Hi guys!
As I have promised you, I would like to post some pictures of the latest of my projects that has been completed a few months ago.
Due to the unique specs, I feel quite certain that this is the most exotic MM phono preamplifier ever made. Several posts will follow during the next days.
This is one of the few phono preamps around where no active regulation is applied to any of the active stages. Here, we are not involved with ECC82 / ECC83 tubes which draw a fraction or a few milliamperes, we are dealing with Siemens D3A tubes which draw 30 milliamperes of current each! It is a classic MM design, two stage preamp where all tubes are inductively loaded. Yes, one interstage and one output transformer per channel, in a phono preamp! It gives 45 dBs of gain and in order to use it with premium quality MC cartridges you will definately need a pair of MC step up transformers (not presented here).
Each tube has its own seperate filaments and HV supply. HV rectification is performed with the best tubes ever made, the legendary Telefunken RGN4004 equipped with black mesh plates, where filaments rectification is performed with germanium diodes.
Several more comments will follow, for the time being enjoy the pictures.
Greetings from Athens, Greece!
Peter Avgeris
As I have promised you, I would like to post some pictures of the latest of my projects that has been completed a few months ago.
Due to the unique specs, I feel quite certain that this is the most exotic MM phono preamplifier ever made. Several posts will follow during the next days.
This is one of the few phono preamps around where no active regulation is applied to any of the active stages. Here, we are not involved with ECC82 / ECC83 tubes which draw a fraction or a few milliamperes, we are dealing with Siemens D3A tubes which draw 30 milliamperes of current each! It is a classic MM design, two stage preamp where all tubes are inductively loaded. Yes, one interstage and one output transformer per channel, in a phono preamp! It gives 45 dBs of gain and in order to use it with premium quality MC cartridges you will definately need a pair of MC step up transformers (not presented here).
Each tube has its own seperate filaments and HV supply. HV rectification is performed with the best tubes ever made, the legendary Telefunken RGN4004 equipped with black mesh plates, where filaments rectification is performed with germanium diodes.
Several more comments will follow, for the time being enjoy the pictures.
Greetings from Athens, Greece!
Peter Avgeris
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Hi Peter,
I applaud your effort and countless hours of workmanship in building these. The metalwork and finishing looks excellent. While I know little of the RGN4004's, I do like your choice of the D3A's. And I'm also of the opinion that for a class A stage regulation is not necessary and sonically doesn't buy you anything. But for what this is, a phono preamp, it is truly a spectacle.
I applaud your effort and countless hours of workmanship in building these. The metalwork and finishing looks excellent. While I know little of the RGN4004's, I do like your choice of the D3A's. And I'm also of the opinion that for a class A stage regulation is not necessary and sonically doesn't buy you anything. But for what this is, a phono preamp, it is truly a spectacle.
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I'm a fan of black boxes, but after seeing the white power amps, these leave me a little 'cold'.
I still remain amazed by the level of detail....... and lack of detail (if that makes any sense).
One things for sure, you must love winding transformers if that table shots / previous post is anything to go by
I still remain amazed by the level of detail....... and lack of detail (if that makes any sense).
One things for sure, you must love winding transformers if that table shots / previous post is anything to go by
Thank you very much for your comments!
Regulation makes things worse in terms of sound quality. I am referring of course to active regulation. But due to the fact that low freqs are amplified a lot, it is really painful to get rid of this 50 Hz hum and oscillation at fraction of one Hertz! This is close to the boundaries of impossible. That's why each choke measures more than 300 Henries!
Once you've experienced motorboating because of insufficient decoupling (PS rail impedance rising at subsonic frequencies), you'll reconsider that.
BTW, love the Sowell quote. "Knowledge and Decisions" is one of the best books on economics I've ever read.
Wow!
Last time I heard figures like that, my uncle Dave was explaining things about Bloodhound surface to air missiles radar system
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Peter, my head just exploded (that is twice today already). It is simply beautiful.
One question though, why black this time around? The white of the power amp (I believe that was yours also) will surely contrast with this, won't it?
This must be a horrible mistake. Please ship either to me immediately -- I will dispose of it for you as a favour.
One question though, why black this time around? The white of the power amp (I believe that was yours also) will surely contrast with this, won't it?
This must be a horrible mistake. Please ship either to me immediately -- I will dispose of it for you as a favour.
I'm a fan of black boxes, but after seeing the white power amps, these leave me a little 'cold'.
I still remain amazed by the level of detail....... and lack of detail (if that makes any sense).
One things for sure, you must love winding transformers if that table shots / previous post is anything to go by
Hello from Athens!
This phono preamp is going to be installed in a system with components thst are dark-colored, so it is made black.
Yes, you are tight, it is a passion for me, to design, calculate, wind and then listen to aufio transformers. You can name it either a supply t/f or choke or interstage t/f or an output t/f or even MC step up transformer, a new transformer is always a new challenge for me!
Thank you for your kind words.
Peter.
Peter, my head just exploded (that is twice today already). It is simply beautiful.
One question though, why black this time around? The white of the power amp (I believe that was yours also) will surely contrast with this, won't it?
This must be a horrible mistake. Please ship either to me immediately -- I will dispose of it for you as a favour.
Thank you very much for your kind words!
This phono preamp is going to be installed in a system with dark colored components, it would be a disaster to mate it to the white 211 amplifiers. Nikos (the owner if those amps) is soon going to give me an order to manufacture the same phono in white color, to match the aesthetics of his system.
There exists one more phono like this, identical in every aspect, which is going to be installed in a system thoroughly designed and manufactured by me, a trully 'ecotic' system with out of this world amplifiers, mc step up transformers, speakers and the best turntable in the world (in terms of sound quality). The 'table is made by a greek designer, where all other components are going to be manufactured by me.
I will present this effort here soon...
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WHile I can appreciate the workmanship and sheer audacity of such over-the-top builds...what is the purpose of these "most exotic" threads?
Seems to be purely narcissistic...whereby the OP posts pics of these gi-normous and seemingly complex builds waiting to bask in the reflected glory of the oohing and ahhhing crowds without one whit of technical background or specifications to accompany it...despite assurances such will be forthcoming.
What am I able to learn from such posts? Virtually nothing, of course. That seems to be the point...
I am used to reading threads way above my level of expertise or capacity to fully comprehend, but inevitably I learn something or am directed to resources where I might learn more but this is pure spectacle and more properly belongs on post pic threads....where, truth be told, one can glean a lot more useful information...why not create a new section specifically for such other-wordly spectacles of excess
....suggestion: "Audio Lifestyles of the Rich and Overblown."
I think you're missing the point of the art-form and are looking for engineering rather than design. This fellow enjoys winding transformers and building eye candy. So the electrical performance isn't the key thing here (one can engineer this sort of thing much better if that's the goal), it's the art and craft of creating something distinctive that incorporates the elements of what he enjoys doing.
No problem with that at all Sy...I can appreciate art-form without having to know the artistic techniques used to accomplish the work...that is, unless I am an artist looking for some insight into technique, tools and process.
The OP routinely promises to share some of the technical "specifications" which make his builds the most "exotic" etc. Yet, while the OP is exceptionally quick to respond to enthusiastic backslapping his silence is deafening regarding any technical queries.
Being woefully non-technical myself, I nonetheless am able to learn a lot from those who are willing to share some technical insights and objective data...it would be better if the OP simply stated this is about pics and nothing else will be forthcoming.
This would likely not be the thread for that, but for those of us who engineer but mostly produce gear whose looks take a back seat to functionality, this is useful and enjoyable. Fortunately, we have both kinds of threads here.
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