5E3 want more headroom - GZ31 and 2 6L6s?

[leevc5]

Will it go up in smoke or give me the additional headroom I want?

[sluckey]

Probably neither.

GZ31 wants 3 amps of filament current. Your PT may not be happy.

[leevc5]

Any alternatives? How about a 5U4GA rectifier and 6L6s?
Any suggestions on how to get more headroom?

[sluckey]

5U4 also wants 3 amps of filament current. How about GZ34? Or two 1N4007 diodes?

I think you will need a major circuit change to get a lot of headroom. Simply changing output tubes probably won't do it.

[dude]

Well if you want to try it, just to see if you like the tone you can try this:


But be aware that your PT probably can't can't handle the load and might blow, so if it's getting hot (before you blow up the PT,) touch it, hot, take the 6L6's out.


Raise the cathode bias resistor to 10 watt (250, 10 watt)
Change the rectifier tube to a GZ34 or 5AR4
add screen grid resistors (1K5, 5 watt) don't have to do it just to try
if you have an 8 ohm speaker, use the 16 ohm spk jack with your 8 ohm. 4 ohm use the 8
There are a few power rail resistors to change but you can do that later.


Give it a go, but like Sluckey says you won't get the true headroom you want at least yet
The biggest problem is the PT probably can't handle the 6L6's, and you'll need a bigger PT.
Original OT is too small too, need a 25/30 watt at least
6L6s need a higher voltage, a bigger PT will give that and higher rating will keep it cool (meaning won't blow)


PS "Not responsible for a blown PT" 



One other thing: I put switches in my 5E3, 6V6s or 6L6's, with all the "proper changes", new PT and OT, too. Maybe a little more kick and a tad more headroom but not a Deluxe Reverb sound, closer to a 5E3 on small dose of steroids. My switches have been on the 6V6 settings for the last three years and I'll probably take the PT and OT out for another project when I get the time and bug. IMO, really don't brother, BTW, Neil Young runs 6L6's in his, if you like his tone go for it.

[leevc5]

Scary stuff there...went with just the GZ34 & 6L6s....just enough to get the headroom needed and can compensate for the tone change.
Thank you all once again...fine fix quick!

[dude]

If your PT is hot, that's real bad. Feel it after playing for fifteen minutes.
If it's just warm, that's OK
Don't just keep playing cause you like it, check the PT.


You really should change the bias resistor from 5 watt to 10 watt, that too will get hot and blow in time. It's a dollar part. If you don't know where it is, I'll tell you just ask.
You can forgo the screen resistors, I wouldn't but..., your choice. Changing it is for safety only.


You can just put the 5Y3 back for 6V6s, and GZ34 with 6L6's. That 250 ohm biasing resistor is the same for both tubes but the 6L6s need 10 watts.

[tubeswell]

Besides the PT's power handling rating, the OT will also have a power handling rating that you should consider.