# 12ax7's



## a Pack of Wolves (Sep 5, 2007)

thoughts?

faves,in terms of cost to quality

and why

(just interested in some random advice)


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## Budda (May 29, 2007)

apparently a tung sol in V1 and JJ's in the rest will make most tube amps sound pretty kickin compared to their stock form.

me, i plan on just throwing JJ tubes into my JSX when i get the money


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## Wild Bill (May 3, 2006)

a Pack of Wolves said:


> thoughts?
> 
> faves,in terms of cost to quality
> 
> ...


TungSol 12AX7's are nice and quiet. Very little hiss and spit. JJ's sound good but have a tendency to go microphonic after a while.

You have to watch for some amps like Peavey or Carvin that instead of putting in an extra 12AX7 they flog the hell outta the 1st preamp tube by running plate voltages far higher than spec. That can make some brands like TungSol start squealing. Not the fault of the tube but rather the amp designer. If you try one and get the problem don't blame the tube! Keep it for another amp that was designed properly.

Me, I like ElectroHarmonix 12AX7's. Decent quality without a BIG price! Not cheapest but not a silly high price, either. I don't put much stock in big sonic differences once you get above crap tubes between brands but I do think I hear a bit of vintage Mullard from the EH's.

It's important to note that 99.999999999999999999999999999999999999% of any sonic differences will be heard from changing the 1st preamp tube in the signal chain. After that I defy anyone to tell any difference, if blindfolded and kept in a different room while someone ELSE changes the tubes!

The amount of mojo and out and out BS going around about this matter is truly mindboggling! When reading a review that seems a bit over the top pay attention to who wrote it and whether or not he's looking for your money...

:food-smiley-004:


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## Geek (Jun 5, 2007)

RCA black plates. Sometimes found for a steal on fleabay. Great mids, rarely microphonic and very reliable.


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## searchin4signal (Sep 23, 2006)

Budda....a TungSol works fine in V1 in my JSX. Try sticking a JJECC81 (12AT7) tube in the PI spot. 
If you have a 16ohm cabinet cabinet connected to the head....flick the speaker impedance selector switch to 8ohms and play for a while. Tell me if you like what you hear.


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## Stratin2traynor (Sep 27, 2006)

I tried a Tungsol in the V1 of my Peavey Delta Blues (classic series) and it sounded horrible. It was buzzing and spitting and generally sounded like sh!t. Interestingly enough the Peavey sounded better with Sovteks than anything else. So I put all the Sovteks back and enjoy th eamp stock.

I then threw it into my Epi Valve Jr and found a nice home for it. Sounds awesome - very smooth like butta. 

I do have some EHX 12AX7's but haven't found a home for them yet.


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## NB-SK (Jul 28, 2007)

Wild Bill said:


> It's important to note that 99.999999999999999999999999999999999999% of any sonic differences will be heard from changing the 1st preamp tube in the signal chain. After that I defy anyone to tell any difference, if blindfolded and kept in a different room while someone ELSE changes the tubes!
> 
> The amount of mojo and out and out BS going around about this matter is truly mindboggling! When reading a review that seems a bit over the top pay attention to who wrote it and whether or not he's looking for your money...
> 
> :food-smiley-004:



The Tungsol 12ax7 is great. They are definitely the way to go if you have Tungsol 5881 power tubes in the amp. I have a pair of NOS Tungsol 5881s and my reissue sound practically identical. I also have a pair GE 5881, which are a bit less nasal than the Tungsol. I just use the reissue and keep the NOS tubes as an investment. 

I agree. Most of the tone you get will come from the first preamp tube. There is a slight difference if the other tubes in the chain are not cheap tubes, but the difference is probably not worth the price.


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## Budda (May 29, 2007)

so are you guys saying that if you put a good 12AX7 in V1 of an amp and leave the rest sovtek, you're doin ok? 

s4s, did you just say "put a lower output? tube in V1 and then change the ohms setting to drive it harder"...? lol

i kinda just want a retube. i know 2 years or so isnt much on an amp, but then i have spares.. yeah that's right, spares...


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## NB-SK (Jul 28, 2007)

To the first question: I noticed that it produces the greatest difference when switching the first tube. Switching the rest has a less noticeable affect on the tone (which is why a tube that squeals in the first position will do fine in others). In other words, there will be slight differences but they might not be worth the extra money to you. Start by switching the first tube with a higher quality one and see if you like the results.


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## searchin4signal (Sep 23, 2006)

Budda said:


> s4s, did you just say "put a lower output? tube in V1 and then change the ohms setting to drive it harder"...? lol


No no dude....NOT V1...put a 12AT7 in the PI spot...the Phase Inverter....right next to the power tubes.


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## GuitaristZ (Jan 26, 2007)

just wondering...you dont have to bias a preamp tube right?

so im my marshall jcm2000, I could just stick in a new preamp tube in slot 1? without changing anything else?


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## NB-SK (Jul 28, 2007)

GuitaristZ said:


> just wondering...you dont have to bias a preamp tube right?
> 
> so im my marshall jcm2000, I could just stick in a new preamp tube in slot 1? without changing anything else?


As long as you stick with the 12ax7 family (5751, ECC83, 12at7, 7025, etc.), they are direct substitutes (although some will give out less gain), no rewiring needed...except for the Russian military 6H2Π (6N2P or 6H2Pi) tubes that are sold on ebay as dirt cheap 12ax7 substitutes. Using that tube would probably require some rewiring. The 6N2P runs at 6V and I think (don't take my word on it, though) that the preamp sockets in most guitar amps are wired for 12V. Without knowing if and how this would affect the tone (and if the 6N2P sucks or not), rewiring the socket to 6V wouldn't be as drastic a mod as it seems because you'd still be able to switch back to 12ax7 since they can run at 6 or 12V.

http://tdsl.duncanamps.com/show.php?des=12AX7

http://tdsl.duncanamps.com/show.php?des=6N2P*


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## GuitaristZ (Jan 26, 2007)

ah ok thanks! Might go ahead and stick a different tube in for some fun.  thanks again for the help


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## NB-SK (Jul 28, 2007)

Glad I could offer some help.


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## Budda (May 29, 2007)

searchin4signal said:


> No no dude....NOT V1...put a 12AT7 in the PI spot...the Phase Inverter....right next to the power tubes.


so V1 isnt the phase inverter spot? i figured they'd be one and the same, hm...

i will try that, cheap experiment!


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## JSX/6505 (Nov 18, 2007)

I've found a very good combination that works great in my JSX. 
V1 JJ ECC83S, V2 EH 12AX7, V3 JJ ECC83S, V4 Sovtek LPS.

The JJ in the input preamp tube, AKA V1 position, was a great improvment in tone, response and clarity.
I prefer an EH in the V2 spot, which supplies gain to the crunch & ultra channels. The EH made the gain sound much better and gave my ultra channel more of an aggressive bite with tighter attack. The JJ was sluggish and dull sounding in comparision in this spot.

I suggest mixing and matching preamp tube brands because each vary depending on the slot they're put in.


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## Guiary (Oct 10, 2007)

Wild Bill said:


> TungSol 12AX7's are nice and quiet. Very little hiss and spit. JJ's sound good but have a tendency to go microphonic after a while.
> 
> You have to watch for some amps like Peavey or Carvin that instead of putting in an extra 12AX7 they flog the hell outta the 1st preamp tube by running plate voltages far higher than spec. That can make some brands like TungSol start squealing. Not the fault of the tube but rather the amp designer. If you try one and get the problem don't blame the tube! Keep it for another amp that was designed properly.



Hey Wild Bill, 

Would you be willing to shed some light on to which Carvin and Peavey amps suffer from this syndrome? 

Rolling the dice of luck, here comes Legacy and 5150!!!


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## Wild Bill (May 3, 2006)

Guiary said:


> Hey Wild Bill,
> 
> Would you be willing to shed some light on to which Carvin and Peavey amps suffer from this syndrome?
> 
> Rolling the dice of luck, here comes Legacy and 5150!!!


Well, the Legacy does and the 5150 doesn't!

Peavey's like the Classic series run V1 really hot. And so does the Legacy. I put a TS in a Legacy for one player. He had bought a set of tubes from some self-appointed tube guru vendor on the 'Net who had recommended a different brand of tube for each and every position. Utter tripe! I wouldn't trust that guy to put a new plug on a lamp!

Anyhow, the poor TS squealed like a stuck pig! I put an EH in and it immediately leveled out and started flying right. Not the TS fault, of course.

The 5150 runs a BUNCH of 12AX7's, choosing to get a modest amount of gain from each one but cascading up to a huge crunch! It's more expensive of course 'cuz Peavey had to put in more tubes, sockets and "glue" parts like caps and resistors but it seems to make for a "creamier" preamp distortion than with other amps that flog just a few tubes to their very death.

Me, I'm just an old guy. I still believe the best sound comes from a relatively clean amp and a straight boost pedal like a Tube Screamer. That's how we started out and then the world went all "Yngwie"...:wave:

:food-smiley-004:


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## Budda (May 29, 2007)

JSX/6505 said:


> I've found a very good combination that works great in my JSX.
> V1 JJ ECC83S, V2 EH 12AX7, V3 JJ ECC83S, V4 Sovtek LPS.
> 
> The JJ in the input preamp tube, AKA V1 position, was a great improvment in tone, response and clarity.
> ...


I dunno, i have JJ's in the entire preamp section of my JSX, i like it better then the stock EHX's. do you have a mk1 with two inputs, or a mk2 with the one input?


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## fraser (Feb 24, 2007)

i bought a few of these-
http://thetubestore.com/sovtek12ax7wb.html
12ax7-wb

was a bad choice for me- in my amps they sound kinda harsh- i wanted more gain- but they have a very "modern" type gain, for lack of a better word.

i like the chinese 12ax7 pretty well, 
my faves are some ancient rca and westinghouse ones ive gotten - most of the writing on them is gone-


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## Canman (Oct 21, 2007)

How much difference the preamp tubes make depends on the circuit of the amp. For example a Marshall Clubman takes a lot of tone from the second gain stage so you better have good tubes in both.

If you put a crap tube anywhere it can change the sound. Often the PA -driver tube is overlooked as not being critical and it isnt so much but it will make a difference. Put in an el cheapo and swap it out for...say a Mullard and you should be able to hear the difference.

I always thought the signal chain Yngwie plays loud and Clean and employs an overdrive and a delay. 

PICKUPS?

I prefer Lace Alumitones in a Strat set up. 

They are current driven rather than voltage? I dont understnd the difference but I presently am using a low voltage high current amplifier design so I thought I'd try them, and they seem to fit.

IMO The pickups make a lot of difference, A lot depends on what sound you wish to do have.
There is a great variety and it may take some trial and error to find the sound you want to hear especially if it isn't what the majority are selling like Fralins and Dimarrzio's or what ever.


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## JSX/6505 (Nov 18, 2007)

Budda said:


> I dunno, i have JJ's in the entire preamp section of my JSX, i like it better then the stock EHX's. do you have a mk1 with two inputs, or a mk2 with the one input?


I have the second issued JSX, with two inputs. 
I only have an EH in the V2 spot, because it makes the gain sound better than the JJ in that spot.


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## Budda (May 29, 2007)

nice, nice. i thought that the 2nd version of the jsx had 1 input.. the one i tried in a store only had 1 input. unless they changed the noise gate or something and put out another 2-input model.. w/e works.

the tubes in mine were 3 years old when i swapped 'em, it needed it.


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## JSX/6505 (Nov 18, 2007)

Budda said:


> nice, nice. i thought that the 2nd version of the jsx had 1 input.. the one i tried in a store only had 1 input. unless they changed the noise gate or something and put out another 2-input model.. w/e works.
> 
> the tubes in mine were 3 years old when i swapped 'em, it needed it.


Yeah, the very first ones had a single input, and apparently somewhat of a noise problem. The latest version, which came out soon after, has the two inputs and adjustments made to the noise reduction circuit (not the noise "gate") 
I think the noise gate is actually labeled wrong. It's really a noise suppressor, because there is no gate/clamping effect. It's nice because it squashes all that ssshhhhh-ing at high volume levels. I use a NS-2 for a gate.


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## Budda (May 29, 2007)

thanks for the info


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## JSX/6505 (Nov 18, 2007)

Budda said:


> thanks for the info


Nice to chat with another JSX user. I don't often get to.


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## Budda (May 29, 2007)

i know how you feel


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