El Rey
Well-known member
Mesa still has some of the best service on the planet.
Just got my 92 MKIV A from Mike Bendinelli after cap job, all new tubes, and other service.
No way I could do everything on the invoice in 3.25hrs.
01/05/22 Mike Bendinelli: A shorted .1/400 v cap at the bass for ch 3 caused the static and crackle and jumping plate voltages at V1. Also dirty pots and pulls, and when input cable is unplugged the short contact was not closing well. Fixed and cleaned the jack. Cleaned all the pots, pulls, pre tube sockets, jacks etc. The switchable loop jack was also intermittent. Rebuilt the output Lvl pot. Replaced all the electrolytic caps in the amp, all were original. Upgraded the .1/400 caps at V5 to .1/600 volt. Rev plate resistor was far off spec, replaced. Added grid isolation resistors at the class A/B tubes. Soldered all the “crimped” LDR extender leads on stacked LDRs. Cleaned a couple sliders and relubed as needed. Rev well with bench tank and w/ bench FTSW all is good. Install new set of tubes, burn in and playtest.
Labor 3.25 hrs.
I did recapping of my other MKIV myself. It turned out fine but took me a lot longer.
It sounds marvelous and phantom quiet!
They really did a great job of separating the tubes in their own packaging, and molded foam packing of the chassis (sent the chassis only without tubes). I watched the UPS Driver claw it out of the truck and drop it 4 feet in the truck. I don't want to think how much worse it was handled on the way.
Just got my 92 MKIV A from Mike Bendinelli after cap job, all new tubes, and other service.
No way I could do everything on the invoice in 3.25hrs.
01/05/22 Mike Bendinelli: A shorted .1/400 v cap at the bass for ch 3 caused the static and crackle and jumping plate voltages at V1. Also dirty pots and pulls, and when input cable is unplugged the short contact was not closing well. Fixed and cleaned the jack. Cleaned all the pots, pulls, pre tube sockets, jacks etc. The switchable loop jack was also intermittent. Rebuilt the output Lvl pot. Replaced all the electrolytic caps in the amp, all were original. Upgraded the .1/400 caps at V5 to .1/600 volt. Rev plate resistor was far off spec, replaced. Added grid isolation resistors at the class A/B tubes. Soldered all the “crimped” LDR extender leads on stacked LDRs. Cleaned a couple sliders and relubed as needed. Rev well with bench tank and w/ bench FTSW all is good. Install new set of tubes, burn in and playtest.
Labor 3.25 hrs.
I did recapping of my other MKIV myself. It turned out fine but took me a lot longer.
It sounds marvelous and phantom quiet!
They really did a great job of separating the tubes in their own packaging, and molded foam packing of the chassis (sent the chassis only without tubes). I watched the UPS Driver claw it out of the truck and drop it 4 feet in the truck. I don't want to think how much worse it was handled on the way.