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View Full Version : Any Vintage tube Gurus around? ID this?



LeadedEL84
June 29th, 2010, 06:02 PM
I recently got my hands on some NOS and used vintage tubes. I usually buy modern tubes such as Electro Harmonix,JJ/Tesla,or Tung Sol reissues to replace the Groove tube/Sovteks that my amps have come with. A friend of mine has been trying to get me to try vintage tubes for years. He uses only the finest NOS tubes for his vintage amps and high end modern production tubes in his modern Marshall. I am happy with my current combination of Tung Sol 12ax7s and EH EL84s in my USA Crate V30. No reason to change.
-However-
I have been working on a Crate V5 practice amp project that I upgraded to a 10" celestion speaker and have planned to try some tube swapping experiments for fun and in search of better tone. My plan was to try a 12AT7preamp tube to lower gain,increase clean headroom,and hopefully get rid of the garbled distortion my V5 has at volumes above the halfway mark. ( more on these results later ) I discovered that the modern production tubes (in the brands I usually buy )want a few bucks more for the 12AT7 versions than their 12AX7s. While 12ax7s and power tubes of the popular vintage brands are pricey I discovered there are deals to be had on vintage 12at7s. So I bought a couple lots of vintage tubes. I over bought knowing I could try some different brands,find out what I like,and put a few back for future use. Then turn the rest around to get a few bucks back. This also helped me get a better price per tube of course. All the tubes are tested (with results provided ) and guaranteed.Some are NOS some used. Here is a list of what I have: 12AT7s-1 GE,3 Sylvania,3 RCA w/grey plate,1 RCA black plate,1 Tung Sol,1 Phillips,1 Magnavox,1 unidentified with writing worn/wiped. 12AX7s-1 Silvertone, 1 HP,1 Sylvania. EL84s-2 RCA (matched set).

I immediatly put the RCA black plate,Tung Sol,and RCA EL84s aside as keepers. Then I looked at the rest and tried to decide what to try first in my V5. The next thing was to test the others to verify they work(I have no tube tester). Also want to witness the different sound and characteristics. I realize some on the list will be better for an amp and some better for radio/audio use. I decided to try the Magnavox first.
Question: Who made this tube? I know that some of these tubes like the Silvertone and Magnavox are manufactured by someone(such as RCA or GE) and relabeled. The writing on this Magnavox tube is worn but looking closely I can see "magnavox"and some numbers:512-239-JBT
Meter readings for this double triode tube is as follows:
#1 Tested...............72/68
Tested on Heathkit tube tester

I decided to try this tube first out of curiousity and I had to start somewhere. It has been in the V5 for two days. It sounds great and I'm in no hurry to swap it out.
The first thing I noticed was a great low volume clean tone that reminds me of a vintage Fender type tone. Warm and good highs. It stayed clean even at half volume. 2/3rds volume put it at the point of break up.Pick soft for clean/pick hard for overdrive. I was expecting a little volume loss from the reduced gain but in reality this amp sounds louder now. It has more useable volume now. It used to get garbled sounding overdrive at anything above 1/2 volume. Now it stays clean and clear much longer. When I turned it to 3/4s volume I got this great vintage sounding overdrive. It reminds me of Creedence Clearwater Revival type overdrive from the late 60s/early 70s. A little EQ and volume adjustment on the guitar and pulling the EQ back to 12 o'clock on the amp gave me good blues tone with my Les Paul.
Then I plugged in the Marshall Guv'Nor pedal and played at low and moderate volumes. The tone I got after doing this is what is keeping me from swapping this tube out to try the others just yet. I can't believe the harmonics and touch sensitivity of this combination. There is so much there than before the swap. I have been playing this the last two nights and can't put it down. I am finding sounds that I never thought this cheap china Crate would ever get. It has so much detail and character. It is almost 3 D sounding. I am just floored.
So who made this old Magnavox tube? I didn't think a preamp tube would make THAT much difference in sound. I always thought the power tube made the big difference in sound where the preamp made the difference in the feel and reaction to picking and gain. I still have the stock Sovtek EL84 in there. Can't wait to try one of these vintage RCAs. ????
http://www.thefret.net/imagehosting/thum_113024c2ac15e4f5f9.jpg (http://www.thefret.net/vbimghost.php?do=displayimg&imgid=1658)http://www.thefret.net/imagehosting/thum_113024c2ac15e4f5f9.jpg (http://www.thefret.net/vbimghost.php?do=displayimg&imgid=1658)http://www.thefret.net/imagehosting/thum_113024c2ac15e4f5f9.jpg (http://www.thefret.net/vbimghost.php?do=displayimg&imgid=1658)http://www.thefret.net/imagehosting/thum_113024c2ac15e4f5f9.jpg (http://www.thefret.net/vbimghost.php?do=displayimg&imgid=1658)http://www.thefret.net/imagehosting/thum_113024c2ac52b65dd9.jpg (http://www.thefret.net/vbimghost.php?do=displayimg&imgid=1659)

duhvoodooman
June 29th, 2010, 08:42 PM
I'm no NOS tube expert, but I understand that relabeling of brands was a regular practice, so your "Magnavox" tube could have been made by RCA, Sylvania, GE, Tung-Sol, etc. It helps to have a couple of good photos, because it's the construction of the tube that the experts look at, as opposed to the label on the outside.

LeadedEL84
June 29th, 2010, 10:44 PM
I'm no NOS tube expert, but I understand that relabeling of brands was a regular practice, so your "Magnavox" tube could have been made by RCA, Sylvania, GE, Tung-Sol, etc. It helps to have a couple of good photos, because it's the construction of the tube that the experts look at, as opposed to the label on the outside.

Thanks for the reply, voodooman. I posted a picture of the tube. I added it to my original post.That is the only picture I have to post until I take the amp apart again to switch tubes. I don't know why those extra spaces with Xs showed in the post. I only attempted the quick upload and post once.(?)If that is not sufficient maybe one of the tube experts can let me know what parts or angles they need to see. Might be a day or two until I tear the amp apart again. If it's one thing I dislike about these V series Crates it's the tube access. What a pain! I didn't have this problem when I was a Fender man.LOL

I knew this was a relabeled tube made by one of the big manufacturers. I had never heard of Magnavox being a manufacturer of tubes themselves. I know that RCA is one of the favored American tube makers for guitar amp use. I know that some others are better for radio or high end audio use and are too clean and sound too bright or brittle in a guitar amp. I was expecting this Magnavox to turn out to be one of those type of tubes because I associate that name with TVs and radios rather than guitar amps. It was a pleasant surprise that it is so harmonically rich and balanced. That's why I am curious to know who made it.

LeadedEL84
July 1st, 2010, 01:57 AM
After hours of reading dead end forum and discussion entries given to me by Google I have only run across a couple references to the Magnavox tubes. One mentioned Sylvania and relabeled Magnovox tubes but the actual artical was no longer there. Another mentioned Magnovox 12AT7WA and RCA 12AX7WA tubes as being war time issue. But again the only text I was able to read was the Google search summary. The actual artical it took me to had nothing about Magnavox.

I just found some relabeled Magnavox 12AX7s made by Tung Sol with"Made In USA" stamped on the side( is that right?) and British made Mullards stamped Magnavox. Still tells me nothing about my 12AT7. Sounds like Magnavox bought from many sources

tunghaichuan
July 1st, 2010, 08:41 AM
DVM is correct. Many companies bought tubes from the major manufactures at the time and relabeled them with their own logos.

To muddy the waters even further, major manufacturers of the time would buy tubes from each other rather than tool up for a new run of tubes. I have RCA-labeled tubes marked G.E., for example.

The tube in the photo looks like a GE to me. Are there seven little dots etched into the glass below the "12AT7?" If so, then it was made by G.E.

Bloozcat
July 1st, 2010, 01:51 PM
You might try some of the Ampeg forums and look for some pics of tubes there (if you can find any). Magnavox owned Ampeg for a period in the '70's and they re-branded a lot of tubes as Magnavox. Of course, it's possible that they did the same thing for tubes they used in their TV's as well.

It might be a start...

LeadedEL84
July 1st, 2010, 04:58 PM
DVM is correct. Many companies bought tubes from the major manufactures at the time and relabeled them with their own logos.

To muddy the waters even further, major manufacturers of the time would buy tubes from each other rather than tool up for a new run of tubes. I have RCA-labeled tubes marked G.E., for example.

The tube in the photo looks like a GE to me. Are there seven little dots etched into the glass below the "12AT7?" If so, then it was made by G.E.

That would explain this GE labeled tube I have. It has black plates and looks identical to the black plate RCA with D getter. I noticed the GE had black plates last night but I am looking at it side by side with the RCA now. It looks the same. I am going to look up the test results from both these tubes. I was provided the test results for each of these individual tubes when I bought them. It turns out I have 2 black plate RCAs in the bunch. Might have 3 if this GE turns out to be a relabeled RCA. Makes me want to look closer at all of them and compare likes and differences. I kind of jumped into this vintage tube thing head first. I didn't realize how complicated it was going to get. Kinda fun though.
-also-
Thanks for the suggestion Bloozcat. I will look into the ampeg connection. I will also look for the bumps tunghaichuan refered to on the Magnavox tube when I take it out of the amp to test some of these others.

Even if I don't find a definate answer to who made this Magnavox tube,at least I'm learning some things about the other tubes I have. This is a crash course in vintage tubes. LOL

Out of curiousity: What are some of your favorite vintage tubes and what applications do you use them in?( ie: what positions and for what amps?)

Bloozcat
July 2nd, 2010, 07:20 AM
...Out of curiousity: What are some of your favorite vintage tubes and what applications do you use them in?( ie: what positions and for what amps?)

These are NOS tubes that I currently own and use.

Pre-amp tubes: NOS JAN Philips 12AX7WA, NOS GE 12AX7WA, NOS RCA Blackplate 12AX7A, NOS BEL 12AX7 (Made in India for Mil use, same design as Mullard Blackburns), NOS Tesla (not JJ) ECC83, NOS GE 5751, NOS JAN Philips 12AT7.

Power Tubes: NOS JAN Philips 7581A (upgraded 6L6GC), NOS Polam/Telam EL84, NOS Tesla Roznov (not JJ) EL84, NOS Russian Mil. 7189 (6P14PEB - Mil grade EL84 type).

Rectifier Tubes: NOS JAN Philips 5AR4, NOS GE EZ81.

After standing idly by and watching the old standby NOS tubes disappear (GE, Mullard, Tungsram, Tung Sol, et al), I started buying NOS tubes that were still considered "deals" at the time. When deals came along on the remaining US made tubes I bought. When the deals came along on the lesser known foreign tubes, especially the EL84's, I jumped on them. So, I have enough NOS tubes for my short term needs (long term for EL84). Fortunately, the market for newly manufactured tubes has greatly inproved. With guys like Mike Mathews buying up old NOS names like Tung Sol, Mullard, Genalex and making tudes under these names in the Reflektor plant at Saratov in Russia (that he now owns), the quality levels of these "new" old brand name tubes has improved markedly. And tubes produced in the Shuguang plant in China are getting better by the year.

NOS was always the way to go for good tubes. But, with the out of reach prices on what's left in that market, and the great improvements in the new manufactured tubes, I think I'm finally done buying NOS. I'm priced out of that market...it was inevitable.

LeadedEL84
July 3rd, 2010, 12:06 AM
Cool man. Sounds like you have a pretty wide selection there. A couple of those I don't even know that I've heard of before.

I have to agree with you on the new production tubes coming out of the Reflektor plant. I think it's called New Sensor now? My first couple go arounds buying new tubes were Sovteks or Groovetubes and then I tried Electro Harmonix. That was back in the early 90s. I wasn't real impressed with any of them. They never lasted that long. My ear wasn't as developed then but I don't remember the tone being great either. I stopped playing for a number of years. I started playing again in about 2000 but was playing solid state amps for 4 or 5 years. Then I got a used tube amp and it wasn't long until I had to replace the original groovetubes. The only EL84s the dealer had in stock were Electro Harmonix. He assured me they had improved so I bought those and the matching 12AX7 preamps. Played that blues junior for about three years before I sold it. The tubes lasted and I liked the tone. I liked the new JJ/Teslas for the Fender Deluxe reverb reissue I had for a while. That's what it had when I bought it and I never changed them. I am really happy with the Tung Sol 12ax7s and E.H. EL84s I put in my USA V 30. The combination seems to be working well.
I'm now learning about the vintage stuff. Messing around with it for my little 5 watter. Mainly because the good deals I got on these tubes. I can't really afford to become a vintage convert. But hey at least with this little amp it's only 2 tubes per replacement! I'm going to have fun and experiment. I'll put a couple power tubes and a couple pre amps back for future replacements.

deeaa
July 3rd, 2010, 11:27 PM
I have a couple of pretty old Siemens tubes that sound great, I keep one in the 1st position on my Ceriatone. Somehow I've collected quite a few tubes, nothing fancy, but anyhow at least a couple dozen of them.

I don't find there to be a big difference in preamp tubes used except in the first tube the signal sees. That makes a huge difference, swapping the old Siemens to a Sovtek for instance makes it very much colder and less 'tubey'. But swapping the others to whatever makes no big difference you'd notice if you swap one tube in whatever position - if you use all NOS or vintage tubes or all Sovteks you do notice a clear difference, it gets already too vintage and tubey is everything is NOS, but anyhow I've decided to focus on the first tube as it makes the greatest difference.

I suppose it depends on the type/amp design but at least on mine the preamp n.1. tube is the key to everything. On 6L6 and EL34 based amps I didn't hear a significant difference swapping power tubes either, but on the EL84 Ceria they make much more of a difference. It makes sense, as those tubes are always ran hard & the amp at near full power being lo-wattage, whereas I hardly ever got to crank a JCM800 or 2203 - or them Fender combos.

At the moment I have a Siemens, an old Peavey and Sovtek in my amp. The power tubes are all Sovtek now. I used a bunch of EH's but the sovteks sound better. I also have an octet of mil-spec sovtek EL84M tubes, but those do sound a tad cold. I just keep 'em as emergency backup. They worked fine in my Classic 60/60 poweramp though.

I'm no tube expert, and never have really tested other NOS tubes than my Siemens' ones and some old Marshall etc- nameless tubes - there were a few real old ones in my VT-22 Ampeg, but anyway I've still tested a huge number of tubes, especially in the H&K CreamMachine and ValveJr., enough to be bored of the whole issue already ;-) but my take is, in the end, that you always want a _good_ first tube in your amp and you don't want mil-spec tubes in your amp even though they last forever...more than that seems excessive tinkering to be in relation to changes achieved - much like debating which sounds better as guitar body, plastic, cardboard or mahogany - it's more to do with religious belief than actual changes in sound IMO.

LeadedEL84
July 4th, 2010, 05:52 AM
I have a couple of pretty old Siemens tubes that sound great, I keep one in the 1st position on my Ceriatone. Somehow I've collected quite a few tubes, nothing fancy, but anyhow at least a couple dozen of them.

I don't find there to be a big difference in preamp tubes used except in the first tube the signal sees. That makes a huge difference, swapping the old Siemens to a Sovtek for instance makes it very much colder and less 'tubey'. But swapping the others to whatever makes no big difference you'd notice if you swap one tube in whatever position - if you use all NOS or vintage tubes or all Sovteks you do notice a clear difference, it gets already too vintage and tubey is everything is NOS, but anyhow I've decided to focus on the first tube as it makes the greatest difference.

I suppose it depends on the type/amp design but at least on mine the preamp n.1. tube is the key to everything. On 6L6 and EL34 based amps I didn't hear a significant difference swapping power tubes either, but on the EL84 Ceria they make much more of a difference. It makes sense, as those tubes are always ran hard & the amp at near full power being lo-wattage, whereas I hardly ever got to crank a JCM800 or 2203 - or them Fender combos.

At the moment I have a Siemens, an old Peavey and Sovtek in my amp. The power tubes are all Sovtek now. I used a bunch of EH's but the sovteks sound better. I also have an octet of mil-spec sovtek EL84M tubes, but those do sound a tad cold. I just keep 'em as emergency backup. They worked fine in my Classic 60/60 poweramp though.

I'm no tube expert, and never have really tested other NOS tubes than my Siemens' ones and some old Marshall etc- nameless tubes - there were a few real old ones in my VT-22 Ampeg, but anyway I've still tested a huge number of tubes, especially in the H&K CreamMachine and ValveJr., enough to be bored of the whole issue already ;-) but my take is, in the end, that you always want a _good_ first tube in your amp and you don't want mil-spec tubes in your amp even though they last forever...more than that seems excessive tinkering to be in relation to changes achieved - much like debating which sounds better as guitar body, plastic, cardboard or mahogany - it's more to do with religious belief than actual changes in sound IMO.

Hmmm.......Very interesting, Dee. Your "first tube in the chain" theory makes alot of sense. When I first changed the preamp tube in this V5 from the stock 12ax7 Groovetube to the NOS 12at7 I was surprised at the big difference in sound. Not in the difference in gain, I was fully expecting that. The presence,creamyness,and overall tone quality I gained was surprising. It has not been my experience in the past that a preamp tube swap alone made much difference in the sound unless they were worn out,dead,and totally lifless tubes being replaced. The 12ax7 I took out is barely broken in. I guess only having 1 preamp tube makes it the first and only in the preamp chain so it had a bigger influence on the sound.

I was in agreement with everything you said on the subject. However,we must part ways when you bring up the tone wood subject ;) I am a religious ,cork sniffer in that regard. Mahogany vs lamanate vs alder vs ash vs poplar vs basswood,rosewood vs maple vs ebony,and poly vs nitro debates make me speak in tongues and reach for my corkscrew....:poke

deeaa
July 4th, 2010, 09:38 AM
Well, that's a favorite argument for many of us, tone woods...

In short my take on the subject is that there are of course differences to various woods and how they sound even in an electric. A bit like there are differences between very similar lager beers. And there are some materials that are absolutely not suitable for guitar bodies. Leo Fender himself selected guitar woods from a very practical standpoint: he wanted something that was as cheap as possible and as sonically dead as possible. If he had wanted something that really might effect the sound, he would have used spruce like on acoustic instruments. Mahogany too is very porous and sonically dead wood compared to most anything else - very good to fight feedback in electric guitars. My granddad used spruce from logs he salvaged from lake bottom, once properly dried they sounded marvellous in his violins...water somehow made them more capable of transmitting sound vibrations.

But like in blind tests we've done with my friends on beer (and cola drinks too) - after a few tastes you can't tell your favorite apart from the competition no more. I myself like basic Coca Cola for instance and always can tell when I get Pepsi instead, but when I'm faced with 5-6 different colas there is no way to tell which is which. By the time I've tasted them all, they all taste the same. I've tried that with a dozen friends of mine and nobody's been able to pick out their favorite.

Same with guitars. I've spent a couple of days killing time with my luthier friend swapping bodies in a strat - mahogany to alder and anything in between, and I rest assured that nobody who listens could tell them apart no matter how hard they tried. Still, in the long run, as a player, you'd notice subtle differences, sure. But if given 100% similar strats with different woods in the body and weight compensated so that won't help guess which is which, I'd wager my year's salary _nobody_ can tell any difference playing it a minute or two. While it has an effect, it's so subtle a minute twist of the amp tone knob can negate it anyway. Hence we have guitars made of lexan and plastic and metal and whatever, still work great...I even built a guitar out of stone and it sounds pretty much like any other electric guitar does.

BUT it's also true that great instruments are entities made of small nuances, and of course it makes sense to select best possible woods for best guitars. When all those nuances stack up, it amounts to something, sure. But even then, hm. In Les Pauls for instance maybe the best sounding one I came accross was made of walnut entirely, not mahogany. I loved my '92 Standard, but in the end I could get better sustain and more low end from my floyd-equipped Jackson, so...

Check out my hard rock guitar :
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