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Old 14th October 2011, 04:24 PM   #11
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Notice: Due to a software glitch, this post by AndrewT is being reposted by me.

Post:

R1 & R28 don't work. The Vdrop with Iq=1.15mA is far too low.

C8 seems to interfere with audio quality.

R8 with Iq~100mA seems good, but R7 with Iq~1mA seems wrong.

Which part of this schematic is loosely based on BA-3?
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Old 14th October 2011, 06:05 PM   #12
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Default Specifications

This amplifier should meet the following specifications
1. Be pleasant to listen to
2. Effortlessly reproduce any material
3. Get as loud as the power supply will permit without getting unpleasant (within the limits of safe listening)
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Old 14th October 2011, 07:33 PM   #13
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Default buffer and power supply

This amplifier can be used with the suggested buffer here http://www.passdiy.com/pdf/B1%20Buffer%20Preamp.pdf or your favorite buffer. The suggested power supply is attached. But feel free to put in your own touch.
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Old 15th October 2011, 03:48 PM   #14
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Quote:
Originally Posted by OnAudio View Post
Here it is. Have fun.
Thanks!
I have spare pcb for symasym,
I think that I will use it to build your amp
of course with a few modifications, like reverse input transistors, etc...
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Old 20th October 2011, 12:01 AM   #15
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Quote:
Originally Posted by Cal Weldon View Post


Notice: Due to a software glitch, this post by AndrewT is being reposted by me.

Post:

R1 & R28 don't work. The Vdrop with Iq=1.15mA is far too low.

C8 seems to interfere with audio quality.

R8 with Iq~100mA seems good, but R7 with Iq~1mA seems wrong.

Which part of this schematic is loosely based on BA-3?
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regards Andrew T.
Hi Andrew T. did everything work out ?
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Old 21st October 2011, 08:22 PM   #16
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The amplifier can easily be adapted to use jfets for the input stage.
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Old 28th October 2011, 06:59 PM   #17
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Default pcb

Volunteer needed to do the pcb.
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Old 28th October 2011, 08:59 PM   #18
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Quote:
Originally Posted by OnAudio View Post
The amplifier can easily be adapted to use jfets for the input stage.
A Jfet and a cascode should be a good thing to add.

And I don't think Hafler or anyone can patent any of this... fortunately.
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Old 28th October 2011, 09:37 PM   #19
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Originally Posted by carlmart View Post
A Jfet and a cascode should be a good thing to add.

And I don't think Hafler or anyone can patent any of this... fortunately.
Thanks Carlmart,

The first part of the amplifier (Before VAS) can operate on lower rails lets say +-15V DC thus the cascode may not be necessary.

However I did not notice any advantage over the current design though I stand to be corrected.

Yes this maybe one flavor.
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Old 3rd November 2011, 05:32 AM   #20
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Default Alex

Hi Alex,

This is how the full amplifier looks.

Thanks.
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