JLH 2003 Class A - how good is it?

I have a full sized cost no object build of a JLH69 with fully regulated PSU + PEH169 caps. Very nice and not to be underestimated into Klipsch Heritage speakers. Sounds so ’right’ and one of my favourite amps.

can‘t for the life of me see how those small Chinese copies could possibly function with those tiny heatsinks - unless they run the output transistors below spec. They need a large surface area.

Hi pesky_wabbit,

I fully agree - the components in built up or kit JLH amps are garbage.  I had posted a link to bare boards available on AliExpress - the ones I received were of high quality.

The quality of the components one populates the boards with, along with power transformer, casework, etc. be up to the individual constructor's requirements and budget...

My personal experience with the JLHs is, as you say - they sound 'right', especially in the midrange, but they can't play very low, due to the capacitive coupled speaker outputs.

Did you also try the 1996 / 2003 circuit variants?  If so, what was your experence with them?

Regards,

Ross

hi Ross, I only built the original, but it has a 300VA transformer, huge PEH169 psu caps, fully regulated +_ rails, and roedersteib gold output caps. I've never noticed any issues with the bottom end, but then I usually run it with pretty efficient speakers. The idea of modifying it has never really appealed as I have been pretty happy with it as is.

This is a kit that you need to complete it with other parts, so of course you need a transformer. And what included is not the full heat sink , it is a heat transfer piece to a full size heat sink. These kits are decent , feel free to replace any component as you like.