NOSValves Posted May 31, 2010 Author Share Posted May 31, 2010 Thebes, Actually in recent times not many high end preamps are being designed with the 6DJ8 and its variants. Most of the high end manufacturers dumped it for the very same reasons Mark did. The big problem with the 6DJ8 is that as it ages it will not absolutely test as bad in most tube testers.... that is not the aging symptom the tube usually displays... in fact many test stronger as they age in basic Hickok type tube testers... The major problem with these tubes is they become noisy and unstable as they age which most basic tube testers will not reveal. Another problem is the tube has to really heat up before it becomes noisy in most cases so again even a tube tester with a noise test may not catch the noisy tube... So you have tons of these tubes circulating as "good" and being plugged in respectable pieces of gear which in turn makes the novice user start pointing at the piece of gear as defective. No win situation for the designer and cost valuable support time. It's kind of like the dreaded ground loop support syndrome its gets real old explaining and diagnosing ground loops but that is unavoidable for the most part. The 6U8, 6BL8 and 6GH8 that Scott uses as a driver/phase inverter has the exact same kind of aging problem..So I know all too well what helped drive Mark's decision. Lucky thing with the Scott tube is nice NOS variants are readily available and only costs about $10 at the most. Craig Quote Link to comment Share on other sites More sharing options...
Audible Nectar Posted May 31, 2010 Share Posted May 31, 2010 Craig and Mark hit on a LOT of good points. The 6H30 is absolutely the easier tube to work with, and given the availability of TRULY NOS 6dj8 family tubes, I certainly can understand the reasoning. The fact is that there really isn't much out there in the realm of TRULY NOS 6dj8 family tubes, so people go shopping for "test NOS" tubes that are actually used beyond the point of quiet service in a no-negative-feedback preamp like a JM. This is a risky endeavor for the tube roller.....you takes your chances with current vintage 6dj8 family stock, and that's no fault of the designer. In fact, the designer has done everything reasonable to discourage vintage tube rolling, because in the end he doesn't want to take responsibility for the "adventurism". This is a reasonable position. I have approached my preferences (or at least enjoyment) of the 6dj8 vintage flavors with the full awareness and knowledge of these risks. I have a luxury most don't - a good stock of 6922/7308 vintages that I know for sure are new/NOS. For MOST who are seeking out a JM preamp for the first time and have no NOS 6dj8 family stock, it is very safe and reasonable to go with 6H30....or prepare to get your wallet out on the 6dj8 stuff, and the risks associated with that tube in this preamp. In my case, I have other components that can make use of 6dj8 tubes not uber quiet enough for the JM (Ah! Njoe Tjoeb 4000 CD).....so I don't have to waste any of my NOS stock that turns out less than JM suitable. This mitigates the risk of my preferences. I am also aware of similar phenomena regarding the 6U8 tube. I have a sizeable stash of FrenchRadiotechnique 6U8 for this very reason - key to good sonics on my MX110. I would also be game for a Craig-created tube VRD preamp. Couldja make one around a 5AR4 rectifier and maybe a 12AX7[8-|]? Quote Link to comment Share on other sites More sharing options...
seti Posted May 31, 2010 Share Posted May 31, 2010 Thebes, Actually in recent times not many high end preamps are being designed with the 6DJ8 and its variants. Most of the high end manufacturers dumped it for the very same reasons Mark did. The big problem with the 6DJ8 is that as it ages it will not absolutely test as bad in most tube testers.... that is not the aging symptom the tube usually displays... in fact many test stronger as they age in basic Hickok type tube testers... The major problem with these tubes is they become noisy and unstable as they age which most basic tube testers will not reveal. Another problem is the tube has to really heat up before it becomes noisy in most cases so again even a tube tester with a noise test may not catch the noisy tube... So you have tons of these tubes circulating as "good" and being plugged in respectable pieces of gear which in turn makes the novice user start pointing at the piece of gear as defective. No win situation for the designer and cost valuable support time. It's kind of like the dreaded ground loop support syndrome its gets real old explaining and diagnosing ground loops but that is unavoidable for the most part. The 6U8, 6BL8 and 6GH8 that Scott uses as a driver/phase inverter has the exact same kind of aging problem..So I know all too well what helped drive Mark's decision. Lucky thing with the Scott tube is nice NOS variants are readily available and only costs about $10 at the most. Craig Thanks. I've never heard this explanation but it certainly reflects what is going on with this tube on the market. I've spent allot of cash on noisey pairs myself. Quote Link to comment Share on other sites More sharing options...
gartenman Posted June 1, 2010 Share Posted June 1, 2010 I 've learned a lot by this thread. Thanks all for the insight. 1 Quote Link to comment Share on other sites More sharing options...
Marvel Posted June 2, 2010 Share Posted June 2, 2010 I'm glad the Merlin only uses ONE... [] Bruce Quote Link to comment Share on other sites More sharing options...
kaiser SET say Posted June 2, 2010 Share Posted June 2, 2010 I'm glad the Merlin only uses ONE... Bruce Neat, huh! Indeed and it makes easy for Bruce to find a matched single[] LOL Quote Link to comment Share on other sites More sharing options...
thebes Posted June 2, 2010 Share Posted June 2, 2010 Wow, Craig and Mark, I really do appreciate those responses.I know first hand the trials and travails of getting good 6DJ8's since I have an Anthem pre that uses four of them. It took over a year, a batch of money, and some serious experimentation to come up with some world class winners. Now I understand why designers liked them so much. I think this is the kind of knowledge base that makes this place so special, especially when the forum wise-ones check in. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted June 4, 2010 Author Share Posted June 4, 2010 I ended up ordering a EH and a DR version... SO I won't be accused of not knowing something tubey again [] Now if UPS would deliver my BBX I'd be all set...... week and half from Mark's place to mine.... how the heck does UPS get away with that kind of service? Craig Quote Link to comment Share on other sites More sharing options...
Audible Nectar Posted June 4, 2010 Share Posted June 4, 2010 I ended up ordering a EH and a DR version... SO I won't be accused of not knowing something tubey again Now if UPS would deliver my BBX I'd be all set...... week and half from Mark's place to mine.... how the heck does UPS get away with that kind of service? Craig Cool[H] I will be looking forward to your opinions on those tubes. This is a subject that has interested me a great deal. As for UPS, I wouldn't be worried about the TIME they take as much as I would worry about how they handle the package during that week and a half. I would wait a month if I knew they wouldn't hammer on my preamp. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted June 4, 2010 Author Share Posted June 4, 2010 Cool I will be looking forward to your opinions on those tubes. This is a subject that has interested me a great deal. As for UPS, I wouldn't be worried about the TIME they take as much as I would worry about how they handle the package during that week and a half. I would wait a month if I knew they wouldn't hammer on my preamp. Well knowing the Apes at UPS all too well I cringe at the thought of every day something of mine is in there hands... the longer they take the more chance for damage. Quote Link to comment Share on other sites More sharing options...
klipsch4life Posted January 30, 2011 Share Posted January 30, 2011 Craig Never heard your thoughts on the 6H30 shootout. You have a preference? I just bought a Blueberry Extreme and I am going to A/B it with my Mac C-11 with all Tele's. Kevin Quote Link to comment Share on other sites More sharing options...
Audible Nectar Posted January 30, 2011 Share Posted January 30, 2011 As an owner of an MX110 (much like the C11 sonically) and a JM Peach I can tell you there is really good stuff in both. I chose to use these preamps as control centers for two systems, as these two preamps are quite different - and give me two distinct sonic "angles" that I really love. I have also noted that it's not just the preamp that matters - it's the synergy between the preamp AND amp that brings the real magic. My MX110 loves the vintage Mac amps (and are the midrange KINGS with a tonality I love) - and the JM/VRD combo is a display in clarity, accuracy, and liquidity that is too good for the money invested. From what I know now of the 6H30 it's primarily a difference in "finish" vs. the 6DJ8 family of tubes in the JM....it won't change the basic sound of the BBX, more like a "tube roll" difference. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted January 30, 2011 Author Share Posted January 30, 2011 Craig Never heard your thoughts on the 6H30 shootout. You have a preference? I just bought a Blueberry Extreme and I am going to A/B it with my Mac C-11 with all Tele's. Kevin Kevin, I'm kind of embarrased to say my 6H30-DR is still in the box as deliivered countless months ago right next ot my BBX. My lack of interest in swapping in should give you a hint as to the importance of messing with that tube IMHO. I think the EH sounds outstanding and I just have not felt the need to roll the DR in. The BBX has worked flawlessly since it was upgraded to the last revision with remote so I have employed the "If it ain't broke" don't mess with it theory. As far as if the 6H30 is an upgrade/down grade from the gold pin early 60's phillips 7308 I was using before the mouse destroyed my BBX....I honestly could not say I was without my BBX for almost 2 years for various reasons (mostly my own laziness and lack of time to get to retrofitting it myself) so my audio memory is way past being realible on that. I can say "I do not regret in any way changing to the 6H30" . The remote was really a waste of my money since I 've used it like twice... but I knew I would hardly use it when using the preamp in my shop. I figured it would add value if I ever sold the preamp and come in handy at trade shows. Craig Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted February 1, 2011 Share Posted February 1, 2011 Wish I had caught this thread when it started. Very informative. But please correct me if wrong. Isn't one of the strict definitions of New Old Stock tubes something like: It shall test to within 20% of its original design value??????? If true, that doesn't say NIB or address how many hours the tube has on it. Pulls could qualify as NOS. Must think that audio quility vintage Brand Spanking New tubes are few and far between. tc Quote Link to comment Share on other sites More sharing options...
Audio Flynn Posted February 2, 2011 Share Posted February 2, 2011 Totallly OT but just a quick note to tell you how much I love the VRDs that you freshened up for me from Mile Lindsay. I am a walking commercial fot your products. With JM sadly gone forever- so it appears-Maybe you could step up to the plate and start making VRD PREAMPS????? Make no mistake- CRAIG is the man. Craig is all about customer satisfaction. VRD preamps would be an exellent endeavor which most likely the conomics of today would not fund for a self funded business like NOS Valves. If Criag went foward I would vote for a a 12AX7 based preamp. I tortured him with updating my AMPEX vintage 12AX7 preamp many years ago. Nice preamp but a boomy mid bass on the phono section since it was voiced for early high end console stereo systems. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 2, 2011 Author Share Posted February 2, 2011 The strict definition of NOS is N = Absolutely new never used O = Old as in from the 60's, 70's or 80's ...... S = Stock from those years listed and has been sitting on the shelf or stored away in some box. An NOS tube can also be NIB which just means New In Box (original box). A tube that has been used in the past no matter how it tests in the tube tester is not new so it does not qualify as NOS. Many tube types will test just like the day they were made right up to the point where they become unusable for various reasons many times noise related like with the 6DJ8 family. Heck some tubes even tested stronger then new even though they are unuseable like the 7591 output tube. You test them and think man these are strong! Only to have them run away going cherry red once placed in circuit. At the very least a used NOS tube should always be listed as being USED NOS or UOS. Quote Link to comment Share on other sites More sharing options...
Audible Nectar Posted February 2, 2011 Share Posted February 2, 2011 If Craig ever built a preamp I would line up for one. Now I LOVE my JM (and someday will find me another one), but I would LOVE to see Craig do this someday.......especially if it were tube rectified around the 5AR4[8-|].....and knowing Craig's taste I wouldn't be too surprised if he chose 12AX7 for da line[H] Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted February 2, 2011 Share Posted February 2, 2011 The strict definition of NOS is N = Absolutely new never used O = Old as in from the 60's, 70's or 80's ...... S = Stock from those years listed and has been sitting on the shelf or stored away in some box. An NOS tube can also be NIB which just means New In Box (original box). A tube that has been used in the past no matter how it tests in the tube tester is not new so it does not qualify as NOS. Many tube types will test just like the day they were made right up to the point where they become unusable for various reasons many times noise related like with the 6DJ8 family. Heck some tubes even tested stronger then new even though they are unuseable like the 7591 output tube. You test them and think man these are strong! Only to have them run away going cherry red once placed in circuit. At the very least a used NOS tube should always be listed as being USED NOS or UOS. Thanks for explaining that to me. tc Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 4, 2011 Author Share Posted February 4, 2011 Yea but the problem is those common sense rules are rarely adhered too by folks selling tubes. Quote Link to comment Share on other sites More sharing options...
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