Preamp tube suggestions for a JCM900 SLX

tully

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I want to re-tube an SLX
It sounded good when I bought it, but I think it could be better
So far, I messed around with V1 and V2
It came with a Marshall branded 12AX7 in 1 and a JJ in 2
I figured swapping these valves would make the tone change the most
I ended up leaving the JJ in 2. I tried a Ruby and a Groove Tube in that slot, but went back to the JJ
I ended up putting a gold pin Telefunken in V1 and it smoothed out the tone, but reduced the gain a bit
The Groove Tube and the Ruby both sounded pretty good in V1, but the Marshall tube was a bit better I think
Should I change all four of them? Chinese? Russian? NOS?
Any suggestions?
 

Moony

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Marshall, Ruby and Groove Tubes are no tube manufacturers.
So unless you don't give specific information about which Marshall, Ruby and Groove Tubes tubes you are using it's a bit pointless.
They could all be JJs. Or something else.
And nobody knows how old these tubes are, if they were selected, already worn down...

The amp will also work fine with three new JJ ECC83S.
So what are you looking for soundwise?

Like it a bit brighter? Try a Tung Sol 12AX7RI in V1 - buy a V1 selected one!
For V2 maybe find a selected Shuguang 12AX7B.
V3 use a Sovtek 12AX7LPS or a JJ ECC83S. Both are good for this spot.

Note that there are tolerances with tubes and they do matter!
You probably will even notice minor differences if you buy 3 JJ ECC83S and swapping the positions.

The best recommendation I can give is to buy your tubes from a trusted seller who checks and select them.
Buying tubes is a matter of trust (except you have some old good gear to do the measurements by yourself).
 

solarburnDSL50

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I want to re-tube an SLX
It sounded good when I bought it, but I think it could be better
So far, I messed around with V1 and V2
It came with a Marshall branded 12AX7 in 1 and a JJ in 2
I figured swapping these valves would make the tone change the most
I ended up leaving the JJ in 2. I tried a Ruby and a Groove Tube in that slot, but went back to the JJ
I ended up putting a gold pin Telefunken in V1 and it smoothed out the tone, but reduced the gain a bit
The Groove Tube and the Ruby both sounded pretty good in V1, but the Marshall tube was a bit better I think
Should I change all four of them? Chinese? Russian? NOS?
Any suggestions?
When in stock? 12AX7 AC7 HG+ in V1. Mullard CV 4004 12AX7 reissue in V2. Any neutral sounding 12AX7'S in final slots. You can switch V1& V2 tubes as well. V1 and V2 matter most.

Speakers matter more.
 

solarburnDSL50

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These Ruby Tubes are harder to find now.
But you can buy the silver pin Genalex 12AX7 instead.
It's the same tube.
So is the Preferred series from the tube store or TAD 12AX7 7025S.

I always get solid results with this tube. However i have others that tickle my ears too.
 

Rudy v

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I want to re-tube an SLX
It sounded good when I bought it, but I think it could be better
So far, I messed around with V1 and V2
It came with a Marshall branded 12AX7 in 1 and a JJ in 2
I figured swapping these valves would make the tone change the most
I ended up leaving the JJ in 2. I tried a Ruby and a Groove Tube in that slot, but went back to the JJ
I ended up putting a gold pin Telefunken in V1 and it smoothed out the tone, but reduced the gain a bit
The Groove Tube and the Ruby both sounded pretty good in V1, but the Marshall tube was a bit better I think
Should I change all four of them? Chinese? Russian? NOS?
Any suggestions?
Have you try a7025 in v 1
 

tully

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Marshall, Ruby and Groove Tubes are no tube manufacturers.
So unless you don't give specific information about which Marshall, Ruby and Groove Tubes tubes you are using it's a bit pointless.
They could all be JJs. Or something else.
And nobody knows how old these tubes are, if they were selected, already worn down...

The amp will also work fine with three new JJ ECC83S.
So what are you looking for soundwise?

Like it a bit brighter? Try a Tung Sol 12AX7RI in V1 - buy a V1 selected one!
For V2 maybe find a selected Shuguang 12AX7B.
V3 use a Sovtek 12AX7LPS or a JJ ECC83S. Both are good for this spot.

Note that there are tolerances with tubes and they do matter!
You probably will even notice minor differences if you buy 3 JJ ECC83S and swapping the positions.

The best recommendation I can give is to buy your tubes from a trusted seller who checks and select them.
Buying tubes is a matter of trust (except you have some old good gear to do the measurements by yourself
I have mostly 12AX7 tubes from JJ, EH, Sovtek, Mullard, Ruby, Groove Tube, TAD, Mesa, Tung-Sol, Shuguang, Marshall branded, Bugera branded and unbranded Chinese

I also have an NOS National 12AT7, a JAN 12AU7 and a few others I'm forgetting

I want a tone like mid seventies and early eighties - Judas Priest, EVH, KISS, Iron Maiden, Scorpions

Not too bright. Thick and clear. Bombastic!!
 
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Moony

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Not too bright. Thick and clear. Bombastic!!

Best is to try out what you have then.

I started a thread about current production 12AX7/ECC83 tubes on a German forum 9 years ago because there wasn't much information available at the time - and I updated it just a while ago.> Klick < because people asked for it.
It's unfortunately written in German, but maybe Google translate helps.

Note these are just my personal findings to the several tubes and how they sound depends on the circuit you use them in.

Additional info on Groove Tubes 12AX7 > Klick <
 

solarburnDSL50

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Best is to try out what you have then.

I started a thread about current production 12AX7/ECC83 tubes on a German forum 9 years ago because there wasn't much information available at the time - and I updated it just a while ago.> Klick < because people asked for it.
It's unfortunately written in German, but maybe Google translate helps.

Note these are just my personal findings to the several tubes and how they sound depends on the circuit you use them in.

Additional info on Groove Tubes 12AX7 > Klick <
Awh bud...that CP Mullard 4004 is tinky tap microphonic in my 800 in V1.

However I've had some of my beloved ANOS micro in V1 by finger tapping sound fine playing. Meaning I didn't hear it. The CP Mullard rang and tinkered.

Tubes, know when to ride...Know when they are a PI tube.:D
 

tully

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Best is to try out what you have then.

I started a thread about current production 12AX7/ECC83 tubes on a German forum 9 years ago because there wasn't much information available at the time - and I updated it just a while ago.> Klick < because people asked for it.
It's unfortunately written in German, but maybe Google translate helps.

Note these are just my personal findings to the several tubes and how they sound depends on the circuit you use them in.

Additional info on Groove Tubes 12AX7 > Klick <
I have made a selection (for now, LOL)

V1 - Marshall branded 12AX7 (I tried a Telefunken Gold Pin which smoothed it out - However, it lowered the gain/distortion too much for my liking - TAD 7025 sounded good here)
V2 - JJ ECC83S (this tube easily sounded best in this position)
V3 - Marshall branded 12AX7 (didn't mess with this one)
V4 - Electro-Harmonics 12AX7 balanced ( i tried a Tung-Sol in this spot, it was too bright - The Sovtek LPS sounded good though)

V5-
- Ruby EL34
V6-

Thanks for you input
 
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