Listening results of the three diffrential tube configs
Dear all,
Following up here with the listening results.
At the DAC four outputs I placed RCRC (10k/220p/10k/470p) filters which do a very good job at suppressing the rubbish coming out (see pic).
Unfortunately I was not able to make accurate measurements because the test CD I use with a 1KHz signal was burnt on my PC and the CD player does not like it, meaning that I hear a lot of noise.
So here are the listening results:
SRPP and Grounded Cathode
However, I admit I am rather disappointed because I was expecting a wow effect by using tubes vs. good opamps. There is indeed an improvement but not so much to really get me excited.
Has anybody any further idea on how to improve?
Thanks again,
Fabrizio
Dear all,
Following up here with the listening results.
At the DAC four outputs I placed RCRC (10k/220p/10k/470p) filters which do a very good job at suppressing the rubbish coming out (see pic).
Unfortunately I was not able to make accurate measurements because the test CD I use with a 1KHz signal was burnt on my PC and the CD player does not like it, meaning that I hear a lot of noise.
So here are the listening results:
SRPP and Grounded Cathode
Nice sound, warmer and slightly bigger stage than with Burson. A bit too much amplification (but no distortion) will require an L pad attenuator at the output, before RCA...unless there's a different way to reduce gain. I did not notice any difference between SRPP and Grounded Cathode
Broskie Cathode Follower
Flat, cold sound. Did not like it
So, unless there's something else I can try, I have a winner which eliminates the need for the (very good!) Burson opamps.
However, I admit I am rather disappointed because I was expecting a wow effect by using tubes vs. good opamps. There is indeed an improvement but not so much to really get me excited.
Has anybody any further idea on how to improve?
Thanks again,
Fabrizio
Attachments
Oh, not at all. Referring to the first three differential schematics I proposed on #12 I prefer the first two, which receive filtered signals from the DAC (see above #22)
I am now considering trying a White Cathode Follower. Any experience with that?
Just replacing opamp for tubes are no garantee for nicer sound.
You need often a long path of trail and error. Say 30 years.
My personal experience is that i like the pcm1794/2 dac most with no filtering just SE 6n6p srpp stage with 200v CLC filtered anode supply and DC C filtered heater. With spraque oil output capacitor.
You need often a long path of trail and error. Say 30 years.
My personal experience is that i like the pcm1794/2 dac most with no filtering just SE 6n6p srpp stage with 200v CLC filtered anode supply and DC C filtered heater. With spraque oil output capacitor.
Dear Breezio, inspired by "Lampizator old website" I have "lampized" a Sony cdp 227esd cd player. It has 2 TDA1541 DACs. The result was far above expectations. I still have a Sony cdp xa5es and a Sony cdp xa50es but the lampized 227esd sounds much, much better than these on my audio system. That's why I recommend you to look for "lampization" cd player with TDA 1541. You will be delighted.
Thanks Vidax, my goal for now is to make the best out of my current AMC CD9 on which I already made several other modifications (rectifier diodes, clock, low nois DC supplies, caps..)
Ha! 30 years...by then we might get nanotubes directly implanted in our ears ;-)
Anyway, I want to try a few more things. For instance, do you remember the values of your CLC filter's components?
One more configuration will also be an anode follower as depicted on #4, however with differential inputs as in the grounded cathode on #12
+1
tda 1540 and tda 1541 is for me,the best chip all over the world for tweak and mods .
Gain control (reduction) for differential SRPP
So I did some more tests and here is the final brief recap
Now the final question is, how can I reduce the differential SRPP gain, without adding attenuator L pads at the four inputs?
Thanks again,
Fabrizio
So I did some more tests and here is the final brief recap
- Differential ground-cathode (slightly better audio performance than Burson)
- Differential SRPP (slightly better audio performance than Burson)
- Broskie cathode follower (not as good as Burson)
- Differential anode plate follower - on two different bias points (on par with Burson)
- Differential anode plate follower + cathode follower (on par with Burson)
Now the final question is, how can I reduce the differential SRPP gain, without adding attenuator L pads at the four inputs?
Thanks again,
Fabrizio
Attachments
Last edited:
Nice journey your on. Hope you get the last few bumps ironed out.
At some time I would like to hear a tubemodded player to see if I need to build one. I however have some special desires for it to really suit me. First of all Ive missed the numerical buttons for choosing a song, ever sincethey got out of fashion. Also I have a few CDs with the blue HDCD-dot on them that i really enjoy, and they sound off to me on non-hdcd players. Does any of the contributors know of such a player with a nice-sounding dac? Cheers!
At some time I would like to hear a tubemodded player to see if I need to build one. I however have some special desires for it to really suit me. First of all Ive missed the numerical buttons for choosing a song, ever sincethey got out of fashion. Also I have a few CDs with the blue HDCD-dot on them that i really enjoy, and they sound off to me on non-hdcd players. Does any of the contributors know of such a player with a nice-sounding dac? Cheers!
Hi Guerrilla,
I suggest you go through the old Lampizator website.
Lots of information and very enjoyable reading. Although he wrote 10+ years ago, most of the content is still relevant since technological evolution is relatively slow in this field.
Another reference for me is John Broskie, for more advanced tube configurations.
Enjoy!
I suggest you go through the old Lampizator website.
Lots of information and very enjoyable reading. Although he wrote 10+ years ago, most of the content is still relevant since technological evolution is relatively slow in this field.
Another reference for me is John Broskie, for more advanced tube configurations.
Enjoy!
The voltage gain of the left circuit is -mu/2. Not much you can do about that
except use a lower mu tube because of the symmetry. See page 464 here:
http://www.nj7p.org/Manuals/PDFs/Books/MIT-Radiation-Lab-Series-V18-Radar-Engineering.pdf
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.