I'm using EH EL34s in my Modified ST70. I tried the SED's, new Mullards,Sovtek current and older vintage, Tunsols, New and Old Teslas, and the winner is EH EL34's. The old Teslas are really the best of all but so hard to get. The SED's were clean and quiet but lacked life and bloom and high end extension (to my liking). The Mullards were BLAH, just boring just like the SED's. I just epent $90 on a matched Quad. The older Sovteks were pretty good but they lacked dimensionality. The Tunsols were pretty much the same as the others BLAH. No excitement!
The EH's in my circuit has top end extension, excellent midrange, clean sounding but bass needed a little more control.The entire audio spectrum is better than all the other tubes. I did the same test on a friends ST 70 with the Triode input board with the SED's in the first round, then the Sovteks, and then Mullards (new). I then put my EH's in there and it was a night and day difference. I do suggest whom ever you buy them from that they do their own testing and give you a warranty. My last 2 sets or EH EL34's matched quads were purchased from Jim McShane. They lasted 2 years. I just bought a new set. All but one tested
good and I noticed the channel imblance in my amp. That's my amps way of letting me know when a tube is weak. I have been living with it for nearly 11 years. I have tried to replace it with many much more expensive amps but none were able to. My ST 70 requires a match Quad. No other configuration will work well in it. I'm dying to purchase a Matched Quad from Jim McShane of Gold Lion KT77's. They may sound better than the EH's but for the $$ how long will they last? If I am to spend $200 to $400 on matched Quad it better last as long as some of the NOS back in the day. So, why spend $200 to last me only 2 years when I can spend $70 and it last me the same lenght of time and I get 98% of the sound for less money. Same for NOS I can't justify the extra $$$ if they don't last longer. I'm not sold on cryo either! Google Jim McShane you won't regret it. Ask him about his warranty too.
Thats my 2 cents worth.
The EH's in my circuit has top end extension, excellent midrange, clean sounding but bass needed a little more control.The entire audio spectrum is better than all the other tubes. I did the same test on a friends ST 70 with the Triode input board with the SED's in the first round, then the Sovteks, and then Mullards (new). I then put my EH's in there and it was a night and day difference. I do suggest whom ever you buy them from that they do their own testing and give you a warranty. My last 2 sets or EH EL34's matched quads were purchased from Jim McShane. They lasted 2 years. I just bought a new set. All but one tested
good and I noticed the channel imblance in my amp. That's my amps way of letting me know when a tube is weak. I have been living with it for nearly 11 years. I have tried to replace it with many much more expensive amps but none were able to. My ST 70 requires a match Quad. No other configuration will work well in it. I'm dying to purchase a Matched Quad from Jim McShane of Gold Lion KT77's. They may sound better than the EH's but for the $$ how long will they last? If I am to spend $200 to $400 on matched Quad it better last as long as some of the NOS back in the day. So, why spend $200 to last me only 2 years when I can spend $70 and it last me the same lenght of time and I get 98% of the sound for less money. Same for NOS I can't justify the extra $$$ if they don't last longer. I'm not sold on cryo either! Google Jim McShane you won't regret it. Ask him about his warranty too.
Thats my 2 cents worth.