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Last week I fixed two Bad Cat amps for a customer -- a Lynx 50 head and a Black Cat 30R 2x12 combo. Both had power section failures. The customer is a Bad Cat endorser and so I had to deal directly with Bad Cat for all parts -- they were very nice and easy to work with and overnighted the stuff to me. The overdrive sound isn't my bag but the clean sound is fantastic. The Black Cat has an EF86-based preamp channel, very cool.
Guts-wise, they have their own house brand of capacitors... so I don't know whose stuff they're relabeling. Both amps were carbon comp resistors throughout. Both were cathode-bias, which I don't really see much of (I do a lot of huge high-power amps for metal guys). The Lynx had an arc on a power tube socket, pins 2-3 (bad cabinet wiring), the Black Cat had leaky phase inverter coupling caps that had melted down the output tubes. Both amps had bad phase inverter tubes, not sure why.
Anyway...
Both also had insanely high idle current in the power amp. The Lynx 50 runs 2x EL34s in push-pull cathode-bias, and they idle at 35W a piece! The Black Cat has 4x EL84s and each of them is idling at 16W. I had to contact the company to see if this was correct, and they assured me it was. The customer complained that the amps are not reliable at all (duh) and that some previous tech told him they had "design flaws" that he wanted to correct at a later date. As far as I can see, the only thing that needs correcting is the cathode resistor values.
Anybody else had experiences with Bad Cats? They didn't give me a schematic for either amp, so I just had to eyeball it. Are these basically souped-up Vox circuits? I guess I always assumed they were just clones of some classic amp with some extra boutique mojo.
Guts-wise, they have their own house brand of capacitors... so I don't know whose stuff they're relabeling. Both amps were carbon comp resistors throughout. Both were cathode-bias, which I don't really see much of (I do a lot of huge high-power amps for metal guys). The Lynx had an arc on a power tube socket, pins 2-3 (bad cabinet wiring), the Black Cat had leaky phase inverter coupling caps that had melted down the output tubes. Both amps had bad phase inverter tubes, not sure why.
Anyway...
Both also had insanely high idle current in the power amp. The Lynx 50 runs 2x EL34s in push-pull cathode-bias, and they idle at 35W a piece! The Black Cat has 4x EL84s and each of them is idling at 16W. I had to contact the company to see if this was correct, and they assured me it was. The customer complained that the amps are not reliable at all (duh) and that some previous tech told him they had "design flaws" that he wanted to correct at a later date. As far as I can see, the only thing that needs correcting is the cathode resistor values.
Anybody else had experiences with Bad Cats? They didn't give me a schematic for either amp, so I just had to eyeball it. Are these basically souped-up Vox circuits? I guess I always assumed they were just clones of some classic amp with some extra boutique mojo.
hint, hint.
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