Hi There:
here is the link for the schematic:
http://f2.grp.yahoofs.com/v1/ILimRB...So7224l2hWFI4/Schematics/Luxman_MQ3600_p1.gif
art
here is the link for the schematic:
http://f2.grp.yahoofs.com/v1/ILimRB...So7224l2hWFI4/Schematics/Luxman_MQ3600_p1.gif
art
Maurizio,
what I did find on:
http://www.allaudios.org/detail-7211106.html
\
AFAIK, an 8045G IS a 6550 wired as a triode (by jumpers in the base).
See: http://www.triodeel.com/images/8045.gif
Most of the "8045G" labelled tubes I've seen were US made 6550's
with jumpers added in the base.
| This may be a difficult and expensive
| change, though less expensive than finding new 8045Gs.
Wiring the socket for a 6550 or KT88 is not difficult,
nor should it be expensive.
Ned Carlson Triode Electronics Chicago,IL USA
www.triodeelectronics.com
Then connect about 100 ohm, a couple watt resistors from pins
| 3 to 4.
|
| With no output tubes installed, fire it up (preferably with a
| Variac, but *SAFETY FIRST* in any case - allow no children or
| pets in the room).
|
| Observe voltages at points marked "C1" and C2". Adjust the 30K
| ohm bias pots for maximum voltage.
|
| Power off. Observe all supply voltages and wait until they've
| fallen to a low level, maybe a coupla volts.
|
| Install your new matched quad of Svetlana or maybe JJ power tubes.
| Fire it up again and observe. Everything OK?
|
| Bias is measured at the cathode pins (pin 8). I'd run modern
| tubes at between 50 and 70 mA (500 mV and 700mV on pin 8).
| The 10K ohm pots are to balance the current in each pair.
|
| Try various bias currents and use the least that doesn't affect
| sound quality. And no more than 80mA.
Hope this will help.
Alain.
what I did find on:
http://www.allaudios.org/detail-7211106.html
\
AFAIK, an 8045G IS a 6550 wired as a triode (by jumpers in the base).
See: http://www.triodeel.com/images/8045.gif
Most of the "8045G" labelled tubes I've seen were US made 6550's
with jumpers added in the base.
| This may be a difficult and expensive
| change, though less expensive than finding new 8045Gs.
Wiring the socket for a 6550 or KT88 is not difficult,
nor should it be expensive.
Ned Carlson Triode Electronics Chicago,IL USA
www.triodeelectronics.com
Then connect about 100 ohm, a couple watt resistors from pins
| 3 to 4.
|
| With no output tubes installed, fire it up (preferably with a
| Variac, but *SAFETY FIRST* in any case - allow no children or
| pets in the room).
|
| Observe voltages at points marked "C1" and C2". Adjust the 30K
| ohm bias pots for maximum voltage.
|
| Power off. Observe all supply voltages and wait until they've
| fallen to a low level, maybe a coupla volts.
|
| Install your new matched quad of Svetlana or maybe JJ power tubes.
| Fire it up again and observe. Everything OK?
|
| Bias is measured at the cathode pins (pin 8). I'd run modern
| tubes at between 50 and 70 mA (500 mV and 700mV on pin 8).
| The 10K ohm pots are to balance the current in each pair.
|
| Try various bias currents and use the least that doesn't affect
| sound quality. And no more than 80mA.
Hope this will help.
Alain.
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