Reference DIY amplifiers

[horus]

What do you say about making a list with reference DIY amplifiers?

I've seen lots of people that are searching for the "best" amplifier schematic. It would be useful for them(me included) to have a list with all of the DIY amplifiers that are the most popular around DIY builders and that can compete with high-end commercial ones.
A little review about it's design/overall sound would make the choosing easier.

[lineup]

Originally posted by horus
What do you say about making a list with reference DIY amplifiers?

A little review about it's design/overall sound would make the choosing easier.
.

the first amp that comes into my mind is:

Professor (in electronics) Leach amplifier ( or amplifiers, as he has got a couple of variants )
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Link, with description build instructions, schematic:
W. Marshall Leach, Jr., Professor
Georgia Institute of Technology
School of Electrical and Computer Engineering

http://users.ece.gatech.edu/~mleach/audiothings.html

.
# The Leach Amp Plans - The latest version of the Low TIM amplifier that I published long ago in Audio magazine.

# The Leach SuperAmp Plans - Plans for the Double Barrelled Amplifier that I published long ago in Audio magazine.

# Construct a Wide Bandwidth Preamp - An article I wrote for the Feb. '77 issue of Audio magazine that many people have asked me to post.
.

Review/Opinion:
I can not give a personal review. As I have not built one yet.
But there are many others at forum, THAT CAN!
Because there are 1.000 happy builders of Professor Leach amplifiers.


Regards
lineup
Lineup Audio
http://lineup.awardspace.com/




This image shows
one of his student's version of ' Low TIM Leach amplifier '.
Student Dan Leverett's amplifier:

[XEAGLEKEEPER]

Its a leach cage. You can watch the electrons do there thing.Is that muffin fan pretty quiet?Those look like SSR heatsinks.Real tidy layout , a must with see thru case! Would look real neat with one of those cold-cathode lighted fans.

[chipco3434]

You gotta figure that the "chip amps" would be in there somewhere.

Google "LM3886 chipamp" and you're bound to see twenty variants. Which one is the reference? I wouldn't hazard a guess or offer an opinion. Most all approach mathematical perfection from the standpoint of amplification and are very simple to build.

Then there's the Alephs from the master himself.

There will be many other suggestions... SKA, Class D Tripath based, Randy Sloan's designs. Too many to mention.

[Leolabs]

www.passdiy.com

[lineup]

Originally posted by chipco3434

You gotta figure that the "chip amps" would be in there somewhere.
.

No.
As we all know there are no chips in Leach Amp.

There is not even one MOSFET to find in Leach 'LowTIM' Amp.

TIM means TransInterModulation, and is a form of distortion
that is said to be more harmful to sound, as we hear it,
than for example THD, harmonics distortion.

Professor Leach Amplifier, is from beginning an attempt to design amplifier
with LOW such distortion.
And without measuring it myself, I have no doubt,
that these Leach amplifiers have lower TIM than most other amplifiers.
Otherwise, why publish such a failure.
And what I know, professors normally does not do this

About MOSFET.
Mr Leach explains why he did not use them in his amplifier at the time
he developed this amplifier.
He even performed tests with FET Output

Why not another configuration of output stage?
He answers some questions/suggestions he has got for alternatives output.
And explains why he stayed
using a rather common Triple Darlington arrangement.


New Year 2007
lineup
Lineup Audio Lab

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See my attachement for details of professor Leach power amplifier output stage.
The rest of a long story about a very good amplifier
and all the many details, you can read for free at:
The Leach Amplifier ( LowTIM )

* fotenote.
PMA ( Pavel Macura, another member here)
has suggested a new kind of test signal for audio amplifiers,
that shows more than only harmonic distortion.
Among this, I think, Intermodulation distortion within amplifiers.

[chipco3434]

I think you have mistaken my comments.

Chipamps are "in there" was meant to indicate that they would be present in "the reference list".

[horus]

How come you did forget the Krells? KSA 50&100
Krell KSA 50 pcb
Krell KSA 100mkII Clone

[fizzard]

The Leach Amp already mentioned is the de-facto solid state reference amplifier for the DIY community. Affordable to build, powerful enough to get a good party going, crystal clear sound, and robust.

[paulb]

http://sound.westhost.com/project3a.htm