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Hello, I need a quad of tubes for my 8B. In the 90s I lived near Bob Hovland and he selected some Svetlanas (not the winged C, but with the big S symbol). He said it was his favorite at the time.
I would be happy to get a quad of the same tubes. They sound good. But I'm also interested if there is any new tube out that might be better.
My sonic priority is transparency, as in very fine resolution of detail, from the woody string vibrations on a double bass, to the exquisite shimmer of cymbals. Transparency and clarity.
Also, is it necessary to get the matching RAM tubes does, or is Antique Electronic Supply, Tube Works, etc just as good?
Thanks a lot.
Jim
Follow Ups:
I own a VAC Avatar int. amp (EL34's) that I think is supposed to be based on the 8B (correct me if I'm wrong.) I've tried Winged C's, JJEL34B, the stock Shaugang, Valve Arts, new Tung Sols and I prefer by far the new Tung Sols. But, I am choosing them because of the midrange punch that helps me to FEEL the cello or bass etc., From what you describe, my guess would be the Valve Arts, or the JJ's. I have both if you're interested in auditioning shoot me an email.
Happy listening!
I sold most of my vintage EL34 after listening to the Groove Tubes EL34M. I havent heard another EL-34 that I liked better, and I have tried almost all of them. And I do NOT like most Chinese (or Russian) tubes as a rule, I have almost all NOS oldies in my collection. I wish some of you would give them a shot and post your opinion, I havent met anyone other than guitar players running these guys. Mikey-I'll loan you a set to give them a try if you're interested?
Well if you would like for me to try them in my 8B I would be happy to. I can tell you how they sound compared to the Svetlana S logos in there.
Jim
Now this is talking a dynaco using the kt66s but I assure you that you search,you will find those that used them in the 8b..Im not saying to switch but I am saying they are worth a roll because they sound incredible in the 8B as I have heard them in my 8 and my friend's 8b.
When problems become increasingly difficult,we can always rely on our collective knowledge and seek relief.
Look at the schematic. How did the designers choose to deal with g3 and the cathode? Why did they do what they did? Does a 6L6 or KT77 allow this circuit to operate as designed? Just because the thing operates without blowing up doesn't mean that it operates as it should. Web references from persons unknown changes nothing in this regard. You could use automatic transmission oil in your car's engine and it would probably run okay but that doesn't mean you should. Go ahead and roll 6L6s into your 8B and sure, it will probably work. You may even like it. But it ain't an 8B any more.
you will see there are several scenarios as far plate load operating points go.We learn new things everyday.The mids in an EL34 are very nice..The extremes are cut off even in the 8 by comparison when I use the EL34.Also,my xf2s and Xf1s are mushy by comparison to the KT77 and the KT66 as well the RFT el34s..The metal EL34s are ok when you bias them hotter.
As I have said,nobody has to quit using the EL34..I have over 200 el34s of my own..Its just fun to roll and experiment.Why do people soup up their cars?Its fun and its a nice effect.
When problems become increasingly difficult,we can always rely on our collective knowledge and seek relief.
"Does a 6L6 or KT77 allow this circuit to operate as designed?"
I know what you mean, but...
... But if it operates in a way that pleases the ear of the listener - and it doesn't blow up - who's to say they are wrong?
...That tells me they don't care for an 8B. So why not get an amp that's designed for tube rolling? If I'm not mistaken, Roger Modjeski makes a point that some of his designs can take all kinds of output tubes with minor only adjustments. There are others. Bottom line is that if one owns an 8B and likes 6L6 types in it, fine with me. What I do find bothersome is when someone makes a tube rolling recommendation to someone else for an amp like an 8B w/o also stating that circuit operation will be changed by the sub. This is more than just sampling the different flavorings of tube; it's technically a circuit change too.
Steve
If you look on the HongKong threds,you will find many people running Kt66s in the 8B..Before you criticize it,why don't try and see for yourself.
I run kt77s and 6ca7s in mine as well as the KT66..Whats wrong with rolling tubes? People obviously like the effect.
When problems become increasingly difficult,we can always rely on our collective knowledge and seek relief.
...do you know why the 8B cathode/g3 circuit is the way it is? I know I don't know for sure. I believe it's irresponsible to recommend what amounts to circuit changes to the amp w/o knowing this and the potential consequences of the changes. Just swapping out tubes and hoping for the best is insufficient IMO, esp when it's someone else's amp.
Understand that I'm not criticizing the sound of the rolled 8B or the tastes of those who do it. Rather, I'm criticizing those who unwittingly recommend making changes to an amp's circuit with no understanding of what they're changing (or even that they're making a change in the first place) and the possible consequences of those changes.
cathode is tied to the beam forming plate thru the 3.3 ohm resistor.Most of the 8B character comes thru its FB and transformer design.Yes,the some tubes tie 1 and 8 together but that isn't an issue that causes real problems that I have found.I will sweep my model 8 with kt77s again and kt66s and I will see if there is any issues with the FR being all over the place.In the meantime,you have an 8B,why not try some different tubes and see how you like it? Its not going to hurt the amp.
When problems become increasingly difficult,we can always rely on our collective knowledge and seek relief.
Edits: 06/25/12
In the 8B it's 6.8Ω paralleled by 0.02µF. I doubt that a simple frequency sweep will reveal much of anything since I suspect the network has to do with either stability and/or response linearity into reactive loads. The 8B was advertised as unconditionally stable into any load with any signal and each output transformer was individually tweaked at the factory with a couple of trimmer caps in the feedback circuit to help assure this.
As far as trying different output tubes, I already stated that I tried NOS GEC KT77s and didn't care for them. I thought the Mullard/Amperex EL34s were best with the RFTs not far behind. RFTs are in there now. Based on this, I'm sticking with EL34 types, thank-you. YMMV.
The RFTs are my favorite of the EL34s because they have upper and lower detail that I felt was lacking in most EL34s including my Amperex D getters..I do like the metal base after they are on a while but I still get that mushy sound that kind of smears everything. The mids are nice tho..Try the kt66s grey bottles..Those are the ones I really liked in my 8 as well as the RI KT66 Gen..I may get the nines out and play around with them..They were given to me by one my of old audio mentors who bought them new in 1964 along with a Scott 4310 and s 7c..I never took the 7C or the 4310 and I ended buying a 4310 for 1600 a couple years ago.
When problems become increasingly difficult,we can always rely on our collective knowledge and seek relief.
Edits: 06/25/12 06/25/12
I have had extensive ezperience with the JJ Blue Glass E34L and found they matched uo well with truly light buse xf1 Mullards in a shootout. I had poor luck with JJ KT-77s and have avoided them after an Arcing problem in my and a friends amps. I have had good luch with the EH 6CA7 in power amp applications much to my surprise. I should mention that the High End extension of the Xf1 nmatched or exceeded all the tubes we tried. I haven't had much experience with the KT-66s family of Tubes I hope to purchase the newer KT-77s when I can. I am ill at ease to pay all that the much to try the Chinese black glass which obviously precludes the currently followed Black glass. I am looking for apart.
Steve
You will a few options for that amp..THe best I have ever heard the 8B is when I put KT66s in it..Yes,you read that correctly..The other tube that really rocks in that amp are the RCA 6L6gc black plates and very close is the 6P3Se russian tubes.
If I were to go with an EL34,the one I would consider is the Gen KT77 reissues..They give you top and bottom detail like a 6L6 and they are just a better tube for audio all around. Jim McShane has all the tubes you need with the best matching that even the factory can't do in a practical sense.
When problems become increasingly difficult,we can always rely on our collective knowledge and seek relief.
But wait, an 8B can't use 6L6s??????????????
I was speaking mostly of the kt66 which you may have to change a bias resistor,but I found those and the 6L6gc black plates to incredibly good in that circuit because of the good driver characteristics. EL34s are limited at a both ends of the spectrum as far as detail and even tho the mids are fine,by comparison to the kt66s an the 6L6gcs they come up short in most instances..You are talking to guy here that owns almost every vintage tube amp ever made outside of Western electrics.I have been there done that.I'm not saying to discard EL34s all together,but I have a pair of nines that I inherited that I have packed away and I also have an 8,which is similar to an 8b and both are really nice with the kt66s..I did have to change a bias resistor in the nines for added range but,it still biased el34s just fine..
THe kt77s are the best EL34 based tubes I have heard..I have everything from XF2,xf1,metal base Ampoerex, sq getter Amperex. five staple Telefunkens,4 staple RFTs,and many more such as SEDs..Here is a photo of a few..I can tell you honestly,they don't touch the Genelex kt66s in the 8b with a bias tweak.I could kid you all day long about how good EL34s are if you want me to..I have them all and you are welcome to come and test for them for yourself.THe best EL34 are the KT77s and thats my opinion..They were designed more as an audio tube and not as a guitar or industrial application tube to handle higher voltages.
When problems become increasingly difficult,we can always rely on our collective knowledge and seek relief.
Edits: 06/25/12
...the 8B was designed specifically around the EL34. Note that the EL34 is one of the few audio power pentodes where g3 is brought out to a separate pin instead of the usual practice of internally strapping it to the cathode (6L6 etc). If one looks at the schematic of the 8B, one finds that g3 is not tied directly to the cathode as it is in almost all other EL34 type amps but rather, goes thru an RC network instead. Therefore, by stuffing 6L6 types in there, one defeats this design subtlety that is unique to the 8B AFAIK. Due to how the sockets are wired, 6L6 types will work ok but the output circuit is not as designed.Persons who should know better indisdciminately make tube substitution recommendations w/o proper familiarity with the details of the amp under consideration. Bottom line: an 8B is not an ST70 and should be treated accordingly...IMO of course.
Edits: 06/20/12
AMEN!
~!
The Mind has No Firewall~ U.S. Army War College.
Roger that!
Seems like one persons opinion that all EL34 designs are no longer good means an auto substitution using these Russian mil surplus 6L6 types. Same items that have been relabeled for years by almost all commercial tube sellers...and all of a sudden their God's gift to the tube world!
Yea right! They may work but not the definitive answer to many questions.
Im not saying that at all..I'm saying if he looking for something to roll in his amp,KT66 is a great candidate,as are the 6L6gc black plates. Usually when people hunting around for tubes,they usually are looking to enhance an area of their amplifier..He can keep EL34s as I also have a shit load of them..It doesn't mean you can't try other tubes.
When problems become increasingly difficult,we can always rely on our collective knowledge and seek relief.
...with the El34 and SV83/6π15π tubes, the so-called Hazen Grid Mod. The Decware mod is just a 0.1µF film cap from g3 to cathode instead of a jumper wire as in most circuits. I don't know how the 8B's network compares in sonic effect, but there is a noticeable sonic benefit from the Decware mod with the SV83 (I haven't heard an EL34 with this trick yet.) So I agree it is worth staying with true EL34 pentodes in the 8B to keep this part of the circuit operating as designed.
Fenderlover, are you talking about these tubes in a hifi amp, or guitar amp?
Thanks...
Jim
In guitar amps & hi-fi (CJ, EICO & Dynaco, most recently). The 1990-2000 made Svet's (St Petersburg) and JJ E34L have a much richer texture & good harmonic quality to me (and the owner of those hi-fi amps), than the Siemens (RFT).
All tubes biased to original amp & tube manufacturer's specs. Run in over a good week. Bias rechecked.
My opinion.
I think the E34L and E34LS are very good tubes for detail also..Still,the KT66,the Rca black plate 6L6gcs,and the 6P3SE are the creme de la creme in the 8b AFAIC.
My opinion.
When problems become increasingly difficult,we can always rely on our collective knowledge and seek relief.
How is your back doing? I have a friend in NJ that went in for a minor operation to repair unwanted nerve pressure at three disks. He said he was out in one hour. He also said it looked like an assembly line of patients that day. Three weeks later my friend feels like a new man. Must be one great doctor if you are interested. Some of the best doctors in the world are in the NY & NJ area.
Back is ok but Sciatica is still giving me morning fits.My left foot still killing me from the Osteo arthritis but I am getting better.
When problems become increasingly difficult,we can always rely on our collective knowledge and seek relief.
Anybody know how a Seimens EL34 would compare to the KT-77s? Jim McShane seems to like the KT-77s, but Roger Modjeski suggested the Seimens he still has.
Thanks.
Siemens is ok. Really, I like the 1990's Svets (S-logo) & the JJ E34L better.
...in a guitar amp or an 8B???? I ran NOS GEC KT77s in my 8B for a short while and didn't care for them at all. The Siemens were much better. The best were/are NOS Mullard or Amperex but not by a whole lot. However, these aren't on the table at the moment.
I Like the siemens EL-34 very much - have been running them in my RM-9 for the last 20 years (I hadn't really added it up before - a long time) and have been quite satisfied with the sound!
Happy Listening
6bq5, if you have tried other tubes, can you compare the sonic characteristic of the Seimens?
Thanks...
Unfortunately the only other tubes that I have tried were the Chinese 6CA7s form the early '90s - and I did not like them as much as the Siemens - too 'round' and not as tight in the Bass. A nice mid-range, but not better than the Siemens.
Happy Listening
siemens never ever built own EL34 (as i know). most siemens labeled ones have RFT origin ("dimple top"). also mullards (B-coded = blackburn plant) were labeled as siemens tubes. so siemens freaks enjoy with RFT or mullard...
N.
The times, they are changing...
All the Siemens labeled EL34's I have were made in the Sittard, Holland Philips plant.I think they are every bit as good as the Mullard made in the Blackburn, England Philips plant or the Amperex made in the Heerlen, Holland Philips plant.
All three are Philips tubes made to the Philips standards.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Edits: 06/22/12
Gold Lion KT77's
Treasure 6CA7's
Alan
Thanks Alan. Any comment on how these will sound compared to the 90s Svetlana "S" logo tubes I had?
Thanks,
Jim
Better clarity in the midrange, cleaner more defined bass, and a more open top end vs. the "Svetlana "S" logo tubes"...now whether the Svetlana tubes I had were 90's editions is unknown.
YMWV
I really can't but having listened to a lot of el-34/6ca7/kt-77 tubes the Gold lion just sound more like real music to me than any other tube I have heard.
Deep accurate base, sweet extended highs and very high resolution over all. Also dynamics are outstanding. By the way my amp is a VTL ST-85. I have not heard an 8B in many years.
Alan
You like then the 6ca7 Treasures?
When problems become increasingly difficult,we can always rely on our collective knowledge and seek relief.
Yes, I think the 6CA7 Treasures are very good but the Gold Lion KT77's are the best
Alan
Those EL34 are some of my favorite. 1990's vintage seem the best. Along with similar logo 6L6GC, some of the best tubes made.
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