Telefunken 12AX7

As noted (in order):

-The older (late 70's, 80's, or early 90's) Ei 12AX7 are very nice tubes if you can source them. They sound very similar to Telefunkens.

-Hageman has made you a very nice offer. Not much to lose there

-You could get some older used US: GE, RCA, etc tubes.

Also, the Sovtek 12AX7LPS is a very nice, quiet, new production tube.

Another quality tube vendor is: http://pages.prodigy.net/jimmcshane/

I'd say get some inexpensive new or used tubes to try out and go from there.

Enjoy your Mac!
Paul

 

Matt,

Do you really think that McIntosh would jeopardize their multi-million dollar brand name by putting an inferior tube in their top of the line, $6000 preamp? I don't think so...... I'm sure that Mac realizes that anyone who is willing to spend $6000 for a preamp, would certainly be able to spend another $200-$300 for a set NOS tubes.

Also, my experience collecting and restoring tube amps does not confirm that a tube failure in either the the line or phono stage of the preamp section of your integrated would do any harm at all to your amp. If the failure is in the section that your are using, the amp will simply stop playing.

If you doubt this, the next time your amp is playing (either line or phono) pull one of the tubes out and see what happens. Just don't burn your fingers!

The situation that Steve experienced must have started with a component failure (probably a resistor or capacitor) which in turn caused the tube failure.

Don't take my word for any of this. Instead, I suggest that you call McIntosh and talk to one of their technicians. Ask them their opinion of the Svetlana tubes that they are currently installing in their top of the line preamps. Here is their number 800-538-6576

Regards, HG

 

Not to throw confusion in the works, but what about the alternate designations?

http://www.vacuumtubes.com/12ax7.html

Any prizes among these others?

 

Michael Marx tells it like it is. A great tube seller, with tons of useful information on his website. Plus, you gotta love the words of wisdom posted on his site:

 

I've got to agree with Steve on this one. Spend the extra dough to get some Tele's, Bugle Boys, or Mullards. I have Telefunken 12AX7's and RCA Cleartop 12AU7's in my Primaluna Prologue 3 pre-amp at the moment, and that combo sounds amazing. I would get them now because the price is always going up. People covet these tubes because sound better then anything produced today, not because the glass is pretty.

 

Any of the suffexes that I should stay way from re: the 12ax7? The stock ones in my Mac are 12ax7a's.

I'm really excited to start experimenting and finding out what sounds best to me. I'm very much into 50s and 60s jazz, so I use Art Blakey a lot as a reference. Whatever tubes make "Mosaic" sound best, then those are the tubes for me.

-MTC

 

Matt, the "a" means the tube has a heater that has a controlled warm up time. Don't worry about the distinction between 12AX7's or 12AX7A's.

And remember, it's not either Chinese or Telefunkens. Try both (and other makes) and see which ones you like. If you buy vintage tubes that test well, you will be able sell and get your money back, no problem. But do remember on thing, there are no exact "copies" of the great vintage tubes. They try to get close but mostly it's about a current tube maker purchasing the name rights.

 

Golden Dragon moved production to Russia some time ago.

 

I didn't know that, but my valves (tubes) were the Shuguang (is that how it's spelt) ones from around 1990-92.

JG

 

Thanks for the recommendation list Paul, I just placed an order for 4 Sovtek 12AX7LPS with TubeDepot for my Dynaco Preamp.

I don't know why SED Winged C stopped making 12AX7's.

I love Russian Vodka, Russian Composers, Russian women, and now Russian tubes !

- Sushimaster

 

I never tried Telefunken, but I certainly agree about Mullard.

Goran

 

I'd say the Sovtek KT88s are worse than a bad match for the Dynaco Mark 3s. I had to crank the grid bias down to 1 volt (instead of the old 1.56 specified, that worked with the KT88s of yore) to get the plates to stop glowing, and even at that, one set had one blow after 2 1/2 months, and the other set lasted about 3 or 4 more months.

I went back to the mid-80s vintage GE/MPD 6550s I'd been using, with the grid bias set to 1.3 volts, and have had no problems since....

 

I also believe that the 12AX7A has the hum-canceling spiral heater a la the 7025 (which, btw, is identical to the 12AX7A but not the 12AX7)

-Aaron

 

Reportedly, the 12ax7LPS has some problems with microphonics and feedback in some preamp circuits (because of its large plates) so I'd be curious how it works in the Dynaco. Report back here!

 

Excellent!

 

I certainly will. Thanks for the heads up.

- Sushimaster

 

Wow - nice discussion! While there are clearly several opposing views this is one of the most mutually respectful and useful discussions about something gear-related I've seen here on the SH Forums.

Two comments:

First by all means YES, keep the Chinese tubes. When I first rolled in the Teles (and again, sure, I'd encourage you to try some Teles no matter what - you gotta eventually do it and figure this out for yourself, they're audio classics, and who knows, they may be the stuff for you!) I thought I preferred them, and only over time did I find they were not suited to my current situation. Upon re-rolling in the stock Chinese tubes, only then did I realize fully how good they were to my ears. I would respecfully suggest that one reason that people conclude the Teles are superior is they never complete the loop - e.g. they roll them in, and sure they have some very nice qualities like their conveyance of detail, and that's exciting, but then they don't go back and compare them with whatever tube they started with again later. If you do that, you just might find you gave up more than you remember to get that "different" sound (or not - you may prefer the Teles - but the key is you will never know unless you go back and compare for yourself).

Second - yes McIntosh sells the Chinese branded Svetlanas that I have in my C2300, I bought a replacement set to keep as backups and may buy more over time, $20 apiece. I'm not sure where else to easily get these slightly older versions of the Svetlanas in fact, none of the usual suspect online retailers have them in stock that I could find, listing now only the newer version with a different design (I want to eventually try them to see if they sound the same or not because they can be had for even less, about $10 apiece). Anyway, just call the McIntosh parts department if you are interested and they'll hook you up. They may also sell the Russian version; I didn't ask about that since I liked the Chinese tubes I had.

 

Hmmm....Before switching over to Penta KT88SC's in my Citation II, I ran a set of Sovteks for over a year with no problems. Since I'm retired, I'm certain that I play my system much more than the average forum member.

While running the Sovteks, I had the bias on the Citation set at 1.5 volts DC measured from the #8 tube pins to ground. This voltage is developed by a 100ma. bias current flowing through the 15 ohm cathode resistors. This is the factory setting for the Citation II. Not one glowing plate or tube failure at these settings.

I rate the Sovtek's second only to the Penta's. The Penta's in combination with the Citation II deliver a tighter base and a tad less harshness on the top end than the Sovtek's.

HG

 

OK, so I'm gonna take HG up on his generous offer to send me some vintage Teles in exchange for my Mac branded chinese 12ax7s. However, I need to buy some new production tubes to use while my chinese 12ax7s are en route to HG as well as something to use as backups and comparisons to the Teles that HG will send me.

I'm looking at trying some new productions of classic tubes. Anyone have any experience with the new Tung Sol's or Mullard's?

I've been reading good things about the ElectroHarmonics 12ax7 and the guys at Deja Vu Audio in VA seem to love them.

So while I wait for the Teles, what advice do you have?

Thanks,
MTC

 

For current production 12AX7 I like the Sovtek LPS and JJ tubes (though the latter can sometimes be hit-or-miss...try and buy from someone who will test the tubes before shipment).

 

UPDATE:

First the bad news. I took HG up on his generous offer (my Chinese tubes in exchange for his Teles), but the mail had other ideas as the tubes have been either lost or stolen. We will file for the insurance (I am still hopeful that out of the blue, these tubes will just show up). Imagine the poor thug who stole the tubes...opens 'em up to find four vintage Telefunkens that he can't do anything with. Sad, I know.

OK, so to help me with the Telefunken Blues, I bought a pair of 1962 RCA gray plates for my line stage. When I took the Chinese tubes out for HG, I put reissue Tung Sol's in my phono stage and Electro Harmonix in my line stage. I liked the Tung Sols OK, but HATED the Electros. They make music sound harsh and it was hard to listen for long periods. Then, enter the RCAs. Holy s&**t! I can't even explain it. The RCAs just sound so full and sorry, "natural". They are not harsh at all. If anything they are a little softer on the top end, which is fine by me. I listened for over 8 hours yesterday with sources ranging from Uncle Tupelo's acoustic stuff to classic Bo Diddley and from Art Blakey to Red Sox Baseball on XM Radio.

Now, I feel like I need to get the reissue Tung Sol's out of my phono stage and get some NOS tubes in there. I'm thinking of staying with NOS RCAs or trying vintage Tung Sols? Maybe I should try and find some reasonably prices Teles for phono (if I can find any).

I'm waiting on some Teles 12at7s to drive my KT88s and then I'm upgrading the KT88s to Gold Lion reissues. Then, I'm gonna sit back and quit tube rolling for a while (if I can). I mean, it's a disease. It's hard to stop. I love the RCAs in my line stage, but that makes me wonder, if the RCAs sound so good, how would the Teles sound in that same slot, OR Amperex OR Mullards? Aaaaah! Honestly, though, I'm having a good time with all this. Tubes are way more fun and offer such a reward over solid state, in my opinion.

Thanks again for all the help everyone on this thread has provided. Any suggestions for the phono stage?

-Matt

 

In well designed audio applications failures, even catastrophic, on _small signal_ tubes, will not cause damage, or at least not catastrophic damage. A smoked ten cent resistor is no big deal. RF applications can be otherwise, it can take out IF transformers which may be today irreplaceable.

Power tube failures can take out output and/or power transformers, although again in theory proper design means a fuse or cheap resistor goes first.

My father had MC75 monoblocks (three of them) and he changed power tubes _once_ in the years (maybe ten?) he had them. They were used every day all day,as the Zenith TV was modified to provide transformer coupled line out and we watched way too much TV. The small signal tubes were the same-the drivers were changed with the power tubes and one other one got noisy and was changed. That was IT. The Zenith lasted that long too and also needed two tubes in its life:regrettably, one was the CRT.