I would just solder the replacement tubes, since it is a sideways mount and there are no clamps I suspect sockets may not be reliable.
If you can find the space for clamps and the tubes do not hit the enclosure with sockets I think you would be good to go.
I would also start looking for spare boards, I can't imagine too many tube replacements are practical given the quality of the board if you cannot use sockets..
If you can find the space for clamps and the tubes do not hit the enclosure with sockets I think you would be good to go.
I would also start looking for spare boards, I can't imagine too many tube replacements are practical given the quality of the board if you cannot use sockets..
Hello, I wanted to post an update, I have changed all capacitors, jumped the burned section and amplifier is working much better- now right valves light up even faster than left ones - sound is superb with my new PMC speakers, really lovely 🙂 but fuse still blows up, now after some time playing.
I hope that the cause will be the valves, I bought JJ Tesla / EL34/6CA7-JJ TESLA Quad with ceramic sockets, it will be better to avoid changing them too often, haven't heard yet about new spare boards.
I will let you know later how it worked with new valves 😉
I hope that the cause will be the valves, I bought JJ Tesla / EL34/6CA7-JJ TESLA Quad with ceramic sockets, it will be better to avoid changing them too often, haven't heard yet about new spare boards.
I will let you know later how it worked with new valves 😉
An image showing how it's now joined:
An externally hosted image should be here but it was not working when we last tested it.
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Hi, this might be not a professional question, when I was setting up a center voltage adjustment, V have showed 213, when I was adjusting the gauge nothing much have changed until I gone too far and fuse blown. I have set up the voltmeter to symbol V and DC symbol and line with dots underneath it. Is that correct or am I doing something wrong? Correct drawing would be this one: http://diagramasde.com/diagramas/audio/AMC CVT3030.pdf
Cheers
Cheers
Everything is fine now, appears that both channels had voltage and bias settings set completely wrong I have corrected them and so far so good everything is working now 🙂.
Update to last post: the gauges are very sensitive it's easy to jump much over the scale, for everybody who will need to fix their amp- good video showing how to do this is available here: https://www.youtube.com/watch?v=bO2X7NDo6nU.
New valves are on the way I will post an update when they will arrive 🙂 Kind Regards
Update to last post: the gauges are very sensitive it's easy to jump much over the scale, for everybody who will need to fix their amp- good video showing how to do this is available here: https://www.youtube.com/watch?v=bO2X7NDo6nU.
New valves are on the way I will post an update when they will arrive 🙂 Kind Regards
Great.
I was looking at the schematic and all PS rail have fuses which is a good practice.
Slo blo 1A for the B+, Slo blo 250 mA elsewhere.
Do you know which one was blowing?
I was looking at the schematic and all PS rail have fuses which is a good practice.
Slo blo 1A for the B+, Slo blo 250 mA elsewhere.
Do you know which one was blowing?
If it's indeed the bias it's f401. And it's indeed 'popping after a while, not directly. Which is good because it makes you able to set the bias 😉
I agree with kelvin to solder the replacement tubes, or drill a hole in the pcb to give the tube good space to go fully in the socket. New tubes also means re-biasing. Good luck !
I agree with kelvin to solder the replacement tubes, or drill a hole in the pcb to give the tube good space to go fully in the socket. New tubes also means re-biasing. Good luck !
Yes it was bias and voltage settings 🙂 everything is working fine now, and thanks to changing capacitors it's stable, I will receive new boards as well probably, when new valves will come by I will post final review.
Thanks for all helpful information's finally I have working amp, top job! 🙂
Thanks for all helpful information's finally I have working amp, top job! 🙂
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Hi I'm still trying to get this amp sorted @hvlemmi do you know where can I find the remaining drawings for this amplifier? I might make new pcb boards
http://diagramasde.com/diagramas/audio/AMC CVT3030.pdf
Check page 7, but the schematic is at page 12.
I would recommend you to keep your old boards as a reference. If you make a board yourself, use a tube socket. Perhaps it is easier to make it hard wired, ditching the white plastic connector for soldering it straight to the board. Good luck and be sure to triple check everything! Post updates on your considerations and steps of your build; a lot of minds combined means more than one on its own. Cheers!
Check page 7, but the schematic is at page 12.
I would recommend you to keep your old boards as a reference. If you make a board yourself, use a tube socket. Perhaps it is easier to make it hard wired, ditching the white plastic connector for soldering it straight to the board. Good luck and be sure to triple check everything! Post updates on your considerations and steps of your build; a lot of minds combined means more than one on its own. Cheers!
Thanks for fast reply, will do with updates. The problem with the drawings is that the service manual on amc site is for newer boards mine middle one is 19-1213 rev. 2 from 1992 year and it is different, same as on valve boards - for example mine doesn't have an additional diode on right side of the drawing nearby r525 and r526. I have received new boards from amc but when I plugged those in to the amp,e sound problems appeared so I get back to mine old boards. I saw nice self made boards online with valve sockets on the other side of the boards and that would be my goal.
I have sorted old plates this amp have amazing sound quality after changing capacitors, still if I will find the drawings for this model I will make new pcb boards and post updates in this thread.
I meet with slight problem that valves are heating very much is there any way to make them drain less power? I'm only listening on half of the power and I guess lamps are working on full throttle.
I meet with slight problem that valves are heating very much is there any way to make them drain less power? I'm only listening on half of the power and I guess lamps are working on full throttle.
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