[baronbeehive]

While circuit might be the main deciding factor it seems as if some circuits can sound very different depending on tubes used. Old School/New School?

Yes but it's the electrical characteristics of the tube vis a vis the circuit that matters I think. A given tube will express in a certain way depending on the relation of its gm, voltage swing, transconductance, amplification factor, plate dissipation etc etc. to the circuit characteristics. That's probably why as Bcowen said the 300B could sound SS like in some circuits.

And when you have gyrator plate loads instead of resistor loads the characteristics of the preceding capacitor will be negated, ie it will sound completely transparent. I think that also applies to the tube so that the tube will just do it's voltage amplification and nothing else. The gyrator will take care of the current, relieving the tube of that duty. And we know from Sonic that the Citadel is more transparent if anything than the Oblivion meaning that there is very little of the tube sound that you would get in more traditional amps. I think that the flat load line that gyrators enable also diminishes the tube sound because we mainly associate tube sound with a certain amount of distortion and you don't get that with a flat load line because it is always in the no-distortion area of the tube grid.

That's my take on it anyway.

 

[Isaacc7]

Yes but it's the electrical characteristics of the tube vis a vis the circuit that matters I think. A given tube will express in a certain way depending on the relation of its gm, voltage swing, transconductance, amplification factor, plate dissipation etc etc. to the circuit characteristics. That's probably why as Bcowen said the 300B could sound SS like in some circuits.

And when you have gyrator plate loads instead of resistor loads the characteristics of the preceding capacitor will be negated, ie it will sound completely transparent. I think that also applies to the tube so that the tube will just do it's voltage amplification and nothing else. The gyrator will take care of the current, relieving the tube of that duty. And we know from Sonic that the Citadel is more transparent if anything than the Oblivion meaning that there is very little of the tube sound that you would get in more traditional amps. I think that the flat load line that gyrators enable also diminishes the tube sound because we mainly associate tube sound with a certain amount of distortion and you don't get that with a flat load line because it is always in the no-distortion area of the tube grid.

That's my take on it anyway.

All we can hear is how the circuit interacts with our speakers/headphones. When you change tube types you have literally changed the circuit, it isn’t the same amp! We get carried away, obsessing over tubes giving us sounds but what we are really doing is tweaking the circuit.

 

[senseitedj]

well when it comes to the 300b circuits argument and changing the sound, the WA5 and the Telemachus sound different with similar tubes used (Rectifier, 6sn7 and 300b)

The only difference in WA5 is the extra tube rectifier in the PSU. TLDR: I would describe the WA5 to be more lush sounding compared to the Telemachus.

 

[triod750]

This is an interesting question; is the tube part of the circuit or not? What would the circuit be without tubes?

Wasn't Oblivion supposed to be ignorant to tube rolling but in reality wasn't?

 

[Isaacc7]

This is an interesting question; is the tube part of the circuit or not? What would the circuit be without tubes?

Wasn't Oblivion supposed to be ignorant to tube rolling but in reality wasn't?

I don’t understand the question. None of the parts in an amp are optional. Remove any capacitor, resistor, transformer, or tube and the amp will no longer function properly or at all. You also can’t just plop in a solid state replacement for a tube without modifying other parts of the circuit. Everything in the circuit depends on everything else In it.

Changing an el34 with a 6l6 changes the way voltages propagate through the amp. They present different loads, have different output impedance, different gain, etc. etc. The circuit will (probably) still “work” in the sense that an amplified signal will come out of the amp but it’s undeniable that the circuit has been altered.

 

[triod750]

The question wasn't supposed to be taken too seriously. But tube rolling obviously changes the circuit. If I understand things correctly, more so in old school amps.
So we are circuit changers, even if we call ourselves tube rollers. I'm a CC by TR...

 

[Isaacc7]

The question wasn't supposed to be taken too seriously. But tube rolling obviously changes the circuit. If I understand things correctly, more so in old school amps.
So we are circuit changers, even if we call ourselves tube rollers. I'm a CC by TR...

Ah, I’ll stop being so serious and go back to listening to music lol.

 

[TheMiddleSky]

Wasn't Oblivion supposed to be ignorant to tube rolling but in reality wasn't?

Not completely "ignorant", it's just the effect in sound is smaller compared to old school amp such odyssey.

Anyway, my friend just snatched Mullard 6AT6, i should give it a try

 

[TheMiddleSky]

From what you're describing, if Oblivion is value for money in terms of sound and cost, Ultimate is even more so, especially with the latest tubes I'm using. Personally I still don't dig soild states. I had the chance to listen with Enleum 23R and I prefer Odyssey and Oblivion. What you're describing of Lina, sounds like Enluem 23R to me.

This guy reckons the Enleum 23R as the BEST amp he has ever heard but that's not my opinion. It's good but I still prefer good tube amps.

I easily prefer Oblivion than Enleum as well. Lina Amp is a clear upgrade over 23R in various spectrums.

 

[Nick Ryan]

Thanks for this most informative discourse on tubes. I think my days of tube rolling are over. The RCA 6AV6 and Siemens EL81 that Sonic send me sounds perfect. I've no inclination to swap to a different brand of the same type.

Tee heee I just found this when reading through past forums, Dec 29 2019. i bet you thought your tube rolling days were over !! LOL We all know what happened.

 

[UntilThen]

Tee heee I just found this when reading through past forums, Dec 29 2019. i bet you thought your tube rolling days were over !! LOL We all know what happened.

I was talking to MrCurwen. Wish he is still around. A most knowledgable and wounderful person. https://www.head-fi.org/threads/oblivion-ultrasonic-studios.902926/post-15382365

When I had Oblivion initially, the feeling is similar to when I had Odyssey initally and also similar to when I had Ultimate similarly. The impact of these 3 tube amps in my life is great.

 

[TheMiddleSky]

Oblivion is "singing" with Mullard 6AT6 tonight. Adding clarity, texture, and soundstage nicely. Vocal slight more laidback, but still in good presence and body. Bass has the same character like standard tube, but add more layer for texture.

To pair with my ZMF Caldera + ZMF 2K Copper cable, this one is better match than standard 6AT6 tube. A lovely pairing indeed.

 

[senseitedj]

Oblivion is "singing" with Mullard 6AT6 tonight. Adding clarity, texture, and soundstage nicely. Vocal slight more laidback, but still in good presence and body. Bass has the same character like standard tube, but add more layer for texture.

To pair with my ZMF Caldera + ZMF 2K Copper cable, this one is better match than standard 6AT6 tube. A lovely pairing indeed.

Mullard never fails to deliver

 

[TheMiddleSky]

Mullard never fails to deliver

Haha yeah, after an hour of use, the advantage in clarity is even more obvious. Good thing my headphones are on balance-warm side.

For more 6AT6 rolling:

 

[TheMiddleSky]

Had compared multuple 6AT6s, somehow my "heart" back to RCA again. The synergy with my whole chain produce very "complete" sound from fast transient, full body tone, and spacious soundstage image.

I plan to add some match pairs for back up, but apparently searching for them is not easy lol. Found in two different webs, but apparently they sold out already.