Guest " " Posted October 31, 2006 Share Posted October 31, 2006 I spoke with the folks at Cary Audio today while ordering some schematics for the pair of monoblock amps I picked up, and they mentioned that The amp (like most that use el-34's) can use KT-77's. Has anyone one interchanged the EL-34 for the KT-77. A google search turns up that the KT-77 sounds a little tigher than the EL-34. The amp uses EL-34's, 12AX7, 12BH7. Are there any other swap out oppurtunities other than manufacture's or brand names? http://forums.klipsch.com/forums/1/815806/ShowThread.aspx#815806 Quote Link to comment Share on other sites More sharing options...
chops Posted October 31, 2006 Share Posted October 31, 2006 I spoke with the folks at Cary Audio today while ordering some schematics for the pair of monoblock amps I picked up, and they mentioned that The amp (like most that use el-34's) can use KT-77's. Has anyone one interchanged the EL-34 for the KT-77. A google search turns up that the KT-77 sounds a little tigher than the EL-34. The amp uses EL-34's, 12AX7, 12BH7. Are there any other swap out oppurtunities other than manufacture's or brand names? http://forums.klipsch.com/forums/1/815806/ShowThread.aspx#815806 The KT77 is the same thing as a 6CA7, which is a beam tetrode whereas the EL34 is a pentode. The KT77/6CA7 does provide a fuller, meatier sound than the EL34, more of that "tube" sound you might say. I just sold my two Quads of 6CA7's a few months back. I preferred the Vavle Arts over the EH's. Just as a side note, you may want to contact Cary again and ask them if your amps can run 6550 tubes which are tetrodes. My Consonance M100SE (when I had it) could also run the 6550, KT88 and KT90 and that amp sounded best with the 6550s, with the VA 6CA7s a real close second. Quote Link to comment Share on other sites More sharing options...
chops Posted October 31, 2006 Share Posted October 31, 2006 BTW, for the 12AX7s, you can roll them out with ECC83 or 5751 tubes. They're a high gain triode. I think the 5751's are a JAN tube (Joint Army Navy), which usually means they are built a little more rugged than the rest. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted October 31, 2006 Share Posted October 31, 2006 chops Intresting. I'll call them again and ask about the KT-88's and 6550's. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted October 31, 2006 Share Posted October 31, 2006 chops Intresting google read on the 5751. Lower gain (70 vs 100) and "sweeter sound". Any swap canidates for the 12BH7. Looks like I'll be buying some of the variants to see how they sound. Quote Link to comment Share on other sites More sharing options...
chops Posted October 31, 2006 Share Posted October 31, 2006 chops Intresting google read on the 5751. Lower gain (70 vs 100) and "sweeter sound". Any swap canidates for the 12BH7. Looks like I'll be buying some of the variants to see how they sound. I haven't had any experience with the 12BH7 tube. I'm guessing that one is used for the driver tube and the 12AX7 for the preamp section. My M100SE used 12AX7s for the preamp section which I rolled over to 5751 NOS GE tubes Grey Plates, and the driver tubes were 6SN7s which I found a sweat pair of NOS Raytheon Baldwin Black Plates. If you look closely, you can see that I was running a quad of KT88s in this bottom pic... Quote Link to comment Share on other sites More sharing options...
Guest " " Posted October 31, 2006 Share Posted October 31, 2006 chops ok, I'll keep hunting. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted November 4, 2006 Share Posted November 4, 2006 Status update. I replaced the el-34's with KT77's. The sound change was consistent with claims. So this is a keeper. Also tried the 5751 swap for the 12ax7 that Chops recommended, thats a keeper as well. I also put in a 5814 in place of a 12bh7. This was just done to put a new tube in the experiment for the phase inverter. Very intresting how yo can drop in a tube, and change the sound. Here's some info i found MU Tube Sub100 12AX7 - ECC83, 7025, ECC803, E83CC, 6681 70 5751 - 60 12AT7 - ECC81, 6201, 6679 45 12AY7 - 6072 41 12AV7 - 5965 19 12AU7 - ECC82, 5963, 5814, 6189 This one I'm still looking into. 20 12BH7 (JJ ECC99 or 5814) Quote Link to comment Share on other sites More sharing options...
chops Posted November 4, 2006 Share Posted November 4, 2006 I'm glad to hear the KT77s and 5751s did the trick for you. Tell me, did the 5814 do anything for the sound at all? Quote Link to comment Share on other sites More sharing options...
Guest " " Posted November 4, 2006 Share Posted November 4, 2006 "did the 5814 do anything for the sound at all? " It's hard to say, since I replaced every tube in both of my amps. I mainly replaced the 12BH7 so that I would have a "new" baseline since all the other tubes would be new. Technically I was supposed to use a 5814, or a JJ ECC99 in place of the 12BH7, but I came up short on tubes when the tubes I ordered ("NOS" 12BH7), were mixed vendors (RCA and GE), and I did not want to use them. Did some checking, and the 5814 had a MU of 19, vs the 12BH7's MU of 20. I also had some ecc82's that I would have tried, if the 5814's did not work out. I am probally going to use the 5751's in my pre-amp as well, once it arrives. BTW, it turns out a lot of folks are using the 5751 in place of the 12AX7's. Quote Link to comment Share on other sites More sharing options...
chops Posted November 4, 2006 Share Posted November 4, 2006 BTW, it turns out a lot of folks are using the 5751 in place of the 12AX7's. Yeah, I think the reason for that is mainly because the 12AX7 is such a high-gain tube (MU 100) that it can be a little noisy and even a little bit harsh. This is one of the reasons why I went with the 5751s and why many go with the AT7s and AU7s as a replacement. Quote Link to comment Share on other sites More sharing options...
Tarheel Posted November 10, 2006 Share Posted November 10, 2006 Speakerfritz....just curious... how did the tube swap go for you? Any thoughts on the kt-77s? I did the same swap in Quicksilver Horn Monos with good results. Chuck Quote Link to comment Share on other sites More sharing options...
Guest " " Posted November 10, 2006 Share Posted November 10, 2006 Electrically the tube performed very well. I wanted to try the KT-77 becuase it was reportedly slightly broaded iin bandwidth as well as crisper or "tighter" sounding. Mechanically, however, the pins and center pin guide have issues. There has been some discussions about the issues at other internet sites. Basiclly the pins or the center pin guide on the kt-77 is slightly smaller than an el-34. To get around this, I cut a small peice of balc electrical tape about 1/4 of an inch wide and 3/4 of an inch long. I wraped the tape around the center guide pin. This provided a snug fit that was properly centered. Quote Link to comment Share on other sites More sharing options...
Deang Posted November 10, 2006 Share Posted November 10, 2006 The 12AX7 and it varients are typically used as driver/input tubes. Swapping these around definitely changes up the sound. 12AU7 and its varients are normally used as phase splitters -- I've never been able to tell a difference playing with these. 12BH7 (ECC99) is also used as a phase splitter. You can normally interchange the 12AU7 and its varients with the 12BH7 -- I've done it plenty and could never hear a difference. Play with driver tubes. In preamps you have to be very careful with this kind of thing. Quote Link to comment Share on other sites More sharing options...
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