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The Most Symmetrical CLASS A Amp I've ever made
The Most Symmetrical CLASS A Amp I've ever made
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Old 15th September 2010, 10:19 AM   #1
lineup is offline lineup  Sweden
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Location: the north
Smile The Most Symmetrical CLASS A Amp I've ever made

Symmetry is beautiful!

This is perhaps the most symmetrical amplifier I have ever made.
It is so symmetrical I have sometimes hard to see what side it is.

It should be regarded hifi, as THD is low.
It is Class A, max output more than 100 mA
It is Buffer. No gain.
No feedback. Pure follower.
Can be used for any line level hifi buffering.
This version shown is for 32 Ohm Headphone.
This version uses Output Caps.
There is a version 2 where you remove output caps and add a trimpot.

Nice feature is you need only common component:
7 x BC550C
7 x BC560C
+12V 3-pin regulator
-12V 3-pin regulator

a few resistors + a few caps + small trafo 2x12VAC

Those caps C1, C6, 470p makes the amplifier roll off nicely at 20 MHz.
Into 32 Ohm it put out well above 100 mW RMS

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Old 15th September 2010, 11:16 AM   #2
Workhorse is offline Workhorse
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Default I love symmetry

I like your symmetric designs Lineup......
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Old 15th September 2010, 11:23 AM   #3
jam is offline jam  United States
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Location: Auburn, CA, USA
Hi lineup,

Good looking design.

Have you tried replacing R1 and R11 with current sources.
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