Can anyone explain this about pinch harmonics? (Tonal differences)

[311boogieman]

I look at tubes like spices for a steak. I've tried a few tubes and I make my decisions around tempo mostly. Microphonics and noise are next. My gain stages for a 5150 or a Mesa Mark I want triodes that measure -87 to -89.5 in gain stages (going higher now with pin cleaning). Rectos or other amps I'd go lower like -85/-86 in gain stages. Something like a phase inverter position I'd be willing to go much lower like -82 because it's not as critical.

I don't think JJs are terrible but I don't like them for playing metal. I'd much rather have CSF, Grammont Malakoff, Siemens or a Tungsram Tillburg over a JJ.

Oh yeah man. I get that. The tube brands you mentioned would invariably be better than a JJ.

I guess where I was going is that for mass production high gain amps these days, I prefer JJs over some of the other trash that goes into new amps today.

I'll have to look into this tube pin cleaning thing a bit deeper thanks. PS: I like a 5751 in the PI slot for my amps, like a JAN Phillips.

 

[napalmdeath]

Unsure about which brand, it's just the ones that come in the 5150 iconic el34. Just got it, didn't open it up or change anything out.

I think they use PSvane in the Iconic. Not for their tone, for their cheap price-point. The amps are made in China, might as well use Chinese tubes.

I would expect better harmonic content in an older Marshall than a Chinese hybrid.

 

[tjnx]

Def think it's circuit specific. Wah didn't help either but I would want to be able to do it without a wah engaged anyway.

Packed up the head already but the internet is saying it has the JJ 12AX7 / ECC83.

Thanks for doing that eq comparision but the problem is still there even in the 2nd part. Def seems like a circuit thing about certain heads as another poster mentioned.

Don't know if it matters but I've been able to replicate this before in ToneX between models. IRL we were testing a 2203x vs smallbox through the same cab and the 800 had a top end chime the smallbox couldn't hit even with diming out the upper frequencies.

So I think it makes sense that there is an allowable frequency range the eq can manipulate and if the higher order harmonics aren't allowed you wont get them. However in my case a buffer or wah would allow me to maximize the upper limit of my amps voicing. Compressor would probably help too

Would be cool if there was a solution

 

[CDawg]

Oh yeah man. I get that. The tube brands you mentioned would invariably be better than a JJ.

I guess where I was going is that for mass production high gain amps these days, I prefer JJs over some of the other trash that goes into new amps today.

I'll have to look into this tube pin cleaning thing a bit deeper thanks. PS: I like a 5751 in the PI slot for my amps, like a JAN Phillips.

I can find uses for a JJ it's just not a great choice when you have other tubes.

I think a lot of tube choices are more preference or tolerance than right or wrong. I hate Psvane because of poor quality control mostly. I hate most new production tubes but there's a few I like for some things. I don't use a 5751 myself and rarely swap variants but I should try it more.

If 10 minutes with a tooth brush and some rubbing alcohol gets a change of a dBv then I believe abrasives and chemicals used properly would do even better. A few people I know who are very selective have all said that Andy is the best but he doesn't detail his methods to anyone. Never tried anything from him myself but that guy has some amazing equipment and an incredible reputation so I believe it.

https://vintagetubeservices.com/laboratory/
https://vintagetubeservices.com/selecting-your-tube-is-an-art/
https://vintagetubeservices.com/testing-selecting-procedures/

 

[zaq2121]

at 7:20 - Rivera Tbr amp

 

[messageinblood]

at 7:20 - Rivera Tbr amp

Yup, that's it too. Horrible

 

[Omnipotent1]

Yup, that's it too. Horrible

Gross….

 

[Omnipotent1]

maybe @glpg80 could chime in on this thread.. He would probably know more of the technicalities that lead to overly saturated pinch harmonics…

 

[messageinblood]

maybe @glpg80 could chime in on this thread.. He would probably know more of the technicalities that lead to overly saturated pinch harmonics…

Would love to hear an explanation of the cause for it.

 

[glpg80]

maybe @glpg80 could chime in on this thread.. He would probably know more of the technicalities that lead to overly saturated pinch harmonics…

Modelers typically aren’t going to capture a harmonic of a note very well because at a high frequency it can’t discern from a note played or a harmonic struck by a player. It only knows what an amps response is supposed to do at a particular frequency and replicate whatever the amp is supposed to do with the knowledge it has of what frequencies it’s being fed. To make things even more complex, pinch harmonics themselves actually have their own even and odd mode overtones/harmonics as well, so it’s not surprising they’d sound off or limited. They don’t have the ability to capture overtone responses and infinite Taylor series of an overtone. An example of hearing this problem stated more musically and how challenging it is - eventide was bragging endlessly when they figured out how to harmonize complex chords with their sparkle pretty settings you can’t do anything with. Apply the same complexity but now you have harmonics that are pinch harmonics. Same problem and way harder.

 

[Music&Chaos]

I actually use my pinch harmonic sounds to dial in my amp and guitar pickup heights for myself and clients.

If it doesn't scream the right way on the Low E or G string - I get to tweaking settings.

 

[311boogieman]

at 7:20 - Rivera Tbr amp

What am I supposed to be looking for exactly? The 7:20 mark?

I actually use my pinch harmonic sounds to dial in my amp and guitar pickup heights for myself and clients.

If it doesn't scream the right way on the Low E or G string - I get to tweaking settings.

Interesting

 

[messageinblood]

What am I supposed to be looking for exactly? The 7:20 mark?

Yeah, 7:20ish mark is the sound we're talking about ITT. That youtuber doesn't really have a technical explanation for it either but he recognizes it... Hopefully someone can ID why exactly that sound happens.

 

[boltzthrower]

Regarding the OP topic, I’ve owned dozens of preamps and 10 or so power amps and IME the weak squeak vs full scream pinch thing is always preamp related, not power amp related.

 

[messageinblood]

Regarding the OP topic, I’ve owned dozens of preamps and 10 or so power amps and IME the weak squeak vs full scream pinch thing is always preamp related, not power amp related.

Any idea what exactly causes it?

 

[311boogieman]

Any idea what exactly causes it?

I'll let an expert answer but I think it was described already. I mean, you can do a pinch harmonic on an acoustic guitar

So it is not the 'what' so much as the 'why is it better with a tube amp'? Right? Is that your question?

At a basic level, tube amps are analog and compress the signal in a certain way. That compression and gain makes the artificial harmonic (squeal) ring out better. Someone can correct or add on to that. I have some relatively poor examples of doing squealies on my Peavy Vypyr 60 (tube power, ss pre) but I won't put anyone through that

 

[messageinblood]

So it is not the 'what' so much as the 'why is it better with a tube amp'? Right? Is that your question?

No, the question is what exactly in the tube amp circuitry / components that causes pinch harmonics to sound either like a whiny dying cat or the proper way as documented in the examples ITT.