JAN-GE 5751 in MarkV Head

[mesa metal]

.I have a lot of old stock tubes that were pulls from radio and hi-fi units that are still much better than any new production.Radio and hi-fi dont stress tubes like guitar amps do,so tubes from these units are absolutely fantastic.If you see preamp tubes used in radio for sale on ebay,grab them,they will still have a lot of life.

i been doing just that lately,,purchased about 20 NOS tubes in the past couple of months(GE,SYLVANIA,RCA blackplates,raytheons,tungsram. etc.)some of them didnt cost any more than current tube prices..
anyway,,the first nos tube i put in the mkv was a jan phillips 5751,,sounds really good,,clarity is amazing.....then a couple of weeks ago i put a JHSsylvania tube(1961) in V2(had a jj high gain in there) and was totally impressed with that channel..i have several baldwin labeled sylvanias and rca blackplate tubes that i will be rolling in soon..i intend to get all nos tubes in the V and i will definately post my review on these...i forgot to mention that these old tubes sound fantastic in the triaxis......i also am waiting on another set of jan sylvanias and i got a few sovtek LPS tubes that were made in 2000 and 2003
supposedly they sound better that the current LPS made today,,,,we'll see.. :?:
looks like i will be buying a tube tester very soon :wink:

 

[bandit2013]

That is great. Needless to say I have put the old Mesa tubes back into the Mark IV. They sounded the best and they are not as grainy as the current Mesa tubes. Thus far I have favored the EH 12ax7 in the V. The second runner up is the old Mesa tubes.

Keep us posted on your results with the various NOS tubes.

I am happy with what I got for the time being. I will have to research ebay for tube listings.

 

[bandit2013]

I know this is a beaten horse and I should have let it die. It has been a while since I have used the Jan/GE 5751 simply because I broke it while attempting to try it in a different amp. While this is not a cure all tube since it is practically a 12ax7, it may not always sound great depending on the application.

I have tried many other tubes in the Mark V but just could not settle on one mix. I did buy a replacement Jan/GE 5751 as there is no other substitute for the NOS tube (current production tubes just do not compare from what I have read). For a while I have had various other tubes in the Mark V but just was not happy with all channels. I did find a use for it on the RA100 as a driver tube for the reverb circuit. I finally decided to re-install it into the Mark V in the V1 position. (note: it worked well when used in V7 while I was using KT77 power tubes).

Current tubes in use:
V1 JAN/GE 5751
V2-V6: Old Mesa 12ax7a (Chinese, bought in 1990's)
V7 Sovtek LPS
V8-V11: SED 6L6GC

It seems that the JAN/GE takes much of the mud out of CH3 (less compression) Now I can appreciate the complex harmonic content of the SED 6L6GC. It may thin out CH2 slightly but it is an improvement. Mark I mode sounds incredible as does the Crunch mode. Tone is close to running EL34's but with enhanced bass. CH1 is nice and crisp, I can get it dry to saturated sweet tones for expressive leads with a single coil guitar. I was almost considering getting more JAN/GE 5751 to use in all preamp tube positions in the Mark V. Not sure what the side effect would be. It just seems like current production preamp tubes are just junk. I either get mechanical noise, the JJ type tubes that Mesa is branding can be nasty with vibration due to the flat stamped metal halo getter. I have many that sound like broken light bulbs when you tap them. They are almost as noisy as Mullard re-issue tubes which seem to translate mechanical vibration into the signal if used in early gain stages.

Is it worth the extra money, yes. It may not be the Holy Grail tube but it really makes a difference in the Mark V. I like to get down and dirty with my tone and love the chugging tones of this amp when dialed in for Metal tones. I was finding it difficult to use just one amp to get the tones I like for blues, jazz, classic rock all the way to Heavy Metal. It is more achievable with the JAN/GE 5751 in V1 with some decent tubes in the other positions. It is not necessary to have high gain versions of the 12ax7 tubes to make the Mark V sound awesome.

I know what works in the Mark V for me. So when the old Mesa Chinese tubes with square getter fail, what can I get to replace those. I am also using them in the RA100 as well for the Clean circuit. I may try the Chinese tubes, maybe the preferred series from The Tube Store (I believe they may be ruby tubes since the pictures look similar to the one ruby tube I have). Not sure what to do next, but getting more JAN/GE may be an option....