Metropoulos Forum

sorry if this has been discussed already. I'd like to build the 1987 plexi head but use a lower power output section (6V6). My question is, would it be easier to buy parts for a JTM45 kit (since it's transformers are better suited to lower voltages), then mod the preamp into the 1987 circuit... OR... buy parts for the 1987 50 watt kit and use jtm45 transformers or another lower voltage transformer??

Which will be the easier way to go? I'll be using metro amps instructions and sourcing parts from metro, valvestorm and mojo most likely.

thanks in advance for any help and sorry again, if this has been covered already.

Probably better to go with 1987 chassis jtm 45s have tube rectifier.

I think that makes more sense. Is there a recommended set of transformers to accomodate the 6v6's?

You can use a 1987 chassis, but a tube rectifier will drop the voltage to accommodate the 6v6's. Using a 5y3 would probably get you there with a PT using the low voltage tap such as this tranny. Quality and reasonably priced, I've used these on 45 and 50 builds.

http://www.classictone.net/40-18054.html" onclick="window.open(this.href);return false;

Not sure about the OT. I've been wanting to try this as well.

OnTheFritz wrote:You can use a 1987 chassis, but a tube rectifier will drop the voltage to accommodate the 6v6's. Using a 5y3 would probably get you there with a PT using the low voltage tap such as this tranny. Quality and reasonably priced, I've used these on 45 and 50 builds.

http://www.classictone.net/40-18054.html" onclick="window.open(this.href);return false;

Not sure about the OT. I've been wanting to try this as well.

You can use JJ 6V6s and they can apparently cope with 450v or so that you see in JMPs and JTMs.

neikeel wrote: You can use JJ 6V6s and they can apparently cope with 450v or so that you see in JMPs and JTMs.

They most certainly can, and much more besides. I ran a pair at 470V for best part of a year. Just need to flip your impedance selector DOWN one step to account for the mismatch, change your bias circuit to suit (usually just changing a feed resistor is more than adequate) and yer away.

The JJ's are more like a 6L6 in terms of structure and a little bit that way tonally too.

Brimars are also good for around 450V and sound grrrrreat. Quite like classic EL34's in a way. Not quite as splatty as some other old type 6V6's.