ML,
When you build out amps you gamble that the sonics will come up to par.
If you are driving 1.8R (this is a very bad piece of speaker design, BTW) you really nearly three pairs of laterals, and if you gunning for the best of all worlds you might use four pairs.
Driving the gates of these devices will be more difficult; all mosfet gates should be shaken, not stirred.
Ideally to drive three or four pairs you might consider emitter follower drivers. This will add another stage, and certainly will preclude the FetZilla pcb, which integrates all the power supplies for both rails. Furthermore, the rail voltage will be higher, and this might knock some of the small jfets/mosfet carefully chosen for this design.
This is a large project, many hours of careful work to complete. Be away there is a great of effort, and arguably expertise to bring it to a successful conclusion. This would cost a lot of money for a professional designer, so I'd suggest you find a clever hobbyist who shares the same passion.
Good luck!
Cheers,
Hugh
When you build out amps you gamble that the sonics will come up to par.
If you are driving 1.8R (this is a very bad piece of speaker design, BTW) you really nearly three pairs of laterals, and if you gunning for the best of all worlds you might use four pairs.
Driving the gates of these devices will be more difficult; all mosfet gates should be shaken, not stirred.
Ideally to drive three or four pairs you might consider emitter follower drivers. This will add another stage, and certainly will preclude the FetZilla pcb, which integrates all the power supplies for both rails. Furthermore, the rail voltage will be higher, and this might knock some of the small jfets/mosfet carefully chosen for this design.
This is a large project, many hours of careful work to complete. Be away there is a great of effort, and arguably expertise to bring it to a successful conclusion. This would cost a lot of money for a professional designer, so I'd suggest you find a clever hobbyist who shares the same passion.
Good luck!
Cheers,
Hugh
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Hi Hugh,
I am most honored, that you have commented on my post, also a pleasure to be saying how greatful I am to be able to converse with you on this thread considering the health issues that you have overcome.
We have cross paths on another forum.
JUst a reminder the 1.8ohm are, yes a very bad design but they are full panel ribbons and I just like the sound of these compared to most speakers apart from Maggies. I have an old jfet with original Hitachi 2 pairs of 2sj56/2sk176, and these modules have been driving these panels since 1994 and I have never had a fault. Yes the heatsink do get warm to hot. For the better or worst SS has come along way, and I really need to take these out of commission so I can service them(recap). So Im looking at GregH2 high power version of this that he has just posted: http://www.diyaudio.com/forums/solid-state/223357-fetzilla-builders-place-5.html
Alternatively, Im looking at aussie amps that do have 3 to 4 paired o/put devices or are you recommending a something with BJTs(emitter follower)?
I am most honored, that you have commented on my post, also a pleasure to be saying how greatful I am to be able to converse with you on this thread considering the health issues that you have overcome.
We have cross paths on another forum.
JUst a reminder the 1.8ohm are, yes a very bad design but they are full panel ribbons and I just like the sound of these compared to most speakers apart from Maggies. I have an old jfet with original Hitachi 2 pairs of 2sj56/2sk176, and these modules have been driving these panels since 1994 and I have never had a fault. Yes the heatsink do get warm to hot. For the better or worst SS has come along way, and I really need to take these out of commission so I can service them(recap). So Im looking at GregH2 high power version of this that he has just posted: http://www.diyaudio.com/forums/solid-state/223357-fetzilla-builders-place-5.html
Alternatively, Im looking at aussie amps that do have 3 to 4 paired o/put devices or are you recommending a something with BJTs(emitter follower)?
Hi ML,
I am curious to meet you knowing you live in Melbourne!
I am not sure how Greg will design his high power FetZilla, but I trust is in his approach. He is a very smart man, and he decides to do it, then he will.
The Aussie amps are very good, but the sound presentation, used with HexFets, will be different to the FetZilla which uses lateral FETs. Many people really enjoy the sound of lateral FETs - rounded, organic and a bit like a tube - so you might need to think about this.
I can let you that a simple post to you is a doddle now I'm recovering so well, so you should consider came to Heidelberg for a coffee at Matto!
Cheers,
Hugh
I am curious to meet you knowing you live in Melbourne!
I am not sure how Greg will design his high power FetZilla, but I trust is in his approach. He is a very smart man, and he decides to do it, then he will.
The Aussie amps are very good, but the sound presentation, used with HexFets, will be different to the FetZilla which uses lateral FETs. Many people really enjoy the sound of lateral FETs - rounded, organic and a bit like a tube - so you might need to think about this.
I can let you that a simple post to you is a doddle now I'm recovering so well, so you should consider came to Heidelberg for a coffee at Matto!
Cheers,
Hugh
Hugh,
It would be an absolute pleasure to meet you in person and the drive to heidelberg from Point Cook will be well worth it. I have some compulsary time occupying things I must do so it will have to be early next year unless and emergency happens like yesterday.
I have not heard a hexafet implementation, I have read alot about them and can someone who have the experience to describe there sound signiture compared to lateral fets like the Hitachi. 2ndly can some one confirmed they like laterals that have a negative temperature coefficient, Ijust cant remember its been a while.
It would be an absolute pleasure to meet you in person and the drive to heidelberg from Point Cook will be well worth it. I have some compulsary time occupying things I must do so it will have to be early next year unless and emergency happens like yesterday.
I have not heard a hexafet implementation, I have read alot about them and can someone who have the experience to describe there sound signiture compared to lateral fets like the Hitachi. 2ndly can some one confirmed they like laterals that have a negative temperature coefficient, Ijust cant remember its been a while.
Aha, as a young Army Officer I spent a year at the RAAF School of Languages at Pt Cook! I know the area well.....
Let me know next year, very happy to meet up. I can't drive just yet; waiting for a neurologist check to recover my driver licence!
Hexfets have higher transconductance, and much easier to source. Lat Fets do, however, sound more organic, more like a tube.
Cheers,
Hugh
Let me know next year, very happy to meet up. I can't drive just yet; waiting for a neurologist check to recover my driver licence!
Hexfets have higher transconductance, and much easier to source. Lat Fets do, however, sound more organic, more like a tube.
Cheers,
Hugh
Hugh,
isnt it a small world,
Im a contractor for a company that does copiers, and I look after 2 high speed color production and 6 B&W production machines at Defence Publishing Services @ The RAAF Williams Base in Point Cook! At least 95% of DOD printing comes out here!
Unfortunately 25yrs in this job has stuffed my electronics knowledge up, so Im very behind on the latest SS knowledge because all I do is being a glorified cleaner and a parts jockie
isnt it a small world,
Im a contractor for a company that does copiers, and I look after 2 high speed color production and 6 B&W production machines at Defence Publishing Services @ The RAAF Williams Base in Point Cook! At least 95% of DOD printing comes out here!
Unfortunately 25yrs in this job has stuffed my electronics knowledge up, so Im very behind on the latest SS knowledge because all I do is being a glorified cleaner and a parts jockie
OK, starting to get a little bit of an idea on fetzilla sound... tight bass, smooth midrange, extended treble and a nice sense of ease. it sounds about what i'm looking for... a nice neutral amp that isn't too dry or clinical or overly romantic and thick.
i still get lost in all the shop talk though and wonder if it's something i should avoid as it sounds like i'd need to buy test equipment to complete it to "set the bias" as you can't just build it and be done with it.
i liked the comment about this thread being for non-techs like me, even if there is a lot of tech talk that sounds like muted trumpets to me.
i still get lost in all the shop talk though and wonder if it's something i should avoid as it sounds like i'd need to buy test equipment to complete it to "set the bias" as you can't just build it and be done with it.
i liked the comment about this thread being for non-techs like me, even if there is a lot of tech talk that sounds like muted trumpets to me.
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