gonzp Posted March 17, 2006 Author Share Posted March 17, 2006 Anybody tried a 5751 in their Blueberry? I have a pair of Rayhteon 5751 windmill getters in my Fisher 400 and I might just have to pull one out and try one in my Blueberry. I have a Amperex 6dj8 pinch waist in my Blueberry and it's not noisy at all,thank goodness. I didn't notice a whole lot of difference btween the pinch waist and the Siemenss Cca. Cheers, Robert Not being the designer of the phono section mind you. I would venture to say that is not a good Idea. The 5751 is a lower gain version of the 12AX7 and usually the last thing you want to do is lower the gain in a phono section. But check with Mark to be sure on this. Have you tried these in the 12AX7 slot in your VRD's?? Go for it you should see a big change but I'm not going to say what. Let me know what you think. Remember let them cool off a few minutes before flipping them back on!! Craig Inquiring minds want to know....... Quote Link to comment Share on other sites More sharing options...
robster Posted March 17, 2006 Share Posted March 17, 2006 Hi Craig, I tried the 5751 Raytheon Windmill getters in my VRD's but a big poof of smoke exited my amps! Just teasin' I'll try the 5751's tonite. Cheers, Robert Quote Link to comment Share on other sites More sharing options...
garymd Posted March 17, 2006 Share Posted March 17, 2006 Besides Mark, I'm guessing I've tried as many tubes as anyone else in the BBX. I've always focused on the phono stage however. The Tele ECC801S is by far the best tube I've ever heard anywhere, anytime for any purpose. HUGE difference! I now use one in both V1 and V3. It's the only Telefunken tube I've ever used that is extremely detailed and not bass heavy. It wasn't at all what I expected which is a good thing. I now have a beautiful Seimans Cca in the 6DJ8 slot although the PW was nice until it became noisy. Not too much different with LPs between the 2 but the Seimans seems to be very quiet is a great match for in 6DJ8 slot. I really like my Amperex 12AX7. Yes, it's way more detailed then the Tele. The Tele is VERY lush sounding. It's nice on leaner recordings but overall, I prefer the detail of the Amperex. I'm perfectly content with my tubes now. I bought a couple spares so I'd never run out of ECC801S's. If you can afford to pay about $135/tube, go for it. For phono, you really just need one in the V1 slot to hear how good it is. Quote Link to comment Share on other sites More sharing options...
gonzp Posted March 17, 2006 Author Share Posted March 17, 2006 Awsome guys, this is exzctly what I was looking for when I started this thread!!!! I appreciate you all sharing your experiences. PDG Quote Link to comment Share on other sites More sharing options...
robster Posted March 18, 2006 Share Posted March 18, 2006 I tried out my 2-Raytheon 5751 windmill getters in my VRD's,sound has more sparkle and vocals are richer. Before I was using Amperex Bugle Boy 12AX7's. Cheers, Robert Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 18, 2006 Share Posted March 18, 2006 The 5751 is not compatible with the BB phono stage. Using a 5751 will: -Bias incorrectly causing the 5751 plate to burn out -Vastly increase distortion -Fail to have a low enough output impedance to drive the RIAA equalization network -Upset the bias in the remaining phono tubes -Reduce gain by around 10dB The BB phono stage is not a "generic" set of 3 sockets into which one can simply plug any 9-pin miniature tube out there. Every tube stage has been meticulously balanced and biased for a VERY specific tube type to minimize distortion, optimize impedance matching between stages, and maximize gain within a "no feedback" topology with passive RIAA filtering. It's essential to understand that in a zero feedback design, minor deviations in the Gm, rP, Mu of the tube type cause major deviations of the circuit operation, as there is no feedback to "swamp out" and cover up such deviations. Upsetting the balance of any one stage upsets the balance of all three stages. While there is only a slim chance of "damaging" the actual preamp, it's also not impossible with some weird combination of tubes. As the 3-stage BB phono circuit exists, there are no stages which can be swapped for a different type type, and retain any hope of proper operation. Yes, "sound" might come out, but there exists no substitute tube which can in any way "improve" (or even meet) the proper operation, unless wholesale parts changes were made to the design. Best results will be obtained by using the intended tube types. md I thought you would say something to that effect. Actually the exact same thing can be said to some degree with all tube gear including VRD's. The tube types that I deliver will perform the best on the test bench. You might like a different compliment but your really listening to higher distortion in most cases. I have no worries about damage changing the small signal types. I went through every combination in the front end that I could think of and they all run in the safe margin of operation. Now when swapping different types of output tubes that I list as workable in the amps you have to be careful!! When using KT100, KT90, KT88's and 6550's no worries and no changes required except to bias them to the spec provided. But if your thinking of using any other tubes I listed you have to be carefull since the VRD will run them at there maximum ability. Its advisable to install a 5U4 rectifier to knock down the B+ slightly and check the bias often and start real low!! Like .40 volts. Keep an eye for the cherry red plate syndrome if it happens back the bias down. Some will be able to bias up to .55 volts other will refuse to go any higher then .45V Trying these tubes is not for the faint at heart. IMHO all of the tubes other then the first 4 mentioned are a step backwards to my own preference. Craig Quote Link to comment Share on other sites More sharing options...
3dzapper Posted March 18, 2006 Share Posted March 18, 2006 Mark, Another great explaination, your on a roll! You should include that statement in your manual. I am running a Seimans ECC88 gold pin right now. I like it better in my system than either a BugleBoy or CCa. The latter I found too "forward" for my tastes. This Seimans has, to me, the best of both, better HF extension than the BB and less pushy yet extremely clear mids versus the CCa. Rick Quote Link to comment Share on other sites More sharing options...
3dzapper Posted March 18, 2006 Share Posted March 18, 2006 Quote Link to comment Share on other sites More sharing options...
gonzp Posted March 18, 2006 Author Share Posted March 18, 2006 Mark and Craig, Thanks for being a part of this thread. It looks like it was time for this conversation(again) Quote Link to comment Share on other sites More sharing options...
Gilbert Posted March 18, 2006 Share Posted March 18, 2006 Try a Mullard 10M version of the 6DJ8. Very nice too, but even rarer than a pinch waist. Quote Link to comment Share on other sites More sharing options...
Gilbert Posted March 18, 2006 Share Posted March 18, 2006 According to our good pal Kevin Deal over at Upscale Audio, the Amperex pinch waist is a notoriously noisey tube. Kevin says that he doesn't understand why the pinch waists are so sought after. He says they are big bucks, and nearly all of them are microphonic. He said he paid a fortune for a huge lot of them, and all but one was noisy. Apparently he took it in the a$$ on them. Perhaps that's the reason for his severe sarcasm regarding the pinch waist? Here's a quote from Kevin Deal. This is when I initially called him 8 months back to enquire about purchasing a pinch waist, "why do you want to buy the worst preamp tube possible? Why not get a nice tube like a Cca?" Sorry, but that just left a bad taste in my mouth. I have no axe to grind here either way. Just relaying what he said. I could probably live with either if I were to stumble upon a non-microphonic pinch waist. Yea, Kevin says alot of things.......just keep an industrial sized salt shaker near by when you talk to him. Quote Link to comment Share on other sites More sharing options...
ben. Posted March 18, 2006 Share Posted March 18, 2006 I read my manual twice, then lost it. It's around here somewhere... I've had a bit of fun with small tubes lately, too. Digging through boxes of tubes that haven't been opened since I bought the Paragon proved quite fun. I found a great mint NOS Orange Globe 6DJ8 and a Tele 12AX7 like I don't rmember ever seeing - ribbed plate with large lettering and was labeled 12AX7, not ECC83. Sound good in the BB together. I went back to the stock ATs after some playing around with those became frustrating. I had a Motorola AT that came from an old Bassman I found in that first slot for a while, but swapped it out for the original when I ripped things apart for the listening room move several weeks back. Both sound fine, but are equally noisy. The noise is about 55dB down from peak levels when record a CD from LP. Line stages are nice and quiet. Time to go look for ATs, I guess. I also found a pair of smooth-plate Tele ECC83. I'd like to hear them in the BB, but I think they're going straight in the Mc30... I found some other useful stuff in there, too. A couple good but oddball 12BH7 for the Mc. An (unfotunately only a single) Amperex 12AU7, some NOS RCA 7591 leftover from the 299C years, along with the originals. And just a mess of 5U4, strangely enough. Quote Link to comment Share on other sites More sharing options...
garymd Posted March 18, 2006 Share Posted March 18, 2006 Check with Mark before using any questionable tubes in the BB. I had a BEAUTIFUL and RARE matched pair of GEC A2900s in the 12AT7 slots that didn't mate correctly with the BB. It turned out to be a good thing since I ended up with the ECC801S which sounded a little better I think. Quote Link to comment Share on other sites More sharing options...
tillmbil Posted March 19, 2006 Share Posted March 19, 2006 So Robster has caught on to my VRD set tup. I am running the following in my VRD's: GEC KT88's tele smoothplate 12AU7 and the highly reveled Sylvania Gold 5751's - switched to the matching tlele 12ax7 at times Yes, the highs become crisper, and the overall sound more detailed. No worry about power loss witht he Cornwalls, they play as loud as you would possibly want to hear. I run mine with the ultra linear setting. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 19, 2006 Share Posted March 19, 2006 Another real interesting side note when developing and testing the VRD's electrically speaking. First I will give a minor description of how the the 12AU7 and 12AX7 react to each other to set the stage for the little side note. The 12AX7 is the input tube and is directly coupled to the 12AU7 so it actually biases and effects the operation of the 12AU7 phase splitter. I found that when mating tubes if you used TFK/TFK, Mullard/Mullard JJ/JJ, Sovtek/Sovtek and so on the amp almost always landed this bias near design center line. When mixing a matching brands it would vary off center line by a larger margin in most cases. But once again with any conbination I plugged in it was always well within a safe margin of operation. (talk about time consuming I used some 40 different brands and pairs). A local customer had a operation late last year and I gave him the 40 sets to try while recovering. He came back with some interesting opinion's. He actually thought the original JJ's was one of the top performers out of the bunch. Another tube that has yet to be tried by VRD owner that I know of and would be completely safe in a VRD is to try a 12BH7 or ECC99 in the 12AU7 phase splitter slot. I electrically tested it but never listened so I'm guilty as everyone else. I need to quit putting it off and try them. Craig Quote Link to comment Share on other sites More sharing options...
garymd Posted March 19, 2006 Share Posted March 19, 2006 I've never swapped ANY tubes in my VRDs or MkIIIs. They seem to sound great with the JJs so I never even tried. The Pre seems to be way more tube sensitive anyway. Someday................ Quote Link to comment Share on other sites More sharing options...
Audible Nectar Posted March 19, 2006 Share Posted March 19, 2006 Craig - How about an Amperex 7316 for the 12AU7?? Familiar with that one? Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 19, 2006 Share Posted March 19, 2006 Nope never even heard of it. Quote Link to comment Share on other sites More sharing options...
Piranha Posted March 19, 2006 Share Posted March 19, 2006 According to our good pal Kevin Deal over at Upscale Audio, the Amperex pinch waist is a notoriously noisey tube. Kevin says that he doesn't understand why the pinch waists are so sought after. He says they are big bucks, and nearly all of them are microphonic. He said he paid a fortune for a huge lot of them, and all but one was noisy. Apparently he took it in the a$$ on them. Perhaps that's the reason for his severe sarcasm regarding the pinch waist? Here's a quote from Kevin Deal. This is when I initially called him 8 months back to enquire about purchasing a pinch waist, "why do you want to buy the worst preamp tube possible? Why not get a nice tube like a Cca?" Sorry, but that just left a bad taste in my mouth. I have no axe to grind here either way. Just relaying what he said. I could probably live with either if I were to stumble upon a non-microphonic pinch waist. Yea, Kevin says alot of things.......just keep an industrial sized salt shaker near by when you talk to him. And laughing all the way to his bank while he's driving one of the exotic sports cars that he has parked in his garage. Quote Link to comment Share on other sites More sharing options...
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