12ax7 identification?

[ledvedder]

I have these 2 tubes. I'm assuming they're NOS? One appears to be a Mullard and one appears to be a JJ/Tesla. What can you tell me about these, characteristic-wise?

 

[steve_k]

Left is a Brimar (British Military Mullard) 12AX7. Its a premier NOS tube and great for V1 in anything. The Tesla is also an excellent NOS 12AX7 tube and made at the Rosnov plant and is similar to a Tungsram. Also a great V1 tube. Notice the gold contacts on the Tesla.

 

[ledvedder]

Left is a Brimar (British Military Mullard) 12AX7. Its a premier NOS tube and great for V1 in anything. The Tesla is also an excellent NOS 12AX7 tube and made at the Rosnov plant and is similar to a Tungsram. Also a great V1 tube. Notice the gold contacts on the Tesla.

Which would you recommend for V1 of a hot rodded Marshall type of amp? And would the other work well in V2 or V3 (pi)?

 

[Dopethrone]

The one on the right looks like an RFT to me!

 

[Loudness250]

2 killer tubes you got there man! As was said, enjoy!

 

[Loudness250]

The one on the right is an original Tesla, one of the best you can get!

 

[Loudness250]

It does look like an RFT basically but different companies.

 

[ledvedder]

These came in the Ceriatone Chupacabra that I got last week. I had no idea what types of tubes they were.

Here's a few more pics.

 

[John4021]

That amp will blow those tubes up....send em to me for proper disposal.


...just kidding man.
Christmas came early for you. Nice score

 

[psychodave]

Left is a Brimar (British Military Mullard) 12AX7. Its a premier NOS tube and great for V1 in anything. The Tesla is also an excellent NOS 12AX7 tube and made at the Rosnov plant and is similar to a Tungsram. Also a great V1 tube. Notice the gold contacts on the Tesla.

This. End thread.

 

[Racerxrated]

These came in the Ceriatone Chupacabra that I got last week. I had no idea what types of tubes they were.

Here's a few more pics.

Score!

That's the 'Christmas morning' aspect to buying used amps. You never know what tubes might be in there. I can't tell you how many times I've bought a used amp and found great vintage tubes inside.
Most of my tube collection came from these purchases. When I sold the amp I swapped tubes..put JJs or whatever in and kept the vintage.

 

[Deanmachine]

Nice preamps in that one surprised they did not pull those .

 

[FourT6and2]

Left is a Brimar (British Military Mullard) 12AX7. Its a premier NOS tube and great for V1 in anything. The Tesla is also an excellent NOS 12AX7 tube and made at the Rosnov plant and is similar to a Tungsram. Also a great V1 tube. Notice the gold contacts on the Tesla.

Which would you recommend for V1 of a hot rodded Marshall type of amp? And would the other work well in V2 or V3 (pi)?

For the Chupacabra, I really like:

Beijing 6N4-J in V1
NOS RFT in V2
Sovtek Long Plate in V3

The Mullard will sound soft and lazy in the Chupa. The Tesla... never tried. But if it's similar to an RFT, I would try V2. V1 needs to be a stout, solid, bright tube in my opinion. The Beijing used to come in Marshalls and Mesas back in the '80s. Very low noise and plenty of drive for this type of amp.

 

[FourT6and2]

The Chupa also sounds really good with just all modern JJ ECC83S and JJ E34L power tubes. The E34L power tubes are my fav in this amp, followed by NOS RFTs.

 

[ledvedder]

Left is a Brimar (British Military Mullard) 12AX7. Its a premier NOS tube and great for V1 in anything. The Tesla is also an excellent NOS 12AX7 tube and made at the Rosnov plant and is similar to a Tungsram. Also a great V1 tube. Notice the gold contacts on the Tesla.

Which would you recommend for V1 of a hot rodded Marshall type of amp? And would the other work well in V2 or V3 (pi)?

For the Chupacabra, I really like:

Beijing 6N4-J in V1
NOS RFT in V2
Sovtek Long Plate in V3

The Mullard will sound soft and lazy in the Chupa. The Tesla... never tried. But if it's similar to an RFT, I would try V2. V1 needs to be a stout, solid, bright tube in my opinion. The Beijing used to come in Marshalls and Mesas back in the '80s. Very low noise and plenty of drive for this type of amp.

Do you really think the Mullard won't sound good?

I emailed Doug's Tubes just to get their tube recommendations, since I've always been happy with them for all my other amps. This is what Doug said.

"We recommend the RUBY EL34BSTR's and for the 3 x 12AX7's do a Mullard
CV4004 in V1, a Ruby WBC HG in V2 then a Ruby AC7 HG in V3."

 

[FourT6and2]

Left is a Brimar (British Military Mullard) 12AX7. Its a premier NOS tube and great for V1 in anything. The Tesla is also an excellent NOS 12AX7 tube and made at the Rosnov plant and is similar to a Tungsram. Also a great V1 tube. Notice the gold contacts on the Tesla.

Which would you recommend for V1 of a hot rodded Marshall type of amp? And would the other work well in V2 or V3 (pi)?

For the Chupacabra, I really like:

Beijing 6N4-J in V1
NOS RFT in V2
Sovtek Long Plate in V3

The Mullard will sound soft and lazy in the Chupa. The Tesla... never tried. But if it's similar to an RFT, I would try V2. V1 needs to be a stout, solid, bright tube in my opinion. The Beijing used to come in Marshalls and Mesas back in the '80s. Very low noise and plenty of drive for this type of amp.

Do you really think the Mullard won't sound good?

I emailed Doug's Tubes just to get their tube recommendations, since I've always been happy with them for all my other amps. This is what Doug said.

"We recommend the RUBY EL34BSTR's and for the 3 x 12AX7's do a Mullard
CV4004 in V1, a Ruby WBC HG in V2 then a Ruby AC7 HG in V3."

I disagree with Doug. I doubt he's ever played a Chupacabra or messed around with tubes in one.

The Ruby EL34BSTR is a bit bright and clinical. Mullard... meh. Not for this amp in particular.

Ruby AC7 is pointless in the PI section. A long plate tube like the Sovtek will be best. No need for balanced sections either.

You can go with whatever you want, but I've had a Chupacabra and a Yeti for like 8 years now. And I've built 4 of them. I've used all the tubes out there. For ME... and the type of music and sound I go for, I really like the JJ E34L power tubes (or RFT) and the preamp tubes I mentioned already.

The 6N4-J is awesome for amps like this. They are affordable and don't have all that NOS snake oil going on. Doug is recommending tubes he sells. Because he sells them. He has a business to run. The Beijin 6N4-J is much better than the Ruby AC7, which is the 7th generation version of the Beijing. Sort of. You want a long plate in the PI. The Sovtek is cheap, reliable, and works great. This is all my experience. But do whatever you think works.

If you do some research you'll find the Sovtek LP is recommended in lots of hot-rod Marshalls. And the Beijing is a great secret weapon for V1 or V2. The RFT is very vocal and has a unique mid-range. But it's slightly rolled off highs, which is good in V2 of the Chupacabra.

 

[ibzprestige]

These are the tubes that I found sounded best after testing multiple sets. It gave the amp a much more aggressive and 3D tone in my opinion. I really liked the tung sols I put in there over the JJs and other power tubes I tried!

 

[ledvedder]

I disagree with Doug. I doubt he's ever played a Chupacabra or messed around with tubes in one.

The Ruby EL34BSTR is a bit bright and clinical. Mullard... meh. Not for this amp in particular.

Ruby AC7 is pointless in the PI section. A long plate tube like the Sovtek will be best. No need for balanced sections either.

You can go with whatever you want, but I've had a Chupacabra and a Yeti for like 8 years now. And I've built 4 of them. I've used all the tubes out there. For ME... and the type of music and sound I go for, I really like the JJ E34L power tubes (or RFT) and the preamp tubes I mentioned already.

The 6N4-J is awesome for amps like this. They are affordable and don't have all that NOS snake oil going on. Doug is recommending tubes he sells. Because he sells them. He has a business to run. The Beijin 6N4-J is much better than the Ruby AC7, which is the 7th generation version of the Beijing. Sort of. You want a long plate in the PI. The Sovtek is cheap, reliable, and works great. This is all my experience. But do whatever you think works.

If you do some research you'll find the Sovtek LP is recommended in lots of hot-rod Marshalls. And the Beijing is a great secret weapon for V1 or V2. The RFT is very vocal and has a unique mid-range. But it's slightly rolled off highs, which is good in V2 of the Chupacabra.

Cool, thanks for your input. I'm all ears when it comes to hearing someone's recommendations. Especially someone who is very familiar with a particular amp. The Sovtek you're referencing, is that the LPS? I have a few of them around. I also have several JJ tubes.

 

[ledvedder]

These are the tubes that I found sounded best after testing multiple sets. It gave the amp a much more aggressive and 3D tone in my opinion. I really liked the tung sols I put in there over the JJs and other power tubes I tried!

Hey, do I know you?

I liked the tubes that were in the amp, but I'm always a tweaker. I guess it's a bad habit.

 

[FourT6and2]

I disagree with Doug. I doubt he's ever played a Chupacabra or messed around with tubes in one.

The Ruby EL34BSTR is a bit bright and clinical. Mullard... meh. Not for this amp in particular.

Ruby AC7 is pointless in the PI section. A long plate tube like the Sovtek will be best. No need for balanced sections either.

You can go with whatever you want, but I've had a Chupacabra and a Yeti for like 8 years now. And I've built 4 of them. I've used all the tubes out there. For ME... and the type of music and sound I go for, I really like the JJ E34L power tubes (or RFT) and the preamp tubes I mentioned already.

The 6N4-J is awesome for amps like this. They are affordable and don't have all that NOS snake oil going on. Doug is recommending tubes he sells. Because he sells them. He has a business to run. The Beijin 6N4-J is much better than the Ruby AC7, which is the 7th generation version of the Beijing. Sort of. You want a long plate in the PI. The Sovtek is cheap, reliable, and works great. This is all my experience. But do whatever you think works.

If you do some research you'll find the Sovtek LP is recommended in lots of hot-rod Marshalls. And the Beijing is a great secret weapon for V1 or V2. The RFT is very vocal and has a unique mid-range. But it's slightly rolled off highs, which is good in V2 of the Chupacabra.

Cool, thanks for your input. I'm all ears when it comes to hearing someone's recommendations. Especially someone who is very familiar with a particular amp. The Sovtek you're referencing, is that the LPS? I have a few of them around. I also have several JJ tubes.

Yeah, the Sovtek LPS is good for the PI.