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.

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



New version, I changed the power transformer for one from Bassman, the 290DX has the same voltage 325V-0-325V but in this case I have 230mA instead of 207mA. Now I have diode rectification to make the most of the voltage.

Matchless Lightning EL34 Diodes-1.jpg

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

badcat_hotcat_30-1.jpg

Matchless-Lightning-Schematic-1.jpg

Matchless-DC30-Old-Schematic-1.jpg

Matchless-DC30-Old-Schematic-2.jpg

Matchless-DC30-Old-Schematic-3.jpg

Matchless-DC30-Old-Schematic-4.jpg

[Reeltarded]

Neato.

1st thing the 325 might be a little low (even for me) I look for 370+ and would rather it be a target of 400.

Bandmasters want Bassman output. You might actually want to consider Amp Parts Direct JTM45 PT (heyboer) and Bassman output (heyboer).

400v and 3k8.

Send needs cap to block DC at jack... couple other things. I'll leave room for other replies.

[stinga11]

1st thing the 325 might be a little low (even for me) I look for 370+ and would rather it be a target of 400.

Bandmasters want Bassman output.

Send needs cap to block DC at jack...

Have you ever seen the schematics of the matchless or the BadCat Hotcat?

[maxkracht]

Have you ever seen the schematics of the matchless or the BadCat Hotcat?

If you expect us to reference schematics, you should post schematics.

I agree that your transformer choices are a bit strange, el34s could load down a power transformer that expects 6v6s so you might not get your expected voltage. How did you get the 325 number in the first place? Why use el34s if you are running them at 6v6 voltages?

[Stevem]

I can't see why a 4 amp fuse is needed.

Your speaker jack should be of a shorting type when there's nothing plugged in and having a 150 ohm 7 to 10 watt across it is a good & cheap no load save the OT way to go.

Your output tube plate voltage will be on the low side especially once you factor in the cathode voltage that the tubes will idle at.

[stinga11]

If you expect us to reference schematics, you should post schematics...

You are absolutely right, sorry. I just added the original schematics. Thank you

[stinga11]

How did you get the 325 number in the first place?

In the Bad Cat schematic the voltage that appears is 321V.

[maxkracht]

How did you get the 325 number in the first place?

In the Bad Cat schematic the voltage that appears is 321V.

Gotcha, the way you wrote this confused me.

I used the power transformer from a Deluxe Reverb Reissue that gives me (325V 207mA) & (6.3V 4.5A)

Its a 650vct or 325-0-325 transformer. On a deluxe reverb, that gives you somewhere around 420v dc to play with, I would expect less with el34s, and as Steve mentions, you lose more voltage on the cathode resistor(s). Unless you know all the specs of that badcat transformer, I wouldn't count on hitting the same numbers. I also wouldn't count on the badcat being well designed.

[stinga11]

Its a 650vct or 325-0-325 transformer. On a deluxe reverb, that gives you somewhere around 420v dc to play with, I would expect less with el34s, and as Steve mentions, you lose more voltage on the cathode resistor(s). Unless you know all the specs of that badcat transformer, I wouldn't count on hitting the same numbers. I also wouldn't count on the badcat being well designed.

Would it be better to use the transformers from a JCM/JMP? Would the schematic work for me? My english is so bad, sorry for that.

[maxkracht]

Your english seems fine to me. The deluxe transformer might be ok, I haven't tried it with that setup so I don't know for sure. My only concern is your voltage could be a bit low. I would probably go with something meant for 6L6 or EL34. Maybe a Bassman transformer? If you are looking at Marshall replacement transformer and you want to use a tube rectifier, make sure there is a centertap on the high voltage winding and 5v for the rectifier heater. Some JCM use a bridge rectifier.

[wpaulvogel]

A JTM45 power transformer SHOULD have 350-0-350 and that would get you 440-450 volts DC. They make for a great EL34 transformer. If you’re using cathode bias, you’ll be needing about 35-40 volts cathode voltage and you will subtract that from the B+ for figuring out power output. It still should be about 45 watts clean. I’d use fixed negative bias myself. It’s not going to react like EL84’s.

[Reeltarded]

Sold out for now, but this is my choice for the voltage range I like on my amps.

400v on tube rectification.

https://shop.amppartsdirect.com/collect ... ansformers