Bare Knuckle Pickups Forum
Forum Ringside => Guitars, Amps and Effects => Topic started by: Kepu on September 20, 2007, 07:03:38 PM
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Hello there!
I'm about to buy some new tubes for my Framus Cobra, I've already decided on the JJ 6L6GC power tubes and JJ ECC83S pre-amp tubes
there's 4 of ECC83S for sale for about 20 euros, in store they cost 9 per one
and 2 of those 4 are slightly used, does that matter?
but I don't know what that 'matched/selected set' thing means?
so should I buy those 4 and then get 1 new?
or should I get 5 new ones?
Thanks in advance
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Normally slightly used pre-amp tubes - i,e, the Ecc83 (same tube as its American title 12AX7) are ok as they last for ages. Power tubes are the one you want new.
When you change power tubes (the 6L6s) you want a 'Match set' as change of tube normally means re-biasing the amp. Having a match set makes re-biasing easier and more optimum as the tubes all sing from the same hymn sheet in terms of current. Even if you choose not to rebias match sets give you uniformity.
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oh sorry, I didn't explain detailed enough
I'm gonna buy the 6L6GC power tubes new, 4 of them
but it's just that Cobras have 5 pre-amp tubes and that guy is selling only 4, so I should buy those 4 and then 1 new and re-bias all of them?
would that be better than buying 5 new ECC83S tubes?
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You don't have to bias pre-amp tubes, just power ones ;)
I'd buy a new set of 5 - less chance of a problem when gigging that way.
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sorry that's what I meant to say above
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oh alright, sorry for my tube n00biness :oops:
I don't think I'll be gigging in a few years tho
and remember that 2 of the set of 4 are new, so if I buy 1 new more, that'll make 3 new and 2 used
but by the time I'll be gigging I think those particular tubes are blown to dust already :lol:
so should I just get the cheaper set?
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You have a Framus Cobra and you don't gig? :o
In that case, buy what you like!
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Preamp tubes last a long time...
If it was me, I'd be looking at tubes a lot better than JJs especially for a quality amp like that.
For the power tubes, look for the Groove Tubes GT-6L6GE. They sound a little better than anything else on the market, much better than JJ and hold up much better than any of the competition.
For preamp tubes, look for some NOS RFTs. There were Russian RFTs made later which aren't quite as good as the German made tubes, but the German made tubes sound just like old Mullards and cost a fraction of the price.
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You have a Framus Cobra and you don't gig? :o
Yep, but you really can't argue with the price I got it :lol:
I'm not really looking for the 'ultimate tubes' just ones that will get the buzzy/fizzy high-end of the amp away :P
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http://I'm not really looking for the 'ultimate tubes' just ones that will get the buzzy/fizzy high-end of the amp away
i think then you have the right idea getting JJ tubes. better tubes are available, but JJ certinally are damn fine sounding with the right price. like many here i use JJ tubes, very happy with them. in fact i think it was a someone here, along time ago, who suggested them to me.
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Do you use an attenuator? If you're running it at low volumes with gain, it's always going to be buzzy...
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Nope not yet, but I don't really have a problem cranking it as the closest neighbours are about 200 metres away, still the high-end sounds kinda thin and ear pearcing
the rythm tone is excellent tho :wink:
so should I get those JJs?
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This may sound counter intuitive but I find a slightly lower gain pre amp tube in V1 such as a GE 5751 (as opposed to a 12AX7) gives you slightly more headroom and allows you to get the power amp going without loosing clarity from the first valve going into OD. It also, to my ears, allows the character of OD/distortion pedals to come through as V1 doesn't go into OD so quickly.
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so you think I should buy 4 of the JJs for V2 - V5 positions and then something lower gain for V1?
but I gotta decide on the 4 JJ tubes pretty soon cuz the auction ends tonight
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Probably one of my idiosyncracies - but its worth trying if you have a spare 5751 or a 12AT7 lying around :D
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http://I'm not really looking for the 'ultimate tubes' just ones that will get the buzzy/fizzy high-end of the amp away
i think then you have the right idea getting JJ tubes. better tubes are available, but JJ certinally are damn fine sounding with the right price. like many here i use JJ tubes, very happy with them. in fact i think it was a someone here, along time ago, who suggested them to me.
You can do a hell of a lot better for the same price though and much less fizzier.
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Probably one of my idiosyncracies - but its worth trying if you have a spare 5751 or a 12AT7 lying around :D
No I unfortunately don't have :P
You can do a hell of a lot better for the same price though and much less fizzier.
Any suggestions? :wink:
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I recently stuck some JJ preamps into my Peavey 5150-II, and the difference from the old tubes was incredible!
The amp tech I got to look over the amp tested the output of the transformer, and found that one side was very much stronger than the other, so my "matched set" of 4 tubes actually meant having 2 running at about 33 mA each and the other 2 running at nearer to 20 mA each.
He was pretty scathing about "matched" tube sets, because, in practice, for almost every amp it's not that crucial - there are other factors which may (or may not!) negate the matchedness of your tubes.
For high gain amps, the other thing he mentioned was that you're really after something with plenty of headroom that's built very well (and will therefore last longer). I had got some Svetlana Winged C 6L6GC tubes, and he suggested that next time I buy the one up in their range, because they're built better.
The pre-amp tubes are far more important for tone in a high-gain, high-output metal amp, like the 120W 5150-II I have.
I bought 4 JJs and 2 Sovtek ECC84lps tubes, and although I haven't tried mixing them around in the pre-amp section, I could do so. As long as you get good quality tubes for both pre- and post- stages, you'll be fine!
Roo
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This may sound counter intuitive but I find a slightly lower gain pre amp tube in V1 such as a GE 5751 (as opposed to a 12AX7) gives you slightly more headroom and allows you to get the power amp going without loosing clarity from the first valve going into OD. It also, to my ears, allows the character of OD/distortion pedals to come through as V1 doesn't go into OD so quickly.
Often using lower gain tubes will do this. I heard a clip of someones JCM 800 and it sounded amazing. I was talking to him and he said he put a 12AT7 in the preamp for this reason and it still sounded great and had a lot of gain for a non-modded JCM 800.