked volume setting (the one with an 8 on its side, which I think means infinity).

Jonathan, at S & B, said that they'd had a few complaints about the lowest volume setting being a bit on the loud side (especially with CD) so they had changed the transformers to a new one that would take more steps to increase volume.

I guess I got the new transformer (a year ago) but still the old face plate markings! No idea if its MKII or MKIII. Looks a bit silly so should really ask him to change the front face plate markings to reflect the true volume.

 

So that explains your comments about the volume markings when we were at Dev's then Thorsten

 

Any chance of letting me in on whatever Thorston said, Tenson? Dont tell me- my passive pre was one of a batch of duds with horribly el-cheapo transformers- part of a scam between S&B and Walrus. I always knew Les and Pete were up to no good.

 

Lol you got it in one!





Nah, he just commented that the transformers I got had more outputs (or numbered differently) than the ones he was familiar with and wondered why.

 

Okay well it was pretty hard to blow the dust off the 'scope. It had a slight problem with 'double vision' from what Rob suggested might be a reflected signal. It came and went with the wiggle of the 'AC/TV' switch. This meant I had to sit there and wait for the screen to clear up to take a picture

Anyway apart from that annoyance here are my results from a 4KHz square wave.

This first image is a direct connection from the laptop's built-in sound card playing in to a 10K load. No transformer at all.



This next image is with the signal from the soundcard going through the TX-102 in +6dB mode (easier to wire) with 37dB attenuation. Again a 10K load. This is to try and match Murray’s test as close as I could. It does look slightly different because I had to adjust the voltage gain on the 'scope to compensate for the 37dB attenuation.



I also tried varying the load between 10K and 80K. The results were exactly the same. I tried less attenuation and again it looked just the same. At least as close as I could tell after the time it took to change wires about.

I did a 1KHz tone as well which looked fine (actually clearer as the soundcard produced the wave better). I didn't take a pic though.

I was also going to try the amorphous core transformers as in the Django AM and Opera products but only remembered when I was half way through packing away! >.< Thus I couldn't be arsed!

Given that under every test I could throw at it, the transformers output looked as close to the original as I could tell, I would suggest you change your pre-amp Murray!

I look forward to seeing Thorsten’s results.

 

Hi,

You could ask me....

It was something like "S&B is using up an existing stock of cases, but S&B have (in line with the blanket "improvements without notice reserved" notice) improved the content." though my vernacular may have been a bit more ribald.

BTW, it's ThorSten, not Thorston.

Ciao T

 

Apologies, ThorSten

 

Hi Tenson,

I shall certainly try to get hold of a newer one.

I'd be the first to admit that square waves aren't the be all and end all. I've listened to plenty of nasty amplifiers which reproduce good square waves.

I've been trying to make a new linestage for myself using choke loaded 10Y triodes. At the moment this sounds preferable at all signal levels to the TVC but I'll be intrigued to see whether a newer one sounds better than the sample I have here.

rgs,

Murray

 

Hi,

Yes, I checked with S&B/MFA yesterday, they are also not sure what is in this unit, but they do remember it as a one off special. So it may very well be a MKI in there.

Worked on something like that with a friend, but with S&B TX-102 Volume control, battery grid bias and TX-101 2:1 as output Transformer (so only 12db gain) and it does indeed sound excellent. To my ears this is nevertheless ADDITIVE, but in a nice way.

This one and the higher gain versions of this circuit (known as "Final Euridice") using 5687 and 417A/437A/6S45 et al. together with the linestage from the Arthur Loesch Preamp (5687 version) and Kondo's M7 Preamplifiers are certainly among the finest I have ever heard.

Ciao T

 

Hi Thorsten,

I don't know what they've done to it but the Kondo M77 linestage is considerably better than that in the M7.

rgs

Murray

 

Hi,

Interresting. Must be that "KSL" stuff. You would not have a chance to pop the hood on a 77 and take some closeups of the internals... ;-)

Ciao T

 

There's a lot going on in There

no doubt it's all additive and nice though...

 

You're basically testing with a combination of 4kHz and a little 12kHz which might be considered not too challenging. I'm guessing Murray used a more capable generator.

Do you have a better signal source? And it would be interesting to see what the transformers do to the output of a NOS type DAC.

Paul

 

Hi,

I do. I'll see if I can do anything tonite. Still, if the transformer would ring strongly Simons signal would excite this nevertheless...

The MKIII will gently filter the second and onwards set of images.

Ciao T

 

Hi SM,

Seeing inside that M77 only serves to remind me why I can't afford one!

 

I tried burning the signal generated in software to a CDR and playing it in a reasonably pricy DVD player. It looked exactly the same.

I think if the transformers performed like Murray’s it would look a lot worse than it does.

1KHz was far clearer from the soundcard and that looked perfect through the transformer as well. Murray’s clearly shows ringing.

I wish I had tested the AM core. Do you think you might get the chance Thorsten?

 

Will a redbook CDR with 44K sampling (and 20K bandwidth) even play a 4K squarewave that includes any of the frequencies that might make these transformers ring?

I'm not sure how useful your experiment has been. Maybe someone more technically minded will know?

 

There is a lot going inside that M77 but remember that it includes a PSU and phono stage.

 

I know, but it does have a worrying number of silver foil caps and their own, home made resistors and I can't get these items from either RS or Maplin!

I also like the way that it looks like a 1970's Sansui integrated and has absolutely no overt 'bling' appeal. Adds to the charm imho.