Hi All
So i've started planning this rebuild and have a few questions.
The 625 i am stripping for parts seems to be more modern and with different parts which seem better then the 621.
As you can see the difference, my question is could i work on the 625 board by upgrading the parts and then just swap it over to the 621?
These are the 621 potentiometers which feel like they have had better days, when i turn some of them the actual connecters which are soldered move, so not a good sign.
These are the pots from the 625 which are alps and are in much better condition, could i swap these over to the 621?
Plan is to make the 621 perfect and with any known problems sorted.
Another question is about
http://www.londonsound.org/Armstrongrepairs.htm
he quotes
The Armstrong 600 series
I reserve my best to last - the modifications applied to all 600 series amplifiers and receivers. The power supply capacitor can fail, spraying corrosive fluid onto a circuit board, causing massive damage. Often the volume control is noisy, (due to a design defect). The output circuit is slightly unstable, and cannot, therefore, be set to the minimum distortion levels achievable by this circuit. My modifications to resolve all three issues was so modest in cost, it was included in all repairs! Unfortunately, now over 30 years on, I find that too many of these capacitors fail despite the above mentioned modification that I now replace all of these capacitors as a routine service item, but by bulk buying of these parts I have still managed to keep the price down."
any idea on the sort of mods he does?
Thanks.