Hi,
I think this is the same thing I observed in my Aleph5 and Aleph-X. The active current sources ability to deliver current is frequency dependent, meaning that at higher frequencies (from 15kHz) it won´t deliver as much extra current - the active part - as it does at lower frequencies.
Look what happens if you deactivate the active part of the current source (remove the capacitor).
William
I think this is the same thing I observed in my Aleph5 and Aleph-X. The active current sources ability to deliver current is frequency dependent, meaning that at higher frequencies (from 15kHz) it won´t deliver as much extra current - the active part - as it does at lower frequencies.
Look what happens if you deactivate the active part of the current source (remove the capacitor).
William
thanks for the reply!
Can you elaborate on what capacitor are you talking about? Also, did that solve your problem entirely or just made it a bit better?
If you are refering to the 47nF near the Q5? I tryed to use diffrent values and even renove it. It got better in terms of wave shape, but never conpletly ok and with 4ohm load, it gets awfull!
hoping to get some more help oin this,
Banzas
Can you elaborate on what capacitor are you talking about? Also, did that solve your problem entirely or just made it a bit better?
If you are refering to the 47nF near the Q5? I tryed to use diffrent values and even renove it. It got better in terms of wave shape, but never conpletly ok and with 4ohm load, it gets awfull!
hoping to get some more help oin this,
Banzas
Yes, please clue us in who don't have an Aleph-X laying around to play with. I read and read that thread, but I don't remember reading your above conclusion in it....
If it is due to the variable current source, couldn't come up with an alternate current source that doesn't have the problem?
JJ
Banzas,
Are these the DIYgene boards?
http://www.diyaudio.com/forums/showthread.php?postid=1259308#post1259308
You will not like me for this reply but did you get any help from the seller?
/Hugo
Are these the DIYgene boards?
http://www.diyaudio.com/forums/showthread.php?postid=1259308#post1259308
You will not like me for this reply but did you get any help from the seller?
/Hugo
Hi netlist
yes they are the gen boards, I did not contact the seller (for what any way?) I made some interesting experiences, such replace the Mpsa18 with BC550C, and curiously the BC perfom much better than Mpsa, so I am wondering if Ican find a better transistor my problem will be solved. remember, in low frequency the behave is good, with 4 ohms and 8 ohms load at full power I can achive 18v and 21v rms respectively, but at 10khz with 4 ohms load has distorsion which begin at 7v rms.
I also removed the 47n from the circuit, because this is useless.
NP does not answer my question, so I must continue my research, one thing I have been thinking, this design is not so linear than I thought in interely bandwith.
Thanks
yes they are the gen boards, I did not contact the seller (for what any way?) I made some interesting experiences, such replace the Mpsa18 with BC550C, and curiously the BC perfom much better than Mpsa, so I am wondering if Ican find a better transistor my problem will be solved. remember, in low frequency the behave is good, with 4 ohms and 8 ohms load at full power I can achive 18v and 21v rms respectively, but at 10khz with 4 ohms load has distorsion which begin at 7v rms.
I also removed the 47n from the circuit, because this is useless.
NP does not answer my question, so I must continue my research, one thing I have been thinking, this design is not so linear than I thought in interely bandwith.
Thanks
Banzas,
It’s pretty simple in fact. Suppose you designed an amplifier. You did all the hard work to make it sound good, spent countless hours calculating and prototyping, until, after say two years you have a good working amplifier.
Then your neighbor manages to get his hands on your paperwork and starts building boards and kits, making a good profit on your hard work.
Suppose he comes ringing at your door to get help with his kits because some fault occurred he can’t solve. Would you help him?
This is exactly what DIYgene does. Making boards and complete kits from Nelson’s designs for profit.
Would you answer if you were Nelson? Praise yourself happy that he did a few times in this thread.
He most likely didn’t know the Alephs were made with the DIYgene boards.
I reckon you didn’t understand what its all about but I hope you get the message after my lengthy explanation. Note that I do not accuse you, I rather give you the benefit of the doubt and something to think about. 🙂
/Hugo
It’s pretty simple in fact. Suppose you designed an amplifier. You did all the hard work to make it sound good, spent countless hours calculating and prototyping, until, after say two years you have a good working amplifier.
Then your neighbor manages to get his hands on your paperwork and starts building boards and kits, making a good profit on your hard work.
Suppose he comes ringing at your door to get help with his kits because some fault occurred he can’t solve. Would you help him?
This is exactly what DIYgene does. Making boards and complete kits from Nelson’s designs for profit.
Would you answer if you were Nelson? Praise yourself happy that he did a few times in this thread.
He most likely didn’t know the Alephs were made with the DIYgene boards.
I reckon you didn’t understand what its all about but I hope you get the message after my lengthy explanation. Note that I do not accuse you, I rather give you the benefit of the doubt and something to think about. 🙂
/Hugo
Ok Netlist,
You won but, let me tell you something about Aleph, in 1998 I owned an Aleph5, I bought it from a dealer in Portugal, it worked fine 2 years and then I sold it to a friend of mine in 2000, because it hasn't performed well with my wilson Audio 5.1, and Nelson knows what I am talking about. I know very well this amps better than you for sure. At time I notice some issue with highs, but depends what loudspeker do you own and the cables, so it is a very subjective situation. About gene pcbs and alep5 it was for a little loudspeakers (Proac tablet 50) that I have in my garage, where, when I got some time i design a few tube projects, so in this context, you talk about support and stollen designs, in this forum the people are talking to much about gene that have for sale pcbs, but they are many builders, that buy pcbs from another third party sellers, with nelson permission or not, Am i right? I bought this pcbs for a joke and paid 25$ for them (fortune) and for your information this is the cheapest pcbs outhere, probably other people have been won a lot of money with the pcbs, so give me a break, if you want discuss some details about this topoligy is great, otherwise, my will is want to close this gene issue.
You won but, let me tell you something about Aleph, in 1998 I owned an Aleph5, I bought it from a dealer in Portugal, it worked fine 2 years and then I sold it to a friend of mine in 2000, because it hasn't performed well with my wilson Audio 5.1, and Nelson knows what I am talking about. I know very well this amps better than you for sure. At time I notice some issue with highs, but depends what loudspeker do you own and the cables, so it is a very subjective situation. About gene pcbs and alep5 it was for a little loudspeakers (Proac tablet 50) that I have in my garage, where, when I got some time i design a few tube projects, so in this context, you talk about support and stollen designs, in this forum the people are talking to much about gene that have for sale pcbs, but they are many builders, that buy pcbs from another third party sellers, with nelson permission or not, Am i right? I bought this pcbs for a joke and paid 25$ for them (fortune) and for your information this is the cheapest pcbs outhere, probably other people have been won a lot of money with the pcbs, so give me a break, if you want discuss some details about this topoligy is great, otherwise, my will is want to close this gene issue.
Well, I think I reflected the opinion of the majority of the community.
Some people have granted Nelson’s approval to produce boards on a not-for-profit basis.
Although expensive, $25 may not be over the top but it’s the lot of organized selling of boards and kits by DIYgene that should be discouraged in the most severe way and by no means be promoted on these boards.
You made your point, I made mine and any issue you had in the past with Nelson’s designs should of course be discussed with him.
/Hugo
Some people have granted Nelson’s approval to produce boards on a not-for-profit basis.
Although expensive, $25 may not be over the top but it’s the lot of organized selling of boards and kits by DIYgene that should be discouraged in the most severe way and by no means be promoted on these boards.
You made your point, I made mine and any issue you had in the past with Nelson’s designs should of course be discussed with him.
/Hugo
I performed the last tests, so this amp suffer in the highs , unless... If we increase the bias to 750ma, works fine, but the mosfets produce a lot of heat (27w each x 8=216W/each channel)total 432W. As I said at 8 ohms load peform good, 4 ohms load less power. The thermic cycles short the life of the fets, so the best ones for this are IRFs To-3 case.
Now Banzas,
You should by now have figured that you are not welcome to discuss matters regarding anything that has to do with diy-gene or any of his stuff here!
No, we are not going to help you with whatever causes you problems regarding diy-gene products....buld something yourself and you will be welcome here...but not like that.
Magura
You should by now have figured that you are not welcome to discuss matters regarding anything that has to do with diy-gene or any of his stuff here!
No, we are not going to help you with whatever causes you problems regarding diy-gene products....buld something yourself and you will be welcome here...but not like that.
Magura
banzas said:
I think that a number of manufacturers have problems with
diy gene, since he freely uses trademarks that do not belong
to him. I have instructed my IP attorney to contact Ebay.
As to your problems with the high end, all I can say is that the
Alephs were always a delicate balance between bias current,
current source gain, feedback, layout, and compensation. Every
time you alter that balance, you are likely to see some
degradation in performance.
Being single-ended, the Alephs are naturally limited at low
impedances. None of the commercial offerings were touted
as optimal at 4 ohms.
If you want low distortion at full power into low impedances at
high frequencies, or if you want to control the bottom end on
a pair of Wilsons, you want something else.
Babowana said:
For this reason, I like to diy simple circuits (I don't mean chip amps).
you buy them at diy-gene?
diy gene
I don't understand. Why is what 'diy-gene' is doing considered illegal and others like 'KK-pcb design' or maybe the 'mini aleph' is considered legal? Do they (the 'legal' ones) obtain permission from Nelson himself? Or are they just like 'diy-gene'? Should I get one from those 'legal' ones? What are the difference between these PCBs? Should't they be all the same since it is an based 'aleph 5' schematic?
Thanks in advance.
I don't understand. Why is what 'diy-gene' is doing considered illegal and others like 'KK-pcb design' or maybe the 'mini aleph' is considered legal? Do they (the 'legal' ones) obtain permission from Nelson himself? Or are they just like 'diy-gene'? Should I get one from those 'legal' ones? What are the difference between these PCBs? Should't they be all the same since it is an based 'aleph 5' schematic?
Thanks in advance.
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