12AX7 Advice - JJ's vs Chinese

[OlinMusic]

I just got a Fender Bassman LTD and am wildly impressed how well it takes pedals. I missed my Fender days. It occured to me my Bogner does not take pedals as well as people raved, OD's always require a lot of ourput to sound good on the clean channel, and on CH2, it feels like the ODs act as a sort of sheen on top of the distortion, just doesn't blend amazingly.

So I had some extra 12AX7C's lying around and I said lemme pop a new one in and see. Behold, I never touched my Shiva's insides, and I found out V1 was an GT ECC83, AH HA! I ut in the 12AX7C and instantly I could make pedals sound better.

The downside? The Gain CH feels less Gainy, and OD pedals cause some feedback now, whereas before I had NO feedback problems even when GIGGING LOUD LOUD LOUD with the Shiva.

Should I change all my PRE tubes to 12AX7C's and see if that clears it up (could be that the other tubes are a mix of JJ's or something else), OR do I just continue with the JJ's?

I loved the OD I had with the JJ's, but now it takes pedals better. Bogner says use 12AX7C only.

Any help would be wonderful.

 

[Gearjoneser]

Re: 12AX7 Advice - JJ's vs Chinese

I've tried a lot of tubes in my Bogner, and the GT12AX7C's seem to be the best.

Sometimes, I wish I hadn't sold my only Fender, the Bassman LTD. I just found it too loud and clean, and I like 12's better than 10's. It's still a great great amp. I think I had a JJ ECC803S in the 1st position on that amp.

I Shiva and a Bassman is a great duo.

 

[That90'sGuy]

Re: 12AX7 Advice - JJ's vs Chinese

Chinese tubes are the way to go with the Shiva, don't bother with anything else. Shuguang 9th gen crank in mine, definitely liked it a lot more than JJ's. I'm surprised your finding less gain with the Chinese tube, if anything I always felt the opposite, that JJ's preamp tubes just didn't have the gain that higher gain amps needed (atleast that was my experience with the H&K Triamp I used to have, I needed a GT12AX7M to get back some of it).

 

[OlinMusic]

Re: 12AX7 Advice - JJ's vs Chinese

Hey maybe I am wayy off and maybe the Pre's that came in this USED Shiva are a mish mash

this is why I wanted your advice

Maybe I should just go buy all new Chinese and see what happens.

The Chinas def. help the Shiva take pedals better!

 

[shredaholic]

Re: 12AX7 Advice - JJ's vs Chinese

I really doubt changing other tubes is gonna remove feedback induced by the Chinese tube you put in, mixing tube brands definately should not induce feedback. Sounds to me like that Chinese tube you put in was either slightly microphonic or poorly designed/made.

http://www.ptpcircuits.com/nostubes.html

NOS is the way to go

 

[aleclee]

Re: 12AX7 Advice - JJ's vs Chinese

NOS is the way to go

Depends on the amp. Many modern amps are designed around current production tubes so a set of Chinese or Eastern European tubes is oftentimes going to sound at least as good as NOS. To my ear, NOS is better in my Two Rock while I have all 12AX7Cs in my Rivera.

 

[More-Gear-Than-Skill]

Re: 12AX7 Advice - JJ's vs Chinese

Electro Harmonics also have a fairly nice tube, made in Russia by Sovtek. But my JJ's are just right for me, for now.

 

[OlinMusic]

Re: 12AX7 Advice - JJ's vs Chinese

Well here is the story -

I found that all the tubes in the amp can be seen and are clearly marked as "China". They are some un-branded 12AX7.

Positions V1 and V3 were GT Ecc83's. The amp had a gorgeous tone with bloom on the clean if you rolled the treble back, and a very plexi-ish tone on the gain, though it lacked the thickness in the lows.

I changed both out for 12ax7c's when I came home from partying last night - I have major insomnia...lol - effects: tighter bass, gain improved and tightened, takes pedals MUCH better, EQ knobs seem more balanced, esp the highs are easier to dial - but I did not crank and I am still listening to see the effect on the "bloom" of the amp (seemed to have less).

 

[OlinMusic]

Re: 12AX7 Advice - JJ's vs Chinese

SAW THIS ON THE GEARPAGE - MY FINDINGS CONCUR (THIS IS NOT NOT NOT MY OWN POSTING):

Here is the layout of the tubes below

I personally do this, I am sure other have changed tubes differently to suite them. MANY combinations!!

I would be curious to know what others are running!

I think changing V1 or V2 & 3 , changed the color of the amp enough to suite me, and left the rest of the amp circuits to remain consistant for my changes. I change one thing, then I play it for a week. then make another change. I use JJ tubes to create a less bright amp with good dynamics. thats how JJ preamp tubes seem to react to me. This also reflects my personal playing style and song choices for the Weekend or evening. I hope I can keep this straight! LOL.. I use a early 90's Marshall vintage 30 cab. Tc Gmajor in the loop.

When I had just the Shiva, Normal daily tubes in the amp.
Usually just a change to V2 is enough for me. as the OD channel is where I wanted the change. I wanted a smoother darker OD thats a bit hotter. Install JJ ECC83S box marked 113. with V3 Chinese it adds back some higher tone harmonic it seems.

V7 change will also color of the overall sound. So I stayed with the tubes up front then I it seems can do more to modify color. I really like keeping changes to a minimium.

I have Changed V7 with a JJ but seemed to have lost some top sparkle on the clean side I was wanting to keep. so I reverted back to the original Chinese 12ax7.

When I am wanting older rock, like Clapton, Skynard, Zep, etc.. I can load the V1,2,& 3 with JJ's (113's) and nail those tones. really smoothed out the amp and added lots of complexities. (again, to me and my ears) with a strat, simple man, Sunshine of your love.. will give me goose bumps sometimes! it makes me say wow, am I really creating this sound!?? I didnt think it was possible! thats been the MOST rewarding for me and the shiva.

Running the chinese tubes in the amp I get a brighter tone. I use a superstrat and cover newer things that need the top end shimmer, Satch etc.. I sometimes toss in a keeley compressor and do free ride, edgar winter, or add a tad bit of chorus for BTO to ??? ( what ever the program may require)

I have another amp I use now to touch those really hi gain things ( jcm800 style) So I have now left the Shiva with all JJ's in V1,2,3.

out of all this, I know one thing, people love hearing the shiva. Regardless of the tube changes I have made! The changes where for me. as long as it sounds good, they will come.

But that is what "I" liked.

Wow I really rambled on and on! Sorry!


V1: Input tube both channels, 12ax7
V2: 2nd stage for Channel 2, 12ax7
V3: 3rd stage for Channel 2, 12ax7
V4: 2nd stage for Channel 1 and FX Send, 12ax7
V5: FX Return, 12ax7
V7: Phase Inverter, 12ax7
V8, V9: Power tubes, EL34 or 6L6
V11: Reverb Tube, 12ax7

 

[foo3001]

Re: 12AX7 Advice - JJ's vs Chinese

My suggestion would be to try out a re-issue Tung-Sol 12ax7 in the 1st position. It has given all my amps a side I never thought there would be. They have all gotten more dynamic, more bass/treble (yet controllable, not boomy/shrill whatsoever) etc. The tube really lets the playing and the guitar shine through.

And it´s got good gain too, so it propably works well with a bogner also.