No changes
As I understand it, there is no need to change anything other than voltages (and gain setting resistors) to obtain higher output power. At some point one needs to add more output devices as well.
As Harry says, you need higher voltage on the input stage. My design is inefficient (designed that way) with input stage voltage for several reasons so you need at least 25 volts higher rails for input stage. You can get by with less if you choose lower voltage drop across source resistors on current sources (an possibly bipolars there as well). I am dropping like 20V which is radical.
Another thing that you will soon have to do when you increase the voltage on the input stage is to add more cooling. This was already an issue with my first variant when I had more than about 110V rail to rail, and was one of the design criteria for making the second version (much more cooling, particularly on the top MOSFET's.
Petter
As I understand it, there is no need to change anything other than voltages (and gain setting resistors) to obtain higher output power. At some point one needs to add more output devices as well.
As Harry says, you need higher voltage on the input stage. My design is inefficient (designed that way) with input stage voltage for several reasons so you need at least 25 volts higher rails for input stage. You can get by with less if you choose lower voltage drop across source resistors on current sources (an possibly bipolars there as well). I am dropping like 20V which is radical.
Another thing that you will soon have to do when you increase the voltage on the input stage is to add more cooling. This was already an issue with my first variant when I had more than about 110V rail to rail, and was one of the design criteria for making the second version (much more cooling, particularly on the top MOSFET's.
Petter
x100
Harry! I,m glad to see you are keeping an eye on this thread,you are quite right, the voltages are in fact its +/-90 on the input apologies for that. Incidentally re the x200, the aleph 30 can go to +/-35vwith extra trannys on the output yet everyone seems to fret about sticking to low voltages.
Harry! I,m glad to see you are keeping an eye on this thread,you are quite right, the voltages are in fact its +/-90 on the input apologies for that. Incidentally re the x200, the aleph 30 can go to +/-35vwith extra trannys on the output yet everyone seems to fret about sticking to low voltages.
Before you tell me how bad the layout is ...
Just so you know, this was the first layout I ever made (OK I did do one in college as well many years ago). My main design criteria were no sharp corners, minimal physical distance of signal path, 2 layers and a logical layout consumerate with the circuit (draw it as it is).
I succeeded rather well in the miniaturization effort. Hence the need to modify the heatsinks.
Petter
Just so you know, this was the first layout I ever made (OK I did do one in college as well many years ago). My main design criteria were no sharp corners, minimal physical distance of signal path, 2 layers and a logical layout consumerate with the circuit (draw it as it is).
I succeeded rather well in the miniaturization effort. Hence the need to modify the heatsinks.
Petter
i got a trial version of circut maker 2000, and downloading the schematic files from
here
I try to open it, and it imedeatly opens a binary to ascii utility, but the file extension on that is cir.
I've tryed renaming the file as .txt and using a ascii to binary program, but this doesnt work either.
Any ideas on what to do? or could someone send me a file of it that works?
thanks,
ben
here
I try to open it, and it imedeatly opens a binary to ascii utility, but the file extension on that is cir.
I've tryed renaming the file as .txt and using a ascii to binary program, but this doesnt work either.
Any ideas on what to do? or could someone send me a file of it that works?
thanks,
ben
I tried the same and you are right. There must be a corruption in the file. I have since moved all of my version 1 stuff into backup.
However, I am attaching a .CKT file which I know works, but that is just the input stage including trim. BTW if your plan is to simulate you will probably find it troublesome -- more so than building the circuit due to the delicate balance. If you replace all current sources by ideal ones in CM you will be able to simulate. BTW you need to add a ground as well ... If you do that, may I suggest you do it at the input
I do not feel comfortable posting layout both since my second layout has not been built and because of Pass Labs. I will not post any PCB layouts unless I have express permission to do so.
Petter
However, I am attaching a .CKT file which I know works, but that is just the input stage including trim. BTW if your plan is to simulate you will probably find it troublesome -- more so than building the circuit due to the delicate balance. If you replace all current sources by ideal ones in CM you will be able to simulate. BTW you need to add a ground as well ... If you do that, may I suggest you do it at the input
I do not feel comfortable posting layout both since my second layout has not been built and because of Pass Labs. I will not post any PCB layouts unless I have express permission to do so.
Petter
X100 v2
Thanks NP.
These files are now about 7 months old .... but the latest iteration of my X-100. As you can see the board is set up to handle Holco resistors everywhere, with a lot more space for components. I have also set up for triplets everywhere, including bias. There should be plenty room for cooling in case you want to have high rails, and it is a lot tidier than the "original" Petter V1 overminiaturized version.
As you can see on the input, you can do what you want regarding grounding -- extra holes provided.
Note, I have not yet built this particular layout. When you do, consider my component values "budgetary" -- I was after the layout when I built it after lots of iterations where I could not decide on exact values.
When you trim this circuit, remove triplet bias resistors and Re and set up each current source separately. That is 6 such current sources to trim -- make sure you do this accurately and under correct dissipation levels. Afterwards you should not have to trim this again. Now, after hooking up to power stage, increase bias from minimal to suit (final adjustments).
Petter
Thanks NP.
These files are now about 7 months old .... but the latest iteration of my X-100. As you can see the board is set up to handle Holco resistors everywhere, with a lot more space for components. I have also set up for triplets everywhere, including bias. There should be plenty room for cooling in case you want to have high rails, and it is a lot tidier than the "original" Petter V1 overminiaturized version.
As you can see on the input, you can do what you want regarding grounding -- extra holes provided.
Note, I have not yet built this particular layout. When you do, consider my component values "budgetary" -- I was after the layout when I built it after lots of iterations where I could not decide on exact values.
When you trim this circuit, remove triplet bias resistors and Re and set up each current source separately. That is 6 such current sources to trim -- make sure you do this accurately and under correct dissipation levels. Afterwards you should not have to trim this again. Now, after hooking up to power stage, increase bias from minimal to suit (final adjustments).
Petter
V+ versus power
Hi Petter and others, I am new but will introduce myself another time.
I do not understand how you get 100W from the X100 with only +- 25Vdc for V+ on the output stage. I always assume we are talking abut an 8 ohm load. According to me, 50V peak-peak is about 18Vrms which only gives about 40W into 8 ohms, even less with diode losses.
Where am I wrong?
Secondly, I want to know what maximum power into 8 ohms the circuit Petter has developed could be scaled up to, with the same 24 output devices? Maybe a V+ of +-75V on the output stage for 350Wrms int 8 ohms?
Cheers, thanks and hi.
Hi Petter and others, I am new but will introduce myself another time.
I do not understand how you get 100W from the X100 with only +- 25Vdc for V+ on the output stage. I always assume we are talking abut an 8 ohm load. According to me, 50V peak-peak is about 18Vrms which only gives about 40W into 8 ohms, even less with diode losses.
Where am I wrong?
Secondly, I want to know what maximum power into 8 ohms the circuit Petter has developed could be scaled up to, with the same 24 output devices? Maybe a V+ of +-75V on the output stage for 350Wrms int 8 ohms?
Cheers, thanks and hi.
I do not understand how you get 100W
It has a balanced output stage. It does not swing the signal about ground but is swinging one terminal of the speaker toward the negative supply as it is swinging the other terminal towards the positive side. This is the same priciple as a bridged amplifier.
Art
It has a balanced output stage. It does not swing the signal about ground but is swinging one terminal of the speaker toward the negative supply as it is swinging the other terminal towards the positive side. This is the same priciple as a bridged amplifier.
Art
Nelson Pass scales what I believe to be almost exactly the same design to 1000W and allows for connecting multiple units togethern to achieve even more.
I think 100W is a pretty good number myself, but was considering scaling to 150W as it is just a matter of changing the supply voltage as I am so top heavy on the output devices.
One caveat is that if you drop a lot of volts across the current sources you will need to cool them well. So if you increase the voltage to the output stage you also have to increase the voltage to the input stage by the same amount. Some optimization on the input stage might be in order but I have solved this in v2 by allowing more room for heatsinking.
Petter
I think 100W is a pretty good number myself, but was considering scaling to 150W as it is just a matter of changing the supply voltage as I am so top heavy on the output devices.
One caveat is that if you drop a lot of volts across the current sources you will need to cool them well. So if you increase the voltage to the output stage you also have to increase the voltage to the input stage by the same amount. Some optimization on the input stage might be in order but I have solved this in v2 by allowing more room for heatsinking.
Petter
Thanks to Art, AudioFreak (fellow Aussie), Petter, and Nelson.
Sorry, I should have seen the balanced output and worked out the V+/output power relationship myself. Thinking cap on So that means +- 38Vdc for 350W into 8 ohms, or +- 32Vdc for 250W, etc. And add 25Vdc for the input stage.
My question still stands regarding the maximum safe output with the 24 devices modelled. I guess I can work that out too, based on SOAR, but I was hoping a Prophet or Elder may have the answer to hand.
Grant, Adelaide Aust.
PS I think this thread will leap back into life when Petter fires up his prototype!
Sorry, I should have seen the balanced output and worked out the V+/output power relationship myself. Thinking cap on
So that means +- 38Vdc for 350W into 8 ohms, or +- 32Vdc for 250W, etc. And add 25Vdc for the input stage.My question still stands regarding the maximum safe output with the 24 devices modelled. I guess I can work that out too, based on SOAR, but I was hoping a Prophet or Elder may have the answer to hand.
Grant, Adelaide Aust.
PS I think this thread will leap back into life when Petter fires up his prototype!
This thread needs to die
You are right, NP.
This thread needs to die -- there is no useful activity on it any longer.
My experience with communities is that it is a great tool for short projects and idea generation. Most threads seem to fizzle and die within 60 days.
I have learned to use forums with more success with this thought in the back of my head and received excellent ideas and help.
Petter
You are right, NP.
This thread needs to die -- there is no useful activity on it any longer.
My experience with communities is that it is a great tool for short projects and idea generation. Most threads seem to fizzle and die within 60 days.
I have learned to use forums with more success with this thought in the back of my head and received excellent ideas and help.
Petter
X100 revitalized
This thread died out and I do not really understand why.
Well I know, everybody is in the Aleph-X fever now but the X-Series may be still interesting for people who want to build high power MOS-Fet amps and who can`t or don´t want to tolerate the power inefficiency of single ended Class-A.
Not everybody can or want to heat up his room with 1300W of what a 200W stereo X-Aleph would draw from the line at idle (and not everybody has high efficiency speakers which would be satiesfied with low power output amps).
Due to the Class AB push-pull output stage of the X-Series they have much lower power consumption than X-Aleph`s or Aleph`s with equivalent output power.
For driving woofers or subwoofers in active speaker systems also an X-Aleph might be a "waste" and a X-Amp. would "do it " without too much drawbacks in performance if there are any at all (as I assume, possibly advantage of an X-Aleph or Aleph over an X-Amp is mid and higher frequency range performance).
After an X-Aleph an X-Amp IMO seems to be the best choice for this task .
Has anybody actually built a X100 or similar according Petter`s schematic?
If yes what are Your experiences regarding the construction process.
Is it neccessary to have a time delayed activated relay at the output due to any worth mentioning power turn-on or turn-off noise in the speakers?
Any kind of comments are highly appreciated!
This thread died out and I do not really understand why.
Well I know, everybody is in the Aleph-X fever now but the X-Series may be still interesting for people who want to build high power MOS-Fet amps and who can`t or don´t want to tolerate the power inefficiency of single ended Class-A.
Not everybody can or want to heat up his room with 1300W of what a 200W stereo X-Aleph would draw from the line at idle (and not everybody has high efficiency speakers which would be satiesfied with low power output amps).
Due to the Class AB push-pull output stage of the X-Series they have much lower power consumption than X-Aleph`s or Aleph`s with equivalent output power.
For driving woofers or subwoofers in active speaker systems also an X-Aleph might be a "waste" and a X-Amp. would "do it " without too much drawbacks in performance if there are any at all (as I assume, possibly advantage of an X-Aleph or Aleph over an X-Amp is mid and higher frequency range performance).
After an X-Aleph an X-Amp IMO seems to be the best choice for this task .
Has anybody actually built a X100 or similar according Petter`s schematic?
If yes what are Your experiences regarding the construction process.
Is it neccessary to have a time delayed activated relay at the output due to any worth mentioning power turn-on or turn-off noise in the speakers?
Any kind of comments are highly appreciated!
I have built 2 input stages, but not yet mated to the power end. The latest version had a Vbe multiplier. I don't think it should be necessary to use an output relay, but the circuit is very sensitive to current balancing (but not as bad as I had originally thought). Contact me privately if you need assistance.
I am totally with you on your X versus AlephX reasoning. I should have something complete knocked up (he says again) in several weeks. I am also evaluating the use of automatic current setting to avoid having to make adjustments to get things to work. I have created some macromodels for op-amp servoed current sources, but perhaps I should just do the Aleph preamp variant with a transistor based setup since it is so simple.
Petter
I am totally with you on your X versus AlephX reasoning. I should have something complete knocked up (he says again) in several weeks. I am also evaluating the use of automatic current setting to avoid having to make adjustments to get things to work. I have created some macromodels for op-amp servoed current sources, but perhaps I should just do the Aleph preamp variant with a transistor based setup since it is so simple.
Petter