5881 conversion


Got a USA Custom Diamond Amp?  Ready for a conversion to 5881/6L6 power section? You're in the right place. Select this and send your amp to us. We'll do the rest. 

Should I switch? Here's the good/bad news. . . You'll eventually have to convert your amp. The simple fact is, after the closing of the SED (Winged C) factory, there's really not any good EL34's left in our humble opinion. We relied on the Winged C EL34 for over a decade. Can you still find them? Well, yes. But they're approaching $300 for a matched quad now and will go higher until the run out.  So we made the switch to the Sovtek 5881, a tube we KNOW to be great, and reliable. Can you keep using EL34's in your Diamond? Of course. We just don't like any of the EL34's left on the market and have found most of them to be unreliable as well. And we all know how important reliability is when it comes to tubes. More good news. . .after the conversion, 5881's will cost you a whole lot less when it's time for your subsequent re-tubes!

Will it change my tone? Eh, maybe a little. Our experience is that you get a bit more dynamic mid-range (and we could all use that) and a little tighter low's. We'll tell you this. . .we have had a 100% satisfaction rate since we started the switch over (and that's coming from our players). Remember this, no matter what the interweb and forums may tell you, power tubes are really only responsible for about 5% over your amp's overall tone. So what should you really expect? You're not likely to be able to detect a tone difference, frankly speaking, if you could A/B both tube types. What you'll really be hearing more than anything is the difference between old tubes and new tubes. Don't forget folks, tubes aren't like batteries. Batteries just work until they die, then they just stop. Tubes are constantly degrading as you use them, but due to limitations of the human ear, you don't start noticing the change until your tubes are past the point of you needing to change them.

How long does it take? Usually about 1 week in our shop from when the amp is received. 


  • change of power tubes to Sovtek 5881 (current Diamond Amps spec)
  • change of output transformer to matched transformer
  • full re-bias
  • full amp inspection and any necessary warranty-covered work

After checking out, simply forward your confirmation of order to us at techsupport@diamondamplification.com to schedule your conversion!