Variable Harmonizer

[Wavebourn]

Some people insist that we love tubes for their specific sweet distortions.

Here is a thingy that allows to control such a "Tubiness".

Try and report, how do you like details, soundstage, etc...

A single channel drawn. For stereo 100K audio taper must be dual. Dial it in and find the sweet spot you prefer.

Very cheap 6J6 tubes were used (1 tube per channel), very simple schematic with few components.

It may be used as a preamp as well, voltage amplification factor is about 20.

Enjoy!

[DF96]

Why build a cheap circuit like this? That won't impress anyone. Much better to pay good money for a badly-designed prettily-packaged tube buffer built to Chinese safety standards. Then you can impress yourself and your friends with how fine is the discrimination of your ears and the rest of your system when you hear the 'improvement' it brings to the sound.

[SY]

Yeah, that's the problem- it hurts to admit that you're after a signal processing device rather than "musical truth." Wavebourn has committed the cardinal sin of actually saying out loud that his circuit is specifically meant to distort in order to please the ear. I predict that his design will not find use outside of MI, since he gave away the game right up front.

[keantoken]

Oh, the humanity!

Would this would work with 6Dj8's?

You can't get away from distortion, not easily and not without paying a price. Sometimes it is better to improve the distortions you cannot avoid...

- keantoken

[Arnulf]

Originally Posted by Wavebourn

Here is a thingy that allows to control such a "Tubiness".

What a novel idea, "tubeness squared" The really cool part is that by adding just one more stage (one tube conencted like the right one in schematic) you get the tubeness cubed and each successive stage increases tubeness output exponentially ! Tubeness doesn't merely add up as it happens in most cases with to audio devices.

[tubelab.com]

I predict that his design will not find use outside of MI, since he gave away the game right up front.

However if it was marketed as a "hyperspace sound clarifier" with a slick marketing campaign and a couple of well greased magazine reviews, he could sell them for $2000 each. After all you need to capture all of those cosmic rays that snuck into your $1500 interconnects and return them to hyperspace where they belong!

[Pano]

Cool!
I'm kinda with keantoken on this. The signal chain from microphone to your speakers is a long one. Every circuit along the way is going to mess with the harmonics of the signal. Mostly suppressing even order harmonics. If you could "dial them back in" it might go a long way toward a cleaner sounding signal.

How about "Harmonic Balancer"?

[Bigun]

I say leave the harmonic manipulations to SS amps. In those cases they are trying to emulate tube amps. It's simply perverse to apply this back to a tube amp.

There are plenty of tubes that can provide the kind of tubiness being sought - almost any triode with enough 'leaning curves' will do the trick.

And I don't think the harmonic profile is a sufficient condition. Having build a SS amp with control over the even harmonics [TGM amp goes 'tubey' and having listened to my Cellini tube amp I can say with some conviction that for my ears, the harmonic profile is not at all sufficient to produce a tube sound. By itself, the harmonic profile is a blind alley.

[keantoken]

Thank you Bigun, you have made it clear I will have to build or buy some kind of tube device...

It is possible that if you connect two SE devices of opposite polarity, the 2nd harmonics may cancel and leave thirds. I don't know how often this occurs, but it is worth considering. It could be corrected by using a coupling transformer to reverse ground and signal wires...

- keantoken

[Bigun]

I think you'll enjoy playing with some tubes, perhaps it will be an ear-opener! - just don't touch the HT....