Recent content by bluelair

Purchased a fuse-blowing Mark IIb on Facebook about 2 years ago. Quickly determined it had a blown power transformer. Here's how it looked before: Since Mesa doesn't sell the PTs any longer, I went with this one which had the closest specs. http://www.classictone.net/40-18042.pdf...

Hi all, I recently got some time to work on my '81 Mark IIB (no EQ) again. When I got it, it was blowing fuses. I replaced the Power Transformer with what Mesa recommended, a ClassicTone 40-18042. (http://www.classictone.net/40-18042.pdf) Replaced the tubes Replaced the Capacitors with...

I bought a nonworking Mark IIB that was blowing fuses. Immediately determined the PT was bad, replaced with a Mercury 80142 recommended by Mesa. 1. Powered on (with Variac) power on and amp produced sound, but it was sounding very poor sounding, sound was scratchy, harsh, would oscillate, and...

Thanks, so with this one, the total voltage is around 680v, that is different than the 448v that the original PT had, does that higher voltage pose an issue? Do I need to add anything else to the circuit?

Thanks. I want to do this right. Built a current limiter and got a variac. I connected it with tubes in and a fresh fuse via the current limiter and got it powered on. The current limiter bulb light glowed bright indicating a short. 1. Pulled tubes - CL still bright 2. Disconnected Power...

Picked up a very clean looking Mark IIb on Facebook Marketplace. Previous owner said it was blowing fuses and he let it go for $200. Serial is 6414, confirming the model. There is magic marker build date on the chassis saying 1981. I talked with a local amp shop technician. He wouldn't take...