Looking for a tube suggestion

hi, new member here

Looking for a possible tube (12ax7) suggestion for my setup. Based on all the vaiables that come into play I’m hoping for the off chance that maybe a member with a similar collection of gear can shed some light.

My gear-

Harman-Kardon A500 (full rebuild)
Klipsch H3 “Capitols”
Rega P40, Ortofon 2M Bronze (Tracking at 1,6g)

The A500 is running a quad of 1960’s Telefunken 12ax7’s (smooth plate). Just added the Ort Bronze (maybe 10 hours on it) and it’s sounding great- tons of detail, as promised. Compared to my old cart (Elys 40) it sounds like a blanket has been taken off of my speakers... but maybe it’s too much? Not overly bright- but just a different presentation... Vocals really moved up front. I realize it’s far from broken in- but I do enjoy the occasional tube roll. Any suggestion for a warmer 12ax7 I might try?

Any idea which positions have the biggest sonic impact? I’ve got 2 12ax7 in the phono section and 2 in the preamp section (12au7 phase inverter)

Thanks for any insight/suggestions!

Kyle

 

Try one of the new-stock Russian (not Chinese, both exist) Genelex ECC83s. These area a really great and warm sounding tube.

 

Great, thanks for the suggestion!

 

Some early sixty s Mullards. Also I would contact Jim McShane the tube seller. His forte is HK products.

 

Good point about McShane... I always think “parts” but forget he’s got a giant stash of tubes as well.

 

The gold pin ones are the best. Also check out the reissued Mullard 12AX7 but not the 4004's.

 

I believe that the gold-pinned genelex's are the Russian version. The others are Chinese made. And yes these are indeed preferable, but it is not because of the gold pins.

 

Mullard 12AX7 long plate are good in the preamp and a warm phono tube is RCA 12AX7 long plate. These are not cheap tubes, but IMO superior to new manufacture. In fact, your Telefunken are also superior to new manufacture. The Telefunken have slightly more glare & less warmth vs the Mullard and RCA.

 

5751. Start with a GE. They’re very affordable and gives you a good peek into what the 5751 can do. Some like the RCA blackplate, to me it sounds ok, not the best. TungSol sounds great, “liquid” gets tossed around a lot for describing the sound, and it fits. My favorite, the Raytheon 5751 with windmill getter. It’s just a spectacular tube, well worth the hype. Gain is 70 on these, compared to 100 on a 12ax7, so you may or may not hear a difference in volume, I’ve never noticed. Have fun rolling!

 

You do have to be a little careful in phono stages when changing tube type, in some cases the different loading will also alter the RIAA accuracy. Of course, if it sounds better then it doesn't really matter

 

I agree Raytheon 5751 windmill getter is the best tube I ever heard. Not sure about lower gain of 70 vs 100 in phono sections with negative feedback. Some do not use negative feedback though.

 

BTW-Raytheon 5751 can have a little glare in some circuits. Works perfect in my amp. As good as Mullard 12AX7 long plate if not better.

 

I enjoy the mullards, has good bass and mid range but the high end stops short. If you use your tubes like an EQ you can fine tune your sound to endless possibilities. In my setup in my amp and pre:

mC240: Sylvania 12bh7’s, Mullard 12au7’s, RCA gray plate 12ax7’s and for the Chimney stack, Tung Sol 5751.

MX110: Raytheon 5751’s for the phono, Mullard 6u8a’s and TFK ribbed plate 12ax7. It took some time to experiment to get the sound, but to me, it’s as good as it gets for my system.

 

The OP's phono section is definitely a traditional feedback-based design.

 

Mullard's from the Blackburn factory have a sound signature conducive to classic rock, IMHO. Sweet smokey mids, pleasantly rolled-off highs, and bass that isn't bloated.

However, my personal favorite (by far!) is the 1950s RCA long black plate 12AX7s. Huge soundstage, 3D sound, opened top-end that isn't harsh in any way, extremely musical, and bass that is more pronounced yet more detailed than the Mullard.

They don't cost a tremendous amount of money but if you decide to try the RCAs, be sure to buy them from a place you can return them to as long-plated designs can occasionally succumb to extreme microphonics during shipping.

 

RCA 12AX7 black plate do have more issues than other 12AX7s. Microphonic & noisy. And most used on ebay are used up- weak tubes at high prices. Just buy new guaranteed RCA 12AX7 from Brent Jessee for $90 each.

 

Also try an early GE 12ax7. Late 50’s, early 60’s. They sound really good although the top end can be a little peaky. Bass sounds great on them!

 

All Genelex branded, new production tubes are Russian mfr. If any are Chinese, they are counterfeit.
-Bill

 

Genelex 12AX7 is same as Sovtek 12AX7LPS. Both are made by Sovtek. Quotes below.

' I believe that the Gold Lion 12AX7 IS the same tube as the LPS. I bought 5 Gold Lions really hoping that someone would really make a premium tube these days, but I was let down. Perhaps there is a slight difference in the Metallurgy, but I doubt it. The tubes both sounded quite identical'.

'I am writing from Melbourne,Australia.
Just to let you know the Gold Lion (Russian made copies of Genalex) are nothing else than a rip-off.(I have the 12AX7 tube)
Nothing different than a standard Sovtek LPS type, expensive and not worth the money.
I do no’t know how come the company behind it is asking for so much money for no benefit at all. I wouldn'’t recommend the tubes to anyone else'.

Why pay $30 for an average sounding Genelex 12AX7 when for $90 you will get a New & far superior sounding RCA 12AX7 black plate. A Sovtek 12AX7LPS is under $13.

 

If what you claim is true, then virtually every Genelex dealer out there has been knowingly selling these "counterfeits". Because my understanding has been that the 12AX7 (equivalents) is the singular exception in their line-up where Genelex have two offerings: the premium Russian (gold-pinned B759/ECC83), and the less expensive Chinese-made (ECC83).

 

There is two models- Russian & Chinese. I owned both.
But, every Genelex tube dealer has likely sold a counterfeit $13 Sovtek 12AX7LPS with different writing on the tube for $30+.

 

Well, if Genelex has recently introduced a Chinese version, then I stand corrected. The price list that I have does not include any other version. It might be a year old though, no date on it and I am not sure when I printed it. The brand owner also owns the factory in Russia, so it is both odd and news to me that they would do that. The Russian Genelex tubes have received consistently rave reviews by users.
-Bill

 

I don't know if anyone has dissected both. I think both have spiral filaments but I'm not sure all other elements of construction are identical. QC may also be considerably greater with more rejects in the premium lines like Gold Lion vs. the standard lines like Sovtek.

In any event, so there's not confusion, the company that makes Gold Lion and Sovtek (and the new "Mullard" and "Tung Sol" tubes as well as Electro Harmonix tubes and others) is a company called New Sensor Corporation, which makes all these tubes in a plant in Saratov, Russia which I believe the company owns. The company's founder is Mike Matthews who also founded the Electro Harmonix guitar effects company in the late '60.

While I think all the New Sensor tubes are made in the same factory, all the tubes that New Sensor makes of each type aren't necessarily identical (though the company does consumers no favors by buying the rights to these great old brand names and exploiting them).

They're also not necessarily bad. While I haven't used them in years, I used to use the 12AX7LPS a lot in guitar amps and it's a fine tube (personally I'd also choose it ahead of a black plate RCA 12ax7 for hifi use, but I don't like those RCAs in most uses). The Gold Lion KT77 is a very good sounding, extremely low noise (among the tube of their type with the lowest self-noise I've ever run across), and remarkably durable for new production, kinkless tetrode.

 

Right. If they have started selling a lower priced Chinese 12AX7 it must simply be due to pricing pressure. Personally, I think that is a risky move if they can't control quality there as it could ding their brand if they have more problems with them. The premium branded tubes, Genelex Gold Lion, Mullard, and Tung-Sol all have more stringent QC there and all test better here as well. Also my customers who have used them as well as many other types report better performance, so it's not just all hype and marketing.
-Bill

 

I went back and saw that Gold Lion is offering a 12ax7 labelled "Made in China" -- and it's not cheap, $40 a pop on the Electro Hamonix store, though available at a considerable discount from retailers. You never can be sure what New Sensor is going to do or is doing, but at least in this case the tubes are labelled with their country of origin -- not that Chinese manufacture is necessarily better or worse than Russian.

From New Sensor's own Electro Harmonix online shop: