Tubes 101 I got more questions

[faster100]

Just feeling better from being sick and started to demo the Tube pre-amp i just got.. I have some Raytheon 5751 tubes that came with it, these any good? The box says Industrial componets division CK-5751 aND what are other good alternatives to these? it takes a 12ax7a... Now does it have to be A or just any 12ax7 or 7A will work.. and also is their other numbers to be looking for, being the rays are 5751's... I found a semi local dealer that has offered me some GE nos 12ax7a's for cheap, actually one is NOS and 2 are tested great.. I already changed the 6x4 tube to a GE i had... lemme know

[BlueMDPicker]

Here's a link that Henry (HBombtoo) shared with us awhile back:

Tube database (http://hereford.ampr.org/cgi-bin/tube)

Basically, if the tube root ID is the same (i.e. 12AX7 - 12AX7WA) they're swappable. The suffix letters designate such things as higher duty cycle build spec.

If you want to read up on NOS 12AX7's there's always:

Audio Asylum - Joe's Tube Lore (http://www.audioasylum.com/audio/faq/joes-tubes.html#12ax7)

Joe thinks ALL 12AX7's suck and the 5751's are the way to go (if your gear can handle a lower mu triode without gacking.)

[faster100]

Great link, I actually have a set of raytheon 5751's that he mentions as better then some of the 12ax7's....... Thanks MD

[Early B.]

Joe thinks ALL 12AX7's suck and the 5751's are the way to go (if your gear can handle a lower mu triode without gacking.)
Can any of you old tube geeks (emphasis on "old":p) substantiate Joe's statement? I'm interested in rolling the 12ax7's in my Jolida 502, but certainly don't want to spendany more $$ than necessary just to experiment.

Russman -- got any extra tubes layin' around for sale?

[Early B.]

Found some info on swapping 12ax7's for 5751's. A bit of caution should be exercised.

http://thetubestore.com/gainfactor.html

[faster100]

rolling the raytheons tonight and for the next few days to see what the difference is from my groove tubes ive been listening to...

Come on, wheres all the tube guru's.... ive been reading and researching my head off, but their is nothing like someone you trust telling you what's what... not some stuffy reviewer saying this or that about gear and tubes... although after the above mentioned link, i did roll the 5751's in it :D just to see

[organ]

Raytheon is a sought after brand in NOS tubes. Some prefer the sound of 5751 over 12AX7/A and others prefer the opposite. They are swappable.

I trusted Joe before but after a while I think Joe and his Tube lore is full of sh*t. You'll be listening to your system through YOUR ears not Joe's. I've done the 5751 vs 12AX7 on my ASL pre amp. At first I really enjoyed the 5751 but after a while I noticed that it has less dynamics than a good 12AX7. The 5751 did sound slightly warmer and more laid back. It seems like it cut off the extreme high freq a little too. Personally, I'd take a good 12AX7 over the 5751 I've tried.

Here's what I got in my system using various 12AX7 tubes.

SED 12AX7: By far, the warmest, most bassy and tubey sounding. If your amp can produce very warm bass already, it could be overkill. Great for vocals and softer stuff but not a rock n roll tube.

Sovtek 12AX7S: My favorite. Along with the Ei12AX7, this one is the most neutral sounding. Its biggest strength is dynamics, clarity and low noise.

Ei 12AX7: Pretty much the same as the Sovtek with less dynamics and maybe a little smoother sounding.

Sovtek 5751: Can't tell the difference with this and their 12AX7S. Looks identical too.

These current production tubes are cheap. Buy all of them and have some fun:cool: .

Maurice

[faster100]

I have the sovtek 12ax7lps, I thought they were the original tubes included when i bought it used, However spaz just received his New and has chinese tubes.. so i rolled the sovteks today and really actually liked them... Just unloaded my PS audio speaker rope today i mean wire LOL, so now gonna wait for my signal cable to arrive and roll all 3 sets of these tubes and see what sounds best/... Thanks Maurice for the info, Nice to hear from ya again also man..

[organ]

Cool. Let us know how it sounds once you get them in. I made a mistake up there. It's LPS not S.

Not sure about your pre's design but I bet a mixture of SED and Sovtek will sound real sweet. Paul (pjdami) really liked the Sovtek in his tubed cd player. Glad to hear you're enjoying tube rolling. btw, forgot to mention this. Congrats on the new toy:). You're officially tubed and you know damn well there's no going back to ss:D.

Maurice

[faster100]

where did you find the SED 12ax7? can't find em anywhere

[pjdami]

I trusted Joe before but after a while I think Joe and his Tube lore is full of sh*t

LOL Organ. My thoughts exactly. Maybe I shouldn't be saying anything as I haven't tried any 5751s yet but I've heard plenty of great 12AX7s in my Jolida and if gets any better still I'd be floored.

Faster, lots of places man; here's a start....



http://www.tubedepot.com/sv-12ax7.html


ooops.. temporarily out of stock...

I just got some 1961 NOS Sylvanias from another place today too.

[faster100]

man there it is, and out of stock.. i was looking just for the SED as organ mentioned he liked his and i wanted to try a set.. I have 3 sets now to roll... and see what i like. however never enough... lol Thanks for the link,

I have the 5751's and they sound good, alittle better then the Groove tubes i think, But the sovteks i tried today were really nice, seems more dynamic to me if thats the word.

[pjdami]

faster I would email Christian at TubeDepot and ask him how long of a wait for the SEDs. He usually responds the same or next day.

info@tubedepot.com

[RuSsMaN]

Had a pretty big tube score this weekend, among the lot a sleeve (5) NOS 4/69 JAN 5751's.

Cool factor is off the charts, I'll have to see if the sound lives up to the hype.

Cheers,
Russ

[faster100]

Cool man, i liked the 5751 in the limited time i tried them, But again what do i know about tubes.. YET! LOL

any nice 6x4's over there or 12ax7's ya wanna sell?

[BlueMDPicker]

I've rolled a multitude of tubes through my preamp - which uses a 6X4 and 12AU7 x 2 - and found (to my ears) that the 6X4 has a great impact on total SQ. Perhaps more so than the phase and gain tubes. A 6X4 that's mediocre causes significant degradation of speed and punch of bass. With that aspect hosed up, I find it hard to evaluate the subtle differences afforded by various 12AU7's.

The Tungsol 6X4WA and RCA black plate 6X4 can, in my configuration, do their job without muddying the water.

I guess what I'm really trying to offer here is the premise to just keep rolling and listening. It'll happen - you'll hit a combination one day that makes your jaw drop.

[pjdami]

faster,

If you are still having trouble finding the SED 12AX7 I found some Svetlanas at Music Direct:

http://www.musicdirect.com/products/detail.asp?cat=300&sku=ASVET12AX7

It is my understanding that Svetlana and SED are made in the same factory in St. Petersburg, Russia and they both sport the identical "winged C" logo.

[organ]

Paul,
LOL, Yeah, I think Joe is one of those tube snobs that hate everything made today. IMO, some of the signal tubes being produced today sounds just as good as NOS.

triodeelectronics.com used to sell the 12AX7 SED but I don't see it listed now.

Is the 6X4 a rectifier tube? If it is, you can really change the sound character with that. In my amp, I went from a Sovtek GZ34 rectifier to a Mullard and it kicked ass.

Maurice

[faster100]

Yes the 6x4 is a rectifier, It came with a jan phillips 6x4wa in it, i have a vintage GE 6x4 black plate also...

[BlueMDPicker]

Originally posted by organ
Is the 6X4 a rectifier tube? If it is, you can really change the sound character with that. In my amp, I went from a Sovtek GZ34 rectifier to a Mullard and it kicked ass.

Ooops... sorry Maurice - yeah it's the rectifier in my preamp circuit and the preamp circuit in my Hammond B3. So I've got some oldie-but-goodies stashed away over the years - including a Brimar and Haltron CV493, and an RCA black plate 6X4 that's a bass machine.

[organ]

Give it a shot man. You might want to start stocking up on 6X4's if you plan to keep that pre for a long time. I don't see any being produced by today's companies. At $10 a pop, I'd get a LOT http://www.thetubestore.com/janphilips6x4.html and $6 a pop here http://store.yahoo.com/triodeel/rectub5u45ar.html

Maurice

[organ]

Originally posted by BlueMDPicker
Ooops... sorry Maurice - yeah it's the rectifier in my preamp circuit and the preamp circuit in my Hammond B3. So I've got some oldie-but-goodies stashed away over the years - including a Brimar and Haltron CV493, and an RCA black plate 6X4 that's a bass machine.

Cool. Check out the links I gave Faster. You could e-mail Ned at Triode to ask which brand they carry because he didn't list any brands specifically. He might have some good stuff there. LOL my RCA 7199 black plates are bad ass machines too. I wonder why RCA made those black plate tubes? People love them. Must be some magic materials in those plates that makes them sound so good.

Maurice

[HBombToo]

Originally posted by BlueMDPicker
A 6X4 that's mediocre causes significant degradation of speed and punch of bass. With that aspect hosed up, I find it hard to evaluate the subtle differences afforded by various 12AU7's.


These two sentences speak volumes Bro.

Twin

[dbnh]

I've rolled a number of tubes (http://cgim.audiogon.com/cgi-bin/vs.pl?vopin&zz1081031922&viewitem&o15&1108816086#item) in my Jolida JD-100 cdp (http://cgim.audiogon.com/cgi-bin/vs.pl?vopin&1081031922&viewitem&o3), and find that with this unit, in my system, I agree with Joe's comments about the Sylvania Gold Label JHS 5751WA triple mica blackplates.

Tubes I've rolled include: current model tubes including the stock Jolida 12AX7s, Sovtek 12AX7LPS; and NOS tubes including GE JAN 5751 blackplates, GE JG 5751 triple mica blackplates, Fisher-branded Telefunken and Amperex 12AX7s, and the aforementioned Sylvanias. In my system, the NOS 5751s sounded far superior to the NOS and current 12AX7s. The NOS Amperex 12AX7s sounded decent, but still were lacking in the detail, air, 3-dimensionality, killer mid-range, and overall naturalness of the Sylvania JHS 5751WAs. The two matched pairs of Fisher-labelled Telefunkens (yes, they have the diamond on the bottom) were a big disappointment - unfocused with an amazing lack of detail, little bass, brittle top end

Anyway, that's my findings, with my gear. The sound these tubes provide in your system may be different, due to your gear, preferences, etc.

[pjdami]

Originally posted by dbnh
I've rolled a number of tubes (http://cgim.audiogon.com/cgi-bin/vs.pl?vopin&zz1081031922&viewitem&o15&1108816086#item) in my Jolida JD-100 cdp (http://cgim.audiogon.com/cgi-bin/vs.pl?vopin&1081031922&viewitem&o3), and find that with this unit, in my system, I agree with Joe's comments about the Sylvania Gold Label JHS 5751WA triple mica blackplates.

Tubes I've rolled include: current model tubes including the stock Jolida 12AX7s, Sovtek 12AX7LPS; and NOS tubes including GE JAN 5751 blackplates, GE JG 5751 triple mica blackplates, Fisher-branded Telefunken and Amperex 12AX7s, and the aforementioned Sylvanias. In my system, the NOS 5751s sounded far superior to the NOS and current 12AX7s. The NOS Amperex 12AX7s sounded decent, but still were lacking in the detail, air, 3-dimensionality, killer mid-range, and overall naturalness of the Sylvania JHS 5751WAs. The two matched pairs of Fisher-labelled Telefunkens (yes, they have the diamond on the bottom) were a big disappointment - unfocused with an amazing lack of detail, little bass, brittle top end

Anyway, that's my findings, with my gear. The sound these tubes provide in your system may be different, due to your gear, preferences, etc.

dbnh,
Thanks for the reply. I also own a Jolida JD100a modded by Parts Connextion. I have a separate thread on the forum somewhere on the Jolida cdp (its called "ordered some Brimars").
I've tried several 12AX7s. NOS ones include Brimars and 1961 Sylvanias.

I have yet to try the 5751 and find your comments very interesting. Did you notice a considerable "gain loss" when swapping to the 5751? It is my understanding that they have only about 70% of the gain of a 12AX7. So do you have to crank up the volume considerably more to get the same sound level or did you barely notice?

Thanks,
Paul

[pjdami]

dbnh,

One more question. Of the 5751's which one do you recommend me trying out first based on availability (easiest to find) and overall sound. If there is one thing that I could improve I think it would be the three dimensionality that you describe. Tonally, I find the NOS 12AX7s to be pretty sweet.

Thanks again.

[faster100]

yes, the 5751 does drop overall output due to the lower gain, not very much though, what could happen although is if you crank the volume to the higher side to get more volume i think you could suffer some distortion from the pre-amp... I'm not sure as i havnet pushed it that far yet,

Its gonna be a few days before i start testing tubes again, I just had my wisdom teeth out friday and am feeling pretty crappy.. Just had to read the board for a few minutes though :D

later

[dbnh]

Paul,

No, I did not notice anything that would be classified as a considerable gain loss. Then again, considering the amp and preamp I'm running (Odyssey Stratos w/cap upgrade, Odyssey Tempest, respectively) with my SDA 1Cs, I wasn't anticipating much downside: with the cpd, I don't need to have the volume past the 10-10:30 position to get very large SPLs.

Hope the above helps, and happy listening!

[pjdami]

Okay dbnh. Thanks. You've convinced me to try out the 5751s. I was headed that direction anyways, but was going to wait a while since I JUST got these NOS Sylvanias in the cdp like three days ago.
what an addiction this crazy hobby is. By the improvements you describe my system still may have some potential in it to get better which I find amazing.

Now, I'm off to find some of these rare 5751 treasures you speak of.

[dbnh]

Paul,

You asked, "Of the 5751's which one do you recommend me trying out first based on availability (easiest to find) and overall sound. If there is one thing that I could improve I think it would be the three dimensionality that you describe." My answer is that, IMHO, the quest for "easiest to find" and "three dimensionality" are mutually exclusive. Again, first presenting the caveat of 'with my gear in my system', I found the NOS Sylvania Gold Label JHS 5751WA tmb tubes to have that magical three dimensionality, and it seems the tube's well rounded performance plus that feature (and hype) has pushed high the desireability factor, which in turn has greatly reduced availability and increased price - supply and demand curve.

In general, I think the NOS 5751 tmbs are becoming increasing scarce and pricey. With that said, perhaps either the GE JG 5751 WA tmbs or the Sylvania 5751 triple mica greyplates might be more readily available. I note I have not rolled the Sylvania greyplates. Furthermore, the GEs I rolled (I have two matched pairs, one unused, the other used for about 100 hours) were not JG WAs, just the JGs. However, I and my wallet could have easily lived with the GE JG 5751 tubes had I not tried the Sylvanias, so I guess I'd include the JGs in the short list to try, too.

[dbnh]

Originally posted by pjdami
I'm off to find some of these rare 5751 treasures you speak of.

Fat-Cat on AGon is a reputable dealer from whom I purchased a matched back-up pair of Sylvania JHS 5751WA (http://cgim.audiogon.com/i/vs/i/f/1081030148.jpg). Note these have the yellow labels and 1956 date codes, and are the same tube as the Gold Labels. Since I purchased the back-up pair about 10 months ago, I've seen the price on the Sylvanias go up anywhere between 30-50/pair, which makes those GE JGs seem like an even better deal...

[pjdami]

Many thanks again dbnh. You know its great when you can find some advice on something one is about to venture on. Kind of eliminates the "trial and error" approach. Most of the systems I have put together follow on the success of what other people on this forum like to listen to.

After reading your posts on the 5751, I feel like I may be reading my daily future diary and hopefully what I can expect. Some dryness and lack of three dimensionality come to mind as weaknesses in the system I have with the Jolida cdp.

Nice system you have there by the way too. Thanks for the advice and have a great weekend man.

Paul

[dbnh]

Paul,

No problem, glad to offer what worked for me, and remember, that's what works in my system. Thanks for the comments on the system, I try to stay within my wallet and get as much bang for the buck.

On a side note, I absolutely love what the Walker SST does in my system, including when carefully applied to tube pins, RCAs and RCA connectors, etc. Here's a link to the 6moons review (http://www.6moons.com/audioreviews/walker3/SST.html), and there are a number of other reviews out there as well. You can always do a Google search on Walker SST and find the home page, too. (You might want to consider first purchasing/trying some SST, and then see how your current cop of tubes sound before venturing further.) From my experience, and from those in other forums such as AudioCircles, this tweak is the real deal. Mapleshade offers a similar product for about 1/2 the price of SST, but I haven't tried it, albeit I have heard very good things about it.

Peace.

[pjdami]

Welp, I kinda feel like Kevin Costner in the movie "Waterworld" looking for some NOS 5751s. Except I was looking for tubes and he was looking for fresh water. Both which were very common at one time and respectively rare in their own right many years later. I got outbid on eBay twice today on some "triple mica spacer with either halo or square getters, black plate, etc." Its amazing what NOS tubes will go for these days at over $50 pair or more. This guy Joe on Audio Asylum must be a legend or something because current NOS pricing on these things follows his recommendations based on my first day of research and attempts to purchase.

The Sylvanias...man they are really pricey. Too rich for me for now. The RCAs that I scored according to Joe, outperform any 12AX7 out there...we will see.

I did score some black plate NOS 5751s RCA with the triple mica spacers and halo getter (sounds like a hotrod car terminology or something) and look forward to hearing them compared to the current 12AX7s that I have (including NOS 1961 Sylvanias which have replaced the Brimars as my favorite in the Jolida).

I wonder what all these audiophile tube people are going to do in 10 - 20 years when stocks of these rare NOS tubes dry up?

Tubes, you have got to love them. Leave the rest of the rig alone and just find tubes that you like that match the gear and wire you have.

**edit** for typo:D

[organ]

Tubes, you have got to love them. Leave the rest of the rig alone and just find tubes that you like that match the gear and wire you have.

Waaaaa I love that:D Much cheaper than upgrading components and it's certainly more fun!

Let us know what you think of the 12AX7 vs 5751. I still think the Sovtek 12AX7LPS is the best sounding. The SED can be just as good with the right combination of tubes farther down in the audio chain.

Maurice

[faster100]

Maurice,

I have been useing the sovteks all day 12ax7lps's and I do love these tubes the best, i have grove tube mullard remakes, and raytheon 5751's and like the sovteks THEE best so far... Im going to be getting a 5 star GE 6x4 from spaz soon to try... its supposed to be some special GE so well see, I have a regular 60's GE 6x4 black plate in now and it seems to work good.. this pre was used but i dont think much because the more i use it the better its sounding, over the past week or so... not talking warm up time..

its really fun to fool with, I installed some silicone O rings for tube dampers on the 12ax7's today, it came with one on the 6x4 so i have em on all of them, just for kicks

[organ]

Sweet. Glad you're enjoying them. The dynamics on the LPS is so sweet. Let me know what kind of change you hear with the rectifier. Going from a so so rectifier to a great one is a big improvement.

Maurice