Anyone done it, if so what did you think? I'm getting ready to put one together and was wondering if I should get a pair and try 'em in it. Should be just a plug in replacement for the 6L6's with a little higher voltages than a 5E3.
Thanks,
Ken
Printable View
Anyone done it, if so what did you think? I'm getting ready to put one together and was wondering if I should get a pair and try 'em in it. Should be just a plug in replacement for the 6L6's with a little higher voltages than a 5E3.
Thanks,
Ken
If your PT has lower voltage taps (like Weber), I'd use those.
I've got a Weber PT with dual secondaries. I'll hookup the 330-0-330 and see what kind of B+ voltage I get with the 6L6's.
Ken
330VAC, full wave rectified gives 462VDC. (330V * 1.4)
Of course, you need to figure in sag of the rectifier, which will vary with current draw, but for a 5U4 should be ~40V, giving you about 420V. About the max I'd want to put on 6V6 tubes, except maybe those JJ's everybody says can take it.
I don't like most of the JJ's I've tried with the exception of their 6V6's. They're a good sounding tube and I've run them above 420 volts with no problems. They seem to be plenty tough.
If the 6V6's don't work out sounding good in the amp that's OK. I was just curious as to whether anyone else had already tried them. If my amp with 6L6's turns out to sound anywhere near as good as the amp Fezz Parka recorded, I probably won't even bother with the 6V6's.
Ken
Fezz, is the 5E5 naturally a cathode bias circuit or was that one of the mods you added that when you converted your 5E3 to the 5E5 you have ?
5E5=cathode bias, 5E5A=fixed bias
Quote:
5E5=cathode bias, 5E5A=fixed bias
Which of these two (5E3 or 5E5-A) would be easier to convert a 5E5 ? Apologies for my ignorance. I'm still learning what these terms mean.Quote:
The only things you change to make a 5e3 a 5e5 are:
Cathode resistor on the power tubes to a 10 watt.
Resistor values in the B+ ladder.
The rectifier (I use a 5r4).
The OT.
Probably the 5E3. The 5E5A has a different tone stack with treble and bass (Like the 5E7/5F4). The 5E5's circuit is actually closer to the 5E3 than the 5E5A. (Input stages are different) Check the schematics and you can see the exact differences.Quote:
Originally Posted by dmcII
The 5E5A is a 5F4 with a different feedback resistor and different speaker. The 5E7 is also the same circuit with a different feedback resistor and speakers.
Another difference between a 5E5 and 5E3 is that a 5E5 uses one tube per channel so that each input jack gets a triode. The triodes in each tube are wired in parallel.
Ken
Fezz,
Using a 5R4 rectifier, are you using 3 filter caps instead of 4?
Ken
I think it's a matter of the first stage uF value that's more important than how many caps are there.Quote:
Originally Posted by 4960
From what I understand, back in the day these amps were made, finding electrolytic filter caps with the voltage and capacitance needs that fit onto one of these circuits wasn't easy. If you wired two 20uF caps in parallel, in essence, you have one 40uF cap.
I recently drew up a 5F6 circuit for someone who wanted to build it into a smaller chassis while keeping the filter caps inside. I drew it up using a 47uF cap on the first stage instead of the two 20uF caps.
It's like the difference between the 5F1 and 5F2A...traditionally you'd see the extra 16uF cap in the first stage on the 5F2, when it's really just 32uF of capacitance there. I would think you could just use a 5F1 layout and put one cap in there with the higher capacitance.
Someone correct me if I'm wrong!
Somebody I know? :laughing:Quote:
Originally Posted by NTBluesGuitar
Maybe!Quote:
Originally Posted by JAM
:D
Quote:
I think it's a matter of the first stage uF value that's more important than how many caps are there.
That's what I was asking about. I've got the first two caps in parallel for a total of 40 uf on the first filter cap stage. I believe a 5R4 is rated for a max capacitance of 20 uf, so it won't work for me unless one of the caps is taken out of parallel. At some point I may want to try a 5R4 and a single 20 uf first filter stage to see if there is any change.
Ken