Mission Cambridge
Liquias,
Please disregard my prevoius posting in respect of the measurement.
There is no point to compare the offset between different models as in fact the offset of the other channel of my Cambridge is close to zero .
Well .......it seems that the power amp board needs a bit more work .
Will check all soldering one day soon again ...
But in the meanwhile it will play .
Best
AM
Liquias,
Please disregard my prevoius posting in respect of the measurement.
There is no point to compare the offset between different models as in fact the offset of the other channel of my Cambridge is close to zero .
Well .......it seems that the power amp board needs a bit more work .
Will check all soldering one day soon again ...
But in the meanwhile it will play .
Best
AM
I've noticed with these amps that the low voltage supply cap's dry up and by doing so there's a low level hum... there's cap's are the old gold one's 470uf near the reg's and a change with sort that hum. the above comment...it's not good to test amplifiers via using headphone loud pop's with fry the headphones and make you jump...best using an old pair of speakers and keep the level's down low to hear clean sound.
if a scope is handy even better and hook the amp to a resistor dummy load and watch the scope.. these old amps are fine when working.
if a scope is handy even better and hook the amp to a resistor dummy load and watch the scope.. these old amps are fine when working.
The mentioned 470yF caps are at the power supply for the phono amp only - they have nothing to do with the actual amp themselves.
But you are very right: They are mostly dried out and have to be changed, if that did not happen before. As the original Roedersteins are not available anymore, I think Silmic or Panasonic FC or the like are a good choice here.
But you are very right: They are mostly dried out and have to be changed, if that did not happen before. As the original Roedersteins are not available anymore, I think Silmic or Panasonic FC or the like are a good choice here.
Hi all
I am a electronic noob with a cyrus2 amp+psx. Have a problem with amp, one of the channels is gone or almost gone. After some hours of reading posts I opened it and it seems the 470u non polarised electrolytics, parts C43 and C44 have small cracks, those under the green ribon. Should I ask to a technician replace them with Silmic or Panasonic FC as Lohk says? They have 20 years, but not working for 10 years now. Dono what to do cause I love them and dont want someone messing with them.
Thanks
Paulo
I am a electronic noob with a cyrus2 amp+psx. Have a problem with amp, one of the channels is gone or almost gone. After some hours of reading posts I opened it and it seems the 470u non polarised electrolytics, parts C43 and C44 have small cracks, those under the green ribon. Should I ask to a technician replace them with Silmic or Panasonic FC as Lohk says? They have 20 years, but not working for 10 years now. Dono what to do cause I love them and dont want someone messing with them.
Thanks
Paulo
Hi,
It looks like you have some knowledge of the Mission 778 amplifier. I've been looking at mending my partners Mission 778 with my Dad and I can't get hold of a service diagram from anywhere. Mission said the circuit diagrams had all caught fire 13 years ago!! When I phoned them again they said Cyrus had the circuit, so I phoned Cyrus and they didn't have it. Anyway, we have replaced the 4 capacitors (a common problem so I'm told) 100uf 63v, as the insulation had melted on one and one snapped off. This didn't sort it out. So we replaced 2 x LM317T 1.5A ADJUSTABLE VOLTAGE REGULATOR LM317 as there were cracks in one, it had to be attached to a heat sync. It still doesn't work, but my Dad thinks it might be the transistors in the output stage, I have attached a photo with these marked, we have no idea what they are as the writing has been rubbed off. I had to use someone elses photo, hope you don't mind. Any help would be appreciated. Looks like we are hitting a dead end. Kind Regards Wendy B : )Photo
It looks like you have some knowledge of the Mission 778 amplifier. I've been looking at mending my partners Mission 778 with my Dad and I can't get hold of a service diagram from anywhere. Mission said the circuit diagrams had all caught fire 13 years ago!! When I phoned them again they said Cyrus had the circuit, so I phoned Cyrus and they didn't have it. Anyway, we have replaced the 4 capacitors (a common problem so I'm told) 100uf 63v, as the insulation had melted on one and one snapped off. This didn't sort it out. So we replaced 2 x LM317T 1.5A ADJUSTABLE VOLTAGE REGULATOR LM317 as there were cracks in one, it had to be attached to a heat sync. It still doesn't work, but my Dad thinks it might be the transistors in the output stage, I have attached a photo with these marked, we have no idea what they are as the writing has been rubbed off. I had to use someone elses photo, hope you don't mind. Any help would be appreciated. Looks like we are hitting a dead end. Kind Regards Wendy B : )Photo
An externally hosted image should be here but it was not working when we last tested it.
Untitled DocumentBroken Switch Mechanism
Well, I started this post and now I'm back!
Cyrus 2 has been working great, until our 18 month old took to repeatedly pressing the power switch.
Now some red clip has snapped and the power switch doesn't stay on. I've had a look inside (I'm no expert and didn't do anything more than take the cover off) and there's a long red plastic piece that is obviously part of the switch mechanism and needs replacing.
Anyone know where I can get one?
Well, I started this post and now I'm back!
Cyrus 2 has been working great, until our 18 month old took to repeatedly pressing the power switch.
Now some red clip has snapped and the power switch doesn't stay on. I've had a look inside (I'm no expert and didn't do anything more than take the cover off) and there's a long red plastic piece that is obviously part of the switch mechanism and needs replacing.
Anyone know where I can get one?
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