TVC Linestage (BD-Design)
Hi,
The TVC has I think S&B transformers which come with this warning:
The input to the TX-102 must be COMPLETELY free of DC offset; the presence of DC current materially degrades the performance of the TX-102 Transformer, both with respect to level handling and frequency response.
Has anyone experienced this degraded performance from using a dc coupled source?
Also, the output impedance of the Twindacplus! is 2.5k ohm and the TX-102 suggests a number closer to 60 ohms. Has anyone noticed any bass roll-off due to this?
Cheers,
Brian
TVC Linestage
Hi Brian,
With a normal designed DC coupled system the DC voltage will be very low and therefore not much of a problem. The high total impedance with some DC mV will only give very little current (nA).
Don't connect a tube pre-amplifer without output capacitor, then it won't work too well I guess... 
Also, the output impedance of the Twindacplus! is 2.5k ohm and the TX-102
suggests a number closer to 60 ohms. Has anyone noticed any bass roll-off
due to this?
The load on the other end dictates the load on the input. The higher the input impedance of your amplifier the higher maximal output impedance is needed on the input of the TVC. A tube amp with minimal 50k input (better would be 100k) will not be any problem for the 2.5k ohm.
Ciao,
Bert
TVC Linestage
Thanks Bert,
The load on the other end dictates the load on the input. The higher the
input impedance of your amplifier the higher maximal output impedance is
needed on the input of the TVC. A tube amp with minimal 50k input (better
would be 100k) will not be any problem for the 2.5k ohm.
The input Z of the power amp I'm considering is 100k.
Another thought, does the TVC convert single ended inputs to balanced output?
Cheers,
Brian
TVC Linestage
Another thought, does the TVC convert single ended inputs to balanced
output?Cheers,
Brian
Hi there, are the Brian from Basingstoke that came to see me and my Oris system? If so hi, and I'm pleased you made the move!
I obviously didn't put you off then!
Kind regards,
Jonathan
TVC Linestage
Another thought, does the TVC convert single ended inputs to balanced
output?
Sorry I also meant to comment on your notes regarding the S&B TX102's!
The answer to this one is yes, transformers are one way to achieve balanced connections. The S&B TVC is just a transformer, albeit with a lot of different taps on it!
With regards to the TwinDAC and bass roll-off: I think you could be right on this one, as the TwinDAC was noticably lighter in the bass than my valve output stage with its lower output impedance. I think the +6db tap on the S&B' probably helped somewhat though?
Regards,
Jonathan
TVC Linestage
With regards to the TwinDAC and bass roll-off: I think you could be right
on this one, as the TwinDAC was noticably lighter in the bass than my
valve output stage with its lower output impedance. I think the +6db tap
on the S&B' probably helped somewhat though?
Thanks Jonathan,
I am the one, you should ask Bert for your commission :P
I was looking at the S&B site and I think the +6db helps level but with it comes a reduced BW, more significant at the bass end. With a typ 0.4v average voltage from the Twindac+ the input sensitivity of the power amp must be around 0.4v me thinks?
Cheers,
Brian
PS have you built the new amp yet, the one without o/p transformers?
TVC Linestage
Hi Brian,
Since a few months I am listening to another two-stage 300B SET amplifier which is not as tight in the bass and a little bit less dynamic as the BP but in the mid and high frequencies its so smooth and clean sounding. The input sensitivity is also high enough to play my Oris system to extreme loud levels (+6dB on the Django not needed in combination with the TwinDAC+).
At this moment I prefer to listen to that amp more than to the 300B BP.
http://www.diyhifisupply.com/diyhs_ladyday.htm
Don't forget to tell them that I send you there though...
Ciao,
Bert
TVC Linestage
Hi Bert,
Which LadyD version you listening to? Seem there is so much option for that amp...
Little off topic, which AER driver that optimize for singular?
Thanks
Hi Brian,
Since a few months I am listening to another two-stage 300B SET amplifier
which is not as tight in the bass and a little bit less dynamic as the BP
but in the mid and high frequencies its so smooth and clean sounding. The
input sensitivity is also high enough to play my Oris system to extreme
loud levels (+6dB on the Django not needed in combination with the
TwinDAC+).At this moment I prefer to listen to that amp more than to the 300B BP.
http://www.diyhifisupply.com/diyhs_ladyday.htm
Don't forget to tell them that I send you there though...
Ciao,
Bert