Matchless Lightning with EL34 complete Schematic

[stinga11]

I've been wanting to build a Matchless Lightning with EL34 tubes for months, and in my analysis of how to find the correct voltages, and even more complicated, how to find the correct transformers, I found the schematic for the Bad Cat Hot Cat 30. So what did I do? I used the power transformer from a Deluxe Reverb Reissue that gives me (325V-0-325V 207mA) & (6.3V 4.5A), the output transformer is from a Bandmaster with 4,000 impedance in the primary and 40 watts, and a choke from an AC30.

The schematics I used are the Matchless DC30, Matchless Lightning, and Bad Cat Hot Cat 30.

I wired the tonestack in Fender/Marshall style to avoid interaction with the bass that the Matchless tonestack inherited from Vox.

The values of the cathode resistors of the power tubes are not correct but I have not yet calculated the correct value, I just put any value so as not to leave it blank.

Please check it out and give me your advice or warnings. Thanks in advance

[AlNewman]

6V6 has a lot less current draw than EL34.  You may find your PT can't keep up.

[DummyLoad]

290CX will work - Same PT used in Tremolux 35W amp, it'll run a bit warmer with a pair of EL34, 290DX would be my choice with a 1760JB output transformer - EL34 cathode resistor values with 440-450V B+ would be around 470R under each EL34 or around 230R for the pair. I prefer to use individual R for the cathode R, just my preference with EL34/6550/KT88, high slope output tubes in general. Phase inverter as designed works better w/ EL84 - Reconsider the tail R and Ra'/Ra anode resistor pair for better balance with a smaller tail R - E.g., copy the Deluxe reverb LTPI, sans the NFB, yes it's a 12AT7, but 12AX7 works just as well with those values.


--Pete

[stinga11]

290DX would be my choice with a 1760JB output transformer.
--Pete

I am going to use the Hammond 290DX power transformer. It has 230mA instead of 207mA but it has 6.3V 4A. Taking the calculations, the transformer will consume 4.05A, doesn't it matter?

[Backwoods Joe]

Don't forget to check out the first AC50.