100 watt iron

[dcribbs1412]

Have some 100 watt iron OT is 1.7K
wanted to ask the experienced Marshall folks as I am
not sure what to build...I have built SLO and Jubilee and JTM45 style circuits
I guess I should probably start with the classic 2203 or Plexi circuit
I'm not real familiar with a lot of the differences of the JCM JMP, MV and non-MV circuits
any suggestions on a classic circuit are appreciated
Thanks

D

[Jana]

If it was me, I would build a 2203 and do the tweaks I mentioned in my 2204 build.

http://ampgarage.com/forum/viewtopic.php?t=18018

Ignore the parts for the power amp section.

That build is still my favorite.

[dcribbs1412]

Thanks Jana
really appreciate the info
beautiful looking build and some great mod tips
Did you stay with the 375V B+?


Darin

[Jana]

Thanks.

Yes, for a "50" watt amp, I feel that is the ideal voltage.

[Stevem]

Do you need the clean head room of a 100 watt amp, as I much prefer a cranked out 50 watter to a Atenuated 100 !

[dcribbs1412]

Do you need the clean head room of a 100 watt amp, as I much prefer a cranked out 50 watter to a Atenuated 100 !

I agree steve
I like the feel of cranked amps myself
I really do not need 100 watts. I have a 1.7k 100 watt OT.
I have heard of a few amps(Mohave Scorpion) using a 100 watt OT in a 50 watt circuit.

Darin

[Jana]

Do you have the PT yet? If not, there are some other options to explore.

Use the OT you have but use the 4 ohm tap for 8ohm speaker load, the 8 ohm tap for 16 ohm speaker load. You won't have a 4 ohm speaker load selection. Now you have a 3.4K OT. Then use 4 - 6V6 tubes. You will need a PT that gives you about 380 volts B+.

Then build the 2203 or 1959.

[dcribbs1412]

Do you have the PT yet? If not, there are some other options to explore.

Use the OT you have but use the 4 ohm tap for 8ohm speaker load, the 8 ohm tap for 16 ohm speaker load. You won't have a 4 ohm speaker load selection. Now you have a 3.4K OT. Then use 4 - 6V6 tubes. You will need a PT that gives you about 380 volts B+.

Then build the 2203 or 1959.

Thanks Jana
I do not have a PT yet
So I could use 2 el34's I have on hand or use 4 6v6's?

Darin

[Jana]

Darin,

It just happens that I am in the dreaming stage of my next build and I have been contemplating this very amp. Again, if it was me, here is what I would do:

Use the OT you have.
Use a PT from RJ, the EM 0748
http://rjguitars.net/Edcor_Power_Transformers.html

This would give you a lot of options. You could use 4 * EL34. Yes, the B+ is going to be lower than usual but I am guessing you will still get about 70 to 80 watts out of it. It will be some sweet sounding watts too.

Use a mismatch on the impedance selector and you can use 2 * EL34 or 4 * 6V6.