D
dr teeth
Active member
I bought a second Mark IV-A. It was the hardwood cab I thought I always wanted. That is until I picked it up fully loaded with the EVM 12L I love. Now I'm not sure. It's so beautiful and such a great amp but if I keep it I'll have to get a harbor freight small dolly to move it around until getting another combo case with casters.
After buying the amp someone told me about the brown leaky radial caps on the pre amp board so I searched and found people talking about horrid clean up jobs that the factory charges by the handful as it must be a nasty job. I pulled my newest chassis, sub-1000 serial # to have a look. I saw the 3 large brown radials sticking up but mine were 8200uF, not the 10KuF ones I read that everyone was having a problem with.
As a public service clarification for anyone else wondering the same thing I reached out to the factory.
Per Mike B:
"The 8200mf caps are NOT the leaky troubled caps. I have seen a few break loose from the board, but can't recall one that has leaked. The nasty ones were the SPRAGUE 10,000 16 volt."
We need to keep MB working so he'll get back to mods again.
So here you go in case you have the 8200uF and were concerned.
The filters and other E-caps like these are 30 years old now and it sure seems the "new" MB serviced Mark's have better resale value for now despite being contrary to typical vintage collectibles that favor all original. I usually only want replaced electrolytic's when one goes bad or there is sonic evidence (that would likely show on a oscilloscope) that they need changing. If I was gigging it and didn't have a back up I would change them but I do plan very soon to go through my Marks with an ESR meter to make sure the electrolytic banks are healthy. Even 50 yo caps can still be within spec while not expected to be and new caps can always be bad batches that you don't find out about till much later.
After buying the amp someone told me about the brown leaky radial caps on the pre amp board so I searched and found people talking about horrid clean up jobs that the factory charges by the handful as it must be a nasty job. I pulled my newest chassis, sub-1000 serial # to have a look. I saw the 3 large brown radials sticking up but mine were 8200uF, not the 10KuF ones I read that everyone was having a problem with.
As a public service clarification for anyone else wondering the same thing I reached out to the factory.
Per Mike B:
"The 8200mf caps are NOT the leaky troubled caps. I have seen a few break loose from the board, but can't recall one that has leaked. The nasty ones were the SPRAGUE 10,000 16 volt."
We need to keep MB working so he'll get back to mods again.
So here you go in case you have the 8200uF and were concerned.
The filters and other E-caps like these are 30 years old now and it sure seems the "new" MB serviced Mark's have better resale value for now despite being contrary to typical vintage collectibles that favor all original. I usually only want replaced electrolytic's when one goes bad or there is sonic evidence (that would likely show on a oscilloscope) that they need changing. If I was gigging it and didn't have a back up I would change them but I do plan very soon to go through my Marks with an ESR meter to make sure the electrolytic banks are healthy. Even 50 yo caps can still be within spec while not expected to be and new caps can always be bad batches that you don't find out about till much later.
