Interesting tube, how it sound compared to the EL34 ?
I'm sorry it took so long to respond.!? I had a health episode shortly after posting, so audiophile forum posts were the last thing on my mind.
In a nutshell, I have been obsessed with tube rolling for more than 30 years, and my amplification choice has always been DHT/SET designs, as I own 102 dB-sensitive speakers.
However, I had Dennis Had build me a design around the 7581a tube since that is the only pentode I have ever really "liked" and I trust his ears as he has built several pieces of gear for me. Soon after receiving the amp Dennis and I both started experimenting with some not-so-common pentodes in this design...42 w/adapters, 6f6G's, etc.
I took it up a notch after discovering the Telefunken EL12 Spez and this RT EL39 using adapters as I own a Lampizator DAC and the guys on the "What's Best" forum don't screw around. Money is usually no object and they spend the coin experimenting with tubes. I also own some very sought-after EL and KT NOS tubes...probably 50 pairs if you want to split hairs so I sought out these specific variants to try. I quickly noticed how the EL39's sounded more DHT/SET than any pentode I had ever tried. I liken that tube to what a WE 300B is in that world. The Spez are very good too and best pretty much any flavor EL, KT tube I have on hand. The EL39 though was literally mind blowing! It not only produces the DHT/SET signature but adds detail/imaging/separation I have never experienced with a pentode design. The 6F6G's and 42's were pretty special too, but the EL39 was spectacular. The cool thing with that tube is that since not many know of it's existence you can find them NOS and boxed for a reasonable outlay. If your pentode based amp will accept many flavors of tubes I say try them. You will not be disappointed...believe me!
FYI - Use an 80 or 5y3 rectifier... preferably NOS. They even best my NOS WE 274A. Something to do with voltage drop is what Dennis told me?!?
Here are links to suppliers of tubes and adapters. Get em while they are unknown. I bought 3 pairs!
Tubes -
https://www.vintelec.com/en/5094-el39-rt.htmlAdapters -
https://tubeadapter.com/home/ols/products/360546709-1pc-gold-plated-4654k-el39-to-el34-tube-converter-adapterThe adapters look as if they are back ordered but I would email them. I've bought several adapters from this company and they are legit!
Happy listening!
