NOS 12AX7 tubes for Cathode follower ?

[bandit2013]

I believe that may be correct. Not sure when Mesa started using the Russian tubes, it must have been after 1990. I am not even sure when Mesa changed from Tungsram to the Chinese 6N4-J tubes. Bummer, I missed out on that opportunity. Now those tubes cost $139 each.

I guess what I like about the 6N4-J Beijing Square Foil getter tubes, is the shoring up on the low end. It aids it making the preamp of the Roadster much tighter, no sub-harmonic swamp. The sub-harmonic frequency is still present but no longer a swamp which is what I was getting with the stock Mesa 12AX7 (JJ ECC83s). It is mostly related to the V2 position that has the cold clipper circuit.

There is not much influence with the tone stack driver with different tubes, it does change a bit but not a major change.

Also, what I found that improves the amp is to use a matched or balanced triode in the V5 just as you would in the phase inverter. Not sure if the step down from the cathode follower is stepped up to the same level with the FX recovery circuit. This trick also works with the JP2C and Mark VII for the V2 tube selection. Both amps use that for the FX send/Return but no cathode follower used.

Any other tubes as I am out of variables here? The only Russian tube I am running in the Roadster is the Mullard long plate 12AX7 reissue. Phase inverter. Also ran that in V3 when I chose the JAN/Phillips 5751 for the V1 spot. It did not make much of a difference what I used in V3 or V5, the JAN/GE 12AX7WA did add in some brightness that the Roadster was lacking.

 

[luiscristiano30]

Welcome to the forum.

My $0.02 on NOS/VOS.

I’ve been down the NOS rabbit hole many times, and any ‘benifit’ from NOS tubes really depends on the amp’s circuit. Most times it is a very negligible difference that gets lost in the mix of a live band. IMO the benefit of NOS tubes in cathode follower use is their ability to handle the higher voltages used in that position yet remain their composure.

Guitar amps (and their speaker cabinets) are far from high-fidelity audio systems, they are a narrow bandwidth system with a lot of clipping stages, they work in a specific frequency range designed to compliment the guitar’s frequency range and blend with other instruments and their frequency ranges.

This is quite a difference from a full bandwidth, ultra low distortion audio amplifier that is designed to be played in isolation, which will reveal these intricate changes in sound, especially with a great set of headphones.

If someone is happy with using NOS tubes in their gear that is really all that matters. But for me and my experiences, I’ve been through dozens of NOS/VOS tubes in multiple amps over the past few decades, and of all the amps I currently own and play, only one has an NOS tube still in it, my TC-100.

I’ve still got a box full of them…

View attachment 2465

Dom

t

Welcome to the forum.

My $0.02 on NOS/VOS.

I’ve been down the NOS rabbit hole many times, and any ‘benifit’ from NOS tubes really depends on the amp’s circuit. Most times it is a very negligible difference that gets lost in the mix of a live band. IMO the benefit of NOS tubes in cathode follower use is their ability to handle the higher voltages used in that position yet remain their composure.

Guitar amps (and their speaker cabinets) are far from high-fidelity audio systems, they are a narrow bandwidth system with a lot of clipping stages, they work in a specific frequency range designed to compliment the guitar’s frequency range and blend with other instruments and their frequency ranges.

This is quite a difference from a full bandwidth, ultra low distortion audio amplifier that is designed to be played in isolation, which will reveal these intricate changes in sound, especially with a great set of headphones.

If someone is happy with using NOS tubes in their gear that is really all that matters. But for me and my experiences, I’ve been through dozens of NOS/VOS tubes in multiple amps over the past few decades, and of all the amps I currently own and play, only one has an NOS tube still in it, my TC-100.

I’ve still got a box full of them…

View attachment 2465

Welcome to the forum.

My $0.02 on NOS/VOS.

I’ve been down the NOS rabbit hole many times, and any ‘benifit’ from NOS tubes really depends on the amp’s circuit. Most times it is a very negligible difference that gets lost in the mix of a live band. IMO the benefit of NOS tubes in cathode follower use is their ability to handle the higher voltages used in that position yet remain their composure.

Guitar amps (and their speaker cabinets) are far from high-fidelity audio systems, they are a narrow bandwidth system with a lot of clipping stages, they work in a specific frequency range designed to compliment the guitar’s frequency range and blend with other instruments and their frequency ranges.

This is quite a difference from a full bandwidth, ultra low distortion audio amplifier that is designed to be played in isolation, which will reveal these intricate changes in sound, especially with a great set of headphones.

If someone is happy with using NOS tubes in their gear that is really all that matters. But for me and my experiences, I’ve been through dozens of NOS/VOS tubes in multiple amps over the past few decades, and of all the amps I currently own and play, only one has an NOS tube still in it, my TC-100.

I’ve still got a box full of them…

View attachment 2465

Dom

thank you so much

 

[luiscristiano30]

Welcome to the forum.

My $0.02 on NOS/VOS.

I’ve been down the NOS rabbit hole many times, and any ‘benifit’ from NOS tubes really depends on the amp’s circuit. Most times it is a very negligible difference that gets lost in the mix of a live band. IMO the benefit of NOS tubes in cathode follower use is their ability to handle the higher voltages used in that position yet remain their composure.

Guitar amps (and their speaker cabinets) are far from high-fidelity audio systems, they are a narrow bandwidth system with a lot of clipping stages, they work in a specific frequency range designed to compliment the guitar’s frequency range and blend with other instruments and their frequency ranges.

This is quite a difference from a full bandwidth, ultra low distortion audio amplifier that is designed to be played in isolation, which will reveal these intricate changes in sound, especially with a great set of headphones.

If someone is happy with using NOS tubes in their gear that is really all that matters. But for me and my experiences, I’ve been through dozens of NOS/VOS tubes in multiple amps over the past few decades, and of all the amps I currently own and play, only one has an NOS tube still in it, my TC-100.

I’ve still got a box full of them…

View attachment 2465

Dom

thank you so much