fanbrain Posted March 23, 2007 Share Posted March 23, 2007 I just got a Jolida 302b integrated tube amp. I love the sound so far but I'm new to tubes and have a question or two. 1. Are 12AT7 (E.H.) tubes supposed to glow. Mine aren't and I'm concerned. 2. It appears that all tubes are stock- i'm interested in rolling some Svetlana "Winged C" EL34's to improve sound, but should I also replace the (2) 12AX7's and (2) 12AT7's? If so, what should i replace them with? I listen to classical, mostly piano music, jazz, some rock (Led Zeppelin) and organ music. I am most interested in tightening the bass response for jazz and organ. Thanks for the help. I also run Magnepan SMGa's and sometimes Klipsch KSF 10.5's (with Paradigm Studio 20 v.4's arriving soon). Moderate to loud levels. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted March 23, 2007 Share Posted March 23, 2007 On some pre-amp tubes, it is hard to see the glow. The Svetlana Winged "c" are a good choice. If you ever decide to try some KT-77's, I have a brand new set I can sell you at a discount. There are tons of 12AX7's and 12AT7's out there. The 12AX7's have a MU of 100 and the 12AT7's have an MU of 60. Aside from the brand name choices, some folks prefer to swap in tubes of lower MU values for example, 5751's instead of 12AX7's and 12AV7's instead of 12AT7's. Good thing is the pre-amp tubes are inexpensive. 12AU7 17 *4003 195963 195815 196189 19ECC82 17 * 12AV7 415965 41 12AT7 60 *12AZ7 60CV4024 6062016679ECC81 60 * 5751 70 * 12AX7 100 *CV4004 1007025 1006681 100ECC83 100 * Quote Link to comment Share on other sites More sharing options...
fanbrain Posted March 23, 2007 Author Share Posted March 23, 2007 Thanks for the input; the tubes are glowing, although very faintly. One is so dim I'm not sure it really is glowing. speakerfritz, I was unaware that KT-77 tubes were compatible with EL-34's. What is the advantage? What do lower MU values do to the sound? Also, I've read that if you have individual bias adjustments for each EL-34 (in my case), you don't need to buy matched sets. Is this true? Thanks for your help. Tubes are fun. [H] Quote Link to comment Share on other sites More sharing options...
Tarheel Posted March 23, 2007 Share Posted March 23, 2007 Replaced the EL-34s with KT-77s in my Quicksilver Horn Monos...good change. Might want to contact Doug at Dougstubes.com he can tell you what his customers prefer. Chuck Quote Link to comment Share on other sites More sharing options...
Tarheel Posted March 23, 2007 Share Posted March 23, 2007 Didn't read all of Speakerfritz's comments. You might want to consider his KT-77s. I think they sound great. Chuck Quote Link to comment Share on other sites More sharing options...
fanbrain Posted March 23, 2007 Author Share Posted March 23, 2007 How do the KT-77's sound? If they offer a significant improvement over stock EL-34's and the winged c EL-34's, let me know how much $$ and a description of it's sound and I'll mull it over. Again, I'm looking to tighten up the bass and any other improvement over that is welcome. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted March 23, 2007 Share Posted March 23, 2007 There are numerous sites that have rave reviews about the JJ kT-77's. Go to this link and scrow down to the bottom and you will see some comments from folks who have tried the KT-77's. The KT-77 is a drop in replacement for the EL-34 resulting in both a improved and well defined bottom end as well as clear and accurate highs with out sacrificing the mid range. Before I bought them I could not find any site that had anythign bad to say about them. I bought a few sets in November, but have since sold the amps that I was stocking them up for. I paid 70 bucks for them from Dougs tubes, I sell a matched quad for 50 bucks plus shipping. http://www.eurotubes.com/euro-u.htm You can google JJ KT-77 to come up with more sites. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted March 23, 2007 Share Posted March 23, 2007 "Also, I've read that if you have individual bias adjustments for each EL-34 (in my case), you don't need to buy matched sets. Is this true? " Amps that have individual bias adjustments for each tube are more forgiving than those that do not, but matched tubes factor in other tube qualities if done correctly such as transconductance, aside from plate resistance. My impressions are that the bias adjustment process really is fine tuning proerties associated with differneces in plate resistance between tubes to balance them, but can not compensate for significant differences in transconductance. Anyone fee free to clarify or correct. Quote Link to comment Share on other sites More sharing options...
fanbrain Posted March 24, 2007 Author Share Posted March 24, 2007 speakerfritz, you have a PM. To all members of the Klipsch forums: I'm into tubes now and it's all your fault. I hope you're all happy. Sheesh. Quote Link to comment Share on other sites More sharing options...
Mallette Posted March 24, 2007 Share Posted March 24, 2007 speakerfritz, you have a PM. To all members of the Klipsch forums: I'm into tubes now and it's all your fault. I hope you're all happy. Sheesh. No, not yet. Don't see a TT in your profile. [6] Quote Link to comment Share on other sites More sharing options...
fanbrain Posted March 24, 2007 Author Share Posted March 24, 2007 It's not in my profile, it's sitting here unused. Luckily that bug hasn't bitten.[] edit: profile updated. Quote Link to comment Share on other sites More sharing options...
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