Time for new tubes in the Shiva!?

[richedie]

Hey guys,

It is time to retube my 20th Shiva. I already have new Tung Sol EL34Bs and now I want to replace the preamp tubes. I have been using JJ ECC83s tubes in every slot, because I have a habit of using JJs in everything. Feels chewier to me.

I contacted Bogner and they recommended I at least use the Chinese tubes in V3 and V4 since the voltages are so high. What do they mean? Why do I have to use Chinese tubes there?

For all other slots I was going to just use JJs, but wanted to try long plate JJ ECC803s tubes in V1 and maybe V2.

Suggestions? Keep in mind, I never hear big differences with tubes, we are talking seriously subtle.

Thanks

 

[Adambomb]

I'm in the same boat with my preamp tubes. Swapped them so much that the original stock tubes were best but the got spent quick getting hot and cold. I'll always just go with 12axyB from now on. Power tube are new, just need all new pre's. Right not I have JJ's in there except an LPS in phase inverter spot. The sound of the 20th Shiva sound a little congested with every tube I've tried except the stock tubes. TungSol in V1 and Ruby HG+'s in V2-3, then cheap Chinese tubes in the rest, that's the best tone I've found for the amp and I've done hella tube swapping for last 9 month since I got it.

I'm just leaving stock tubes in amps from now on until they wear out. New production tubes seems to sound all the same pretty much to me anyway.

 

[jamme61]

you need the Chinese tubes ( like Bogner said) because of the higher voltages in those spots. The Chinese 12ax7's can take the higher voltages, other 12ax7's can't(nos can but that's bucks). I think Mesa Boogie put out something about this back a couple of years ago. I really like the ruby Chinese 12ax7's. I think my last bogner xtc came with a jj in V1 and everything else was China.

 

[Ventura]

Shuguang/Chinese in everything but the V1 and PI slot. Those two can take an LPS and EiYugo if tastes warrant it

 

[Adambomb]

Yea I always thought the 20th Shiva sounded better with regular Chinese 12ax7B's but mine are worn out. So right now I'm running Mesa branded JJ's in V1-5. And I experimented with the PI phase inverter for awhile today between 12ax7LPS balanced, JJ, Tung-Sol, and Mullard 12ax7 RI. I actually liked the Mullard RI so I stuck with that. Biasing SED EL34's at 29-31ma when amp is hot is key to the power section though (as many have stated with Shiva, it's true).

 

[richedie]

I am running JJ ECC83s and ED34L tubes and it rocks!

 

[richedie]

Yea I always thought the 20th Shiva sounded better with regular Chinese 12ax7B's but mine are worn out. So right now I'm running Mesa branded JJ's in V1-5. And I experimented with the PI phase inverter for awhile today between 12ax7LPS balanced, JJ, Tung-Sol, and Mullard 12ax7 RI. I actually liked the Mullard RI so I stuck with that. Biasing SED EL34's at 29-31ma when amp is hot is key to the power section though (as many have stated with Shiva, it's true).

is that bias due to such a high plate voltage? I ask because my PWE Event Horizon has JJ EL34s biased 34-36mA.

 

[Adambomb]

Yea I always thought the 20th Shiva sounded better with regular Chinese 12ax7B's but mine are worn out. So right now I'm running Mesa branded JJ's in V1-5. And I experimented with the PI phase inverter for awhile today between 12ax7LPS balanced, JJ, Tung-Sol, and Mullard 12ax7 RI. I actually liked the Mullard RI so I stuck with that. Biasing SED EL34's at 29-31ma when amp is hot is key to the power section though (as many have stated with Shiva, it's true).

is that bias due to such a high plate voltage? I ask because my PWE Event Horizon has JJ EL34s biased 34-36mA.

29ma is what Bogner suggests in the 20th Shiva and that's kinda cold. Many bias around 30-35 from what I've read. I've switched to KT88's again though. It's really what the 20th is all about. The EL34s sounded too congested when cranked. You can dial in tones easier too with KT's.