6L6's in a 5E3

[Gerard]

Hi, I built a Mission 5e3 about 2 years ago and love this amp. I would like to bulid another 5e3 with 6l6's based on ceriatone layout.

http://www.ceriatone.com/images/layo...3Ceriatone.jpg

I would also like to use this volume/tone mod.

http://cdn-2-service.phanfare.com/im...90395a441e97_1

I have most of the 6l6 parts, O.T and P.T. waiting to be used. I guess I am looking for any wisdom on what will and won't work. I am not looking to have an exact copy of my other 5e3. I just want a 5e3 with a twist and wanted to draw on some of your 5e3 knowledge to guide me. Any comments and recommendations would be appreciated.
Thanks, Gerard

[tubeswell]

Inspired by the sounds mcinku (who is a member here and over at the Dumble forum) was getting of of a similar idea, I built a 5E3 for 6V6 or 6L6GC last year (also can run a range of rectifiers as the 5V winding was 3A. The OT has multi-tapped secondaries, so you can change the load resistance by plugging the speaker into another tap (4k for running the 6L6s vs 8k for the 6V6s). (I recall mcinku's one had a 6k6 primary Z on the OT, but I was going for inter-valve versatility and variability)

The cathode resistor is around 250R (255R to be precise) and this stays the same no matter what tubes are running in it. The plate voltage is around 412 with 6L6s and a GZ34, and makes the 6L6s idle at about 17W, which sounds nice. With a 5Y3GT and 6V6s the plates are about 360-370, and the tubes idle at 14W. The OT is about 25W, so its got nice bass. The PT is 325-0-325 @180mA, 6.3V@4A, and 5V@3A, and it sounds good with a 20W greenback either way. The main threads about it are here:

http://music-electronics-forum.com/t10966/

http://music-electronics-forum.com/t9091/

http://music-electronics-forum.com/t9154/

It also has a switchable choke/resistor filter and it is really jazzy, funky and bluesy. I eventually sold it a few months ago - while it was a lovely sounding amp, I am a sickly consumed amp builder and I just haven't got room to keep everything (but I would've kept it if I could, because I am a sick amp hog).

[txstrat]

..., because I am a sick amp hog).

I'd like to claim that for myself too.
Anyone here who wouldn't?

[TD_Madden]

Here's Weber's take on a "Proluxe":

https://taweber.powweb.com/store/5e3p_schem.jpg
https://taweber.powweb.com/store/5e3p_layout.jpg

Of course, that design is fixed-bias.

[Gerard]

Thanks for all of your posts!! Any comments on the tone/volume mods? also will I need the 40uf caps as opposed to the 16uf if I am using 6l6 tubes? What B+ voltage is "ideal" around 400v ? I'm tring to get the rest of parts list together so I can start my build. I have an OT from an organ that used pp6l6's. Any comments on organ OT's. Are they good guitar amps?

Thanks again, Gerard

[tubeswell]

Hi Gerard

For 6L6s you can get by with 20uF, but a GZ34 (which is what you want to drive then with if you're running off a 325-0-325VAC HT) can easily take up to 60uF. Your PT's High Tension winding should be rated for at least 150mA to run 2 x 6L6s in a 5E3, and your heater (6.3VAC) winding should be rated at least 3A. In my book, you want at least 400VDC on the plates for 6L6GCs. (5881s can run from 350 to 440ish)

[Gerard]

I have a PT rated at 300-0-300 @ 150ma, 5v@ 3amps and 6.3v@ 5amps. Looks like I'm right there.

[tubeswell]

That's also good for a tweed tremolux (5G9) BTW

[mazzbob]

This is the design I would like to build with switch mod for fixed/cathode bias anyone have a drawing or layout for that?

[tubeswell]

This is the design I would like to build with switch mod for fixed/cathode bias anyone have a drawing or layout for that?

You use a DPDT switch - schematic attached - criticism welcomed.

I know it works because I've tried this on one of my amps. However IMHO the type of bias will usually sound better as either one of the other on any given amp. Its more fiddly to get an amp that sounds good with both types 2CW