I have read Aleph-X threats now for 8 hours and I have to admit that I am not yet through with everything. But even with extensive usage of the search functionality I have found some comments how to come to a high-power version of an Aleph-X, but I am not sure if they included all information to be considered. Therefore I would like to collect some of your experiences on that topic as I can imagine that there are some more DIYs out there who have planned to go for an Aleph 2, changed now there mind and want the same thing in terms of power, but with advantages of the Aleph-X.
Here now some thoughts / questions:
- Heatsinking: Also when utilizing now IRFP044 under very different voltages, we are in the same ballpark with the Aleph 2, right ?
- Voltages: Instead of 45 VDC, we are looking now for 15 VDC in the schematics I have seen. Will this hold to be true if raising the IRFP044 from 4 pcs/channel to 12/channel ( The Alephs raised voltages with growing number of fets ?)?
- Components to be trippled: When now coming from 4 044 up to 12: Will really only the fets be trippled or all components around them as well ( what my understanding is right now): In Grey's schematic this would be r7, r5, q1, q2, r6, r9. What about the circuit around the mpsa18 which drive q1 ? Will this drive as many IRFs as I put in parallel or has it as well to be trippled ?
- Are there any other issues to be considered, why in some threats is has been stated that the time is not yet there to go for a high-powered version ?
Regarding Components: What would be your recommendation: IRFP240 (which gives me the option to go back to the Aleph 2 if the Aleph-X is not my pair of shoes) or thhe IRFP044N (which cost me the same, but if have read somwhere the the N-Version is not that suitable for audio; the superior 044 VErsion is diffcult to get though).
Regarding separate PSU for the driver-stage: Do the same comments on the Aleph apply here (meaing not possible as part of the concept) or could this be an improvement ?
THanks & Best Regards
Here now some thoughts / questions:
- Heatsinking: Also when utilizing now IRFP044 under very different voltages, we are in the same ballpark with the Aleph 2, right ?
- Voltages: Instead of 45 VDC, we are looking now for 15 VDC in the schematics I have seen. Will this hold to be true if raising the IRFP044 from 4 pcs/channel to 12/channel ( The Alephs raised voltages with growing number of fets ?)?
- Components to be trippled: When now coming from 4 044 up to 12: Will really only the fets be trippled or all components around them as well ( what my understanding is right now): In Grey's schematic this would be r7, r5, q1, q2, r6, r9. What about the circuit around the mpsa18 which drive q1 ? Will this drive as many IRFs as I put in parallel or has it as well to be trippled ?
- Are there any other issues to be considered, why in some threats is has been stated that the time is not yet there to go for a high-powered version ?
Regarding Components: What would be your recommendation: IRFP240 (which gives me the option to go back to the Aleph 2 if the Aleph-X is not my pair of shoes) or thhe IRFP044N (which cost me the same, but if have read somwhere the the N-Version is not that suitable for audio; the superior 044 VErsion is diffcult to get though).
Regarding separate PSU for the driver-stage: Do the same comments on the Aleph apply here (meaing not possible as part of the concept) or could this be an improvement ?
THanks & Best Regards
Blitz,
- Heatsinking: Also when utilizing now IRFP044 under very different voltages, we are in the same ballpark with the Aleph 2, right ?
> Yes <
- Voltages: Instead of 45 VDC, we are looking now for 15 VDC in the schematics I have seen. Will this hold to be true if raising the IRFP044 from 4 pcs/channel to 12/channel ( The Alephs raised voltages with growing number of fets ?)?
> I’ll go for 22 VDC on 12 IRF240 <
- Components to be trippled: When now coming from 4 044 up to 12: Will really only the fets be trippled or all components around them as well ( what my understanding is right now): In Grey's schematic this would be r7, r5, q1, q2, r6, r9. What about the circuit around the mpsa18 which drive q1 ? Will this drive as many IRFs as I put in parallel or has it as well to be trippled ?
> Include r36, r38, r40, r41, q10 and q11. “Only” q1, q2, q10 and q11 are controlled by the circuits around q3, q4, q8 and q9 (MPSA18). <
- Are there any other issues to be considered, why in some threats is has been stated that the time is not yet there to go for a high-powered version ?
> Uplift the current sources, I’ll go for some 7A all-in-all, using 0R39 source resistors <
Jens
- Heatsinking: Also when utilizing now IRFP044 under very different voltages, we are in the same ballpark with the Aleph 2, right ?
> Yes <
- Voltages: Instead of 45 VDC, we are looking now for 15 VDC in the schematics I have seen. Will this hold to be true if raising the IRFP044 from 4 pcs/channel to 12/channel ( The Alephs raised voltages with growing number of fets ?)?
> I’ll go for 22 VDC on 12 IRF240 <
- Components to be trippled: When now coming from 4 044 up to 12: Will really only the fets be trippled or all components around them as well ( what my understanding is right now): In Grey's schematic this would be r7, r5, q1, q2, r6, r9. What about the circuit around the mpsa18 which drive q1 ? Will this drive as many IRFs as I put in parallel or has it as well to be trippled ?
> Include r36, r38, r40, r41, q10 and q11. “Only” q1, q2, q10 and q11 are controlled by the circuits around q3, q4, q8 and q9 (MPSA18). <
- Are there any other issues to be considered, why in some threats is has been stated that the time is not yet there to go for a high-powered version ?
> Uplift the current sources, I’ll go for some 7A all-in-all, using 0R39 source resistors <
Jens
Re: High power A-X
A high power Aleph-X, Just what I also had in mind... 🙂
Can someone please post schematics on a few versions of this?
Something around 150W+ would suit me perfectly!
Arne K
NORWAY🙂
A high power Aleph-X, Just what I also had in mind... 🙂
Can someone please post schematics on a few versions of this?
Something around 150W+ would suit me perfectly!
Arne K
NORWAY🙂
Lotsa conversions goin on with 700 bds out there!!
Blitz, you beat me to it! I think there are a lot of people out there with Aleph 2's or that they might want to convert or who just want a more powerful Aleph X.
In my case a have 24 IRF 140's, and 2) 37.5 volts toroids.
Cobra:
Because people will be converting from the Aleph 2 could we agree on 100w. ch for the moment? That extra 50 watts would hardly be noticed maybe?
Everyone: Does the standard Aleph X that you have been discussing have a lower voltage just because it is lower powered? or the the X use lower volts for the same output?
Can I use my toroids?
Thanks all
Blitz, you beat me to it! I think there are a lot of people out there with Aleph 2's or that they might want to convert or who just want a more powerful Aleph X.
In my case a have 24 IRF 140's, and 2) 37.5 volts toroids.
Cobra:
Because people will be converting from the Aleph 2 could we agree on 100w. ch for the moment? That extra 50 watts would hardly be noticed maybe?
Everyone: Does the standard Aleph X that you have been discussing have a lower voltage just because it is lower powered? or the the X use lower volts for the same output?
Can I use my toroids?
Thanks all
Cobra,
nobody, that I know of, has drawn up the schematic for this yet, actually I did but that's besides the point. If you plan to be successful in your high power Aleph X you got to be ready to study the aleph, Zen4, and AlephX thread in detail and thuroghly understand what you dealing with and be ready to make mods when mods need to be made. Even though all the info you need are pretty much available, nobody besides Pass labs has built anything close to what you want.
Calculate all voltages and currents, size out all the components. If you have SPECIFIC question on points that you don't understand I think members will be happy to help out.
nobody, that I know of, has drawn up the schematic for this yet, actually I did but that's besides the point. If you plan to be successful in your high power Aleph X you got to be ready to study the aleph, Zen4, and AlephX thread in detail and thuroghly understand what you dealing with and be ready to make mods when mods need to be made. Even though all the info you need are pretty much available, nobody besides Pass labs has built anything close to what you want.
Calculate all voltages and currents, size out all the components. If you have SPECIFIC question on points that you don't understand I think members will be happy to help out.
Cobra2:
To get 150W on 8 ohm, you need about 28VDC, 4,35 A current, 12 x Power MOSFETs and source resistors of 0R68 – if I’m not wrong on this.
Variac:
Compared to the Aleph, the Aleph-X used 1/2 voltage and double bias.
Jens
To get 150W on 8 ohm, you need about 28VDC, 4,35 A current, 12 x Power MOSFETs and source resistors of 0R68 – if I’m not wrong on this.
Variac:
Compared to the Aleph, the Aleph-X used 1/2 voltage and double bias.
Jens
Thanks Jens, that's the sort of concise reply that is soooo helpful
For me this is just for long term planning. Now I know to use those toriods in another project- unless I want 200w/ ch !!!!!
For me this is just for long term planning. Now I know to use those toriods in another project- unless I want 200w/ ch !!!!!
Jens, the current you are proposing is really bare bones for 150W,
you are going to be short if your speakers impedance drop to even 6ohms.
Nelson uses 8amps and +-30V for 200W. I would plan for at least 6 amp bias xchn.
you are going to be short if your speakers impedance drop to even 6ohms.
Nelson uses 8amps and +-30V for 200W. I would plan for at least 6 amp bias xchn.
Choke-Input ?
Variac,
I have not yet simulated this in PSU-Designer, but I would consider a choke-input-setup, where you have a anyhow a much lower VDC compared to a pi-filter (in theory instead of VDC= VAC*1,414, it would be VDC=VAC*0,9). MArk Levinson has used this in his Cello-Amplifiers as it reduces power-supplier-noise (smoothes the spikes produced by a pi-filter)and gives nice regulation. The trick is to calculate the inductance correct, which is quite small here compared to tube equipment. So, in the case of 28 VDC with 4,350 A it would be 6,5 mH (more is no problem). If you still have to much VDC, have another RC-filter to follow (so you end up with an LCRC-Filter).
Best REgards
Variac,
I have not yet simulated this in PSU-Designer, but I would consider a choke-input-setup, where you have a anyhow a much lower VDC compared to a pi-filter (in theory instead of VDC= VAC*1,414, it would be VDC=VAC*0,9). MArk Levinson has used this in his Cello-Amplifiers as it reduces power-supplier-noise (smoothes the spikes produced by a pi-filter)and gives nice regulation. The trick is to calculate the inductance correct, which is quite small here compared to tube equipment. So, in the case of 28 VDC with 4,350 A it would be 6,5 mH (more is no problem). If you still have to much VDC, have another RC-filter to follow (so you end up with an LCRC-Filter).
Best REgards
Mark:
100W on 8 ohm means about 23VDC and 3.55 A bias.
200W on 8 ohm means about 32VDC and 5A bias.
grataku:
I said 8 ohm… you are right
150W on 6 ohm means about 28VDC and 5A bias.
150W on 4 ohm means about 28VDC and 6.12A bias.
Jens
100W on 8 ohm means about 23VDC and 3.55 A bias.
200W on 8 ohm means about 32VDC and 5A bias.
grataku:
I said 8 ohm… you are right
150W on 6 ohm means about 28VDC and 5A bias.
150W on 4 ohm means about 28VDC and 6.12A bias.
Jens
Jens,
I just found a threat around Aleph X-Biasing:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=4758&highlight=aleph+bias+calculation
It seems that your cals are right for one side of the Aleph-X, but as we have two (per channel), the current needs to be doubled, so for 150 W into 8 ohms it would have to be 8,66A @ 34,6 V. Sorry, just found these formulas a minute ago. So, let'S do some calcs with them:
8 ohm:
60 Watt: 21,9 V, 5,4 A
100 Watt: 28,3 V, 7,1 A
150 Watt: 34,4 V, 8,6 A
6 Ohm:
60 Watt: 19 V, 6,3 A
100 Watt: 24,5 V, 8,2 A
150 Watt: 30 V, 10 A
4 Ohm:
60 Watt: 15,5 V, 7,7 A
100 Watt: 20 V, 10 A
150 Watt: 24,4 V, 12,2 A
Well, how much Fets should I use now to get the power desired ? From Mr. Pass we learn that he uses his devices at 18 Watt dissipation, 2 Amp each and max 70volts (I wonder from where these 70V should come from). On the other hand he states that he gets 200 Watt from 32 fets. If I get this right now, for 100 Watt we would need not the originally planned 12 fets, but 16. If you want to go for 150 Watt. this would be 24...wow.
I just found a threat around Aleph X-Biasing:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=4758&highlight=aleph+bias+calculation
It seems that your cals are right for one side of the Aleph-X, but as we have two (per channel), the current needs to be doubled, so for 150 W into 8 ohms it would have to be 8,66A @ 34,6 V. Sorry, just found these formulas a minute ago. So, let'S do some calcs with them:
8 ohm:
60 Watt: 21,9 V, 5,4 A
100 Watt: 28,3 V, 7,1 A
150 Watt: 34,4 V, 8,6 A
6 Ohm:
60 Watt: 19 V, 6,3 A
100 Watt: 24,5 V, 8,2 A
150 Watt: 30 V, 10 A
4 Ohm:
60 Watt: 15,5 V, 7,7 A
100 Watt: 20 V, 10 A
150 Watt: 24,4 V, 12,2 A
Well, how much Fets should I use now to get the power desired ? From Mr. Pass we learn that he uses his devices at 18 Watt dissipation, 2 Amp each and max 70volts (I wonder from where these 70V should come from). On the other hand he states that he gets 200 Watt from 32 fets. If I get this right now, for 100 Watt we would need not the originally planned 12 fets, but 16. If you want to go for 150 Watt. this would be 24...wow.
woohoooo we're off!!
Blitz: Ironically about 6 months ago, after bothering lots of people here, I got the message about the inductor being first in line lowering the voltage. This was to use my 37 volt transformers in a Son of Zen. I had been looking forward to using them in a more conventional pi configuration in an Aleph 2.
But now suddenly now that the Aleph X is the hot ticket, I'm back to the same problem. Oh well, I guess I'l just leave them in the SOZ (stll not hooked up- but verry close) I believe Nelson says even 2 mH does a great job filtering- but for the
LC arrangement you are prob right! Thank you
HAppy holidays
Blitz: Ironically about 6 months ago, after bothering lots of people here, I got the message about the inductor being first in line lowering the voltage. This was to use my 37 volt transformers in a Son of Zen. I had been looking forward to using them in a more conventional pi configuration in an Aleph 2.
But now suddenly now that the Aleph X is the hot ticket, I'm back to the same problem. Oh well, I guess I'l just leave them in the SOZ (stll not hooked up- but verry close) I believe Nelson says even 2 mH does a great job filtering- but for the
LC arrangement you are prob right! Thank you
HAppy holidays
Just remember that a choke-input filter needs to be loaded with a minimum current at all times, otherwise the output voltage will rise, possibly exceeding the rating of your caps! *kapow!*
That would <i>not</i> be pretty! 😱
That would <i>not</i> be pretty! 😱
Re: High power...
Now we are getting somewhere...🙂
I have read almost all of the documentation, but silly me, do not understand more than half... And these treads spreads, and tend to get very long...
So I really appreciate when scaling info is posted, with examples.
And the "X" have hold me back from assembling the "2", witch I otherwise would have asked for help for making into a "1,6" (something inbetween the 2 and 1,2).
Yes, I woud probably be happy with 100W, If I did not know...
ArneK
NORWAY
(With europeean all time high price on el-power coming...)
Now we are getting somewhere...🙂
I have read almost all of the documentation, but silly me, do not understand more than half... And these treads spreads, and tend to get very long...
So I really appreciate when scaling info is posted, with examples.
And the "X" have hold me back from assembling the "2", witch I otherwise would have asked for help for making into a "1,6" (something inbetween the 2 and 1,2).
Yes, I woud probably be happy with 100W, If I did not know...
ArneK
NORWAY
(With europeean all time high price on el-power coming...)
OK, reading further does not necessarily help to avoid confusions...I am studying not the Aleph-X-Thread and just have found some calcs from GRey which look quite different:
The voltage has to multiplied by 0,8 and the current is only half of the current which was stated in the link above, so Jens would be in the right ballpark again.
Is this now the right formular ?
The voltage has to multiplied by 0,8 and the current is only half of the current which was stated in the link above, so Jens would be in the right ballpark again.
Is this now the right formular ?
OK. It does not become clearer when looking into the XA-200 Owner's manual:
http://www.passlabs.com/pdf/xa200man.pdf
There it is stated that the xa-200 powersupply with +-35 Volts at 30 Amps ! This is quite different from the 30 Volts at 5 Amps stated somewhere in the threat. So do we have to double now the current or not ?
BTW: The XA-200 has about 400000uF on board. Wow.
The comment on the choke-input is absolutety correct, that is especially true for tube equipment, if you have not heated the tubes and they don't draw any current yet. Voltages raise and your capacitors can blow, if you have not a bleeder resistor which always draws some current. But with SS ? Should draw current all the time, or ?
http://www.passlabs.com/pdf/xa200man.pdf
There it is stated that the xa-200 powersupply with +-35 Volts at 30 Amps ! This is quite different from the 30 Volts at 5 Amps stated somewhere in the threat. So do we have to double now the current or not ?
BTW: The XA-200 has about 400000uF on board. Wow.
The comment on the choke-input is absolutety correct, that is especially true for tube equipment, if you have not heated the tubes and they don't draw any current yet. Voltages raise and your capacitors can blow, if you have not a bleeder resistor which always draws some current. But with SS ? Should draw current all the time, or ?
fortunately with class A especially I think the coils are always loaded. Now if the mosfets blow? then no current then the caps go bang? On my Son of Zen this might be an issue with only 2 Mosfets per channel but balanced, so if one blows, current shuts down! Luckily I used higher voltage caps.
This brings up a point: A huge cap supply is cheaper with the lower voltage X aleph since lower voltage rated caps are a lot cheaper. BUT you wouldn't want to do the coils right after the bridge topography with the lower rated caps- rather you should use the "correct" transformer
As always, p;lease correct me
This brings up a point: A huge cap supply is cheaper with the lower voltage X aleph since lower voltage rated caps are a lot cheaper. BUT you wouldn't want to do the coils right after the bridge topography with the lower rated caps- rather you should use the "correct" transformer
As always, p;lease correct me
Well, with PSU-Designer you can see nicely what the voltage after the choke would be. If you set the inductance higher then needed you have enough headroom, even if one mosfet would blow up. As well it has been reported that the oversizing of the transformer has not to be done like you normally do it: This seem to become very clear when you look at the current spikes generated in a pi-filter. Most Transformer are heavily oversized for normal operation, but the spikes are so huge, that any reserve to handle them is appreciated and improves the sound. With a choke-input you have no spikes. So, you have solved the problem at its root...
Scaling of the Aleph-X
Based on Blitz, to have an output of 150W at 8 ohms, we need a +/- 34.4V @ 8.6A power supply. At this voltage which is more than double the original +/- 15V supply, do we need to rescale the values of the other resistors in addition to those used for bias adjustment?? If we do, can I use those values of the Aleph 60 that runs at +/- 35V ??
For bias current adjustment, the low value resistors will be calculated to give a total 8.6A as required.
ckt
Based on Blitz, to have an output of 150W at 8 ohms, we need a +/- 34.4V @ 8.6A power supply. At this voltage which is more than double the original +/- 15V supply, do we need to rescale the values of the other resistors in addition to those used for bias adjustment?? If we do, can I use those values of the Aleph 60 that runs at +/- 35V ??
For bias current adjustment, the low value resistors will be calculated to give a total 8.6A as required.
ckt
Correction
DIYman,
As stated above, I have read further through the threat's (not should mean now...typo...). Grey stated that the voltage has to be mupliplied by 0,8, so it is not 34,4, but 27,7 for 150 W at 8 ohms.
Still, we have a bit confusion: If I understood Audiofreak right we need 8,6 A (see link above). Grey clearly stated that half of this is enough (in the Aleph-X-Threat). So, let's wait and see if we can receive some feedback from them.
By the way: Grey has as well published a formular to calc the source resistor accordingly: Rs=(0,5/(I/2)) which in this case would lead us to 0,23 ohm for 4,3 or 0,115 ohms for 8,6.
Best Regards
DIYman,
As stated above, I have read further through the threat's (not should mean now...typo...). Grey stated that the voltage has to be mupliplied by 0,8, so it is not 34,4, but 27,7 for 150 W at 8 ohms.
Still, we have a bit confusion: If I understood Audiofreak right we need 8,6 A (see link above). Grey clearly stated that half of this is enough (in the Aleph-X-Threat). So, let's wait and see if we can receive some feedback from them.
By the way: Grey has as well published a formular to calc the source resistor accordingly: Rs=(0,5/(I/2)) which in this case would lead us to 0,23 ohm for 4,3 or 0,115 ohms for 8,6.
Best Regards
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