Hi
Impressive waveshape pictures especially at 100KHz!
These must definitively be translated in good sound, don't they?
When I see something like this I can't help to drull over it and
I think that "one more amplifier" doesn't matter, I would like to
build it.
How do I go about to get the boards and how much do they cost?
Thanks for the info
Impressive waveshape pictures especially at 100KHz!
These must definitively be translated in good sound, don't they?
When I see something like this I can't help to drull over it and
I think that "one more amplifier" doesn't matter, I would like to
build it.
How do I go about to get the boards and how much do they cost?
Thanks for the info
Is there anybody built a non feedback amplifier?
Well, I recently built a non feedback preamplifier:
http://web.telecom.cz/macura/dispre.html
Well, I recently built a non feedback preamplifier:
http://web.telecom.cz/macura/dispre.html
Re: Is there anybody built a non feedback amplifier?
I have simulated your project on the base of a sketch that you proposed some time ago in the forum,
but there was high order harmonics in it.
Probably that I only guessed the part values?
Anyway I like NGFB designs and I am impressed of your design (not only this).
PMA said:
I have simulated your project on the base of a sketch that you proposed some time ago in the forum,
but there was high order harmonics in it.
Probably that I only guessed the part values?
Anyway I like NGFB designs and I am impressed of your design (not only this).
Re: Re: Is there anybody built a non feedback amplifier?
Behaviour of circuit like this greatly depends on component values, as this is the only way how to determine operating points.
Anyway, you can see images of noise floor and distortion, both measured in a real preamplifier, not simulated. 0 dB corresponds to 1Vrms. Polish and Czech languages are similar, I believe you can find it in the page.
I will probably discover component values later, but still need some time for evaluation and possible tuning.
The output diamond buffer is heavily biased, its Iq = 20 mA. Output resistors of the diamond buffer are 2.7 Ohm.
padamiecki said:
Behaviour of circuit like this greatly depends on component values, as this is the only way how to determine operating points.
Anyway, you can see images of noise floor and distortion, both measured in a real preamplifier, not simulated. 0 dB corresponds to 1Vrms. Polish and Czech languages are similar, I believe you can find it in the page.
I will probably discover component values later, but still need some time for evaluation and possible tuning.
The output diamond buffer is heavily biased, its Iq = 20 mA. Output resistors of the diamond buffer are 2.7 Ohm.
Re: Re: Re: Is there anybody built a non feedback amplifier?
I got 0VDC at the output (DC coupled) but the gain was at about 1.
indeed, I understood all!
Why you did not decided to DC coupled? Are you afraid about the drift or unstability during switching on?
your PCB is b e a u t i f u l l ! ! !
PMA said:
I got 0VDC at the output (DC coupled) but the gain was at about 1.
PMA said:
indeed, I understood all!
Why you did not decided to DC coupled? Are you afraid about the drift or unstability during switching on?
your PCB is b e a u t i f u l l ! ! !
Re: Re: Re: Re: Is there anybody built a non feedback amplifier?
Well - gain is about 12 dB, and can be set up to some 26 dB and more.
Try R4 = R7 = 4.7k
R11 = R12 = 200 Ohm
R13 = 4.7k
R8 + R9 = 2.4 k approx (this sets gain)
R38 + R42 = 1.97k approx, this sets DC
The DC drifts a little bit, but not that bad. Anyway output cap protects from it.
Regarding PCB - my job is design of electronic instruments, so this is a standard solution.
padamiecki said:
Well - gain is about 12 dB, and can be set up to some 26 dB and more.
Try R4 = R7 = 4.7k
R11 = R12 = 200 Ohm
R13 = 4.7k
R8 + R9 = 2.4 k approx (this sets gain)
R38 + R42 = 1.97k approx, this sets DC
The DC drifts a little bit, but not that bad. Anyway output cap protects from it.
Regarding PCB - my job is design of electronic instruments, so this is a standard solution.
Jareck
Thanks for the answer.
Actually I was intrigued by
" ³a³
Man
what a lovely PCB!
have you got some spare to sell? need for the stereo version. "
__________________
regards, padamiecki
because I couldn't see any layout before that posting.
It would be good to hear what you have to say about the
sound after your listening experience.
Let's wait for that.
Thanks for the answer.
Actually I was intrigued by
" ³a³
Man
what a lovely PCB!
have you got some spare to sell? need for the stereo version. "
__________________
regards, padamiecki
because I couldn't see any layout before that posting.
It would be good to hear what you have to say about the
sound after your listening experience.
Let's wait for that.
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