I have many A-1's excellent Integrated amplifiers!!!
Re furbished and gone over they really shine. Excellent phono stage, this will make a nice preamp for the M-4 if you choose to use it that way.
Athanasios
Restoring / recapping a Yamaha M-4 amplifier in 2026
- Thread starter rupes2
- Start date
Re furbished and gone over they really shine. Excellent phono stage, this will make a nice preamp for the M-4 if you choose to use it that way.
Athanasios
FockeWulf190D
Member
Agree, Athanasios! I doubt many Amps of such a high performance could stand 48/49 years of duty, talks about serius engineering and parts selection, no compromise.... Surely I will test it as a Pre-Amp (Pre-Out is from main circuit trhough 1 resistor), have a good feeling on that.... Thanks!
Asmodeus2112
Super Member
Agreed, I have two A-1's that I will never sell.
FockeWulf190D
Member
Here comes again... Hi rupes2! I´ve just ordered same big caps from Mouser and other parts, too. I wonder which pins were chosen for the connection? Did you have to put some suplement for the top plate to compensate the 2mm difference? It´s like an obsession, planning till parts arrive, but is good to have a fluent roadmap in front. Cheers
@FockeWulf190D it will become clear when you have the caps in hand and hold them up to the board. You will see which + and which - line up with the original slots. I don't seem to have a photo showing the pins I removed. If you download the PDF template I attached to my 2nd post, marking the holes should be straightforward.
As far as dealing with the extra 2mm in height I put a couple of washers under the rear of the hold down plate. For the front I just glued a piece of 2mm rubber under the front lip.
As far as dealing with the extra 2mm in height I put a couple of washers under the rear of the hold down plate. For the front I just glued a piece of 2mm rubber under the front lip.
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FockeWulf190D
Member
Perfect, rupe2! Thank you for the truly valuable help. Some pics, you can see old repairs in the pre-drive boards, resistors, one cap, transistors, but lucky me ... drive boards all original.
