Hart "John Linsley Hood" KIT find....please help with identity/info!!
Came across these Kit Built (?) power amps....and...Oh Boy...the smell!!!
Now in a state of dissembly....each has 4 x Mosfet O/P transistors.
Initially...thought that they'd started life as Stereo Power amps, that had been converted to Mono-Blocks, but now realise this isn't the case.
They certainly are of different vintages, with variations to case cover/front panel.
What appears to be the younger of the two has gold plated binding posts.
Would love to find instruction manual that may have been with the kit, along with any circuit diagrams, and useful service info.
Although my skills are somewhat limited to assembly, (and cleaning) I have the help of a most competent tech, and intend to 'restore' these to drive my main L/R speakers......I understand that although these amps are old (25 to 35 years??)....they are still considered capable today??
So....over to any JLH nutcases out there....hopefully
Came across these Kit Built (?) power amps....and...Oh Boy...the smell!!!
Now in a state of dissembly....each has 4 x Mosfet O/P transistors.
Initially...thought that they'd started life as Stereo Power amps, that had been converted to Mono-Blocks, but now realise this isn't the case.
They certainly are of different vintages, with variations to case cover/front panel.
What appears to be the younger of the two has gold plated binding posts.
Would love to find instruction manual that may have been with the kit, along with any circuit diagrams, and useful service info.
Although my skills are somewhat limited to assembly, (and cleaning) I have the help of a most competent tech, and intend to 'restore' these to drive my main L/R speakers......I understand that although these amps are old (25 to 35 years??)....they are still considered capable today??
So....over to any JLH nutcases out there....hopefully
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Quite possible that the schematic is one of these: The Class-A Amplifier Site
but you'll have to do a bit of checking against the PCB to find it I think.
Edit: Looks like it is the "audio design" one - both schematics are there but no more information.
but you'll have to do a bit of checking against the PCB to find it I think.
Edit: Looks like it is the "audio design" one - both schematics are there but no more information.
Wonderful!!!... What is it please?
Is it possibly the Monoblock (K1100M) that's referred to halfway down the page here, left hand column :
https://www.americanradiohistory.co...ireless-World-1995-11-S-OCR-OCR-Page-0046.pdf
You might want to check out Rod Elliott's site;
The Class-A Amplifier Site
it has schematics for the amp and power supply;
http://sound-au.com/tcaas/ETI5-89.gif
http://sound-au.com/tcaas/ETI5-89a.gif
The Class-A Amplifier Site
it has schematics for the amp and power supply;
http://sound-au.com/tcaas/ETI5-89.gif
http://sound-au.com/tcaas/ETI5-89a.gif
It's the Linsley-Hood 80W Mosfet amp, published in ETI in 1989. IIRC there was an error in the PSU schematic that was published in the magazine but the Hart kit, which is what you have, had resolved this - just saying you might find a discrepancy.
It may be that the discrepancy is between the 1984 and 1989 articles.
Incidentally, John Linsley-Hood lived only a couple of miles away from me and was very gracious and helpful with my project and the visit I made to his home remains a great memory, mainly because of his help with the amplifier but also because of the way he lit his open coal fire with, essentially, a small flame thrower he had connected to the gas supply!
Incidentally, John Linsley-Hood lived only a couple of miles away from me and was very gracious and helpful with my project and the visit I made to his home remains a great memory, mainly because of his help with the amplifier but also because of the way he lit his open coal fire with, essentially, a small flame thrower he had connected to the gas supply!
It's definitely the Hart kit of the 80W Mosfet amp; the stereo version just had two amplifier boards stacked above each other - you can still see the mounting holes for the second amp board. It looks as though someone has just added another chassis/PSU - it might even have been an option Hart offered.
Another link;
A Paul Kemble web page - JLH mosfet amplifiers.
and here's a picture of the fully-equipped stereo kit;
I built mine without the bells and whistles, just a plain front with a passive ALPS volume control.
A Paul Kemble web page - JLH mosfet amplifiers.
and here's a picture of the fully-equipped stereo kit;
I built mine without the bells and whistles, just a plain front with a passive ALPS volume control.
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