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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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18th Apr 2021, 8:36 pm | #1 |
Nonode
Join Date: Dec 2002
Location: Coulsdon, Surrey, UK.
Posts: 2,135
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Lecson AC1 preamp - need a PCB layout
I'm currently working on one of these rather, how shall we put it, unconventional preamps !
I have some useful service information but I'm chasing down a fault with the FET switches of which there's quite a few ! Does anyone know where I might just find the PCB component layout details ? Some lettering is visible on the board ( test points I think ) but most of it seems to have faded badly THANKS Andy |
18th Apr 2021, 11:00 pm | #2 |
Hexode
Join Date: Mar 2014
Location: Peacehaven, East Sussex, UK.
Posts: 278
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Re: Lecson AC1 preamp - need a PCB layout
I have the instruction manual and the circuit diagram but there is no pcb component layout.
if only on one input it looks like a case of tracing the signal from the input din sockets - didn't they have problems with the reed switches for input selection? |
18th Apr 2021, 11:03 pm | #3 |
Nonode
Join Date: Dec 2002
Location: Coulsdon, Surrey, UK.
Posts: 2,135
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Re: Lecson AC1 preamp - need a PCB layout
Thanks Tony
That's probably the same info. I have, but alas no layout. The reed switches are all operating but I need to check signal levels at specific take off/options points and the board is stuffed with transistors, dozens of which are FET switches. It's a bit of a squash ! Andy |
18th Apr 2021, 11:05 pm | #4 |
Hexode
Join Date: Mar 2014
Location: Peacehaven, East Sussex, UK.
Posts: 278
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Re: Lecson AC1 preamp - need a PCB layout
I can imagine. happily I only had to fix a few of the power amps back in the day!
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19th Apr 2021, 6:52 am | #5 |
Dekatron
Join Date: Nov 2010
Location: Oxford, UK.
Posts: 4,992
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Re: Lecson AC1 preamp - need a PCB layout
Lecson was the first company that Bob Stuart and Alan Boothroyd started up. They later started up, and ran, Meridian (originally called Boothroyd-Stuart Meridian).
There is a chance that, although both founders have retired, Meridian still have a service archive of Lecson. And there is a company that specialises in fixing them up in York. They probably have service data http://www.lecson.com/ Good luck! Craig |
19th May 2021, 5:30 pm | #6 |
Nonode
Join Date: Dec 2002
Location: Coulsdon, Surrey, UK.
Posts: 2,135
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Re: Lecson AC1 preamp - need a PCB layout
I have now managed to fix the original problem with the FET switching on this, so this thread can be closed.
Andy |
28th May 2021, 3:59 pm | #7 |
Nonode
Join Date: Dec 2002
Location: Coulsdon, Surrey, UK.
Posts: 2,135
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Re: Lecson AC1 preamp - need a PCB layout
as the thread is still open, I will 'bump' it as a new problem appeared and I now desperately need the PCB layout, annotated with component designations, as there are no markings on mine.
Or, would anyone have a unit which contains a PCB where these are present they could photograph for me ? I'm happy to cover any reasonable expenses incurred. Andy |