HP to review phono stage

[jazdoc]

Those look cool. I have not heard any equipment that uses those yet. If you could separate what the mercury rectifiers bring to the sound what would you say that is?

Speed and resolution.

 

[FrantzM]

I have read that the mercury rectifiers create high frequency noise that needs to be filtered out. I assume this is why they are not more popular. I'm sure if implemented properly they work fine though.

From John Atwood of One Electron fame:

A major problem with all gas or vapor arc rectifiers is radio-frequency noise. This is not the subtle switching noise from a silicon rectifier that takes a sensitive spectrum analyzer to see, this is noise that can blank out an AM radio. When these rectifiers were used in communications equipment or car radios, so-called “hash filters” (composed of inductors and capacitors) had to be installed on both the AC and DC connections to the rectifiers. This noise is caused by the abrupt onset of conduction when the ionization potential is reached. The chaotic condition of the gas or vapor at the cathode surface causes this point of conduction to be somewhat randomized, hence the use of the term “hash” for the kind of noise it generates. It can be argued that in a purely audio amplifier, this noise is irrelevant, but RF can be detected or intermodulated down into the audio band in sensitive circuits. Filtering can only do so much. I would rather not have these major noise generators in my high-resolution amplifiers.

This just one point of view of course ...

 

[MylesBAstor]

Speed and resolution.

I might be wrong but I think Carl also uses the mercury tube in his Allnic? And it's not a drop in replacement as I understand; some modding is necessary by the designer to accomodate the tube.

 

[Mike Lavigne]

Speed and resolution.

++1.

the Found Music 45 and 2a3 amps (both with Mercury tube rectification) had speed and resolution that was breathtaking. pretty amazing stuff.

 

[mep]

It wasn't all that long ago when I worshiped at the alter of tubes and thought that SS was the spawn of the devil. Now, I think it's a little silly to talk about tube rectifiers like they are something special in the world of audio-especially tube amps. The majority of companies who manufacture high-end tube amps such as ARC, VTL, BAT, VAC, etc., don't use tube rectifiers and for good reason. Tube amps suffer in the bass compared to SS amps. Throw in a tube rectifier and you have just made the problem worse. Even way back in the day when tube rectifiers were still common, companies like Marantz dumped them in favor of SS rectifiers as soon as they could. The Marantz Model 8/8B and Model 9 amps don't have tube rectifiers. I think you have to go all the way back to Marantz Model 2 and Model 5 amps to find ones with tube rectifiers.

 

[cjfrbw]

I might be wrong but I think Carl also uses the mercury tube in his Allnic? And it's not a drop in replacement as I understand; some modding is necessary by the designer to accomodate the tube.

I modified it myself with my miniimalist electronic skills.

The answer to "why" in my estimate is utter liquidity and smoothness.

Not many manufacturers will allow mercury vapor due to the liability issues of potential spilled mercury.

 

[mep]

I modified it myself with my miniimalist electronic skills.View attachment 8061

The answer to "why" in my estimate is utter liquidity and smoothness.

Is that tube really hanging out the side of your preamp?? Does that make it Allnicstein?

 

[cjfrbw]

Is that tube really hanging out the side of your preamp?? Does that make it Allnicstein?

No, it makes it VaporNic.

That is just the power supply, not the chassis. Plates should be upright and parallel.

 

[mep]

I remember when mercury vapor bulbs were used in street lights.