JLH solid state 10W class A amp

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pre65
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JLH solid state 10W class A amp

Post by pre65 » Thu Jul 26, 2012 2:42 pm

As an alternative to the "Naimish" amp thread, what about the designs of John Linsley Hood, particularly his 10W (later versions 15W) class A transistor amp ?

Typically there is an e-bay option. :wink:

http://www.ebay.co.uk/itm/SC-HOOD-JLH-1 ... 2308wt_699
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colin.hepburn
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Re: JLH solid state 10W class A amp

Post by colin.hepburn » Thu Jul 26, 2012 3:47 pm

pre65 wrote:As an alternative to the "Naimish" amp thread, what about the designs of John Linsley Hood, particularly his 10W (later versions 15W) class A transistor amp ?

Typically there is an e-bay option. :wink:

http://www.ebay.co.uk/itm/SC-HOOD-JLH-1 ... 2308wt_699
A very popular Amp over the net this one here’s the site for the JLH amps plus PSUs
http://www.tcaas.btinternet.co.uk/index-1.htm
And a Nelson Pass mosfet Version
http://6moons.com/industryfeatures/zen/plh.pdf
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Paul Barker
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Post by Paul Barker » Thu Jul 26, 2012 6:08 pm

Good call.

I'm just waiting now for the inverted gainclone and the tpath amp to rear their heads one more time.

For me the latter two are both well and truly history compared to the pass amps.

Did anyone ever build that amplifier which consisted of a 317 regulator? It may be a gem. someone should check it out.
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Mike H
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Post by Mike H » Sat Jul 28, 2012 12:32 pm

This is interesting, some years ago now an 'old' Maplin workmate was going to make a JLH one, he started telling me about it, then he moved and I couldn't get in contact again :(

Also interesting is how closely it resembles an old germainium amp topology (whose name I can't remember), from when they stopped using transformer phase-splitters. It weren't class A though, germaniums can't handle that :D

Ergo more caps were involved to reorganize the DC biasing and arrange class B operation, which made it rather more messy TBH.
 
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Mike H
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Post by Mike H » Sat Jul 28, 2012 12:49 pm

Found it :D
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A15 amplifier.gif
 
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