I've owned a pair of 57's for about 30 years, and had them rebuilt about 5 years ago by Wayne Piquet. A long term love affair. But recently one of them sounded muffled, and when I checked, the power supply light was out. Pulling the plug made no difference, so indeed it's not getting powered up. Frankly I was surprised it played at all. Any ideas before I start taking things apart?
The 57 uses a remarkably simple circuit without much of the safety frou-frou of more more 'modern' stuff, so they're simple to debug and work on.
OTOH, they'll also electrocute your pets or burn down your house with a rather casual British indifference to the consequences...
If the neon glow lamp is out, there's no AC voltage reaching it - start at the wall socket, confirm AC, then check the supply cord for continuity (the silly 3-prong round 'Bulgin' connectors can fail at either female or male ends...), and finally check across the 57's power supply input pins - there should be 8-12 Ohms resistance.
Open (or infinite) resistance implies either a bad internal connection or an open primary in the transformer - here's a link to a schematic for the older 57's:
http://tinyurl.com/osydmuo
And one to the a pretty complete document on rejuvenating the beasts.
http://www.quadesl.com/pdf/quad_book.pdf
Cheers & good luck
Jim
OTOH, they'll also electrocute your pets or burn down your house with a rather casual British indifference to the consequences...
If the neon glow lamp is out, there's no AC voltage reaching it - start at the wall socket, confirm AC, then check the supply cord for continuity (the silly 3-prong round 'Bulgin' connectors can fail at either female or male ends...), and finally check across the 57's power supply input pins - there should be 8-12 Ohms resistance.
Open (or infinite) resistance implies either a bad internal connection or an open primary in the transformer - here's a link to a schematic for the older 57's:
http://tinyurl.com/osydmuo
And one to the a pretty complete document on rejuvenating the beasts.
http://www.quadesl.com/pdf/quad_book.pdf
Cheers & good luck
Jim
Last edited:
- Status
- Not open for further replies.