NOSValves Posted December 20, 2002 Share Posted December 20, 2002 Okay need some feedback on what current production 6550/KT88 is going to have the best sound for the Mark III project. I'm pretty sure we will mod these amps with a replacement all triode front end board and also most likely run the outputs in triode also. These amps have way to much power for Khorn or Lascalas so triode should be a great option and safety factor. I can't turn them up past about 11:00 with my lascalas !! It hurts Mobile and others, These amps are going to need the multi section filter cap replaced one is original and the other has been replaced with a less then spec voltage rating cap. What do you think of using Neds replacement board for this setup it ups the value by almost double. But also AES has the exact factory replacement available. I think from a visual standpoint the AES option would be better. I have a funny suspision that these replacement boards were brought out only because there were no multi section cap replacements available and the rest is hype. The factory option is being trumpt as not reliable but there a factory original still in one amp going strong ! I have to get a game plan going on these so we can get the parts ordered once Dale gives me the go ahead. Craig Quote Link to comment Share on other sites More sharing options...
Deang Posted December 20, 2002 Share Posted December 20, 2002 Craig, while you are out at Ned's site, pick up a quad of the Svetlana KT-88's. I ran these in both of my AE-25's, and they sound dynamite. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted December 20, 2002 Author Share Posted December 20, 2002 They have a new 6550-C also and its on special for $90 a quad what do you think it may be like ? The KT-88's go for $119 a quad. Craig Quote Link to comment Share on other sites More sharing options...
Deang Posted December 20, 2002 Share Posted December 20, 2002 If I remember from earlier threads regarding this subject -- I believe the 6550's will offer more bottom end slam, but will be lacking in the warmth department. If it's any consolation -- I don't think Kelly cares for 6550 all that much. I believe he would say, "The 6550 offerings do not deliver a classical tube sound. While they do put foward in the area of dynamics, I find them unable to deliver much bloom, or contribute much to midrange liquidity, which I find essential in experiencing the next level of engagement with the music. As a matter of fact, they might sound much like Dean's Apollos -- stay away" Quote Link to comment Share on other sites More sharing options...
sunnysal Posted December 20, 2002 Share Posted December 20, 2002 I would agree, I have heard both tubes (not on my own amps but...) and the kt-88 seemed more pleasing to me...the highs seemed kinda "strict" with the 6550...tony Quote Link to comment Share on other sites More sharing options...
NOSValves Posted December 20, 2002 Author Share Posted December 20, 2002 Well looks like KT-88's are winning the Opinion pole so far ! Here are some pics of the amps Quote Link to comment Share on other sites More sharing options...
Dale W Posted December 20, 2002 Share Posted December 20, 2002 Holy wack craig , you were'nt kidding about these things having some "MAJOR IRON". Should cost me a fortune to get them home. lol Cosmeticly they seem in good shape, Now lets make them sound sweet. Could you also pop a set of 5 way binding posts or so on the back. My monstercable sigma has battery cable size spades.Anyway we can talk over the phone or by e-mail on the rest. Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted December 20, 2002 Share Posted December 20, 2002 I have to say, the 6550 and KT-88 are not my favorite output tube in general. Like Dean predicted, I think they are more sterile with less of that endearing tube thing going than good EL-34. On the other hand, some amps sound better with KT-88 option. In listening to the Super Amp, and comparing Svetlana EL-34 with the China KT-88 in triode mode, I actually LIKED the KT-88 better. This was a first to me. IF going between the Svetlana 6550 and the Svetlana KT-88, I would definitely side with the KT-88. To me, it's a better sounding option just tube wise. Although neither is my first choice for power amp, the KT-88 easily wins in this spot. So go for the Svetlana KT-88. As for the AES debate, you might want to up the PS capicitance on this. I think it could use it. On the other hand, it's nice to look stock too. I dont know. It's your call here. Perhaps I would do some more research in Tube Asylum for people doing mods. Talk to some of the guys there that have done these amps that seem on the ball sound wise. As for the triode output, do some research here as well. Some transformers dont take as well. See how many guys have switced to triode wired hat did this amp. I actually prefer UL wired in a lot of PP, believe it or not. And save the triode for the real triode tube amps. Others disagree. you might test it since it's an easy mod. Those amps look in GREAT shape, though. kh Quote Link to comment Share on other sites More sharing options...
NOSValves Posted December 20, 2002 Author Share Posted December 20, 2002 Mobile, The triode mod is a simple 4 resistors to solder in so its easily reverse I'll have to play that one by ear ! I still think adding new cans is the way to go. If it seems like it needs more compitance I'll just add some Sprague Atoms under chassis to up the value. They make a nice 20 uf @ 600V that would do a nice job. The 5AR4 can't take more than 60 uf on the first stage anyway. Looks like KT88's are thee winner all around. Craig Quote Link to comment Share on other sites More sharing options...
mike stehr Posted December 20, 2002 Share Posted December 20, 2002 I can't turn them up past about 11:00 with my lascalas !! It hurts Oh! So you do have a threshold for pain. Yer ears didn't go girl on ya, did they? Quote Link to comment Share on other sites More sharing options...
sunnysal Posted December 20, 2002 Share Posted December 20, 2002 I have a small switch wired into my mkIVs that allow me two switch to triode strapped and back again (NOT on the fly, turn it off before switching!) and I liked the EL34s in triode strapped mode. but you get a real nice kick in the butt when in tet mode...regards, tony Quote Link to comment Share on other sites More sharing options...
Chris Robinson Posted December 20, 2002 Share Posted December 20, 2002 I'll just toss something in here for discussion sake ... Mobile has a quad (soon to be five) of the old vintage ('50's) Marconi TT22, which is very similar to the KT88 except that it has a top anode connection. This means that they need the little "hat and wire" to run it. I accidently picked these up from a guy in the UK who was selling them. They're selling on Tube World for $400 A PAIR in NOS condition and matched. Kelly's going to test them out (hell, they could be all bad) but for those of you who are looking for the "ultimate" KT88 and have the flexibility to set them up this way, it could be quite nice. This from Tube World (http://www.tubeworld.com/europe.html) KT88 GENALEX EQUIVALENT = GEC TT21 The TT21 is a GEC transmitting BEAM TETRODE that looks just like a KT88 with a top cap connection. The specs are the SAME as a KT88, except the TT21 has a HIGHER PLATE VOLTAGE maximum rating. The top cap anode connector gives better isolation between anode and grid. Superior sonics to KT88 Genalex / GEC. TT21 data sheet available with order. TT22 GEC ENGLAND (TT22=TT21 with 12.6V filament) Quote Link to comment Share on other sites More sharing options...
Chris Robinson Posted December 20, 2002 Share Posted December 20, 2002 Here's a photo of the TT21 and TT22 ... They're a bit bigger than the normal KT88. Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted December 20, 2002 Share Posted December 20, 2002 Craig, You can change the Mark III's to a Mark II's and use el-34's instead.Or if I am not wrong,one of the amps has a pair of very desireable Tung-sol 6550's so in case that they are indeed Tung-sols and test ok,try to find another good used pair and I am sure that they will sound much better than new production tubes. Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted December 20, 2002 Share Posted December 20, 2002 The Sogvtek KT88 have bigger anodes and sound better than the Svetlanas. Triod Electronics have special sale prices on some of these tubes at the moment. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted December 20, 2002 Author Share Posted December 20, 2002 Guy, Not sure if either set is Tungsol's one set are Ruby Tubes made in china and the other just say Made in the USA . But neither test very strong and don't pass a life test so I believe new ones are in order. The EL-34 option sounds interesting havn't run into anyone or anything talking about doing this yet but I'll keep looking. Thanks Craig Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted December 20, 2002 Share Posted December 20, 2002 Guy, I have read that the Svetlana KT-88 sound better than the Sovtek in more than a few places. Have you compared both? The only Sovtek tube I like is the 2A3. Their 5AR4 is supposed to be ok when it doesnt have problems. But NOS vintage is ALWAYS better if you have them! See below. As for the TT22, see below. I just took this shot now. Anyone interested, drop me a mail. kh Quote Link to comment Share on other sites More sharing options...
Chris Robinson Posted December 20, 2002 Share Posted December 20, 2002 Kelly, you are TALENTED! Quote Link to comment Share on other sites More sharing options...
Allan Songer Posted December 20, 2002 Share Posted December 20, 2002 Quote Link to comment Share on other sites More sharing options...
Allan Songer Posted December 20, 2002 Share Posted December 20, 2002 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.