Hello,
I've been very interested in wiring up a TVC like the S&B TX-102 or the Dan Slagle AVC, but I'm concerned about comments I've been seeing about a slight lack of drive and impact using these units unaided (since they are passive).
I'm going to try the TVC by itself first, of course, to see if I notice this effect. But if I do, would adding a buffer help out? I realize there will be other trade-offs by adding an active stage.
Also, if I do add a buffer, is there a general consensus as to which is preferable: before or after the TVC?
Thanks,
KT
I've been very interested in wiring up a TVC like the S&B TX-102 or the Dan Slagle AVC, but I'm concerned about comments I've been seeing about a slight lack of drive and impact using these units unaided (since they are passive).
I'm going to try the TVC by itself first, of course, to see if I notice this effect. But if I do, would adding a buffer help out? I realize there will be other trade-offs by adding an active stage.
Also, if I do add a buffer, is there a general consensus as to which is preferable: before or after the TVC?
Thanks,
KT
Hi KT:
I had a chance to listen to both the S&B and Sowther TVC and must say I could not hear any drive-related irregularities. IMO, such problems occur when the source has a high output impedance. So, when using a buffer, it should be placed before the TVC. The TVC, unlike other passive attenuators, does not exhibit any issues relating to output impedance.
In case you're interested, I have designed an autotransformer volume control, which I am currently using in my system. I tried the version with and without the buffer (ECC86-based) and did not notice any significant differences (nor did my friends). You may check out the TVCs at my web site.
Regards,
Milan
I had a chance to listen to both the S&B and Sowther TVC and must say I could not hear any drive-related irregularities. IMO, such problems occur when the source has a high output impedance. So, when using a buffer, it should be placed before the TVC. The TVC, unlike other passive attenuators, does not exhibit any issues relating to output impedance.
In case you're interested, I have designed an autotransformer volume control, which I am currently using in my system. I tried the version with and without the buffer (ECC86-based) and did not notice any significant differences (nor did my friends). You may check out the TVCs at my web site.
Regards,
Milan
Hi wilbur-x:
It's not so difficult to wind an ATVC. All you need is time and patience, and perhaps a good quality transformer core. If you have a couple of old transformer laying around that you can use for building your own ATVC, you can send me a picture and their dimensions and I'll do the calculations for you.
Regards,
Milan
It's not so difficult to wind an ATVC. All you need is time and patience, and perhaps a good quality transformer core. If you have a couple of old transformer laying around that you can use for building your own ATVC, you can send me a picture and their dimensions and I'll do the calculations for you.
Regards,
Milan
I finally finilized my Integrated amp with TVC front end and can definitely state that it sounds better without a buffer in front. As and integrated solution, it also does not seem to need a buffer behind.
As a source, I was using my NOS DAC with passive I/V and 0.1uF coupling caps. I tried it with a buffer and I was loosing immediacy and adding coloration.
The buffer, OTOH, worked very well with a resistor devider based volume control in front of the same amp.
As a source, I was using my NOS DAC with passive I/V and 0.1uF coupling caps. I tried it with a buffer and I was loosing immediacy and adding coloration.
The buffer, OTOH, worked very well with a resistor devider based volume control in front of the same amp.
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