[biscottino]

The Mafia thinks of Megahertz Audio as a bad joke.

Think the Carbon is a no-brainer at that range. I'd stretch for a custom BH build.

I think it is correct to express opinions if you know a product, you have listen it and how it is built.
what you see is a Guerra, el34 push pull that sounds better than a Wes, only costing the 50%!

 

[paradoxper]

Post the schematics and let's see what it's worth.

 

[biscottino]

Post the schematics and let's see what it's worth.

This is the otl inside, very simply, 2xecc82 and 2xecc99 jj like output tube.

 

[purk]

You should really try the KGSSHV though as it is a whole lot better than the original KGSS. What's the price point on your Megahetz amps?

 

[biscottino]

This is my Guerra inside, the prerogative of this push pull is the output stage made with inductors in place of the transformers to achieve higher speed.

 

[biscottino]

You should really try the KGSSHV though as it is a whole lot better than the original KGSS. What's the price point on your Megahetz amps?

I try this:

...and I did not like it with my 009, I'm sure the new HV version is better, but I do not particularly like solid-state amplifiers, for the use of dynamic headphones i use a Viva Egoista, right compromise between pleasure and speed.

 

[paradoxper]

This is the otl inside, very simply, 2xecc82 and 2xecc99 jj like output tube.

For a relative 2.5k, I sure hope it outperforms even an HV.

BTW, does Marco foresee a Golden Gate version?

 

[purk]

The KGSSHV Carbon is a good bit better than the KGSSHV both versions. Meanwhile those same KGSSHVs are drastically better than the older KGSSS in every way. Your will be super impressed by the Carbon so u should really check it out.

 

[JimL11]

This is my Guerra inside, the prerogative of this push pull is the output stage made with inductors in place of the transformers to achieve higher speed.

So, some technical considerations. As a general rule, the output stage of an amplifier produces the most distortion because it has the widest voltage and current swings. It appears the OTL uses resistor output loads, and you say the Guerra uses inductor output loads. Here's the issue with both those approaches. Electrostatic headphones resemble a capacitor (more or less) in parallel with a resistor (which represents the power lost from producing audio output). This means that the headphones are very high impedance, particularly at low frequencies, which is where the musical signal has most of its power (approximately half the audio power in music lies below around 300 Hz). A resistor load has to be significantly lower resistance than the headphones. An inductor load has its lowest impedance at low frequencies (rising with frequency). What this means is that the vast majority of signal current generated by the output tubes is burned up in the resistor or inductor load, while only a small fraction of the current actually goes to drive the headphones. Thus the output tubes have to work much harder to drive the headphones, resulting in significantly higher distortion, as well as decreased drive capability.

For electrostatic headphones in particular, this means the best approach is constant current loads, because a good constant current load wastes essentially NONE of the signal current, so a much higher proportion of signal current goes to driving the headphones (some is burned up by the feedback resistors, if any). Result - the output tube doesn't work nearly as hard, distortion is reduced and drive capability is improved. For example, substituting constant current sources for the resistor loads in the SRM-T1 doubles its drive capability. There's good reason that all the Stax amps designed since the 1990s use constant current loads, as do all of the Gilmore amps (other than the all triode design, which was the basis for the GES).

 

[biscottino]

For a relative 2.5k, I sure hope it outperforms even an HV.

BTW, does Marco foresee a Golden Gate version?

It was an experiment, that is, after trying the 600 limited, modest amplifier but i found it intrested because it used as a final stage a modern valve that did not seem to hurt to drive a 009 directly for high current it play.
So to simplify the project, it was chosen to pilot a valve, ecc99, with a valve, ecc82. the price of the project is about 1,500 €, but I chose for my clarity cap because I found them synergistic with my Stax.

 

[biscottino]

The KGSSHV Carbon is a good bit better than the KGSSHV both versions. Meanwhile those same KGSSHVs are drastically better than the older KGSSS in every way. Your will be super impressed by the Carbon so u should really check it out.

I hope I can try it.

 

[biscottino]

So, some technical considerations. As a general rule, the output stage of an amplifier produces the most distortion because it has the widest voltage and current swings. It appears the OTL uses resistor output loads, and you say the Guerra uses inductor output loads. Here's the issue with both those approaches. Electrostatic headphones resemble a capacitor (more or less) in parallel with a resistor (which represents the power lost from producing audio output). This means that the headphones are very high impedance, particularly at low frequencies, which is where the musical signal has most of its power (approximately half the audio power in music lies below around 300 Hz). A resistor load has to be significantly lower resistance than the headphones. An inductor load has its lowest impedance at low frequencies (rising with frequency). What this means is that the vast majority of signal current generated by the output tubes is burned up in the resistor or inductor load, while only a small fraction of the current actually goes to drive the headphones. Thus the output tubes have to work much harder to drive the headphones, resulting in significantly higher distortion, as well as decreased drive capability.

For electrostatic headphones in particular, this means the best approach is constant current loads, because a good constant current load wastes essentially NONE of the signal current, so a much higher proportion of signal current goes to driving the headphones (some is burned up by the feedback resistors, if any). Result - the output tube doesn't work nearly as hard, distortion is reduced and drive capability is improved. For example, substituting constant current sources for the resistor loads in the SRM-T1 doubles its drive capability. There's good reason that all the Stax amps designed since the 1990s use constant current loads, as do all of the Gilmore amps (other than the all triode design, which was the basis for the GES).

unfortunately not being the designer, I do not have the knowledge to answer you appropriately.
The fact remains that I use my amplifier for 3 years and I've had a lot of comparisons, including the top of the Wooaudio sound that was less dynamic listening.
Stax schemes are well-known to the designer who has chosen to do differently, and the result is right because no Stax amplifier sounds better at my ear.

 

[biscottino]

Blue Hawaii, costs 5800 $ while the carbon cc last revision is 5500$.
One looks like a luxury product packaged in a beautiful and finished dress, while the other is the classic diy product, no customization, someone who heard them both could say what are the differences and if one sounds better than the other one?
I have a decent collection of el34 nos, xf2 and xf4 valves, but I would rather understand how Blue Hawaii can play with modern valves and with no special effect vs Carbon. I got to hear it at the first Canjam in London, and I was not impressed, but surely the source that was present, a dac Ayre, is far from my Bricasti M1.

 

[astrostar59]

'Realmassy' on here has the Guerra. Maybe PM him to chime in? he has the 009s and has heard other Stax amps and DIY I believe. May get some more opinions. My thoughts are possibly the Guerra has a warm signature and more body in the mids which is classic SE tube sound. I realise the Guerra isn't SE, and also understand JimL11 in-depth information re amp design. Possibly even though a tube amp of this type of design is incredibly inefficient, it doesn't affect it too much as DHTs or high output tubes may have enough power to drive it anyway?

On the BHSE with stock tubes on certain DACs it can sound a bit bright as many here know. But a different DAC or tube roll and it changes (enough) to be a really great amp with the 009s IMO. The Carbon is a bit less bright I would estimate, but has no tube rolling luxury available, so to have a sweet sounding Carbon + 009 combo IMO requires careful DAC selection. And this can also apply to the BHSE. We are into high end so tons of information and detail, and it will punish you if the front end it not perfect. If an all tube electrostatic amp is really working for some as commented on here, I think it may be the warmth and body it brings to the table? Wether that is accurate or desirable is probably up to the end user. Regardless, I would like to hear the Guerra to know for sure, though no idea how that will happen, as the user base seems tiny.

This brings me back to my 'obsession' that tubes somewhere is good, in the DAC or amp. Full SS DAC & Amp (for me) is a step too far in both my 009s and my HT system.

 

[biscottino]

I know good Realmassy, first participated in our Italian headphones forum, he has always been very happy with the Guerra, and he is a great classical musician.
I know well that realmassy has tried other amplifiers for stax and the war has always been very good.
I would like to make a joke that the Guerra builder does about his project, the amplifier does not know that it is a push pull but it becomes when he attacks the headset, understood as a load, i think.
I really can not explain this statement but it's nice to let it know ...