5751 in V1 of LSS

[Jared Purdy]

Anyone try this - in the LSS - and if so, what were the results? Or what about other tubes, such as NOS or Tung Sols, or Jan Phillips??

 

[Jared Purdy]

I posted the same question over at tdpri.com and one of the members replied back that changing the tubes voids the warranty. I seriously couldn't believe it. Following is the post that I submitted to him after I spoke with the tech at Mesa:

"When I read what you had written I seriously thought it was nuts. As I had already put a call into Mesa to find out about using the 5751 in V1 (not knowing about the voided warranty thing prior to the call), when they finally called back I lobbed a few questions at the tech. You're right! Holy Sh&%&$t batman! I couldn't believe what I was listening to. I then asked him where the tubes are sourced from, and the 12AX7s are currently JJs (not my favorite by a long shot). The rationale is ridiculous, that the alternate tube could blow and fry the amp, that was the reply I got!

I then asked him about a mod that I have read about on The Boogie Board where some users of the LSS and the LSC do what's called a "Reeder Mod" (named after the originater of the mod, Charles Reeder), which simply involves swapping the gain and master pots on channel 2 to get what they are describing as identical sounding channels prior to dialing in any drive or gain. That will NOT void the warranty! Taking apart the amp, desoldering some pots and swapping them will not void the warranty, put changing the tubes, whether it be one, or all of them will!!! That's insane IMHO!"

 

[Vogelsong]

Anyone try this - in the LSS - and if so, what were the results? Or what about other tubes, such as NOS or Tung Sols, or Jan Phillips??

I just happened to put one of these in my Paps bandmaster. The people I got it from on the web advertised it as the SRV tube. As it helped with getting a little more growl out of the fender amps. It helped with the bandmaster a lot. So I took it out and tried in V1 and V2 of the LSS. I gotta say my ear didn't notice a bit of difference.

 

[lespauljoe1]

Anyone try this - in the LSS - and if so, what were the results? Or what about other tubes, such as NOS or Tung Sols, or Jan Phillips??

I just happened to put one of these in my Paps bandmaster. The people I got it from on the web advertised it as the SRV tube. As it helped with getting a little more growl out of the fender amps. It helped with the bandmaster a lot. So I took it out and tried in V1 and V2 of the LSS. I gotta say my ear didn't notice a bit of difference.

That is an odd result in the Fender. Typically, a 5751 tube will create a slower breakup. They are supposed to break up roughly 30% slower than a typical 12AX7.

I like 5751's for clean stages and V1 typically if I want to slow down breakup. Actually, they are supposed to have around 70% the amount of gain. That is a better description. I have noticed a difference using them, but I wouldn't say it was dramatic. It was more subtle.

I had a similar experience with another preamp tube though. I bought an NOS RFT 12AX7 and tried it in my amps. The description said thay are a little darker than many preamp tubes. I didn't find that at all. It made a very nice musical improvement, but it actually added clarity to my tone.

I guess that proves that every amp may react differently and every ear is different.

 

[Jared Purdy]

Thanks for the reply. I put a 12AY7 in V1 of my PRRI (to help tame the farty bass at volumes 5 +), and the effect was dramatic. Not only did it tame the flab, but it had an overall tonal improvement. I have not tried it in the LSS as I don't have a flabby bass from that amp at all. The 5751, I have been told is between a 12AX7 and the 12AY7. One other forum member said he tried it and didn't hear a difference in his LSS, where as another poster said he did notice a difference (both the 5751 in V2). I'll probably buy one just to experiment. I think I have found the "Grail" in my sencond channel.

 

[Vogelsong]

That is an odd result in the Fender. Typically, a 5751 tube will create a slower breakup. They are supposed to break up roughly 30% slower than a typical 12AX7.

It must not be for that particular brand though as the people selling it advertised it that way.

 

[thom]

I recently put a 5751 (Electro Harmonix gold) in V1 of my LSS. I thought it sweetened up channel 2 but not really a massive difference. I was just browsing Watford valves' web site and had a look at their preamp kits for Lonestars. One of them comes with a 5751, but Watford said to put it in V2, which I just tried. This is all subjective and there are many other variables going on. But, wow, sounds fantastic. Put a big smile on my face. How does it sound? Just sweet, not sure how else to describe it, and a low cost experiment if you wanted to try and didn't like it. Again this stuff is very subjective but I can't imagine why you wouldn't like it.