el-34 or kt88

[audioray]

i dont know how many eiclones have been built useing REV b board.
i would like to know what tubes are more prefered.
the EL 34 or kt 88 plus what brands. price not to much of a problem

[EWBrown]

Once I get the final mechanical assembly completed on my Ikes, I plan on using Svetlana 6 "Winged C" 6550Cs, and some Tango OPTs I purchased a few months ago. I'll keep the power level to 50 watts each.

/ed B in NH

[Shannon Parks]

i dont know how many eiclones have been built useing REV b board.
i would like to know what tubes are more prefered.
the EL 34 or kt 88 plus what brands. price not to much of a problem

I like both, but the KT88's would allow you to run your Ikes pretty aggressively (if you chose to do so).

On the flip side, JJ E34L's are cheap (close to $40 a matched quad). They test well in my rig and sound fantastic! I will admit I hate their socket pins though. I've had problems squeezing them into NOS octal sockets before, and getting them into the chinese ceramics is even worse. The pins just aren't smooth like old octals, and the last batch I purchased didn't have cone shaped tips - they were flat! Grrr. :letitallout:

Shannon

[TerrySmith]

I've noticed that Electro-Harmonix has a version of a KT90 now! Are KT90's the same as KT88's, or do they have higher ratings? :?:

And there not ugly like the Ei tubes! :pottytrain5:

[EWBrown]

A good use for those old metal 12SK7 (and similar) tubes, is to use them to "loosen up" those tight octal sockets. Rather than risk breaking a pricey glass tube, a cheap "junk" metal tube does this very well, and they are tough enough to take the abuse.

Similarly, I save a couple of bad 6BQ5s for loosening those ceramic 9 pinners from AES that are used on the DIY35. I wrap the bottle in tape, just to prevent any breakage and finger cuts.

I used the JJ EL34s in my "stainless steel behemoth" ST70 dynaclone, they sound great!

/ed B in NH

[audioray]

last night i was talking to uncle NED and he said when he builds his amps
he will use kt-66 tubes . what are these tubes. are they in the 6l6 family.
are they better than EL34 or KT88 tubes.
allso is there any input for the kt90 tube. is it same the same as kt88 tube
im trying to find the best tubes i can so i dont end up with a box full

[erichayes]

Hi All,

The KT66 was the Brits' answer to the 5881/6L6GB. The "KT" designation stood for "kneeless" or "kinkless" tetrode (depending on which sources you want to believe), and referred to the plate curve characteristics of the beam power tube versus an equivalent power pentode. Power pentodes had a little hiccup at the base of the curve which was dramatically reduced with the beam power design. Yawn.

The KT77 is equivalent to the 7581/6L6GC, and the KT88 is the Limey version of the 6550. Of course, now that all these tubes are being built in eastern European and former Soviet countries, all bets are off as to how they compare to the original English and US tubes' specs.

The KT90 was created by Manley Labs and built by EI of Yugoslavia. It was supposed to have the virtues of the 6550 and KT88 and the shortcomings of neither. I guess the patents expired, as I see other manufacturers are now producing it as well as something called a KT100.

[gogzhad]

My experience with EL-34's in Dynaco ST-70's and Marantz 8B's led me to believe that the Mullard tubes are very nice, and not too hard to come by. The Genalex KT-88's are very nice. I think Vacuum Tube Valley has done shootouts of a variety of each of these over the years - I'll see if I can dig up the issues and post some of the top listening tested tubes.
I think a lot of ST70's came with Mullard tubes, some possibly were Dynaco branded.
Ymmv, but I have had only good luck with the Mullards.
best of luck,
dave

[Shannon Parks]

last night i was talking to uncle NED and he said when he builds his amps
he will use kt-66 tubes . what are these tubes. are they in the 6l6 family.
are they better than EL34 or KT88 tubes.
allso is there any input for the kt90 tube. is it same the same as kt88 tube
im trying to find the best tubes i can so i dont end up with a box full

Yes, Ned highly recomends these. With their premium over the EL34's, I probably won't get a quad anytime soon. I'm more broke than a cheapskate, really.

I have tried Sovtek KT88's with great success. These are stout tubes, and they take a beating. Thermion has a quad that has over 2000 hours and they test on his Hickok as new. JJ KT88's are excellent too, though expensive.

I purchased a couple discounted quads of Type III KT90's from Jim McShane in the past year. I think these EI's are ugly/cool! From a Freudian viewpoint, they are winners hand down. They test well and should be able to be beat hard, but I haven't done much testing with them, either on the bench or in the listening room.

I've yet too hear <any> of these tubes not sound stellar in the Ike topology, though.

Shannon

[Shannon Parks]

I've noticed that Electro-Harmonix has a version of a KT90 now! Are KT90's the same as KT88's, or do they have higher ratings? :?:

And there not ugly like the Ei tubes! :pottytrain5:

I think Jim McShane was looking at these. He probably has an opinion of them. :mrgreen: He is a EH fan and a KT90 fan, so I imagine he'll love them.

Max Plate + Screen Dissipation from EI website
Actual Wa + g2 is probably about 10% less
http://www.eierc.com/rc/6L6GC.htm -- 21.5W
http://www.eierc.com/rc/EL34.htm -- 35.5W
http://www.eierc.com/rc/6CA7.htm -- 35.5W
http://www.jj-electronic.sk/tube_kt88.htm -- 50W (Genelex is more like 40W)
http://www.eierc.com/rc/KT90.htm -- 54W

After compiling this data and looking at NOS and modern power tubes, I would highly recommend looking at the datasheets.

Shannon

[Thermion]

I have tried Sovtek KT88's with great success. These are stout tubes, and they take a beating. Thermion has a quad that has over 2000 hours and they test on his Hickok as new. JJ KT88's are excellent too, though expensive.
Shannon

I have well over 2000 hours (maybe as much as 3000 hours) on my quad of Sovtek KT88s. As Shannon says, they still test like new on my Hickok 6000A. These are great tubes!!! Especially at ~$100 bucks a quad. What he is not telling you is the following. He recently created a prototype mod board for Dyna MKIII's and I built a pair and put them in my MKIII's. It was a "substantial" upgrade from David Hafler's 6AN8 design. I am currently using a quad of JJ KT88s that I bought last summer. Shannon has had some reservations about JJ tubes, but I feel that JJ are the best currently manufacturered tubes available today. Anyway, we tested my MKIIIs for gain and distortion before and after the mod on Shannon's test bench. When doing the after mod tests, we replaced the much newer JJ tubes with the very used Sovteks. The result was surprising. The sovteks had lower distortion then the JJs. I still think the JJs are built better, and sound a little better. (especially in the low end) But the Sovteks would be a good choice for anyone building the Ikes. I still haven't decided what tube type I will use for my Ike project.

I bought a matched quad of Svetlana 6550C's for my MKIIIs about 7 years ago. (the quad before the Sovtek KT88s) After 2000 hours on these, two of them were completely used up. Also, the tubes are extremely filament sensitive. If using Svetlana's make sure the voltage is close to 6.3 vac. Based on my experience, I would never reccommend these tubes.

I am planning to buy a quad of Russian "Electro-Harmonics" 6550s. They have the same shaped glass as the KT88s. Will let you know how this works out.

JT

[audioray]

i have been reading feedback on AA about this tube 6ca7EH fat bottle
and most people regard it better than the el34. the more i read the more
difficult it is to pick the correct tube.
el34eh
6550eh
6cateh
kt88eh
6sn7eh
12ax7eh
HELP
thank you every one.

[TerrySmith]

I tried 6CA7-EH in my ST-70 and my MK-IV's, and they sound superior to the EL34's I had. :thumbup:

[TerrySmith]

A couple of years ago, I got two matched quads of Svetlana 6550-B2. Did a little tube rollin' in my Music Reference RM9. Well, some looked normal, some had red spots, and one had fireworks! These are the only "B2" suffix 6550's I've seen.

Anyone else had any experience with these?