Well in the early days I did ask about sinking of the 4ma of current but that time you hadn't have a trafo that was suited.
Right now I use about 9 Ohms seen by DAC (reflected from the secondary), but I do not see any significant impact to the sound with 20 Ohms too in terms of noise floor. Decreasing of the i/v impedance is more actual for me in terms of downward expansion of the frequency band than fighting with the noise floor. But the output voltage swing is lowering too of course. I did some measurement half a year previously, I can searching if needed...
Probably a year and a half has passed since your question ...
But I do not see competitors for 1541A within dozens of modern DACs for my ear, that's why I do not see another way but to digging in its direction.
... thanks for the input, so buffer mandatory I assume as a follower. I quite like my TDA direct coupled while I have no experience with tubes, I assume to a point, at ther serie output, film cap or outputt trafo is near from a personal preference. But never tried traffo with I/V, never heard good things in the past with all the experimentation with it VS best tube I/V stage or transconductance silicon based without feedback.
Have to try one day, all the testimonials I read here recently make me fear about the layout I saw... so I took it with a grain of salt.
Have to try one day, all the testimonials I read here recently make me fear about the layout I saw... so I took it with a grain of salt.
41A is a weak enough DAC compared to modern chips. My target is -3dB at 3-4Hz on LF (HF not a problem) so that is why I can get 0.2Vrms only from a single 41A after trafos (I do not like the sound of paralleled/differential modes, so I do not want to bettering in this way). Or 0.6Vrms at -2.5dB@20Hz, and so on. Of course the output after SUT will be high impedanced and it depends from the next stage what to do with it. To use the Current Follower or not, to amplify both current and voltage on tubes or not is up to user. Say if someone's amplification (next) stage is a regular tube amp with its highgly impedanced input, then what's a problem?.. Even 10k of the trafos output can be succesfully connected to 100k (x10 times rule is satisfied) input of such amplifier (500K input is not unusual as well). There will be some requirements for interconnection cables in terms of capacitance, but possible way.
But yes, I prefer to use a current buffer on jfets after trafos as my tube amp input impedance plays better at 300 Ohm (300R Volume control).
I have tried many other i/v stages as the sound is the target for me. Despite my trafos, much interested was the i/v stage from Abbas, he uses i/v on germanium transistors+tubes (all from the Babylon era). You can find a short report-compoarison in my thread if interested.
Thanks.
But yes, I prefer to use a current buffer on jfets after trafos as my tube amp input impedance plays better at 300 Ohm (300R Volume control).
I have tried many other i/v stages as the sound is the target for me. Despite my trafos, much interested was the i/v stage from Abbas, he uses i/v on germanium transistors+tubes (all from the Babylon era). You can find a short report-compoarison in my thread if interested.
Thanks.
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Hi,
Is it a compromise with loading the transformer heavily like that?.
Compared with resistor across 1541A output and essentially unloaded transformer secondary (if you want, easy), despite higher noise and theoretical distortion levels (which are reportedly benign under test AMR/TL).
Would be interesting to compare.
Thanks.
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mu for 80-100 is to be where? At 16-20 Vrms? Don't you forget we talking about DAC, not about the whole system including power amplifier and loudspeaker driving?
Trafos/buf/trafos/buf is the best way I see anyway if to talk about the whole path from source to loudspeakers.
I understand your question. I hear that the material of the low valued resistor across the primary has more negative impact on SQ than the loaded trafo
mu for 80-100 is to be where? At 16-20 Vrms? Don't you forget we talking about DAC, not about the whole system including power amplifier and loudspeaker driving?
Trafos/buf/trafos/buf is the best way I see anyway if to talk about the whole path from source to loudspeakers.
Hahaha my bad Bisesek must have caught brain fart. lol
What's the output impedance like ?
Yes Abbas is also a different thinking & approach got me curious when I first saw it on Ebay.
Thank you for sharing. What finally did you prefer as a buffer follower with that please ? (knowing all is relative to what is seen in the next stage : preamp or amp).
Germanium is odd to me as I/V with Abbasz when you see goo transconductance non feed back chip like the opa 861or sorted out diamonds (same guy: P Rogic), than can be quiet in a good layout and only 5V, but well I have no idea, it's above my head...
If you can, try to find a late non crown iteration of the TDA1541A (SouthAsia made), it's a good animal too, same qualities but with more everything like the pcm56 .
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What do you mean by South Asia made Diyiggy ? lol. They were only produced in Taiwan.
As for the CD Pro transport Singapore. Btw I also tested 1 Holland made 41a on Aya, don't sound too bad either.
Yes like I mention to you before & just like Bisesik says nothing sounds better then using trafos.
As for the CD Pro transport Singapore. Btw I also tested 1 Holland made 41a on Aya, don't sound too bad either.
Yes like I mention to you before & just like Bisesik says nothing sounds better then using trafos.
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I beleived some where made Korea or Vietnam plants too with no area marking ?
Nah you said me OT instead cap DC blocking or no cap DC blocking, not traffo in I/V, at least my understanding ! Am I wrong ????
I quite like my dirsct coupling with the next discrete stage I have on my pre, which has an antic very good polarized Nichicon or Elna which are not he usual ones wee see today. Ok the pre is 30 yo, it means it should have a terific esr now, but match well with my low 1V5 outputt on the aya iirc (1K Rhopoint as I/V)
Nah you said me OT instead cap DC blocking or no cap DC blocking, not traffo in I/V, at least my understanding ! Am I wrong ????
I quite like my dirsct coupling with the next discrete stage I have on my pre, which has an antic very good polarized Nichicon or Elna which are not he usual ones wee see today. Ok the pre is 30 yo, it means it should have a terific esr now, but match well with my low 1V5 outputt on the aya iirc (1K Rhopoint as I/V)
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Right now I use a matched pairs of 170V/74V jfets. I suppose some tubes in the current follower mode can do the job better, but proper PSUs for tubes is just another story I am not ready now at least.
Thanks for tip!