Greetings all,
I Have a 25 year old Mk III Simul class, EQ, Combo that has almost "No Miles" on it.
When it was less than a year old I sent it back to Boogie because, If I remember, I was having Volume issues (swells) and the Simul class switch did basically nothing.
They said; again, If I remember correctly, it was a bad Capacitor.
They sent it back and over the past 24 years I used it sporadically at home. It was never consistent. One day it would sound great, the next day it would be totally different and this was without touching the amp at all
Whenever I would use it there was always minor crackling and buzzing and some volume swells. Most of these I attributed to the guitars or chords. but they happened when I would touch the amps nobs too, just not as bad.
The last year or so they became worse and a few weeks ago I saw a bright glow from the back of the amp, heard loud noises and it blew a fuse.
I tested all the tubes as best as I could. None seemed bad but I switched the Power tubes with ones I've had for ages and three of the Pre-amp tubes too. The amp powered up fine, with no more noise than usual.
I figured it was time to clean the pots to tackle the worsening crackling noises that happened every time I adjusted a pot. I figured the pots must be full of dirt as it has sat in a bedroom uncovered all this time.
Why do I adjust the pots? because the amp is that inconsistent, Like I said, sometimes it would sound fine. Other times it was as if every tome pot was adjusted 100$ opposite of what it said.
I pulled the chassis and gave each Pot a cleaning with contact cleaner, Let it dry, put it all back together. and powered it up.
Now, all the pots are misbehaving. the only place I get any volume is if I put it back how I normally have it set. (L to R = 7, 7, 2, 5.5, 2, 7, 2.5) and that's sporadic at best. If I adjust any pot the amp, if it had any sound, immediately drops down to almost nothing. They all crackle and make noise when touched. each channel behaves differently each time its selected, the volume swells up and down etc... If the amp has no sound and i dial the pots back to my std settings some volume will come back, sometimes
I called boogie and they said to send it in. They said for anywhere between $175 and $300 plus tubes and shipping they should be able to get it working as good as new!
Well it never worked good even when new and now 25 years later it seems like a waste of good money.
He seemed to think it was a pot or maybe a Cap. that's bad. But how could a bad Pot effect Every pot?. There is nothing that looks burned or melted in the chassis, In fact there wasn't even a dust bunny in it when I originally opened it up to clean the pots. The chasiss, and amp are Mint.
I'm at a loss . Anybody have any ideas?
I would pay the money to fix it if I knew it would actually fix it and not just be putting a band-aide on what could be worse problems.
Assuming its a bad Pot or Cap as he said, whats to prevent another going as soon as I get it back? or some other major component. I mean it is 25 years old after all.
What would cause a pristine amp with maybe 100 hours of use over 25 years to suddenly go bad?
Could cleaning the pots have messed something up?
I've done it on other amps and guitars over the last 30 years and never had a problem
Any help or ideas would be greatly appreciated
I Have a 25 year old Mk III Simul class, EQ, Combo that has almost "No Miles" on it.
When it was less than a year old I sent it back to Boogie because, If I remember, I was having Volume issues (swells) and the Simul class switch did basically nothing.
They said; again, If I remember correctly, it was a bad Capacitor.
They sent it back and over the past 24 years I used it sporadically at home. It was never consistent. One day it would sound great, the next day it would be totally different and this was without touching the amp at all
Whenever I would use it there was always minor crackling and buzzing and some volume swells. Most of these I attributed to the guitars or chords. but they happened when I would touch the amps nobs too, just not as bad.
The last year or so they became worse and a few weeks ago I saw a bright glow from the back of the amp, heard loud noises and it blew a fuse.
I tested all the tubes as best as I could. None seemed bad but I switched the Power tubes with ones I've had for ages and three of the Pre-amp tubes too. The amp powered up fine, with no more noise than usual.
I figured it was time to clean the pots to tackle the worsening crackling noises that happened every time I adjusted a pot. I figured the pots must be full of dirt as it has sat in a bedroom uncovered all this time.
Why do I adjust the pots? because the amp is that inconsistent, Like I said, sometimes it would sound fine. Other times it was as if every tome pot was adjusted 100$ opposite of what it said.
I pulled the chassis and gave each Pot a cleaning with contact cleaner, Let it dry, put it all back together. and powered it up.
Now, all the pots are misbehaving. the only place I get any volume is if I put it back how I normally have it set. (L to R = 7, 7, 2, 5.5, 2, 7, 2.5) and that's sporadic at best. If I adjust any pot the amp, if it had any sound, immediately drops down to almost nothing. They all crackle and make noise when touched. each channel behaves differently each time its selected, the volume swells up and down etc... If the amp has no sound and i dial the pots back to my std settings some volume will come back, sometimes
I called boogie and they said to send it in. They said for anywhere between $175 and $300 plus tubes and shipping they should be able to get it working as good as new!
Well it never worked good even when new and now 25 years later it seems like a waste of good money.
He seemed to think it was a pot or maybe a Cap. that's bad. But how could a bad Pot effect Every pot?. There is nothing that looks burned or melted in the chassis, In fact there wasn't even a dust bunny in it when I originally opened it up to clean the pots. The chasiss, and amp are Mint.
I'm at a loss . Anybody have any ideas?
I would pay the money to fix it if I knew it would actually fix it and not just be putting a band-aide on what could be worse problems.
Assuming its a bad Pot or Cap as he said, whats to prevent another going as soon as I get it back? or some other major component. I mean it is 25 years old after all.
What would cause a pristine amp with maybe 100 hours of use over 25 years to suddenly go bad?
Could cleaning the pots have messed something up?
I've done it on other amps and guitars over the last 30 years and never had a problem
Any help or ideas would be greatly appreciated
