I assume you are talking about the Xaleph here...
Let me ask you this- Do you really need a class A amp running at 4 amps of bias for 20 watts? How about a p/p class B amp? The point is that it is all about what you system requires, and what level of quality you are going for. What if you have speakers that have a constant low impedance? I think you would need at least some more bias, even if it isn't 10 amps. The bias does have an effect on the sound quality though.
You're talking apples and oranges here... I was talking about the remark you made about the X-lite.
With the <I>ALEPH</I>X, not only do you have an active current source, you have a dynamic active current source! If it was biased with a regular, non-modulated active current source, you would need twice the bias, which would put it at 16 amps! Now, think about using a passive current source, which decreases the efficiency even more. Are you getting the picture yet? Of course, if you don't care about getting full output capability out of the circuit (even into 8 ohms), go ahead and under-bias it as much as you want! I even said that in the first place. Just remember, anyone can criticise someone else's design preferences. It would help your credibility to get your facts straight before you spout off about why a design is so ridiculous. Also, how many posts have you read where increasing the bias on any of the Pass Labs designs or their derivatives has made a significant improvement in sound quality? Nelson himself has said so.
Steve
Steve,nobody special said:
Yeah, but you're still completely wrong on that one! The high currents needed are for even a 6 ohm load without current limiting... which most 8 ohm speaker get down to.
Simulate it or build it and see for yourself!
Free YOUR mind.
The aleph sources in the X make a big difference. I am actually planning on using 1 device/side in my AlephX, because of everything you mentioned. No need for more. If I were going to be using these with my 4 ohm MTMs, however, I would up the current to be on the safe side. Why limit the output capability when you have the voltage headroom (especially when you are talking about a low powered amp... it would be different if you had a clean 100 watts into 8 or 4 ohms). It all depends on your speakers.
Steve
Let us know how your single out devise X works . I plan on building one myself. The speakers are 15 ohm and 100 dB efficient.20 volt or so rails and 1.5 amps through a IRFP044 are what are planned for now. 10 watts is plenty for my system.
Currently I am listening to MikeW's X. The bass and transients are as advertised. It is a revelation in clarity also. The 8 output devises are idling along, putting out mW levels though.
I may be wrong, but hope a single 044 is better suited to drive my speakers. With noraml speakers I bet the sound is much better with a string of 240's and the bias way up.
George
George,
I will let you know how it sounds. I am currently working on the chassis, and I have a whole new respect for Peter Daniel's work!
If you are using 1.5A bias per side with 20 volt rails, you will actually get about 40 watts into 15 ohms.
All this praise for the sound is pushing me to finish mine... I can't wait!
I will be using a single IRFP244 per side with about 2.2A bias/side with 13V rails... pretty typical AlephX. I was going to bias it up to 7A total, but I decided to start small and if I like it build one with 20-25V rails and more bias.
Steve
I will let you know how it sounds. I am currently working on the chassis, and I have a whole new respect for Peter Daniel's work!
If you are using 1.5A bias per side with 20 volt rails, you will actually get about 40 watts into 15 ohms.
All this praise for the sound is pushing me to finish mine... I can't wait!
I will be using a single IRFP244 per side with about 2.2A bias/side with 13V rails... pretty typical AlephX. I was going to bias it up to 7A total, but I decided to start small and if I like it build one with 20-25V rails and more bias.
Steve
nobody special said:
I don't think so. Never mind the AC current source, I am talking about raw DC bias at various voltage in, YES, alephX but this work for just about any aleph:
30V 8amps Nelson Pass, 12-13V 10amps whoever.
There is no disputing, no trying to spin this simple fact that 10 amps are COMPLETELY UNNECESSARY at 12 v rails and that you'll run out of rail margin long before you run out of current when playing actual music.
Actual THD MEASUREMENTS, not suppositions or conjectures confirm that it is bad in terms of distortions to use such lower rails.
Why anyone would want to listen to higher distortion is beyond me. It comes down to personal preferences I guess, so there is no point in discussing this further.
Blown
Well,
That's it for me,
I'm not sure whats going on here so I have elected NOT to enage any futher posts, threads or PICS with this Forum for the moment.
The subject of X appears to create Parkinsons disease which is rather unfortunate for some.
As they say in the classics you are not worthy.
At the start of the original X thread, page one, more meaningful, polite an factual responses came from the creator of all DIY Audio wisdom Grey Rollins.
I will be establishing a home page shortly and those who know me well enough will find out about this.
Of the 700+ A Aleph Boards made, only a handful have published their results.
I mean hello...
Ian
Well,
That's it for me,
I'm not sure whats going on here so I have elected NOT to enage any futher posts, threads or PICS with this Forum for the moment.
The subject of X appears to create Parkinsons disease which is rather unfortunate for some.
As they say in the classics you are not worthy.
At the start of the original X thread, page one, more meaningful, polite an factual responses came from the creator of all DIY Audio wisdom Grey Rollins.
I will be establishing a home page shortly and those who know me well enough will find out about this.
Of the 700+ A Aleph Boards made, only a handful have published their results.
I mean hello...
Ian
Attachments
macka said:
Wonderful! Finish you amp first then you'll have something meaningful to say.
Parkinson's is a very serious business not to be taken as a joke, most definitely not to be used as a derogatory term.
The THD measurements I was referring to come from his majesty himself.
You have your own reason for leaving the forum. fine. Just don't blame others for your actions.
No pic yet....
With the likes of Peter's products, it seems as if my amp is rather ordinary. I didn't publish any pics because my Ax has nothing new to offer. Ian, your point hits home with me; even with average looking achievements, we should feel proud to share our endeavors with one another. Frankly, even with low rail voltages, my Ax is a fine sounding amp and I've yet to hear one better. Practically everyone who listens to my system comes away with a smile. Last night one of our guest told me that I've ruined music for her unless she can come over and hear it on my system.
I'm in the process of constructing Nelson's Zenlite. It will resemble the old p to p wired open chassis 2A3 tube amps of yesteryear. Now that's an amp that will give me a reason to post a pic! The maple is so wild that it resembles the finest gunstock. It should be a beaut.
Ian, you should stay. People will be people, always. I for one would really miss you.
John Inlow
With the likes of Peter's products, it seems as if my amp is rather ordinary. I didn't publish any pics because my Ax has nothing new to offer. Ian, your point hits home with me; even with average looking achievements, we should feel proud to share our endeavors with one another. Frankly, even with low rail voltages, my Ax is a fine sounding amp and I've yet to hear one better. Practically everyone who listens to my system comes away with a smile. Last night one of our guest told me that I've ruined music for her unless she can come over and hear it on my system.
I'm in the process of constructing Nelson's Zenlite. It will resemble the old p to p wired open chassis 2A3 tube amps of yesteryear. Now that's an amp that will give me a reason to post a pic! The maple is so wild that it resembles the finest gunstock. It should be a beaut.
Ian, you should stay. People will be people, always. I for one would really miss you.
John Inlow
Hang in there Ian, the sometimes heated discussion comes from peole who take building audio too seriously. But we all can learn a thing or two from it.macka said:Blown
Well,
That's it for me,
I'm not sure whats going on here so I have elected NOT to enage any futher posts, threads or PICS with this Forum for the moment.
The subject of X appears to create Parkinsons disease which is rather unfortunate for some.
As they say in the classics you are not worthy.
At the start of the original X thread, page one, more meaningful, polite an factual responses came from the creator of all DIY Audio wisdom Grey Rollins.
I will be establishing a home page shortly and those who know me well enough will find out about this.
Of the 700+ A Aleph Boards made, only a handful have published their results.
I mean hello...
Ian
I am\interested in how other Aleph X amps are operated. The drifting absolute dc offset is very important to me. My drivers are direct connected to the amp without a crossover and the wire is about 40 ga or so in the voice coils. A volt or 2 of dc could smoke them. The natural inductance keeps ac from killing them, but without a blocking cap dc is bad news.
Hope you change your mind and stay around.
George
Grataku,
Without stating the obvious, I was referring to the Thread HI Jacking, It would appear the forum endorses it.
We have a way of dealing with that behaviour when you fly Qantas down here. My policy is the same.
If my amp was'nt finished how could I play it.
So please hop into some elses thread, and get out of mine now.
Or Perhaps you can enjoy the Sin Bin for a while.
Ian
Without stating the obvious, I was referring to the Thread HI Jacking, It would appear the forum endorses it.
We have a way of dealing with that behaviour when you fly Qantas down here. My policy is the same.
If my amp was'nt finished how could I play it.
So please hop into some elses thread, and get out of mine now.
Or Perhaps you can enjoy the Sin Bin for a while.
Ian
Gosh, don't read a thread for a day and it all blows up!
Ian, I don't think you need to worry, you are welcome here, and you seem to have a staunch band of comrades to defend your honour, certainly better than I can as a mod 'cos I know nothing about Ax amps
Comments have been made on this thread that are a little sharp, so I will be paying more attention to it now, so hopefully things will stay polite!
Ian, I don't think you need to worry, you are welcome here, and you seem to have a staunch band of comrades to defend your honour, certainly better than I can as a mod 'cos I know nothing about Ax amps
Comments have been made on this thread that are a little sharp, so I will be paying more attention to it now, so hopefully things will stay polite!
macka said:
Macka,
relax, you made your point, I made mine, we can agree to disagree, I thought I left it to that a couple of posts ag before you had to go off with your little charade.
I am sure at qantas they also have a minibar for the people too tense, I suggest you help yourself to that or you can spend some time in the sin bin for spewing bs and accusing people of thread jacking. Last time I checked this was an open forum.
Fine,
I am waiting access to a suitable hi resolution optic before I post the pics.
I am sure all would rather see a it in focus so you can see all the Tit Bits (her I mean).
The description for the moment : Mono blocks 350 x 350 x 150mm Heatsink at the back, the driver board is set in the top panel on black perspex so it can be tweeked and admired, with a nice black perspex front and Led. The heatsinks are Conrad 300 mm@F150 2 flange about 0.25/per watt.
The intention is to let the baby grow up to a 100 watt, the full size adult 200+ by adding more resouces (6 heatsinks, 4 300 va trannies, 32 Fets.......a very hot chick.
I was planning to portray the A/B with Aleph versus XA Alpeh and then mix with BOSOZ and its X sister. The technical conversations are fine but have been talked into the ground in over 1000 other posts thats all.
Ian
I am waiting access to a suitable hi resolution optic before I post the pics.
I am sure all would rather see a it in focus so you can see all the Tit Bits (her I mean).
The description for the moment : Mono blocks 350 x 350 x 150mm Heatsink at the back, the driver board is set in the top panel on black perspex so it can be tweeked and admired, with a nice black perspex front and Led. The heatsinks are Conrad 300 mm@F150 2 flange about 0.25/per watt.
The intention is to let the baby grow up to a 100 watt, the full size adult 200+ by adding more resouces (6 heatsinks, 4 300 va trannies, 32 Fets.......a very hot chick.
I was planning to portray the A/B with Aleph versus XA Alpeh and then mix with BOSOZ and its X sister. The technical conversations are fine but have been talked into the ground in over 1000 other posts thats all.
Ian
Prior to an further auditioning I have been checking a few things.
Regarding the infamous 13.4 volts which Grataku was commenting in part about earlier.
My scientific investigation has revealed this is not by design but is due to about a 7-8% sage in the mains voltage at the power point outlet in the building.
The power company has confirmed the voltage in the street is correct, so there is little I can do about it.
Maybe all the other wealthy residence in this apartment block are in possession of X Aleph boards which are also running at 13.4 volts. (that would account got 30 of the 700 boards)
I better order a truck load of Valium so they can all sleep at night.
Muhahahahahaha.
macka
Regarding the infamous 13.4 volts which Grataku was commenting in part about earlier.
My scientific investigation has revealed this is not by design but is due to about a 7-8% sage in the mains voltage at the power point outlet in the building.
The power company has confirmed the voltage in the street is correct, so there is little I can do about it.
Maybe all the other wealthy residence in this apartment block are in possession of X Aleph boards which are also running at 13.4 volts. (that would account got 30 of the 700 boards)
I better order a truck load of Valium so they can all sleep at night.
Muhahahahahaha.
macka
little you can do?......
Actually, why not test more outlets in your dwelling. When I plug in my air compressor (I'm a carpenter, you know) there are many instances where I blow the breaker. I have to try several locations in order to get the beast up and running. Your kitchen counter and bathroom probably have stronger circuits. If you own your own home, then run a dedicated circuit from the main panel to your stereo and make it 20 amps while you're at it.
Just some thoughts.....
John Inlow
happy listening
Actually, why not test more outlets in your dwelling. When I plug in my air compressor (I'm a carpenter, you know) there are many instances where I blow the breaker. I have to try several locations in order to get the beast up and running. Your kitchen counter and bathroom probably have stronger circuits. If you own your own home, then run a dedicated circuit from the main panel to your stereo and make it 20 amps while you're at it.
Just some thoughts.....
John Inlow
happy listening
Good point John,
I will check this out.
I recall a while ago when I made the Aleph 2 the rails were down to 42.5 volts (dc) but at other times they were up.
I have a feeling some of the neighbours run reverse cycle air conditioning in the winter (here at the moment) which loads down the distribution and there could be power factor problems in here as well.
Ian
I will check this out.
I recall a while ago when I made the Aleph 2 the rails were down to 42.5 volts (dc) but at other times they were up.
I have a feeling some of the neighbours run reverse cycle air conditioning in the winter (here at the moment) which loads down the distribution and there could be power factor problems in here as well.
Ian
grataku said:
OK, OK... I am starting to understand where you are coming from now. 10A bias is completely unnecessary (in an AlephX).
Realistically, you would never ever need it. But, what does it hurt?
As far as the lower rails go, I am completely on your side on this one. Early on it was posted that the low rails are a bad thing, and my simulations prove it to be so. Don't say it too much around here though, or you will have your head handed to you. I agree... there is a reason why Nelson is using higher rails, and why he has said on here that he doesn't recommend going under 25V rails. Of course, when you get to that power level (around 140W into 8 ohms) you don't need the extra bias, because you will have so much power available anyway (why would you need to double and quadruple that into lower and lower impedances?). That, and the dissipation will be way too high.
I still think that the bias should be as high as possible, because it subjectively improves the sound of the amplifier. When the designer of the circuit says so, you tend to believe him. When Nelson says so, there is no doubting it! Of course, there is no point in running a huge amount of bias with low rail voltages, right? I think this is the point you were making?
Anyway, not to beat this horse to death... I understand what you are talking about, but you won't convince anyone here that you are right. I am building an AlephX because I have the parts. Why not... the few people who have built it say it sounds unbelievable! If it works well, I will build one with higher rails (but it will be biased as high as my heatsinks can handle).
Also, it DOES make a difference whether you are using the Aleph source or light bulbs. There is a huge difference in the amount of bias you will need to not current limit into 8 ohms before running out of voltage headroom. No spin, no bull... just fact! That is why I disagree about your comment on the X-lite. Of course, as you said, the voltages on the mosfet are too low, and are not optimal.
Steve
As I understand the use of Constant Current Sources (as in the ZEN) and Aleph Current Sources (ACS´s makes the output stage belive it´s driving 16 ohm load when it´s only 8) they are there to raise the efficiency of the poweramp so they need less current for bias, I dont think they them selves contributes to the better sound. So if you runs 10 amp at the AX, why not try to remoove the active part and just leave in the constant. I think that Peter Daniel once did this with a good result. At 10 Amp you are close to make it with passive sources like the SOZ, I haven´t simulated but i think so.
Happy building
Regards Henrik
Happy building
Regards Henrik
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