Jan 5751 in V1 question

[eudaimonia02912]

I've heard some people say that putting the Jan Phillips 5751 in V1 really helps the tone, removes some harshness, adds some beef, etc. However, will I lose too much gain? On channel 3 in Mark IV mode, I tend to keep the gain and treble between 1-3 o'clock depending on mood, but I tend to keep it very high on crunch mode in channel 2.

 

[MrMarkIII]

A 5751 has 30% less gain than a 12AX7. If you normally run gain at 3 o'clock, you may need to dime that knob to get the same saturation.

 

[Drewtone]

I tried one in V1 of my Mark III and did not like it at all... to me, it was ice-pick city, though there was one crunch sound I thought was awesome at the expense of all the other tones of the amp. Those tubes aren't expensive though, so why not give it a try.

 

[scott from _actual time_]

i tried a JAN 5751 in v1 of my Mark V. it did have a small bit less gain, and i play really high-gain sounds so i noticed it. but the bigger drawback for me was that it sounded grainy, less smooth, on high-gain sounds.

i found that the Mullard Reissue is the perfect tube for me in v1. it has a tiny bit less gain than a JJ or Tung-Sol RI, just a tiny bit, but it is rounder and fatter smoother to my ears, much smoother than the Tung-Sol RI, and not grainy like the 5751.

so you might consider trying that.

 

[eudaimonia02912]

I got a Jan 5751 today and popped it into V1. I think it improved the tone across the board and cut some noise, but at the same time it cut too much gain on channel 2 for me to keep it. Madryan is right--it fattens up the tone and rolls off/smoothes out the highs. The effect is very nice. There was also some definite gain loss, confirmed by swapping the old tube and new in and out. Since I had gain to spare on channel 3, that was fine. But then I found that crunch mode on channel 2 wasn't quite as hotrodded as I wanted it to be, and I didn't want to always have to use a boost there. If I were only playing hard rock and didn't play as much metal, this tube would be a definite keeper.

So, maybe I'll try the Mullard another poster recommended. If I could get a tube for V1 that had the same effect on tone but which had a higher gain factor, I'd be really happy. Of course, the problem might be that the tube sounded smoother because it had less gain, in which case I'm not in luck.

So, back to an SPAX7 for now.

Current set up:
V1: SPAX7
V2: NOS EI
V3: Penta Labs 12ZAX7
V4-6: Stock mesa
V7: SPAX7

I have tried Tung Sols in a bunch of spots, and don't like what they do to this amp, even though I liked them in my other amps.

 

[sevycat]

i tried a JAN 5751 in v1 of my Mark V. it did have a small bit less gain, and i play really high-gain sounds so i noticed it. but the bigger drawback for me was that it sounded grainy, less smooth, on high-gain sounds.

i found that the Mullard Reissue is the perfect tube for me in v1. it has a tiny bit less gain than a JJ or Tung-Sol RI, just a tiny bit, but it is rounder and fatter smoother to my ears, much smoother than the Tung-Sol RI, and not grainy like the 5751.

so you might consider trying that.

Thanks for posting that info on the preamp tubes you tried. I had considered trying a 5751 in the v1 position. But, after talking with the mesa tech support and your write up, I will bag the 5751's. I think I have a mullard 12ax7 preamp tube and some tung-sols as well. Maybe I will play around and see what the difference between the stock mesa 12ax7, mullard, and tung-sol do for me.

 

[MesaDCLP]

I've been told that the 5751 is a good tube for the PI slot. Apparently it has a smoother attack than the 12AX7's. I guess this would come off as a more compressed feel. It has something to do with the transconductance being lower in the 5751, so the tube reacts slower. Haven't tried one ... out of stock when I was ordering last... Anyway, here's a bit of info about the PI slot and tube selection.

http://www.guitaramplifierblueprinting.com/files/Phaseinverter.pdf

 

[Anonymous]

i tried a JAN 5751 in v1 of my Mark V. it did have a small bit less gain, and i play really high-gain sounds so i noticed it. but the bigger drawback for me was that it sounded grainy, less smooth, on high-gain sounds.

i found that the Mullard Reissue is the perfect tube for me in v1. it has a tiny bit less gain than a JJ or Tung-Sol RI, just a tiny bit, but it is rounder and fatter smoother to my ears, much smoother than the Tung-Sol RI, and not grainy like the 5751.

so you might consider trying that.

+1000 on the mullard RI in V1!!!!!! and my second choice in V1 would be Svetlana 12AX7. :wink:

 

[mejoshee]

I've been told that the 5751 is a good tube for the PI slot. Apparently it has a smoother attack than the 12AX7's. I guess this would come off as a more compressed feel. It has something to do with the transconductance being lower in the 5751, so the tube reacts slower. Haven't tried one ... out of stock when I was ordering last... Anyway, here's a bit of info about the PI slot and tube selection.

http://www.guitaramplifierblueprinting.com/files/Phaseinverter.pdf

anyone try this yet in the pi?

i tried a JAN 5751 in v1 of my Mark V. it did have a small bit less gain, and i play really high-gain sounds so i noticed it. but the bigger drawback for me was that it sounded grainy, less smooth, on high-gain sounds.

i found that the Mullard Reissue is the perfect tube for me in v1. it has a tiny bit less gain than a JJ or Tung-Sol RI, just a tiny bit, but it is rounder and fatter smoother to my ears, much smoother than the Tung-Sol RI, and not grainy like the 5751.

so you might consider trying that.

+1000 on the mullard RI in V1!!!!!! and my second choice in V1 would be Svetlana 12AX7. :wink:

good to know. i'm convinced!

 

[Supersonico]

Anyway, here's a bit of info about the PI slot and tube selection.

http://www.guitaramplifierblueprinting.com/files/Phaseinverter.pdf

Myles Rose knows his stuff. I've learned so much about tubes from reading his writings.


Juan