12AX7-A Chinese 1 or Russian 2???

FunkyMonkey · Jul 3, 2007

Hi,

I ordered some spare valves with my new LSC and basically when they arrived they didn't match at all. I was sent STR-430s instead of STR-440s for a start, but that argument with the shop was easy! The more tricky question is that the pre-amp spare I was sent (Mesa branded) is a 12AX7-A Chinese 1, whereas those in the amp are 12AX7-A Russian 2...

My question is does it matter with the pre-amp tubes? will I notice a difference if V1/V2/V3 blow and are replaced with the Chinese 1? Will the shop think I am an arse for wanting to change it so it matches those in the amp?

Sorry one final other little one, should I ask the shop to make sure the pair of STR-440 are coded 'yellow' for bias as in the amp, or won't it matter if they send something else (assuming I change them as pairs!)

Thanks for your thoughts and patience with the newb questions

D

recto-robbie · Jul 3, 2007

No the preamps wont make any difference at all if you replace them with the Chinese or any make for that matter. Other than sound that is.
I would highly suggest looking into other brand preamps.
Same goes for the power tubes,,, they will work fine but may sound a bit different. As long as you are using matched tubes from mesa everything will be fine. I wouldnt go swapping your new power tubes in and out with your older used tubes unless its an emergency. When you decide to replace your old tubes,,, then put in all your new power tubes.
And I believe the color coded system is used for measuring higher or lower plate current,, quicker breakup and so on. I could be wrong here about the color codes though, but if you like the way the yellows sound I would most deffinatly insist on more yellows. I personally have a good friend who only uses mesa tubes and gets into with them every time when he orders because they try sending out what they want.. Wrong.
And I meant it when I said try some different brand preamp tubes because there are much better out there.. These will give you the biggest difference in sound especially in V1. You dont need to match these,,, just plug and play as much as you want.

Try this place,,, you will probably save a bunch of cash too.

http://www.dougstubes.com/

domct203 · Jul 4, 2007

The Mesa 12AX7 Russian 2 is an Electro Harmonix. The Russian 1 is a Sovtek. I'm not sure who's making the Chinese 1's, but yes they will have differences in tone and dynamics, especially in V1. I really like the Tung-Sol reissue in V1 of my Roadster.

IMO the STR-440 is a way better sounding tube over the 430's. If you stay with Mesa power tubes then insist on the Yellow grade if that is what your amp came with.

You will not go wrong with Doug's Tubes. I'm absolutly loving the tube combo he suggested. The SED =C= 6L6GC's are killer in my Roadster and biased up 5mA's higher than the 440's it came with putting them around 28-30mA, just like Doug said they would.

Dom

FunkyMonkey · Jul 4, 2007

Thanks for the feedback. Someone told me that that the Tong-Sol was really good. Would I lose the lower gain sounds with that pre-amp, as I would imagine that if it is in a Rectifier it is pretty high gain

D

domct203 · Jul 4, 2007

I don't think it's a "high gain" tube, it's prob just closer to the actual gain spec of a 12AX7. I've never heard one in the LSC myself.

The GT 12AX7M is a nice tube as well and also sounded good in V1 of the Roadster. I picked the Tung-Sol because I felt it sounded better with my EMG's and a clean boost pushing the front end.

The JJ was too dark in V1, and the Penta (Shuguang) 9th gen. Chinese in V1 felt sterile to me. The EH (Mesa Russian 2) was OK in V1, just a little too harsh for my ears.

Doug's recommendations for my Roadster did actually sound the best to me. (Give him a call or E-mail)
V1 = Tung-Sol Reissue
V2 = JJ ECC83S High Gain
V3 = Shuguang Chinese
V4 - V6 = Stock Mesa Russian 2

SED =C= SV6L6GC Power Tubes

Hope this helps

Dom