I like 7 pins because 2SK389 and 2SK109 devices have 7 pins. Also some well shielded transformers.
The important question here has been how to make a balanced/unbalanced input without too much compromise. Some would like to use cheap IC's and think nothing of it. Others would like to use better IC's, but I have already tried that route, and it fell short with my amp design. Still others would like to use a transformer, and that, at least, makes some sense, but it is too expensive for Parasound to try.
If anyone has any serious input beyond this, I would hope that they would contribute.
Please avoid cheap and dirty solutions, if possible.
The important question here has been how to make a balanced/unbalanced input without too much compromise. Some would like to use cheap IC's and think nothing of it. Others would like to use better IC's, but I have already tried that route, and it fell short with my amp design. Still others would like to use a transformer, and that, at least, makes some sense, but it is too expensive for Parasound to try.
If anyone has any serious input beyond this, I would hope that they would contribute.
Please avoid cheap and dirty solutions, if possible.
john curl said:
Hi John,
What about this. I've tried to find a solution that's more in line with your philosophy. All jfets, no IC's. But it has a price: the distortion is not as low as I would like, although it's almost 2nd harmonic.
As you see, I've adopted your jfet buffer idea, but made it complementary. Now THD is ten times lower.
For single ended input however, I'd prefer to bypass the buffers.
Cheers,
Edmond.
edit: I've opted for a dual servo op-amp, because of symmetry and only one large integrator cap instead of two.
@Bonsai: as you see I've changed my mind.
Attachments
edmond, good approach to John Curl enquiery.
Personally, me lineup, one very experienced Audio thinker,
I would not bother my self to reinvent the wheel.
I would use some smart guys' already IC packaged solution.
Because I am born smart & not born stubborn enough
to think I can do anything better than other can.
(who was I thinking of .. hmmm .. no comments)
It is some times about to TRUST the work of the other fellows.
If you can have any trust at all in any of your fellow humans ...
Maybe some of world's best & leading
Balanced Line Receiver ICs
But evenso,
Analog Devices (the home of AD797) are very good at this.
As is Burr-Brown.
SSM2143 & DRV134
... and the likes.
Regards
Lineup Super IC recommendations & High Fidelity Audio Amplifiers
Personally, me lineup, one very experienced Audio thinker,I would not bother my self to reinvent the wheel.
I would use some smart guys' already IC packaged solution.
Because I am born smart & not born stubborn enough
to think I can do anything better than other can.
(who was I thinking of .. hmmm .. no comments)
It is some times about to TRUST the work of the other fellows.
If you can have any trust at all in any of your fellow humans ...
Maybe some of world's best & leading
Balanced Line Receiver ICs
But evenso,
Analog Devices (the home of AD797) are very good at this.
As is Burr-Brown.
SSM2143 & DRV134
... and the likes.
Regards
Lineup Super IC recommendations & High Fidelity Audio Amplifiers
Hi David,
Surprised? You know I like to do it differently
The tolerance of the resistors is not critical. Even 5% will do, although the offset voltage will be a bit higher. However, the servo will adjust that error. Nevertheless, I recommend !%.
Indeed, the harmonics are canceled, but not completely.
Cheers,
Edmond.
Surprised? You know I like to do it differently
The tolerance of the resistors is not critical. Even 5% will do, although the offset voltage will be a bit higher. However, the servo will adjust that error. Nevertheless, I recommend !%.
Indeed, the harmonics are canceled, but not completely.
Cheers,
Edmond.
hm...Sigurd Ruschkow said:
http://www.diyaudio.com/forums/showthread.php?postid=1608229#post1608229
This one works
- Status
- Not open for further replies.