What happens to my Manley Variable Mu 6386?

[distorter]

Hi guys, I hear muddiness from the low-end of my Manley Variable Mu, I checked with Plugin Doctor, and it looks very weird:

 

[CJ]

Check them tubes. I hope you do not need to go T Bar.

 

[Ike Zimbel]

Manley product also has an issue with Jamecon, and possibly some Xicon branded capacitors leaking. These can and will do a lot of damage to the circuit board if not caught in time. Time to pull that screen off the top (it's one screw, IIRC) and have a look at the board. Don't poke your fingers in there, there is HIGH VOLTAGE inside.

 

[Khron]

Manley product also has an issue with Jamecon, and possibly some Xicon branded capacitors leaking.

Utterly pathetic, from an engineering standpoint, for an audio device (and a renowned one at that) costing 4-5 grand(!!!) to encounter the same issues for the same reasons as bottom-of-the-barrel stuff...

 

[CJ]

i remember this conversation from the wayback machine,

 

[distorter]

Check them tubes. I hope you do not need to go T Bar.

Thanks, I check all my tubes, replaced all of them, including 6386s. Didn’t fix. Could it be the transistor or the rectifier…?

 

[RogerAF]

Could be a combination of things.
1) If your area of the world has mains power at 50Hz, 50Hz peak could be power supply filtering and/or rectification problem.
2) 160Hz dip could be capacitor, or possibly switch or pot contact open.
3) It could be a bad/dirty contact in a tube socket, a jumper connector, or anything having to do with a connector.
I only worked on one Manley product about 20 years ago. I believe the problem was dust in the wind (cooling that is). But I really don't remember. (10 points for those who get all three(?) references.). My impression of the build quality of the Manley I worked on was impressively top notch. Excellent design engineering and manufacture.
Question: Is the scope view with shorted inputs? Suggest try with white noise.

 

[distorter]

Could be a combination of things.
1) If your area of the world has mains power at 50Hz, 50Hz peak could be power supply filtering and/or rectification problem.
2) 160Hz dip could be capacitor, or possibly switch or pot contact open.
3) It could be a bad/dirty contact in a tube socket, a jumper connector, or anything having to do with a connector.
I only worked on one Manley product about 20 years ago. I believe the problem was dust in the wind (cooling that is). But I really don't remember. (10 points for those who get all three(?) references.). My impression of the build quality of the Manley I worked on was impressively top notch. Excellent design engineering and manufacture.
Question: Is the scope view with shorted inputs? Suggest try with white noise.

Thanks a lot! I'll try to replace some components. Also, my electric power is not clean enough for vintage units, lol