My experience with a DIY TVC is not relevant because it is just a prototype - gordan

I can't remember if I described the DIY TVC with double-C core transformers I mentioned in my earlier posts.

It is actually quite hard to describe it. It's a brainchild of a local audiophile who, being a sceptic in hi-fi industry, rejected audio brands 25 years ago (except for Koetsu cartridges and Tannoy/Lowther drivers;)). Everything in his system is built by different low-key, DIY local gurus, but always to the highest possible standards you will seldomly find in brand name audio, unless you have $$$$$$$$ to pay for flashy displays and shiny boxes.

The guy is trying to use whatever a heritage of 60-70 years of audio is. He is not following any fashion or trends. He has been experimenting a lot with the output transformers for both power amps (SET) as well as for his preamp which is an amazing product, a kind of a true single end design (1 valve per channel) with output trannies. A massive, double mono preamp, 30 kilos of iron and chrome, most of it in output trannies.

He studdied trannies for decades. The output trannies made after his design (on iron cores, wound with copper), outperformed Audio Note trannies.

And he has been mentioning transformers as something that should be used for volume control in passive preamps at least for 20 years, when all the hype about resistor based passive preamps started (Creek etc).

How did he come to double-C core trannies? Simply, any 50s book on trannies will teach you their electrical and magnetic parameters are superior to EI cores. And whenever he had a chance to compare them, it was always a double-C core trannie that sounded better than an EI core one, when all other parameters were similar (size & material). Better - meaning more natural, more detailed, better dynamics and better freq. extension. More music, less veil.

Forgot to mention - he is not building commercial products. He is not selling anything to anyone. He generously shares his views with whoever is interested in. There is a number of products here in a local community that are DIY-ed around his and ideas of his buddies.

Luckily, he is based in a country where labour is cheap and you can still find some old materials around (former Eastern European country). So, it wasn't that difficult to experiment with core geometry, different ways how to wind a transformer, to find an optimal ratio between core size and number of windings etc, and to get some valid knowledge about transformers that is not related to commercial restricions .

Now, after so many years - and in light of the current TVC craze - he decided to give TVC a try. To be more precise, he managed to persuade (after years (or decades) of trying) his friend who is a transformer builder (he has a small tube amp manufacture and he winds his own trannies) to wind him 2 trannies for his TVC.

Of course, such trannies had to be wound strictly according to his own beliefs. Two main ones are: 1) the first core geometry to be tried is the double-C 2) the trannies has to be big, if costs of production and materials allow - because the big trannies simply sounds better - have better dynamics and better frequency extremes, compared to any small tranny.

He is not downplaying the importance of materials used - especially permalloy, nickel or whatever - but he just has no access to cores made of anything but good old plain iron. I will check that out soon but I think that he is actually using old iron cores, left from different DIY project from long, long time ago. He is anxious to try the similar geometry (double-C) with better materials but I am afraid this will take time to find the ones he can afford. People don't have so much money here where he lives. R&D is based on different principles than in the West.

Finally, his technician finalized the first (and so far the only) version of a dual mono TVC, with double-C core trannies, with 2 cheap (but decent) German switchers with 9 position volume only and with 1 input and 1 output RCA stereo connectors worth of $1 (not sure if they are gold plated at all).

This was all assembled just to get a flavour of TVC sound so he can carry on developing, tweaking etc.

So what is the catch here, you are wondering?

Problem is that this Frankenstein of a TVC, worth of $50 in iron and copper plus costs of 6-days labour in winding and assembling, has no room to tweak.

It sounds like a $10,000 preamp. Or like a $20,000 preamp. Or $30,000 preamp. I don't know - I've never such an expensive one, but this really sounds like there is no room for sounding better.

There is nothing to add, nothing to complain, nothing to change, nothing to burn-in, nothing to wait.

After a month since it was completed, more than 25 really experienced audiophiles coming from various schools of audio (SET, FR, tube, digital, SS, whatever) heard it in a number of totally, dramatically different systems, with the similar conclusion whenever it was tested.

This ugly little monster is just leaving everyone speechless.

After long talks we have managed to persuede the owner/designer not to touch this piece anymore, just to leave it as it is and to build another one if he believes that anything else - different switches, wire, connectors, box, windings, trannies or whatever - can make a difference and improve its performance.

To be honest, the main scepticism is if he is capable of building another similar unit because he admits that he just wanted to give it a try to see if the TVC principle is something worth of developing or not.

He didn't involve any serious calculations into his project, no rocket science - just a few plain, old tricks of transformer winding old masters, known for almost a century.

But even him, being extremely critical of almost every audio product out there, including his own, agrees that he now doesn't hear a room for improving its performance.

I know that this sounds just like another audio fairytale (and therefore I will accept any doubt you may have), but I can only say that my only wish is to get this guy somehow make one of these for me, as the last preamp I will ever need in my house....

This is unfortunately not sure yet and it depends on how many of these old, double-C cores still lay somewhere, in a corner of someone's attic.

Anyway, if you are still reading this long post: one day, when S&B, Sowther or any of these big TVC companies finally commercially release a double-C core TVC tranny that will be advertised as "better than anything you have ever heard before", just remember when you read it first.

Why we will have to wait for so long, that's another question whose answer is probably similar to when you will get a mobile phone or digital camera or any consumer product that really has everything an advanced user might need. I don't know, but you will be able to buy "a better", "an advanced" or "an improved" product each year.