It’s July 2023, what current production tube you running in cathode follower slot ?

[Adrian R]

None. All vintage GE, Raytheon, EI, RFT.

 

[StingRay85]

All these tubes are measured with my Maxi Preamp 2, and still in my collection. The consistency and quality of a Philips Heerlen tube is unmatched.

 

[FleshOnGear]

I've already stated this before, and provided proof. The Mullard I63 is not really a gainy tube, most of them average between roughly 88 and 95 Mu. Many CP tubes are closer to the 100 range, and for example the Ei long plate and RFT tubes are among the types that are more likely to be 100+ Mu. The highest gain 12AX7 I'm aware of is without a doubt the Sylvania long plate.

Yeah, that tracks with my experience. RFTs are crunchier than others. Sylvanias can get downright fuzzy.

 

[paul-e-mann]

did a search and couldn’t find anything recent. looks Like things have changed over the last few years with tune availability. Wondering what current tubes you guys like that can survive in the cathode follower of a plexi and what you like about them

JJ are reported to be super strong and survive anything (even though I dont like their tone and dont use them).

 

[jeffb]

I

I've already stated this before, and provided proof. The Mullard I63 is not really a gainy tube, most of them average between roughly 88 and 95 Mu (edit: probably a little higher than 95 when looking at my data). Many CP tubes are closer to the 100 range, and for example the Ei long plate and RFT tubes are among the types that are more likely to be 100+ Mu. The highest gain 12AX7 I'm aware of is without a doubt the Sylvania long plate.

I've a couple old mullards (one late 50s, one early 60s ) and I'd agree with that. CP def more gainy.

 

[MonstersOfTheMidway]

In my Marshall it's either a JJ ECC-83 or a EH 12AX7; whatever is in there is working fine for a while now.

 

[TonalEuphoria]

If you guys find particular brands of 12AX7's too gainy, than why not just use a 12AT7 or 5751?

Of course if you guys don't want to use Tung Sol's, than that's just more for me.

 

[jeffb]

If you guys find particular brands of 12AX7's too gainy, than why not just use a 12AT7 or 5751?

Of course if you guys don't want to use Tung Sol's, than that's just more for me.

I'm more worried about tone , rather than potential gain (unless it's not enough). I've been using JJ 803S as V1 in nearly every tube amp I've owned for years. It does have less gain than many of the shorter plate CP tubes, but I choose to use it because of the way it sounds, not because of less gain.

I think the point was rather that original Mullards (and many other celebrated old tubes) have a reputation for a lot of gain, and it's not really true. They just sound far better.

And yes, I often use 5751s too, especially when I had my DSL.

 

[Russ Selzer]

Hmm....well, I run JJ in all preamp positions in my Marshalls. I had a tung sol in the CF socket in my 800....it didn't last long before it had a meltdown. Then tried an EH...it sounded ok but got very hot...like burning hot. The JJ seems to love it, and sounds good too. Alot of folks dislike JJ, but I think they sound great, as do my band members.

 

[James Freeman]

The JJ is the most quiet & the Chinese (Shuguang) are the most robust, in handling the juice pushed.

You can still get Chinese tubes, either from Psvane (which branched off of Shuguang), or Linlai (who branched off of Psvane).

It looks like the current Psvane ECC83 does not have spiral filament, like the discontinued Shuguang, see image below.
I thought JJ ECC83s has a spiral filament and did not do well in CF stages just like other russian tubes, why is it more durable than other russian 12ax7 tubes despite that?

Click to zoom in, filament is not spiraled.

 

[James Freeman]

JJ ECC83S
Filament is spiraled.
Unlike other russian tubes, here I can see the filament.

 

[James Freeman]

Shuguang (China) 12AX7B
Filament is not spiraled.

 

[James Freeman]

I think I know why the Russian spiraled filament tubes fail, the filament strand is half as thick as the Chinese one.
The JJ ECC83S seems to be slightly thicker than the Tung-Sol filament but still thin compared to the Chinese filament.

 

[Dogs of Doom]

It looks like the current Psvane ECC83 does not have spiral filament, like the discontinued Shuguang, see image below.
I thought JJ ECC83s has a spiral filament and did not do well in CF stages just like other russian tubes, why is it more durable than other russian 12ax7 tubes despite that?

Click to zoom in, filament is not spiraled.
View attachment 143246

JJ are Slovak mfgr...

They are not as durable as the Chinese, but, they are quiet, which is why Marshall puts them in V1. They use Shuguang (or used to) in the following positions, because they are more durable & can take a pounding (especially in CF). They tend to be noisier, so, that's how they ended up w/ JJ in V1, to have the compromise of having a quiet pre-amp w/ durable results.

I think they just went to all JJ, since that's what is available...

 

[What?]

I think the point was rather that original Mullards (and many other celebrated old tubes) have a reputation for a lot of gain, and it's not really true. They just sound far better.

I didn't notice it when I first compared a couple of old Mullards to other current production tubes, but I later noticed that the Mullards round off the sharp edges, which does make a difference in my plexi 51 when cranked up, making the amp sound less ice pick and harsh. In my DSL 50 I don't really notice the difference between a Mullard and current production.