class AB and B need a push pull, the alephs are single ended, that's why they can only be run in class A
wuffwaff said:
Felicitations! You just got through the most work intensive part of the project.
I have been on a similar trend myself, buying the heatsinks first then, get enclosures done without the faintest idea of what to put into them and then buy whatever transformers caps etc etc that would fit in and finally the pcb.
Grataku,
mmm, well actually no work has been done until now.🙄 All the parts in the picture are loosely put together and held in place by gravity😉
There´s still a lot of work to be done making a frame and connecting all the parts. Then milling all the edges and look for a nice finish.
As for transformers etc. everything is ordered and will fit in this case but it will take a while before everything has arrived.
The cases a such can dissipate about 300-350 watts for 55° C.
will keep you informed about the progress.
william
mmm, well actually no work has been done until now.🙄 All the parts in the picture are loosely put together and held in place by gravity😉
There´s still a lot of work to be done making a frame and connecting all the parts. Then milling all the edges and look for a nice finish.
As for transformers etc. everything is ordered and will fit in this case but it will take a while before everything has arrived.
The cases a such can dissipate about 300-350 watts for 55° C.
will keep you informed about the progress.
william
Confusion
Hi!
I'm nearly finished with my Aleph-X boards, but the road to completion seems long and winding...
A few questions: (as I cannot find any "std" specs.)
1) What power will the Aleph-X deliver in std. config, (and what version is what...) I have the "Rev.1" boards, and built them after the "original-plan".
2) So many threads, so many versions, and some is talking about "magical" resistors, without mentioning witch Aleph-X, or reference to what resistors....
Please tell me; what R # is "magical"?
And please remember to use R# when discussing changes...as it takes days to find what you mean...
Arne K
Hi!
I'm nearly finished with my Aleph-X boards, but the road to completion seems long and winding...
A few questions: (as I cannot find any "std" specs.)
1) What power will the Aleph-X deliver in std. config, (and what version is what...) I have the "Rev.1" boards, and built them after the "original-plan".
2) So many threads, so many versions, and some is talking about "magical" resistors, without mentioning witch Aleph-X, or reference to what resistors....
Please tell me; what R # is "magical"?
And please remember to use R# when discussing changes...as it takes days to find what you mean...
Arne K
Forgot...
more questions...
Having read some of the bias v.s. power calculations, I wonder;
is there no way to make these beasts behave as "normal" amps?
I mean: when the load drops, should not power output rise?
Would that not be more ideal?
I'm thinking of using Alephs on "normal" speakers, and speakers with better than 90dB/w/m is concidered exotica or CerwinWega...
Arne K
more questions...
Having read some of the bias v.s. power calculations, I wonder;
is there no way to make these beasts behave as "normal" amps?
I mean: when the load drops, should not power output rise?
Would that not be more ideal?
I'm thinking of using Alephs on "normal" speakers, and speakers with better than 90dB/w/m is concidered exotica or CerwinWega...
Arne K
Cobra2
I guess you haven't paid any attention to the posts that now number in the hundreds that have appeared on this site for the past year. Reminds me of some students I've had coming to see me in my last office hour asking me to teach them the entire course in ten minutes. I guess monday it's finals time and you are going to flunk.
😉
Kidding aside, there are no std specs except what was measured by Grey. There are many 'magical' resistors the value of which will influence the gain, people have been playing with those, with various PS voltages so it's kind of hard to answer your question.
In a nutshell, look for the schematic that Chad posted it came with the Ver 1.0 board. The two main things you can change are the input resistors to gnd from 68k to any values you like gain-wise/sound-wise down to 10k, the 6W resistors to gnd can be 100 ohms no problem, the two resistors that go from output back to the differential pair could be 4.7k and probably they are so on the schematic. The X feedback resistor can go from 100k to 220k. Combine that with all the possible variations of the input resistor you can figure how many variations you can have.
Even with Nelson afterburners the upperbound current ie the max power on any load is determined a priori and it basically it comes down to how much power you can dissipate. In my view, that's a pretty rational way to construct an amp.
I guess you haven't paid any attention to the posts that now number in the hundreds that have appeared on this site for the past year. Reminds me of some students I've had coming to see me in my last office hour asking me to teach them the entire course in ten minutes. I guess monday it's finals time and you are going to flunk.
😉 Kidding aside, there are no std specs except what was measured by Grey. There are many 'magical' resistors the value of which will influence the gain, people have been playing with those, with various PS voltages so it's kind of hard to answer your question.
In a nutshell, look for the schematic that Chad posted it came with the Ver 1.0 board. The two main things you can change are the input resistors to gnd from 68k to any values you like gain-wise/sound-wise down to 10k, the 6W resistors to gnd can be 100 ohms no problem, the two resistors that go from output back to the differential pair could be 4.7k and probably they are so on the schematic. The X feedback resistor can go from 100k to 220k. Combine that with all the possible variations of the input resistor you can figure how many variations you can have.
Even with Nelson afterburners the upperbound current ie the max power on any load is determined a priori and it basically it comes down to how much power you can dissipate. In my view, that's a pretty rational way to construct an amp.
Paying attention...
is sometimes hard when you may be cut-off from this forum a week or two (work-periods).
And then there is, as you say, grataku, hundreds, of posts, even thousands...and some explanations and calculations do not add up... YES I AM CONFUSED !
And, you are doing it again...What number resistors do you mean?
-------------------------------
ArneK😕
is sometimes hard when you may be cut-off from this forum a week or two (work-periods).
And then there is, as you say, grataku, hundreds, of posts, even thousands...and some explanations and calculations do not add up... YES I AM CONFUSED !
And, you are doing it again...What number resistors do you mean?
-------------------------------
ArneK😕
magic resistor
Hi Cobra2...I have had same problem,did not know about what magic resistor they are talking about,so someone answer me that the magic resistor is R46 and R47 (4.7K) on Aleph-X revision 1.0...some people use 4.7K some 2.2K...
I hope this help
Josip
Hi Cobra2...I have had same problem,did not know about what magic resistor they are talking about,so someone answer me that the magic resistor is R46 and R47 (4.7K) on Aleph-X revision 1.0...some people use 4.7K some 2.2K...
I hope this help
Josip
" joke " - You are the best!
Thanx a lot.
Having spent about 8 hours searching and reading...I have found most of what I was looking for....
But there is another 237 pages to read...
Arne K
Thanx a lot.
Having spent about 8 hours searching and reading...I have found most of what I was looking for....
But there is another 237 pages to read...
Arne K
Cobra2
relax, grab a cold one, sit down with the schematic and examine it. It's hard for me to tell you the R number, I would have to know which schematic you are looking at and whatnot. It's a very simple schematic, split down the middle: there is only one resistor (per side) going from the output to the joined sources of the input differential with 15v rails 4.7k works for me. I don't believe this resistor was in Grey's original schematic but it's in Chad's for sure.
There is only ONE 6w resistor from output to gnd (per side) it was initially indicated as 30 ohms, 100 ohms works fine. There is one feedback resistor and one input resistor. You can play with the values I told you earlier to get the sound that most suites you. How hard can this be?
relax, grab a cold one, sit down with the schematic and examine it. It's hard for me to tell you the R number, I would have to know which schematic you are looking at and whatnot. It's a very simple schematic, split down the middle: there is only one resistor (per side) going from the output to the joined sources of the input differential with 15v rails 4.7k works for me. I don't believe this resistor was in Grey's original schematic but it's in Chad's for sure.
There is only ONE 6w resistor from output to gnd (per side) it was initially indicated as 30 ohms, 100 ohms works fine. There is one feedback resistor and one input resistor. You can play with the values I told you earlier to get the sound that most suites you. How hard can this be?
I' getting the hang of it (slowly..)
Thanx, grataku.
It's just somethimes, when you think you are all set, there is something you missed, and finding it among all these posts, and even different variations of the schematics...I feel a little(?) lost.
Arne K
(I have found most of it now...)
Thanx, grataku.
It's just somethimes, when you think you are all set, there is something you missed, and finding it among all these posts, and even different variations of the schematics...I feel a little(?) lost.
Arne K
(I have found most of it now...)
I Hate to admit it, but I built an Aleph-X prototype almost exactly like the last posted schematic, and it turned out to be wonderfully unstable. I haven't yet got around to fixing it, but the problem seems to have been a blown FET, and the symptom was the amp would quite literally disintegrate: once one power resistor gets hot enough to unsolder itself, no end of bad things can happen.
Builders of this design should think through the various failure modes! I did not, but luckily mine blew up on the bench.
Builders of this design should think through the various failure modes! I did not, but luckily mine blew up on the bench.
jwb said:I Hate to admit it, but I built an Aleph-X prototype almost exactly like the last posted schematic, and it turned out to be wonderfully unstable. I haven't yet got around to fixing it, but the problem seems to have been a blown FET, and the symptom was the amp would quite literally disintegrate: once one power resistor gets hot enough to unsolder itself, no end of bad things can happen.
Builders of this design should think through the various failure modes! I did not, but luckily mine blew up on the bench.
Tell me more, I have seen no instability problems. I am quite interested in the subject. Something like 1k boards have gone out but remarkably few people have completed the project.
I have run into complications recently when testing something I didn't test before. If I want to move on to the highpower version I need to have all the issues ironed out. I don't want to talk about it yet, it mabe something stupid I am doing. Finally I bought my own function generator so from now on I'll be able to conduct tests on a daily basis.
It seems the AlephX discussion is far from over.
jwb said:I Hate to admit it, but I built an Aleph-X prototype almost exactly like the last posted schematic, and it turned out to be wonderfully unstable. I haven't yet got around to fixing it, but the problem seems to have been a blown FET, and the symptom was the amp would quite literally disintegrate: once one power resistor gets hot enough to unsolder itself, no end of bad things can happen.
Builders of this design should think through the various failure modes! I did not, but luckily mine blew up on the bench.
Tell me more, I have seen no instability problems. I am quite interested in the subject. Something like 1k boards have gone out but remarkably few people have completed the project.
I have run into complications recently when testing something I didn't test before. If I want to move on to the highpower version I need to have all the issues ironed out. I don't want to talk about it yet, it mabe something stupid I am doing. Finally I bought my own function generator so from now on I'll be able to conduct tests on a daily basis.
I fiddelt around with the Excel files that WuffWaff made and updated by Edwin Dorre, and cam across something that confused me.
as you start with 22.7V and up the bias more and more, then from-off bias of 5.2A the power output at 8 Ohm don't rise anymore, it stays at 107.1225Watt.
is this inherent to the voltage that is on it, in combination with the class A? because if you up the voltage it rises again.
if one would check it out, the best one for this would be the excel from Edwin, because of the diagram in it and the inpedance list next to it.
it does rise further under the 8 Ohm inpedance, but for the rest it stays at 107.1225Watt at 8Ohm inpedance.
someone who can shed some light in this??
as you start with 22.7V and up the bias more and more, then from-off bias of 5.2A the power output at 8 Ohm don't rise anymore, it stays at 107.1225Watt.
is this inherent to the voltage that is on it, in combination with the class A? because if you up the voltage it rises again.
if one would check it out, the best one for this would be the excel from Edwin, because of the diagram in it and the inpedance list next to it.
it does rise further under the 8 Ohm inpedance, but for the rest it stays at 107.1225Watt at 8Ohm inpedance.
someone who can shed some light in this??
That's because you can't get more than 5.2A into an 8Ω load with only 45.4V potential. Ohm's law and all that.
jwb said:
😱 😱 😱 😱
so, now i know, that everything i learned at school had drained from my brains to the seawers...... 😱 😱 😱 😱
how could i forget that
- Status
- Not open for further replies.