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Twigman

12AX7 tubes in pre-amps

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12AX7 / ECC83 tubes for preamps
They're all much of a muchness aren't they?
It's all snake oil, isn't it?

Do they really sound different?

Does a Sovtek 12AX7WA really sound different to a Sovtek 12AX7WC or a Philips 12AX7WA or a Mullard ECC83/5751 or a EHX 12AX7 ???

What are the differences?
What do you pay a premium for - other than NOS original valves from the 60s/70s?

Is there really any discernible difference when used in a DHA preamp pedal with a bass?

Discuss

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yep, had a few amps over the years with valves in,

At mo im using swr gear which has 12ax7, a red head in the studio another red head for small gigs and an sm500 for bigger gigs.
I got some "MESSA" valves from ebay the ones in the black and white boxes....run a mile,
they are awfull, the only time my redhead broke at a gig was when i put one of these in that day to try, mid song just a very loud distorted buzzing, nearly took the speakers of the amp and pa out, lucky i had the one i had taken out in my spares box.
i also put one in the red head in the studio but took it out right away and binned them.
found the best one for my amp was the original one that was in it, and have an old mullard that sounds good for live with a good strong kick ass o/p, but found it just slightly buzzy for studio,
i think alot of copys are on ebay so now i always order from source.
As Colin says "Watford valves" are great guys who know their stuff, and fantastic backup.
they do all the "stars" amps and can tell you who is using what and more importantly... why.
cant go wrong there :)
You buy cheap, you buy twice... in this case... maybe alot more.

Edited by funkgod

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Interesting article, saved for future reference (despite this howler in the first page "[font=FranklinGothic][size=2]makes this valve very unique ". )[/size][/font]

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It seems like some circuits respond to swapping different brands of 12AX7 much more than others. In a very clean running Carlsbro (which I was using for bass) or a blackface Fender-ish guitar combo I couldn't hear any difference when swapping preamp valves between EH, JJ, Brimar and a couple of old Mullards, or if I could it was so subtle as to be insignificant to me. But in a guitar amp based on a Marshall circuit with a bit of preamp overdrive going on I could hear more of a difference when swapping valves, so I feel like any comments about a valve having a specific sound are only useful with regard to the gear they're used in.
I don't know whether the DHA pedals would tend to show up those differences or not, though somebody on here must have tried.

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Used lots of different pre-amp tubes in different pre-amps and not found a [i]really [/i]huge difference in 'tone'. But in my experience Mullards [i]et al[/i] were certainly built to a higher standard and last a lot longer than some of the modern pretenders.

At one time had a Burman pre with the original 1970s Mullards in it and it sounded fantastic. But then again pre-amp valves get an easy time of it compared with power stage valves.

Edited by discreet

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They can make a big difference but i think it comes down to your type of pre-amp/rig etc. I've had a lot of success (and a few surprises!) trying different types,i.e. - ECC82 or 5751 instead of ECC83's. Its real trial and error and can get expensive. don't get too drawn into the "it has to be a vintage Mullard / RCA" thing, there are some pearls out there - just got to find them! I recommend the likes of Brimar, GE etc. Groove Tubes have used some good valves too but can be hit and miss as to their origin.

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I spent a fair bit of time swapping the principal pre-amp valve around in my Demeter M800 head.

When James Demeter sent it over he'd temporarily run out of stock of his regular valve so he let me have a Sylvania NOS 1960's one he had.

The Sylvania was worth a lot more but James wanted to get it over as quickly as possible.

Because he's such a pro he then sent a free valve of the regular type just so I could be sure I had the one installed that I preferred.

By chance I had a couple of cheaper valves kicking around so was able to test three different set ups.

The 'stock' valve appeared to have the most gain and was the 'purest' sounding.

The cheaper pair sounded a shade warmer but maybe a bit more 'brittle' - tough to explain but it was the least attractive to me.

The Sylvania was both warmer and richer sounding. Because the Demeter is a very clean amp to start with I decided to choose the Sylvania because it game me a few more options.

The amp has normal, bright and dark options and the bright is a bit too crisp for me (great for people who like a 'hifi' tone). By adding the slightly warmer valve I feel the bright was more useable for my basses.

Anyway - summary is that different valves do sound different but the change can be subtle. The Watford valves guys are absolutely the best people to help, especially if you're looking for valves that will break up and generate pre-amp distortion :)

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[quote name='Beer of the Bass' timestamp='1473591758' post='3131398']

I don't know whether the DHA pedals would tend to show up those differences or not, though somebody on here must have tried.
[/quote]

My DHA VT1 EQ came with an ElectroHarmonix valve but I swapped it out for a Mullard ECC83. Not much difference in gain, but it had a smoother quality to the distortion.

Different valve types, but I vastly preferred the TungSol 6SN7s to the Sovtek 6SL7s in the preamp of my valve amp.

Edited by Roland Rock

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Aren't valve based pedals starved plate so it wouldn't make as much of a difference.

Although I had a dha vt1 swapped the original tube for a mullard and there was a difference I echo what rolandrock says in that it was much smoother. It just had that hint more valve tone.

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This topic has been explained to me very clearly by agedhorse, a Mesa engineer. It all depends on the circuit design. Some circuits do not allow the tube to impart a certain character, while othes do. He suggests, instead of serching for night and day differencies amongst brands, to change tube type, for example running a 12at7 ibstead of a ax7... very different tubes, arguably yelding different results.
Myself, I have a bunch of contemporary and old 12ax7 on hand and tried them in various combinations in my walkabout. Recorded every change and listened after....best way for non being biased. Despite the high current topology of my walkabout pre, all 12ax7 sounded very much alike. Differencies in gain capability was apparent, tone, much less. I choose to mount a Tungsol duo, because the lowend sounded tighter and allowed me to use the low eq more freely, that's it. I'm planning to try a 12at7 when I happen to buy one

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Having looked at 'the' website, I am somewhat underwhelmed by the lack of recent 'tests'.
A cynic (moi ?) might conclude that they are only featuring their own stock (surely not....)
I've used valve amps (some quite loud) on and off since the late sixties - I've never felt the
need to hack about (polite, that) with my valves...but, what do I know ??

:yarr:

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[quote name='taunton-hobbit' timestamp='1474572163' post='3138958']
Having looked at 'the' website, I am somewhat underwhelmed by the lack of recent 'tests'.
A cynic (moi ?)


[/quote]

More likely that the available 'models' haven't changed for many, many years given the few producers of valve products over that time!

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[quote name='Twigman' timestamp='1473526969' post='3131028']
12AX7 / ECC83 tubes for preamps
They're all much of a muchness aren't they?
It's all snake oil, isn't it?

Do they really sound different?

Does a Sovtek 12AX7WA really sound different to a Sovtek 12AX7WC or a Philips 12AX7WA or a Mullard ECC83/5751 or a EHX 12AX7 ???

What are the differences?
What do you pay a premium for - other than NOS original valves from the 60s/70s?

Is there really any discernible difference when used in a DHA preamp pedal with a bass?

Discuss
[/quote]

I would recommend nos valves in my pedals if you can find them. They do sound better then new valves but you pay the price. I fit the a very nice valve as stock that offers good tone at a good price.

Dave

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[quote name='DHA' timestamp='1474967617' post='3141822']
I would recommend nos valves in my pedals if you can find them. They do sound better then new valves but you pay the price. I fit the a very nice valve as stock that offers good tone at a good price.

Dave
[/quote]

Thanks Dave...the tube you supplied with the pedal sounded OK but got smashed very early on in the pedal's life.
Since then I've tried EHX, Sovtek, a no name chinese tube (£3) and they all sounded similar to my ears!!!
I have now got a made in england mullard (i assume it must be an old one) and have some packing foam for the pedal - that'll do me.

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