Metro 100W to 50W

[rd2play]

What does it take to convert the Metro 100 W MV to a 50W MV? I wish a 50W kit was available... As far as I can tell Ceriatone is the only who offers 50W kits. I'm sure they're great, but I would have liked a Metro kit. Is the conversion a big deal? Thanks.

[Kramer]

I think those preamp socket covers will fit over the power amp sockets and filter cap places. In that case..get a few of those (2 for the power tubes and 3 for the filter caps), get the appropriate transformers and do all the necessary adjustments for a 50 watter (i.e. rectifier). Just use ceriatone's layout and the metro instructions to help you along.

[rd2play]

I guess it might be easier if I modified a Plexi 50.

[Kramer]

Well, that's if you want the amp to always be a 50 watter. Something else to consider is building the 100 watter, pulling 2 of the tubes and then dropping your impedance by half to compensate. That'll give you 50 watts, and the ability to go back to 100 if you choose.

But it's not that hard to modify a plexi to 2204 specs. Main difference is just cascaded channels as opposed to having 2 channels in parallel and so then you convert the 2 channel volumes into a preamp gain and a master volume. It might sound harder than what it really is, but it isn't that bad. A 1987 and 2204 are in more ways similar than not.

What are your reasons for wanting the 50 over a 100?

[rd2play]

What are your reasons for wanting the 50 over a 100?

I already have a 2203, which I don't want to modify too much. I need a platform for experimenting and another 100 doesn't make sense.

I started thinking lately about replacing the 2203 board with a Metro board and experimenting on that one. This way I can revert back to stock anytime without buying another amp.

[Kramer]

Well, I guess another amp makes sense if your going to be heavily modifying it. If you only plan on tweaking/refining then the metro board with your current amp might be the best bet. Otherwise you will end up with 2 amps that sound pretty much alike. If you pop that PTP board in your 2203 now it will be really easy to go in and change things and experiment to see what you like, and the 2203 circuit is great for that.