Hy folks!
I´m running QED A 240 CD Mk2 with Q-Acoustics 2020i. The amp is running very well, but if a technical refresh will kick out some more music I´ll do it.
So if you could send me a scheme and tell me some hints it would make me very happy. I suppose LOHK and BRAINF are real experts.
Thanx in advance!
B.
I´m running QED A 240 CD Mk2 with Q-Acoustics 2020i. The amp is running very well, but if a technical refresh will kick out some more music I´ll do it.
So if you could send me a scheme and tell me some hints it would make me very happy. I suppose LOHK and BRAINF are real experts.
Thanx in advance!
B.
Hi Uncle Ben!
I changed the standard rectifiers with Fast Soft Recovery ones when I replaced the 25-year old electrolytics in the PSU stage a couple of years ago. That, and converting it into a power amp by bypassing the preamp stage made it perform in a whole new league.
(Not an expert, but I do love this little gem of an amplifier).
Good luck and check back with your experience.
I changed the standard rectifiers with Fast Soft Recovery ones when I replaced the 25-year old electrolytics in the PSU stage a couple of years ago. That, and converting it into a power amp by bypassing the preamp stage made it perform in a whole new league.
(Not an expert, but I do love this little gem of an amplifier).
Good luck and check back with your experience.
Although this wont help .. I have a P300 I took it to bits last year and its still in bits ..
An externally hosted image should be here but it was not working when we last tested it.
hi yes please
hi all!
I have a QED A240CD amplifier which had a blown left channel. I replaced the BD911 and the BD912 output transistors, the sound is now back...HOOORAAAY! BUT.....sounds very distorted not sure what could be the cause, im thinking to replace the white block resistors that sit right near the transistors. Also thinkingg it could be one of the smaller transistors. Any suggestions are welcome......a service manual would be even better.
hi all!
I have a QED A240CD amplifier which had a blown left channel. I replaced the BD911 and the BD912 output transistors, the sound is now back...HOOORAAAY! BUT.....sounds very distorted
not sure what could be the cause, im thinking to replace the white block resistors that sit right near the transistors. Also thinkingg it could be one of the smaller transistors. Any suggestions are welcome......a service manual would be even better.
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suggestions to get rid of mains humming?
Hi,
I have a QED A240 SA from 1988 as well, and through the years it has come to hum quite a bit, even with nothing attached, and it is also getting quite hot. I'll check on the BIAS voltage, but does anyone have a suggestion what to do about the humming?
Thanks in advance!
Hi,
I have a QED A240 SA from 1988 as well, and through the years it has come to hum quite a bit, even with nothing attached, and it is also getting quite hot. I'll check on the BIAS voltage, but does anyone have a suggestion what to do about the humming?
Thanks in advance!
Also worth checking that the earthing connections within the amp are still good - for safety as well as hum supression. Have you changed the location of anything else in your system? I had a hum which came and went mysteriously when I moved a few (non-connected) components around.
Check the easy things first (sounds like you may already be doing that), but I agree, old capacitors are a prime suspect.
Check the easy things first (sounds like you may already be doing that), but I agree, old capacitors are a prime suspect.
Hello all.
I have just been given a QED A270 pre amp, a P300 power amp and a pair of Lynn speakers. Really pleased. I have a problem that sounds like the one in this thread, anti surge fuse blowing on startup. Because I have the power amp, I don't need the power amp on the a200. I didn't find an answer on the thread about how to dis-connect the a200 power amp. If it's easy, I'll do it, if not I'll learn how to replace the components mentioned earlier. In the mean time, I'm just using the power amp and the volume on the player. Sounds ace.
I have just been given a QED A270 pre amp, a P300 power amp and a pair of Lynn speakers. Really pleased. I have a problem that sounds like the one in this thread, anti surge fuse blowing on startup. Because I have the power amp, I don't need the power amp on the a200. I didn't find an answer on the thread about how to dis-connect the a200 power amp. If it's easy, I'll do it, if not I'll learn how to replace the components mentioned earlier. In the mean time, I'm just using the power amp and the volume on the player. Sounds ace.
Mandobears photographs very useful
my a240SA running very hot lately - found one channel bias running at 100mV, wound it back down just now, will post again once I see what difference it makes.
I'm a bit of a novice at this sort of thing
I have a 50 Hz buzz/ hum which I though was down to old caps, however just discovered that it only happens when inputs are connected - does that make it a ground loop problem rather than an amp problem ?
my a240SA running very hot lately - found one channel bias running at 100mV, wound it back down just now, will post again once I see what difference it makes.
I'm a bit of a novice at this sort of thing
I have a 50 Hz buzz/ hum which I though was down to old caps, however just discovered that it only happens when inputs are connected - does that make it a ground loop problem rather than an amp problem ?
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