Hybrid Amplifiers...Added valve warmth/distortion...

[Chr1]

My current favourite amplifier is a Lazarus H-1A valve/mosfet hybrid that I picked up cheaply on Gumtree several years back. I am assuming that the valves are added to the circuit to simply add distortion/warmth to the sound produced?

As such, I am very happy with this particular alteration to the signal, but am wondering if there would be any other reasons to include the valves?
I was previously using a Technics SE-A1000 MK2 and prior to that a NAD C372 (power section only), both of which sounded good to my ears too...but have to say that I prefer the Lazarus. Guess I like distortion!

I suppose ideally one would be able to listen to it both with and without the valves in the circuit.

Found this online...https://www.gammaelectronics.xyz/audio_09-1990_lazarus.html
Plus a photo and circuit diagram...

 

[Doodski]

It has good linearity of the power output. The 53,000 µF, 50v caps in the supply are for tight voltage regulation of the power supply and the toroidal transformer is hefty. It's probably ~800-900 VA to support that kind of power output linearity. It's a cool piece of gear. I can't comment too much on the tubes because I'm not old enough to have serviced tube gear and don't have much knowledge of them but there are peeps here that are good with tubes.

 

[escksu]

My current favourite amplifier is a Lazarus H-1A valve/mosfet hybrid that I picked up cheaply on Gumtree several years back. I am assuming that the valves are added to the circuit to simply add distortion/warmth to the sound produced?

As such, I am very happy with this particular alteration to the signal, but am wondering if there would be any other reasons to include the valves?
I was previously using a Technics SE-A1000 MK2 and prior to that a NAD C372 (power section only), both of which sounded good to my ears too...but have to say that I prefer the Lazarus. Guess I like distortion!

I suppose ideally one would be able to listen to it both with and without the valves in the circuit.

Found this online...https://www.gammaelectronics.xyz/audio_09-1990_lazarus.html
Plus a photo and circuit diagram...

View attachment 165833

Haha you are not alone. My uncle has a set of valve amps with LS35A. The soud is really magical. I don't care how they measures, they just sound so good to my ears.

 

[wwenze]

There are software plugins that can emulate tubes' transfer function so you can save a few bucks while adding that second-harmonic.

 

[Chr1]

There are software plugins that can emulate tubes' transfer function so you can save a few bucks while adding that second-harmonic.

Thanks. Sounds interesting. Just did a quick search and found this on the Foobar2000 site Hyrogenaudio, so not too sure however:

"Spoken from someone who has a master's in Computer Engineering and has taken Image and DSP processing. I do not believe any "plugin" will be able to adjust the harmonics correctly to give the "tube warmth". It's like trying to reverse the very mechanism with DSP correction, it never works out.

You can bring up even or odd harmonics, or even to the 11th order but the bottom line is you are still going through transistors. I've tried many tube amp plugins and seen the harmonic distortion, but what comes out after an amp + pre-amp, that are solid-state, does not line up. If anything it sounds too smooth and dead to me.

These plugins are likely DSP gimmicks based on mathematical convolving the source signal with some type of Fourier transform, offset, from the original wave. It's still a giant matrix.

The prob is that even if you solve the harmonics with convolving, you still have the issues of inability of the transistors to replicate the transient movements of tubes. It's like having a bottle-kneck in the whole system."

 

[xaviescacs]

I prefer the sound of my Pathos Aurium hybrid headphone amplifier over a SS one. I don't know exactly what it does, and I would very much like to know what it does.

 

[Chr1]

I suspect that emulating the valve sound digitally is not as easy as it seems. If it was possible then nobody would bother with them. It is no doubt similar in the live music world. Jazz and rock guitarist's would stop using their valve amps and shift over to some form of DSP. Doubtless lots have but I bet that most stick with their favoured valve/amp combo if that's the sound they prefer.
(Must see if they ever use hybrids too...)

 

[charleski]

I suspect that emulating the valve sound digitally is not as easy as it seems. If it was possible then nobody would bother with them. It is no doubt similar in the live music world. Jazz and rock guitarist's would stop using their valve amps and shift over to some form of DSP. Doubtless lots have but I bet that most stick with their favoured valve/amp combo if that's the sound they prefer.
(Must see if they ever use hybrids too...)

There's an interesting paper on that here:

https://libraetd.lib.virginia.edu/downloads/1z40kt33t?filename=Braatz_David_STS_Research_Paper.pdf

 

[Chr1]

Thanks. I guess that I vote for hybrids... best of both worlds.
If you like the valve warmth thing....