tube shields. Yay or nay?

[Audiodog]

Question for all your Dumblites....

Do you prefer shields on your preamp tubes or not? I hear a distinct difference without shields. Definately more open and brighter. However, this is not necessarily better depending on the amp and circuit, as well as tube brand and gain.

Currently, my #102 has shields on and my #183 has no shields. Could change any minute!

[hermannbjorgvin]

Question for all your Dumblites....

Do you prefer shields on your preamp tubes or not? I hear a distinct difference without shields. Definately more open and brighter. However, this is not necessarily better depending on the amp and circuit, as well as tube brand and gain.

Currently, my #102 has shields on and my #183 has no shields. Could change any minute!

Controversial topic, I love it. My bias here is to say it's all the same and it's a placebo effect. But then I remembered I have a Fender Champ to test this out on. I sometimes use the Champ to test out different preamp tubes to hear the difference for myself and what kind of flavor each tube brings, 5751 sound creamier and have less gain than 7025 but the 7025 have a clearer less creamy tone that I always revert back to.

To test your hypothesis I selected a NOS RCA ECC83 and placed it in V1 on the 5F1 Champ. After letting it warm up, listening, playing, I can't tell the slightest difference, sometimes the non shield was brighter sometimes the shield was brighter, all to do with my playing and my perception of it, but I did not feel any difference with or without a shield.

Yes this is not a Dumble and it's just one preamp tube but the Champ is great I think for this test because you can hear exactly how the one preamp tube is behaving and I didn't hear a difference.

However, there is a debate to be had on what looks better!

[erwin_ve]

If the tube shield has a ground connection, maybe capacitance between the shield and internal tube components maybe a factor?

[martin manning]

Data sheets have figures for inter-electrode capacitance with and without a shield connected to the cathode (grounded, essentially). I believe there would be some noticeable effect at high frequencies if a large grid stopper resistor is involved due to the increase in Miller capacitance.

[Audiodog]

On V2 of the ODS, the shield is very noticeable. Not close, not placebo. Likely due to the Miller Effect as mentioned. I was quite surprised. I have not run shields for many years and decided to see what would happen. Personally. I like the smoothing it does to the top end in this position. I also run super strong ANOS stuff. No dull new production.

Question for all your Dumblites....

Do you prefer shields on your preamp tubes or not? I hear a distinct difference without shields. Definately more open and brighter. However, this is not necessarily better depending on the amp and circuit, as well as tube brand and gain.

Currently, my #102 has shields on and my #183 has no shields. Could change any minute!

Controversial topic, I love it. My bias here is to say it's all the same and it's a placebo effect. But then I remembered I have a Fender Champ to test this out on. I sometimes use the Champ to test out different preamp tubes to hear the difference for myself and what kind of flavor each tube brings, 5751 sound creamier and have less gain than 7025 but the 7025 have a clearer less creamy tone that I always revert back to.

To test your hypothesis I selected a NOS RCA ECC83 and placed it in V1 on the 5F1 Champ. After letting it warm up, listening, playing, I can't tell the slightest difference, sometimes the non shield was brighter sometimes the shield was brighter, all to do with my playing and my perception of it, but I did not feel any difference with or without a shield.

Yes this is not a Dumble and it's just one preamp tube but the Champ is great I think for this test because you can hear exactly how the one preamp tube is behaving and I didn't hear a difference.

However, there is a debate to be had on what looks better!

[xtian]

Do it at least semi scientifically: set up a loop pedal with a riff or two so you can swap the tube shield while listenening for differences. If it can't be captured in a recording, does it exist?

[hermannbjorgvin]

On V2 of the ODS, the shield is very noticeable. Not close, not placebo. Likely due to the Miller Effect as mentioned. I was quite surprised.

It's easy to dismiss stuff like this sometimes until you get to hear it in person too, would be cool to hear a looper pedal like others mentioned above. I think I'll try out removing the shields on my SSS but mostly because the glow looks so nice.
It's interesting that there's a distinct difference to your ears, which I have no reason to distrust.

[sluckey]

I like these...

[pompeiisneaks]

Oh yeah my sig gen by HP has those cool tube shields on it too. ( the one you helped me fix )

~Phil