5881 in my SFPR?

telecaster1981 · June 25th, 2008, 06:42 PM

So, a while back, I replaced the Power and Output transformers in my SFPR with upgraded versions from Allen amplification. Part of the deal is that the upgraded PT allows the use of 6L6's and EL34 (with a socket wiring mod I believe). I've heard good things regarding the tonal qualities of 5881 power tubes and wondered if anyone had any thoughts regarding using these in a PR.

JohnnyCrash · June 25th, 2008, 07:23 PM

I used the same Allen transformers in my BF Princeton build (modded for adjustable fixed bias). I use 6L6's in that Princeton and it sounds incredible. Very VR-ish when pushed hard.

I haven't used 5881's in any amps in a while, but I believe they were very similar to 6L6's in tight, clear, bottom end.

11 Gauge · June 25th, 2008, 07:52 PM

It's hard to find a good 5881 these days, IMO. When you do find some nice NOS ones, you have to be careful not to kill 'em - sometimes a rectifier swap (and rebias) is in order.

There are a lot of killer 6L6's out now that are bulletproof and cheap. I like the =C= ones, but there's so much out there to choose from.

If you really want the 5881's, I suggest KCA NOS tubes. Just prepare yourself - last time I checked, a pair started at around a C note.

Edited to add: Apparently the new production Tung Sol 5881's are all the rage by some. I find it hard to believe, but the price is low enough to investigate.

June 25th, 2008, 06:42 PM	#1 (permalink)
telecaster1981 TDPRI Member Join Date: Mar 2008 Location: smithton, missouri Age: 26 Posts: 31	5881 in my SFPR? So, a while back, I replaced the Power and Output transformers in my SFPR with upgraded versions from Allen amplification. Part of the deal is that the upgraded PT allows the use of 6L6's and EL34 (with a socket wiring mod I believe). I've heard good things regarding the tonal qualities of 5881 power tubes and wondered if anyone had any thoughts regarding using these in a PR.

June 25th, 2008, 07:52 PM	#3 (permalink)
11 Gauge Friend of Leo's Join Date: Mar 2003 Location: The East Coast Posts: 2,898 10 Photos	It's hard to find a good 5881 these days, IMO. When you do find some nice NOS ones, you have to be careful not to kill 'em - sometimes a rectifier swap (and rebias) is in order. There are a lot of killer 6L6's out now that are bulletproof and cheap. I like the =C= ones, but there's so much out there to choose from. If you really want the 5881's, I suggest KCA NOS tubes. Just prepare yourself - last time I checked, a pair started at around a C note. Edited to add: Apparently the new production Tung Sol 5881's are all the rage by some. I find it hard to believe, but the price is low enough to investigate. __________________

June 25th, 2008, 07:23 PM	#2 (permalink)
JohnnyCrash Poster Extraordinaire Join Date: Mar 2005 Location: Lost Angeles and Orange County Posts: 7,128	I used the same Allen transformers in my BF Princeton build (modded for adjustable fixed bias). I use 6L6's in that Princeton and it sounds incredible. Very VR-ish when pushed hard. I haven't used 5881's in any amps in a while, but I believe they were very similar to 6L6's in tight, clear, bottom end.