Replacing the tubes on my JMP 50

[Rich_T]

Ok, need some advice on the best tubes out there at the moment. I dont really know what the differences are, can someone enlighten me?

Its a Marshall JMP 50 2204 circuit. I want the most warmth and open-ness as possible from this amp, I get most of my gain from pedals, but rarely use a 100% clean sound, its always on the verge of breakup. I need solid lows and low mid, and rounded highs.

So, fire away! Thanks in advance!

 

[kmcguitars]

Re: Replacing the tubes on my JMP 50

You might want to check out the JJ KT 77's.

 

[Rich_T]

Re: Replacing the tubes on my JMP 50

You might want to check out the JJ KT 77's.

Will I have to re-bias for them? Its EL34s at the moment.

 

[Gr8Scott]

Re: Replacing the tubes on my JMP 50

Any time you change power tubes, you should rebias just to be safe. If the bias is adjustable of course, it's usually a good idea. KT-77's are basically the same as EL34's. The main differences are internal construction. They are completely swappable though and much tougher than EL-34's. They don't break up as soon, so power tube distortion is lessened by the KT-77's.

 

[Rich_T]

Re: Replacing the tubes on my JMP 50

Hmm, well i quite like the power tube distortion. So maybe EL-34s are better for me.

 

[Gr8Scott]

Re: Replacing the tubes on my JMP 50

I think the EH EL-34's are supposed to be very good for the money. Not mullards, but fairly close. Those are what I'd be shooting for.

 

[the guy who invented fire]

Re: Replacing the tubes on my JMP 50

The EH EL34's are pretty nice for the money. So far my fav current production EL34 is the reissue Mullard from New Sensor, they are a little higher than the EH but IMO they are worth it...

 

[Rich_T]

Re: Replacing the tubes on my JMP 50

How about pre-amp valves?

 

[the guy who invented fire]

Re: Replacing the tubes on my JMP 50

How about pre-amp valves?

Well, you have 3 12AX7's in there...for current production I really like...

-Sovtek 12XA7LPS
-Electro Harmonix 12AX7EH
-Tung-Sol 12AX7 (New Senson reissue)

 

[Rich_T]

Re: Replacing the tubes on my JMP 50

Ace, cheers for the help Christian. I'll look into them.

 

[the guy who invented fire]

Re: Replacing the tubes on my JMP 50

Ace, cheers for the help Christian. I'll look into them.

I will tell you this...the Sovtek LPS is a low noise/high gain tube, I like the tone of it a lot, the EH tube is a tad warmer sounding and doesn't have quite the gain of the LPS and the Tung Sol is just an all around great tube...it a little brighter than the EH and has more gain but it's not as gainy as LPS.

If you can find some and feel like spending the extra on them the NOS RFT 12AX7's that are going around right now are killer sounding...kind of warm with a nice breakup tone...they are really not too pricy compared to other NOS tubes...I think they are well worth it...

 

[OUTLAW1969]

Re: Replacing the tubes on my JMP 50

Tung Sol is just an all around great tube...it a little brighter than the EH and has more gain but it's not as gainy as LPS.

...

+1 on the Tung Sols

Revolution Guitar also turned me onto the Ei Gold Elite 12AX7's, especially in the V1 position, although it is a toss up between the Tung Sols and the Ei's. Both are GREAT!

 

[the guy who invented fire]

Re: Replacing the tubes on my JMP 50

+1 on the Tung Sols
Revolution Guitar also turned me onto the Ei Gold Elite 12AX7's, especially in the V1 position, although it is a toss up between the Tung Sols and the Ei's. Both are GREAT!

I have tried the Ei 12AX7's but not the Gold Elite ones...how do they compare to the Tung Sol reisues???

 

[34029324079]

Re: Replacing the tubes on my JMP 50

get the ones with full distortion to match your 'metal distortion strings'!

 

[Jeff_H]

Re: Replacing the tubes on my JMP 50

I want the most warmth and open-ness as possible from this amp, I need solid lows and low mid, and rounded highs.

So, fire away! Thanks in advance!

This screams JJ's to me. JJ makes several EL34 versions, so I would recommend e-mailing Bob at Eurotubes...he is the most knowledgable guy I've heard of regarding JJ's. He'll match you up with a set based on what you tell him you want tone wise.

Svetlana Winged "C"'s are great tubes, as are the EH's. I currently use the Svetlana's, and have had good luck with them. If you are willing to go NOS, Siemans make some good ones that are still fairly reasonable, or you can go with the Mullards...which are some fantastic sounding tubes...in the right amp.

 

[Rocker35]

Re: Replacing the tubes on my JMP 50

I will tell you this...the Sovtek LPS is a low noise/high gain tube, I like the tone of it a lot, the EH tube is a tad warmer sounding and doesn't have quite the gain of the LPS and the Tung Sol is just an all around great tube...it a little brighter than the EH and has more gain but it's not as gainy as LPS.

If you can find some and feel like spending the extra on them the NOS RFT 12AX7's that are going around right now are killer sounding...kind of warm with a nice breakup tone...they are really not too pricy compared to other NOS tubes...I think they are well worth it...

+1 for the RFT's especially for V1. My favourite preamp tube. Paired with 2 JJ's, it'll sound killer. Another great tube for V1 are TAD's. My mate has a TAD paired with JJ's in his Cornford MK50h and gets a heavenly tone.