huh? best is elusive, but i gather that best to him could mean generous 2H, that is why he dislike SY's CCS tricks.....
to me "best" may mean the least number of parts....perhaps because i dislike complicated things....
perhaps OP can get inspiration from here....JE Labs Arkiv: JE Labs phono and line preamp
Some people evaluate the sound quality of audio gear by its' THD+N figure, disregarding other measured parameters and disregarding listening evaluations.
Some people evaluate the sound quality of audio gear by its' parts number count.
What I don't get is why some people are being intimidated by an approach different than theirs.
Likewise, I don't get why some people turn technical discussions and considerations into personal issues.
I let it be.
In the end, it's me and the music being reproduced in my living room – not what was written in a forum.
I have already a phono stage which is quite good-sounding and I enjoy listening to it.
Fair enough. That I understand.
Some people evaluate the sound quality of audio gear by its' THD+N figure, disregarding other measured parameters and disregarding listening evaluations.
Imaginary people, perhaps.
Hi,
Thank you.
D3a has lower anode resistance, which is an advantage when transformer loaded.
As for the difference in Cmiller, it isn't crucial in this application.
Also, I have no idea about EC8010 noise in the audio band and its' microphonics.
It may depend which coils you tried. LCR modules can be purchased from Thomas (Vynilsavor). I have a reason to assume they are accurate enough.
Thank you.
Compared to a D3A a Ec8010 is more lineair and specially the Cag is much lower, 1,5pF vs 2,7pF. But S and µ is better for a D3A.
D3a has lower anode resistance, which is an advantage when transformer loaded.
As for the difference in Cmiller, it isn't crucial in this application.
Also, I have no idea about EC8010 noise in the audio band and its' microphonics.
Btw, a lcr is a no go to me. You never get good enough chokes for this: low precision and variable with signal.
It may depend which coils you tried. LCR modules can be purchased from Thomas (Vynilsavor). I have a reason to assume they are accurate enough.
Imaginary people, perhaps.
Not at all imaginary people, I do no some such people.
Compared to a D3A a Ec8010 is more lineair and specially the Cag is much lower, 1,5pF vs 2,7pF.
Try measuring the EC8010. The datasheet is wildly incorrect. 4-5pF is closer to reality.
Hi!
I don't see how the EC8010 is more linear as the D3a as triode. See actual plate curves of the D3a here:
VinylSavor: Tube of the Month: The D3a
Especially for phono I see no issue with linearity at all.
I have not used the EC8010 much since I have plenty stock of EC8020.
Telefunken lists the amplification factor in the data sheet of the EC8010 with 'ca 60' which means about 60. For other tubes amplification factor is spec'ed as '=' and not 'ca'. I am sure there was a reason for this an the mu can deviate from ample to sample. So selecting tubes for equal mu between channels would be important.
Best regards
Thomas
I don't see how the EC8010 is more linear as the D3a as triode. See actual plate curves of the D3a here:
VinylSavor: Tube of the Month: The D3a
Especially for phono I see no issue with linearity at all.
I have not used the EC8010 much since I have plenty stock of EC8020.
Telefunken lists the amplification factor in the data sheet of the EC8010 with 'ca 60' which means about 60. For other tubes amplification factor is spec'ed as '=' and not 'ca'. I am sure there was a reason for this an the mu can deviate from ample to sample. So selecting tubes for equal mu between channels would be important.
Best regards
Thomas
Hi Salas,
Nikon D800 camera with Nikkor 105mm macro lens
Best regards
Thomas
What kind of photographic equipment you use for those shots Thomas?
Nikon D800 camera with Nikkor 105mm macro lens
Best regards
Thomas
Hi Salas,
transconductance measurements will not tell you the amplification factor. But you can match tubes with the tube tester first and then check the amplification factor in circuit and select tube pairs such that the gain of the preamp is the same in both channels.
Best regards
Thomas
transconductance measurements will not tell you the amplification factor. But you can match tubes with the tube tester first and then check the amplification factor in circuit and select tube pairs such that the gain of the preamp is the same in both channels.
Best regards
Thomas
Try measuring the EC8010. The datasheet is wildly incorrect. 4-5pF is closer to reality.
I have no reason to believe that they are incorrect.
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It dosnt matter who made the coils, they are always less good then any resistor or capacitor, just a matter of physics. If the coils have a core then all depends of the intitial permeability of the core material and this is very complex. If its an aircoil then the value of the coil is also not constant ( more leakage inductance and winding capacity)
Hi,
Thank you.
D3a has lower anode resistance, which is an advantage when transformer loaded.
As for the difference in Cmiller, it isn't crucial in this application.
Also, I have no idea about EC8010 noise in the audio band and its' microphonics.
It may depend which coils you tried. LCR modules can be purchased from Thomas (Vynilsavor). I have a reason to assume they are accurate enough.
Last edited:
Hi!
Yes you are measuring both mu and rp.
Those TV-7s are fairly crude when it comes to characterising a tube.
But as mentioned mu can be easily matched in the actual circuit and it should be double-checked there anyways.
Best regards
Thomas
If the tester has good tolerance for gm matching then μ should be derivable but rp differs too across those tubes? Mu = Gm x Rp
Yes you are measuring both mu and rp.
Those TV-7s are fairly crude when it comes to characterising a tube.
But as mentioned mu can be easily matched in the actual circuit and it should be double-checked there anyways.
Best regards
Thomas
I have no reason to believe that they are incorrect.
I do since I've done the measurement. Morgan Jones has done the same and gotten a similar number (see "Valve Amplifiers").
Maybe you are right but i remember that my EC8010 pre amp have much better frequency response then my ecc83 and ecc88.
Morgen Jones says (p560, 3th edition) that all bridge measurement equipment have problems so maybe we can trust no published data of all those tubes?
Anyway i don't think that the D3a is better, simulair problems.
Morgen Jones says (p560, 3th edition) that all bridge measurement equipment have problems so maybe we can trust no published data of all those tubes?
Anyway i don't think that the D3a is better, simulair problems.
I do since I've done the measurement. Morgan Jones has done the same and gotten a similar number (see "Valve Amplifiers").
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Morgen Jones says (p560, 3th edition) that all bridge measurement equipment have problems so maybe we can trust no published data of all those tubes?
Trust, but verify. He used a bridge, I used an RC time constant measurement. When two different methods give the same (or similar) answers, one can have a bit more confidence that the data are correct.
Hi Salas,
Nikon D800 camera with Nikkor 105mm macro lens
Best regards
Thomas
The esthetic qualities of photographs depend on the photographer, neither on the lens nor on the camera.
Your photography looks superb and professional.
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