choosing a good combo of tubes question

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danwelsh
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choosing a good combo of tubes question

Post by danwelsh » Fri Oct 03, 2014 1:24 am

Hi guys. Just looking for some suggestions on which tubes I should go with for my jtm45 build. I have some 12au7s coming that I will be using one in pi. But for the other 2 I'm not sure what will sound best.....I know this is a personal preference thing but I play a lot of rock and hard rock. Also should I got with 6550s for my power tubes or go with el34s. Thanks for any answers.

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Carbia
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Re: choosing a good combo of tubes question

Post by Carbia » Fri Oct 03, 2014 7:59 am

12au7 on the phase inverter?

use a 12ax7 or an 12at7.

In v1, no one can beat a NOS Mullard. in V2 you can go with something cheaper. A Sovtek 12ax7LPS works fine there.

As power tubes, put some KT66. The chinese ones work fine.

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Re: choosing a good combo of tubes question

Post by stef » Fri Oct 03, 2014 2:20 pm

jtm45 is not a hard rock amp IMO (I'd use the lead spec w/rectifier tube) but give it a try...
V1-V3 China 12ax7B or 12ax7A
V4 V5 - EH 6CA7

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Re: choosing a good combo of tubes question

Post by Carbia » Fri Oct 03, 2014 3:22 pm

You'te right, isn't is.
But china 12ax7???

No please

Even if you can't afford a Mullard, a RCA or Sylvania are cheaper and far better than chinese ones.

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Re: choosing a good combo of tubes question

Post by neikeel » Sun Oct 05, 2014 1:44 pm

stef wrote:jtm45 is not a hard rock amp IMO (I'd use the lead spec w/rectifier tube) but give it a try...
V1-V3 China 12ax7B or 12ax7A
V4 V5 - EH 6CA7
I think Stef is after the trashy higher gain tones for rock because most JTM45s are blues rock not really hard rock (I agree a 50w plexi with split cathode etc is a hard rock amp), particularly with a Mullard in V1 (I always use Mullards or Brimars in V1 btw! :wink: )
Neil

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Re: choosing a good combo of tubes question

Post by stef » Sun Oct 05, 2014 8:31 pm

In my limited experience with NOS (two telefunken, 3 miniwatt phillips, 2 mullard, Ei) and modern tubes (jj's, china, tesla's, sovtek, mesa etc) some strong chinese tubes sounded better in my amp than some NOS. I have 3 miniwatt tubes and all three sound different, two of them are nice and I use them in V1 and one of them is dull - dead, compresed and dark sounding in both V1 and V2. I'd say that one is completely unusable. Telefunkens are nice in V3 (not in V1).
The best tube I've ever had in my amp was a china 12ax7b with both triodes balanced and strong, but it died on me just recently after 3-4 years of use, it sounded great in any position :worthy:

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Carbia
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Re: choosing a good combo of tubes question

Post by Carbia » Mon Oct 06, 2014 8:22 am

On the other hand... I found one great sounding china 12ax7 out of 12 or 13... while found 1 bad Mullard out of 13...

Mullard or Brimar in V1, as Neikeel said, it's a winning bet.

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Re: choosing a good combo of tubes question

Post by danwelsh » Mon Oct 06, 2014 4:00 pm

stef wrote:jtm45 is not a hard rock amp IMO (I'd use the lead spec w/rectifier tube) but give it a try...
V1-V3 China 12ax7B or 12ax7A
V4 V5 - EH 6CA7
It's actually a jtm45+ build......and I have a gz34 rectifier tube for a start but before I go waste more money on tubes I won't like is why I posted this question. Thanks guys for your responses so far

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Re: choosing a good combo of tubes question

Post by Haze13 » Tue Oct 07, 2014 2:33 am

You can't write in words what exactly do you hear, so you can't just buy all these tubes that every one is telling you. If you have a chance to listen to the tube without buying it in the first place, than use that option. Like in the shop or at the friend.
I do believe that NOS tubes sounds better then a new one because of their construction and alloys, but I have no money to spend on them. I do hear all the time that EHX power and pre tubes are not so grate and some people are not want to use them, but I do... In JCM800 I have EHX tubes - 12ax7's (not a gold pins) and El34, and I like what I hear. Of course there is always something better, and there is no End to that.
JJ, EHX, Thung Sols, new Mullards, Gold Lions... Try some of those, and decide which one of them you like the most. Anyway you have to have some tubes just if something will go wrong, and this will not cost you as much as buying NOS stuff. Some say that Thung-Sols are no good as CF, so do not use then in V2, and they sound harsh if the gain of the stage is very high (100k on plates and 1.5k on cathode), but that's not the case with your amp. Just saying what to expect...

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Re: choosing a good combo of tubes question

Post by demonufo » Wed Oct 22, 2014 4:41 am

Personally I detest what other a?7 types do in the PI. If you absolutely must clean it up a little (although I think that's a terrible idea in a jtm45) then a 5751 works nicely without going too far. Especially if you're playing harder rock. You might also find raising the value of the coupling caps in the pi beneficial.
So I like purple, okay!!!!!!

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