V5 position

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brees

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ok I have read alot of post and have read about using a jj ecc803 gold pin and a balanced 12ax7 can someone tell me the differece either one would make and why is there a difference between a so called regular 12ax7 and a balanced one.
I am changing the tubes in my Stiletto Ace and so far I have decided on using:
V1 Tung Sol
v2 Tung Sol
V3 JJ
V4 JJ
V5 ??
I am open to any input on my choice cause I have never done this before

Thanks
Steve
 
If you owned a $15,000 all-tube stereo you might notice a difference using so-called "balanced triodes".

Guitar amps? Not so much. Yes, it's snake oil.

All 12AX7s have two sides. The idea behind having those two sides "balanced" is to reduce distortion. There is SO much distortion in any guitar amp pre-amp WAY before the phase inverter that it's ludicrous to think a balanced triode would have any detectable affect.

But, it's a free country, and it's your money, and it's probably only a $20 investment, so why not take the plunge? If it sounds better TO YOU, it makes NO difference what anonymous peoples on the interwebs think anyway, now do it?

BUT, instead of changing ALL the tubes at once, just get a couple and try them in V1. Really, if you can't tell the difference between a $10 tube and a $20 tube, you will have learned a valuable lesson. And possibly saved some money in the process.

I realize everybody desires instant gratification, but if you just change out ALL the 12Ax7s at once, you will have NO idea which tube is doing what and how any replacement is improving your tone, if at all. Tone-chasing takes time. There are no short-cuts.

Contrary to popular belief, pre-amp tubes do NOT wear out at anywhere near the rate that power tubes do, and typically last for many thousands of hours. This is why there is such a market for 40-50 year old Mullards and RCA blackplates.
 
If v5 is the phase inverter, the purpose to balance of triodes is match the positive and negative peak response so that a class A/B power amplifier has similar swing characteristics. This will also help with class A amplifiers to balance the signal on its load line. The cost for balance tube is not that much (depending where you get it from). The offset between the two triodes should not be that dramatic unless you get tubes that were rejects. Balanced triode tube is one that is tested to confirm the gain of both circuits to be matched. Most tubes (if not all) usually go through several screening process to weed out defects or tubes that have certain characteristics that do not meet a specific standard given some operating parameters.

I would agree with MrMarkIII on the effects of distortion. You will not notice a difference.
As part of Doug's Tubes cocktail, typical tube for the PI is Sovetek 12ax7LPS. I did not notice any difference in tone character, power tube distortion or saturation from the Mesa 12ax7a. However, I did try all tung sols in all positions and did not care for that. It was a bit bland or dull sounding (did not change any tone controls on the amp when I made the change, perhaps experimenting further would have revealed something different. The tung Sol tubes did not alter tone when they were used in the driver circuits. The most important preamp tube is the V1 primary and usually secondary gain stage. Each amp is different, so I cannot say much for stilleto.

If you plan on getting another tube for V5, you may want to get some other's along with it. That way you can experiment with a few different tubes.
 
As MrMArk pointed out a balanced triode in guitar amp use is snake oil.In a hi-fi you want pure sound reproduction,your components will be within 1% tolerance,absolutely no distortion.In a guitar amp your components are +/- 10 to 20% tolerance so even if you put a "balanced triode " in the PI it wont be balanced after your circuit gets through with it.I have found that even the output tubes sound a little better if they are not perfectly matched,you dont want total linearity here,I match my power tubes no closer than within 5ma's.Even at its cleanest,a warm sounding guitar amp will still exhibit some distortion if you put it on a scope.If you want to hear the difference,set your amp as clean as you can,listen,then plug your guitar into any stereo and try to get it to sound good,it wont.All you will get is loud and cold.Look,a balanced triode wont sound bad,but it wont improve anything.Even the output tranny in a guitar amp isnt perfectly balanced,that is why a good hi-fi tranny will cost over well $300.Any other position besides the PI uses each side of a triode individually,so again,no need for balance.
 
Focus on V1 & V2, less concern for the loop & converter valves.
I ran around the whole ballpark of preamp valves with the NOS stuff being a big disappointment, had a reasonable improvement with Groove Tube 12AX7M in V1 & V2 and have now ended up with Mesa SPAX in V1 & V2, they're quieter with a good soundstage. Change just V1 first on it's own and spend some time with that sound, the SPAX isn't expensive, I was dubious and pleasantly surprised. I've put the 12AX7M's back in 3,4,5 simply because I've got them. I use the loop for a Creative Audio Labs MK4.23 line boost, it suits the power valves instead of pushing the front end.
Just get 2 valves of your choice maybe a spax and ruby, tung are a disappointment, and experiment with V1 only first, it's the first in line and the most significant, don't worry about V5 just a reliable one.
Keep the pennies in the pocket :mrgreen:
 

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