help understand a tvc

[jarthel]

1. any link on understanding how tvc works? do they have an impedance like resistive attenuators? I somehow got the feeling that tvcs can only be used with stereo stepped attenuator?

I have read s&b's info on tx102 but it seems to me that most of info is specific to tx102. I am buying a different tvc.

2. I somehow read here or in AA that tvc might not be suitable for some circuits. but I have read years ago and I cannot find the thread again.

thanks for the help

[Netlist]

Now I'm clueless.
What's a tvc, s&b and tx102? I could be me of course.

I know AA.

/Hugo

[jacco vermeulen]

Transformer Volume Control

www.stevens-billington.co.uk/page102.htm

[Netlist]

/Hugo

[clem_o]

jarthel,

It's just a transformer. with a large number of taps. All limitations, constraints etc apply to it just like your ordinary transformer, except this is much wider-band, compared to the run of the mill stuff that works pretty much at 50-60Hz.

It is an impedance transformer, the transformation is sqrt(N1/N2), N1 and N2 are the number of turns in the primary and secondary (uh, from memory);

And yes, since you're tapping at different points, then the impedance changes too.

suitability - depends on the impedance of the driving circuit, and what the transformer is going to drive...

Cheers!

[jarthel]

Originally posted by clem_o
jarthel,

It's just a transformer. with a large number of taps. All limitations, constraints etc apply to it just like your ordinary transformer, except this is much wider-band, compared to the run of the mill stuff that works pretty much at 50-60Hz.

It is an impedance transformer, the transformation is sqrt(N1/N2), N1 and N2 are the number of turns in the primary and secondary (uh, from memory);

And yes, since you're tapping at different points, then the impedance changes too.

suitability - depends on the impedance of the driving circuit, and what the transformer is going to drive...

Cheers!

I guess I need to get more info on the transformer. all i know it that it's a tvc :|

thanks clem (feels odd calling you that way since i've always call you sir)

[lineup]

One distinguished member
and very clever audio designer
that likes them Transformer Based Volume Controls, TVC, is Thorsten Loesch.
This was his choice because of quality!

He is the very same man that is much responsable
for the whole Gainclone Chip Amps thing.
Even if this was certainly not his purpose when publishing an inverted LM3875 schematic.

You can find more info about his TVC
by doing this google search:
TVC Torsten Loesch

Here is a picture how such looks in Stereo version:
http://www.theanalogdept.com/images/.../TVCLayout.jpg


lineup
has not tested TVC yet

[NickC]

to find out more about tvc
http://www.promitheusaudio.com/tvcfaq.htm

Best regards
nicholas

[clem_o]

Originally posted by jarthel


I guess I need to get more info on the transformer. all i know it that it's a tvc :|

thanks clem (feels odd calling you that way since i've always call you sir)

You've already graduated, so get used to it! :-)

Seems you got lots of links from the slew of very helpful members - happy reading!

Cheers

Clem