Re-designing 6DJ8 circuit for the 6CG7

[lordearl]

About the 6DJ8 circuit it is very illdesigned with badly chosen component and voltage values.

Apart from R5/R10 being incorrectly placed, what other flaws do you see in the 6DJ8 design?

 

[Positron]

I am also curious revint.

Cheers.

 

[ruffrecords]

"would be completely inaudible" is making an assumption which is not supported by science. Jneutron and I have both reported such. Remember that a change in rise time will change the sound, regardless of the other components. When the overall rise time changes, the sound changes.

Cheers.

I did not say the rise time did not change. I did not say the sound would not change. I did say the change would be inaudible. Point me to some evidence that proves otherwise.

I did say that your effort would be better spent on the poorer bandwidth parts of the chain because changes there might well be audible.


Cheers

Ian

 

[Positron]

I did not say the rise time did not change. I did not say the sound would not change. I did say the change would be inaudible. Point me to some evidence that proves otherwise.

I did say that your effort would be better spent on the poorer bandwidth parts of the chain because changes there might well be audible.


Cheers

Ian

The science that Jneutron posted in the past (1982 study), and I have recently posted (Dr. Kunchur) was because the studies demonstrated the sound did change. It was perceived. We would not have posted otherwise. Note the quote of me in your post where I stated:

Remember that a change in rise time will change the sound, regardless of the other components.

Again neither I nor Jneutron would have posted if it was not actually perceived. That is what studies are for. Do you have any information besides opinion?

I understand your other point concerning the lower FR of the other components, and improving them.

Cheers.

 

[ruffrecords]

The science that Jneutron posted in the past (1982 study), and I have recently posted (Dr. Kunchur) was because the studies demonstrated the sound did change. It was perceived. We would not have posted otherwise. Note the quote of me in your post where I stated:



Again neither I nor Jneutron would have posted if it was not actually perceived. That is what studies are for. Do you have any information besides opinion?

I understand your other point concerning the lower FR of the other components, and improving them.

Cheers.

And I asked you to point me to some evidence. Where can I find the 'studies'?

Cheers

Ian

 

[DF96]

Given that all recordings will have been 'equalised' in the studio, how do we know whether 300kHz or 700kHz (or whatever) brings us closer or further away from the 'correct' sound?

What is the main effect of adding a 500kHz first-order LP filter to a 20kHz channel? A time delay of about 320ns (if my mental arithmetic is correct). So start your CD 320ns earlier.

 

[SY]

Most instruments are recorded using a microphone. Draw your own conclusions.

 

[DF96]

Didn't you do some tests which showed that a digital record-replay chain, with all its brick-wall filters, was inaudible when placed in an analogue feed?

 

[SY]

I've demonstrated that I can't hear it. And others have demonstrated that they can't hear it. No-one has demonstrated that they can. Draw your own conclusions.

This is very reminiscent of the discussions about ESP. After enough failures to refute the null hypothesis, anyone sensible can now place it in the category of "doesn't exist." Open-mindedness requires that one change that opinion if and when solid contrary evidence is presented, but it's not worth holding one's breath for, any more so than the "it's coming any day now!"evidence for the existence of Santa Claus.

 

[DF96]

But we know Santa Claus exists because he leaves presents. What more evidence do you need?

So let me get this straight: a pair of brick-wall filters (anti-alias, reconstruction) - presumably just above the audio range - are inaudible, yet a 500kHz-ish single pole filter might ruin the sound?

I know jneutron believes in the importance of tiny timing issues. I believe he is mistaken.

 

[TonyTecson]

i believe that SY and Positron had a debate on the subject a few years back.....i hope that doesn't happen again....

 

[soulmerchant]

6CG7 is a nice tube. You might try it as a cathode follower without the by pass, and a different power supply (preferably choke loaded using a mains transformer with higher B+). Also constant current sources and diodes will make it more interesting than mere resistors.