Solid State Class A Amplifier

[Pingushome]

Hi Both
Colin
Those seem intresting.
I was looking at the JLH for ESL on the website the PCBs are really simple and all fits in one box for each chanel. Maybee the boards from fleabay can be modded.


and this build is really cool especially the heatsinks


Philip
Yes agree but unfortunately my attempts at using pins/tags or vero board are abissmal they turn out like speghetti junction as my electronics skills are fairly low. Still sorting the Pre 2 CF
Martin

[colin.hepburn]

That’s the older version martin the newer design is the better amp which will fit most standard U4 19” rack type case

[pre65]

Originally Posted by Pingushome

Philip
Yes agree but unfortunately my attempts at using pins/tags or vero board are abissmal they turn out like speghetti junction as my electronics skills are fairly low. Still sorting the Pre 2 CF
Martin

I understand, but you can still use pins on a proper PCB.

[Pingushome]

Originally Posted by colin.hepburn

That’s the older version martin the newer design is the better amp which will fit most standard U4 19” rack type case

You got there before me Colin. I was going to say the PSU from fleabay (you posted the link) and the amp in one rack box. Big heat sinks down one side for the PSU and down the other for the amp....... nice boxs on the Italian site too... (2 Big Black and Silver Macho Boys Toys)
Now that improved circuit any PCBs?
I may have another project
Martin

[colin.hepburn]

Martin
Right that big double flange Conrad heat sinks are the ones you won’t you have two options’
Monoblock one amp and one psu on each heatsink I would not put both amps on one heatsink there is a lot of heat involved on these amp the |PCBs for that schematic are the ones in the eBay link I posted you can also buy a built kit of parts as well
http://www.ebay.co.uk/itm/2-X-JLH-1996-CLASS-A-AUDIO-POWER-AMPLIFIER-KIT-/160642260498?pt=US_Home_Audio_Amplifiers_Preamps&h ash=item2567065e12

PC 2005 PCB notes
http://members.shaw.ca/paul.r.brown/...%20Moss%20JLH/

[Pingushome]

Hi Colin, will order the PSU boards soon think I may give this a go.
The fleabay Amp PCB is different for the one on the "notes" website
http://www.world-designs.co.uk/forum...5&d=1357685317
but may look at getting a few of these made up if it is viable cost wise. Can you enlighten me to the difference between the 1996 (fleabay) and 2005 (JLH website) versions.
As to the enclosures yes it would be one amp/psu in one box, heatsink each side for each board.
Did you see the old JLH site (Hart)? They had an amp and a psu both built and mounted on big heatsinks then mounted back to back so the heatsinks formed to two sides of a box and then just mesh spacer added to make the "box" and a couple of "legs" added always liked that one.
Martin

[colin.hepburn]

Martin yes I remember the hart version
Ok as far as I am aware the green board were designed by geoff.moss the chap that is responsible for the redesign improvements to the amp this is the man who’s site you found for the jlh so the difference is his green boards have the output Transistors off board mounted on the heatsinks
the china boards are just more up to date with the transistors mounted through the board and mounted to the heatsink with the aluminium brackets I think the schematic is the same
Are you aware there is a 15 watt version and a headphone version of this amp? As well
This image is the green board populated
Are

[colin.hepburn]

Martin you have PM

[Pingushome]

Originally Posted by colin.hepburn

Martin you have PM

Thanks Colin I have done that. I'll let you know what happens.
Yes I am aware of the different amps. I have a Chiarra/Andante headphone amp and one of JLHs shunt feedback phono amps with its psu.
Incidentally I also have a fleabay Chinese version hpa and have just found out on diy audio forum that I should have used a couple of extra caps on the output (not really clear on that one yet) either one or two between board and phones socket or a dc servo. Apparently opinion is a bit divided as to how to use the caps or indeed how many. ooops
Martin

[colin.hepburn]

Martin I would be interested in any info you may still have on JLH phono stage I am sure I have the builders manual for it somewhere I got from Geoff was it for both MM/MC carts
Yes I have the manual for the Chiarra/Andante headphone amp I also have the china eBay one on Geoff’s site and this one