Good ol' #25
Having looked at various data sheets, schematics, and having
traced out and metered the output boards on #25. It looks very
simple to hook up as a slightly variant F4.
1) It has irf230 and irf9230 pairs, four per side. Their data sheet
indicates that they are 10 and 7.5 amp devices respectively as
opposed to the irf240 at 20 amps. It would seem that I could
constructively drive four pair of these with the standard F4 front
end, as it seems that the 230 pairs have lower capacitance ratings
so 3 pair of 240's and 4 pair of 230's would be roughly equivalent.
Is this a valid assumption?
2) There are two resistors per device on the boards -- 1 3 watt, 2.1
ohm resistor, and one .5 watt, 262 ohm resistor. I assume that the
3 watt resistors are on the sources, and the 262's are on the gates.
I didn't get out the calipers to detect the physical offset of the pins
from the case centerline to determine the pinout that way. The
question here is: Should I replace the 2.1 ohm source resistors
with the .47 values in the F4 schematic, or is it material? I suspect
that the difference between 100 ohms and 262 on the gates is
much less significant.
3) My final question (on this post 🙂) is one of craft. When I solder
wires to these boards, am I safe laying a wire on the trace and
soldering it? I am reluctant to drill a hole for fear of that lead
contacting the case side, and I sure don't want to desolder the
devices to take the board off, then reassemble it again.
Thansk for the help, not to metion the stuff!
Skip
Having looked at various data sheets, schematics, and having
traced out and metered the output boards on #25. It looks very
simple to hook up as a slightly variant F4.
1) It has irf230 and irf9230 pairs, four per side. Their data sheet
indicates that they are 10 and 7.5 amp devices respectively as
opposed to the irf240 at 20 amps. It would seem that I could
constructively drive four pair of these with the standard F4 front
end, as it seems that the 230 pairs have lower capacitance ratings
so 3 pair of 240's and 4 pair of 230's would be roughly equivalent.
Is this a valid assumption?
2) There are two resistors per device on the boards -- 1 3 watt, 2.1
ohm resistor, and one .5 watt, 262 ohm resistor. I assume that the
3 watt resistors are on the sources, and the 262's are on the gates.
I didn't get out the calipers to detect the physical offset of the pins
from the case centerline to determine the pinout that way. The
question here is: Should I replace the 2.1 ohm source resistors
with the .47 values in the F4 schematic, or is it material? I suspect
that the difference between 100 ohms and 262 on the gates is
much less significant.
3) My final question (on this post 🙂) is one of craft. When I solder
wires to these boards, am I safe laying a wire on the trace and
soldering it? I am reluctant to drill a hole for fear of that lead
contacting the case side, and I sure don't want to desolder the
devices to take the board off, then reassemble it again.
Thansk for the help, not to metion the stuff!
Skip
"... 1) It has irf230 and irf9230 pairs, four per side. Their data sheet indicates that they are 10 and 7.5 amp devices respectively as opposed to the irf240 at 20 amps. ..."
Same, same with the IRF244/IRF9240's I have in chassis # 26 = only slightly better current to 18 A. and 14 A., respectively, instead of 20 A.
No problem-o ...
" ... 3) My final question (on this post 🙂) is one of craft. When I solder wires to these boards, am I safe laying a wire on the trace and soldering it? ..."
This is not good wiring practice as the traces may delaminate or worse, break. Use old fashioned lead/tin solder, not silver solder = keeps the heat down a little. 😱
Same, same with the IRF244/IRF9240's I have in chassis # 26 = only slightly better current to 18 A. and 14 A., respectively, instead of 20 A.
No problem-o ...
" ... 3) My final question (on this post 🙂) is one of craft. When I solder wires to these boards, am I safe laying a wire on the trace and soldering it? ..."
This is not good wiring practice as the traces may delaminate or worse, break. Use old fashioned lead/tin solder, not silver solder = keeps the heat down a little. 😱
SE Amps
Thanks for the info, Nelson.
It looks like FastEddy will be sending me his IRF244/9240s assemblies after all so I'm going to try to stay on the complimentary side, if possible. If I understand what you mean by single ended then I think that I lose that ability to operate in balanced mono mode with an all N-channel SE design.
If I have this, please let me know.
Thanks for the info, Nelson.
It looks like FastEddy will be sending me his IRF244/9240s assemblies after all so I'm going to try to stay on the complimentary side, if possible. If I understand what you mean by single ended then I think that I lose that ability to operate in balanced mono mode with an all N-channel SE design.
If I have this, please let me know.
" ... sending me his IRF244/9240s assemblies ..."
Confirmed: I'm swapping for one of his transformers ...
Confirmed: I'm swapping for one of his transformers ...
A little report on the F4:
I only recently got my F4 towers to a point that I am comfortable thinking of them as "finished". With the help of many- including Nelson- I got them functional but messy during BAF 2007. By the time I got them home they were starting to deconstruct! So I rewired them and took care of a myriad of details which of course ended up taking all year! Yes I'm pathetic, but remember my mod duties, and I even have a job too! Thank god Jan Didden showed up to stay at my house, but he did almost have a heart attack when he saw them again!
They were totally functional and reliable for this year's event, but no balanced highish output preamp around and I was a bit busy so no audition. I took them home and hooked them to my CD player with a passive volume control -NOT balanced which my player doesn't have and they play at a quite reasonable volume in my apartment!
OK, the trick is that my speakers are 95 dB efficient, BUT I think that they will please a lot of people with a reasonable output preamp and reasonably efficient speakers. A balanced pre should be even louder.
While it seems that a complicated preamp arrangement or high output preamps might be required, in real life Nelson mentions that a decent highish end pre will work fine- especially if your speakers are somewhat efficient. Of course there is the Pumpkin- a high output preamp designed by ZenMod which will drive the F4 to max output:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=119070
http://www.diyaudio.com/forums/showthread.php?s=&threadid=119070
Read Nelson's owners manual and you will see that they can also be hooked to tiny "flea power" tube amps which is quite sure to get you full output!
This is REQUIRED reading if you are considering the F4:
http://www.firstwatt.com/downloads/f4_om.pdf
------
Now for the Orions, it depends on the output of the crossover. Possibly it is pretty high already but it would be good to find out from a quick message to Seigfried Linkwitz.
I think that Nelson is coming out with the B3 sometime, which is a buffer with gain- a "preamp" I would call it but maybe I'm missing something. The Pass Balanced Line Source (or Bride of Son of Zen) and the Pumpkin (but I don't know about the B3) will take a single ended signal from the crossover and turn it into a balanced signal.
Turning the bass crossover output into a balanced signal would certainly take care of both of the Woofers. That gives you 100 watts or more if you parallel the two woofers. This makes only three amps per speaker. a single ended F4 for both tweeters, a single ended F4 for the mids and a balanced F4 for the woofers.
Of course something like a Mini Aleph could be used for the tweeters also, but I don't know how similar they all sound.
--------
Ok....sound... This is the revelation- I am finally listening to them in a home environment and F4's are excellent amps!!! Great imaging- side to side as well as depth, great tone, yet great resolution also., and very relaxed with no indication of effort.
As I've tried to show above , they appear to require a lot of accomodation to make them work right, but in fact they are quite versatile. If they are the most reasonable thing to make from these chassis you could do a lot lot lot worse!!
Mark
I only recently got my F4 towers to a point that I am comfortable thinking of them as "finished". With the help of many- including Nelson- I got them functional but messy during BAF 2007. By the time I got them home they were starting to deconstruct! So I rewired them and took care of a myriad of details which of course ended up taking all year! Yes I'm pathetic, but remember my mod duties, and I even have a job too! Thank god Jan Didden showed up to stay at my house, but he did almost have a heart attack when he saw them again!
They were totally functional and reliable for this year's event, but no balanced highish output preamp around and I was a bit busy so no audition. I took them home and hooked them to my CD player with a passive volume control -NOT balanced which my player doesn't have and they play at a quite reasonable volume in my apartment!
OK, the trick is that my speakers are 95 dB efficient, BUT I think that they will please a lot of people with a reasonable output preamp and reasonably efficient speakers. A balanced pre should be even louder.
While it seems that a complicated preamp arrangement or high output preamps might be required, in real life Nelson mentions that a decent highish end pre will work fine- especially if your speakers are somewhat efficient. Of course there is the Pumpkin- a high output preamp designed by ZenMod which will drive the F4 to max output:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=119070
http://www.diyaudio.com/forums/showthread.php?s=&threadid=119070
Read Nelson's owners manual and you will see that they can also be hooked to tiny "flea power" tube amps which is quite sure to get you full output!
This is REQUIRED reading if you are considering the F4:
http://www.firstwatt.com/downloads/f4_om.pdf
------
Now for the Orions, it depends on the output of the crossover. Possibly it is pretty high already but it would be good to find out from a quick message to Seigfried Linkwitz.
I think that Nelson is coming out with the B3 sometime, which is a buffer with gain- a "preamp" I would call it but maybe I'm missing something. The Pass Balanced Line Source (or Bride of Son of Zen) and the Pumpkin (but I don't know about the B3) will take a single ended signal from the crossover and turn it into a balanced signal.
Turning the bass crossover output into a balanced signal would certainly take care of both of the Woofers. That gives you 100 watts or more if you parallel the two woofers. This makes only three amps per speaker. a single ended F4 for both tweeters, a single ended F4 for the mids and a balanced F4 for the woofers.
Of course something like a Mini Aleph could be used for the tweeters also, but I don't know how similar they all sound.
--------
Ok....sound... This is the revelation- I am finally listening to them in a home environment and F4's are excellent amps!!! Great imaging- side to side as well as depth, great tone, yet great resolution also., and very relaxed with no indication of effort.
As I've tried to show above , they appear to require a lot of accomodation to make them work right, but in fact they are quite versatile. If they are the most reasonable thing to make from these chassis you could do a lot lot lot worse!!
Mark
Mark,
I don't have a preamp. I added about 10db of gain before the Orion crossover (ASP) using an opamp, put a pot before the gain stage for a volume control, and input switching and tape loop before the pot. This is basically my old passive preamp transplanted into the ASP box -- I built it with this in mind. No preamp is the best preamp in my experience.
With line-level inputs such as a CD player, DAC, tuner, and phono preamp, the system plays loud recordings up into the low 100db (peak) range with the pot at full. It takes 27db of gain in my amps to make this happen. I'd have to add that much gain between the ASP and the F4 should I build one.
Please correct me if I'm wrong: the F4 is a class A push-pull unity gain power amp with 25 watts per channel into 8 ohms that dissipates around 160 watts in a stereo configuration using three pairs of complementary mosfets per channel.
It looks like the Aleph X could scale to my requirements, but I've read warnings about scaling it up to use more output transistors for higher power. There are implemented designs for 40 watts and 100 watts, but nothing in between. I've also come to realize that you can't dead-bug the driver stage without redoing the compensation and possibly lowering the high frequency cutoff. That's getting into territory that I'm not at all comfortable with. My scope (1970s Tek 1800 series) probably isn't fast enough to look for instability anyways.
- Eric
I don't have a preamp. I added about 10db of gain before the Orion crossover (ASP) using an opamp, put a pot before the gain stage for a volume control, and input switching and tape loop before the pot. This is basically my old passive preamp transplanted into the ASP box -- I built it with this in mind. No preamp is the best preamp in my experience.
With line-level inputs such as a CD player, DAC, tuner, and phono preamp, the system plays loud recordings up into the low 100db (peak) range with the pot at full. It takes 27db of gain in my amps to make this happen. I'd have to add that much gain between the ASP and the F4 should I build one.
Please correct me if I'm wrong: the F4 is a class A push-pull unity gain power amp with 25 watts per channel into 8 ohms that dissipates around 160 watts in a stereo configuration using three pairs of complementary mosfets per channel.
It looks like the Aleph X could scale to my requirements, but I've read warnings about scaling it up to use more output transistors for higher power. There are implemented designs for 40 watts and 100 watts, but nothing in between. I've also come to realize that you can't dead-bug the driver stage without redoing the compensation and possibly lowering the high frequency cutoff. That's getting into territory that I'm not at all comfortable with. My scope (1970s Tek 1800 series) probably isn't fast enough to look for instability anyways.
- Eric
Well, I mentioned what I know about the F4 just to kind of give people a feel for it. Your description of the amp is accurate from my experience.
As far a no preamps is the best preamp., I think that no extra gain is another way to say this. How you accomplish that can vary. In your case now, you are getting required gain in your power amp. Possibly in the future you will have a voltage gain stage to each your new amps,- Nelson has plenty of those designs and plenty of designs that put out substantial power.
I'm sure Nelson will have a plan for you- we will just have to wait for it.
Whatever happens be assured that the chassis with matched output devices and attached hardware is a huge part of the job already done.
As far a no preamps is the best preamp., I think that no extra gain is another way to say this. How you accomplish that can vary. In your case now, you are getting required gain in your power amp. Possibly in the future you will have a voltage gain stage to each your new amps,- Nelson has plenty of those designs and plenty of designs that put out substantial power.
I'm sure Nelson will have a plan for you- we will just have to wait for it.
Whatever happens be assured that the chassis with matched output devices and attached hardware is a huge part of the job already done.
Variac said:
For sure, I realize that. And the dollar value of the parts themselves is $$$$.
I'm a bit frustrated. Much time spent perusing this and other boards shows that the peak activity building Nelson's designs was about five years ago. GRollins et al did the design work, others did PCB layout, still others ran group buys. The schematics for the Aleph amps are gone from passaudio along with the operating manuals. There are lots of dead links in lots of threads. But I'm sure it will come together.
- Eric
A couple of things I know about:
Nelson pulled down the Aleph schematics when Aleph kits were being mass produced in Hong Kong. His web site collapsed shortly thereafter and was redone, so there are a lot of links that don't connect to anything, but the stuff is mostly back online, just not linked.
There was a lot of activity say 4 or 5 years ago, but Brian GT produced some mini-Aleph boards (which work with any sized Aleph) only a few months ago, Peter Daniel made my F4 boards about 2 years ago I think , and the F5 boards are appearing, also the F5 is easy enough to do point to point, Nelson is now selling some of his boards- exactly what are used in his First Watt amps.
When there are a group of people committed to buying any particular circuit board , they usually appear - usually from Peter.
Not to mention the stacks of unused boards that are in people's drawers (me included).
He has said that he will guide those that need it, so there is just no reason to worry. Clearly the Orions have special issues, but interesting special issues. Although I think Linkwitz spec'ed an amp with 60 watts per channel, it really shouldn't require all the channels to be the same output. The tweeters - even the pair won't need a big amp and the bass drivers could use one big amp (rather than two 60 watters I think. I realize that you know this.
My main point is that there is no reason to despair. Nelson has access to all his designs and has made the crazy generous offer to straighten everyone out. The only despair that I see as appropriate is the despair of a kid waiting for Christmas day!!!
Mark
Nelson pulled down the Aleph schematics when Aleph kits were being mass produced in Hong Kong. His web site collapsed shortly thereafter and was redone, so there are a lot of links that don't connect to anything, but the stuff is mostly back online, just not linked.
There was a lot of activity say 4 or 5 years ago, but Brian GT produced some mini-Aleph boards (which work with any sized Aleph) only a few months ago, Peter Daniel made my F4 boards about 2 years ago I think , and the F5 boards are appearing, also the F5 is easy enough to do point to point, Nelson is now selling some of his boards- exactly what are used in his First Watt amps.
When there are a group of people committed to buying any particular circuit board , they usually appear - usually from Peter.
Not to mention the stacks of unused boards that are in people's drawers (me included).
He has said that he will guide those that need it, so there is just no reason to worry. Clearly the Orions have special issues, but interesting special issues. Although I think Linkwitz spec'ed an amp with 60 watts per channel, it really shouldn't require all the channels to be the same output. The tweeters - even the pair won't need a big amp and the bass drivers could use one big amp (rather than two 60 watters I think. I realize that you know this.
My main point is that there is no reason to despair. Nelson has access to all his designs and has made the crazy generous offer to straighten everyone out. The only despair that I see as appropriate is the despair of a kid waiting for Christmas day!!!
Mark
Eric Weitzman said:
Scurrilous lies promulgated by religious extremists who think nothing of using fear as a tactic in an election year.
I gave the rules of thumb in the Aleph-X thread. You can build any size Aleph-X your little heart desires. There's absolutely no reason not to build a 75W version, for instance.
Don't let them scare you off...vote with your MOSFETs.
Grey
You're not an elitist, terrorist-chumming, tax-and-spend socialist trying to lull me into submission with fatuous claims of hope and change, are you? 😀
- Eric
- Eric
GRollins said:
I always liked GR's scribbling, but this one I just love! Needs framing. GR you got my vote!
My fellow Americans...
(and I'm specifically excluding self-aggrandizing, chest-thumping, soi disant 'patriots')
It is your solemn duty as a citizen to build an amp you can live with, that you can listen to pleasurably, that you will be proud of, and that you can learn something from. The Minions of the Empire will attempt to dissuade you. Don't let them succeed. Their greatest desire is to rob you of your individuality--to reduce you to "ditto-amp" status...don't let them steal your courage!
Stand up! Be counted! Build such an amp as will be honored on the Pass Labs website! Take back this nation from those who would use it for their own gain!
In short, build something, dude!
(I'm Grey Rollins and I approved this message.)
I was forcibly kept from posting for a week or so and missed this one. I've called for the formation of a congressional committee to investigate, but have no hopes that the investigation will be completed before the election. (Actually, I tried to change my e-mail address and something went wrong in the process--no idea what--leaving me in some sort of locked-out-limbo. Weird.)
Anyway, as I was saying...although I didn't post PCB artwork for the Aleph-X, I did post art once upon a time for the 'normal' Alephs. It would suffice for any Aleph up to and including a 2, that being the 100W version. That should pretty much cover most everyone, as there haven't been that many of the 200W ones built.
I'm reluctant to post my PCB artwork these days; my primary objection being the death-by-committee thing. I'm just not up for it.
But that wouldn't keep someone from using my old Aleph art if an Aleph seemed like something they wanted to do.
Grey
(and I'm specifically excluding self-aggrandizing, chest-thumping, soi disant 'patriots')
It is your solemn duty as a citizen to build an amp you can live with, that you can listen to pleasurably, that you will be proud of, and that you can learn something from. The Minions of the Empire will attempt to dissuade you. Don't let them succeed. Their greatest desire is to rob you of your individuality--to reduce you to "ditto-amp" status...don't let them steal your courage!
Stand up! Be counted! Build such an amp as will be honored on the Pass Labs website! Take back this nation from those who would use it for their own gain!
In short, build something, dude!
(I'm Grey Rollins and I approved this message.)
Eric Weitzman said:
I was forcibly kept from posting for a week or so and missed this one. I've called for the formation of a congressional committee to investigate, but have no hopes that the investigation will be completed before the election. (Actually, I tried to change my e-mail address and something went wrong in the process--no idea what--leaving me in some sort of locked-out-limbo. Weird.)
Anyway, as I was saying...although I didn't post PCB artwork for the Aleph-X, I did post art once upon a time for the 'normal' Alephs. It would suffice for any Aleph up to and including a 2, that being the 100W version. That should pretty much cover most everyone, as there haven't been that many of the 200W ones built.
I'm reluctant to post my PCB artwork these days; my primary objection being the death-by-committee thing. I'm just not up for it.
But that wouldn't keep someone from using my old Aleph art if an Aleph seemed like something they wanted to do.
Grey
Mr. Pass
I am just wondering what are the thermal specs for the heatsinks on our enclosures? They are interesting thermal chimney designs, but I believe they have smaller surface than traditional heat sinks. I have been thinking on what I want to do and I was deliberating between F4 and Aleph X with jfet input. I decided to go for Aleph X with around 50W - 70W output. I prefer single ended sound and since I need it for mid/tweeter combo it should work nice. Since I have a single box I would hope that it would be capable for that amount of heat dissipation for stereo version. At the Burning Amp you suggested to do 4 F4 amps in that case. I am assuming this would be comparable of what I am trying to do?
In the light of this, I also would like to see if anyone in the group is interested in trading sides? I have two sides with matched 6 complimentary pairs per side of IRFP244 / IRF 9240, or total of 12 of each. This is what is needed for F4. I am looking if you have all N channel MOSFETS IRFP044/240/244.
Please let me know.
AR2
I am just wondering what are the thermal specs for the heatsinks on our enclosures? They are interesting thermal chimney designs, but I believe they have smaller surface than traditional heat sinks. I have been thinking on what I want to do and I was deliberating between F4 and Aleph X with jfet input. I decided to go for Aleph X with around 50W - 70W output. I prefer single ended sound and since I need it for mid/tweeter combo it should work nice. Since I have a single box I would hope that it would be capable for that amount of heat dissipation for stereo version. At the Burning Amp you suggested to do 4 F4 amps in that case. I am assuming this would be comparable of what I am trying to do?
In the light of this, I also would like to see if anyone in the group is interested in trading sides? I have two sides with matched 6 complimentary pairs per side of IRFP244 / IRF 9240, or total of 12 of each. This is what is needed for F4. I am looking if you have all N channel MOSFETS IRFP044/240/244.
Please let me know.
AR2
AR2 said:
I'm pretty happy to think - that that sort of money isn't issue for my own cwayzee photographer
so - take a chance & buy few rails of needed mosfets , variac (this time without capital V
) , two Dale 4E/50W goldies .......select mosfets , just to cut time needed for swap with someone , clamp these two Dales (in series ) to heatsink , put on them wires of some biggie donut , calculate needed current/voltage for target dissipation , set variac (with biggie donut connected) to calculated voltage ( you can call Variac to set variac ) ....... and burnbabyburn!!!
yup - you'll need F-meter , or just use Papalike Palm-method .....
then you'll know capacity of said htsnks , so you can post nice picture of that case , along with smartypanty data .
if I wasn't completely clear in this post , ask JAccolina to translate it to Mormon sprak
Vladimir joined the LSD church ?
Cool !
Back in old days, a poor way to calculate heatsink thermal-R was to hold an adjustable clothing iron to it and measure temperature at (2) different settings.
Cool !
Back in old days, a poor way to calculate heatsink thermal-R was to hold an adjustable clothing iron to it and measure temperature at (2) different settings.
jacco vermeulen said:
yup ;
maybe ya all curlie wiggling habited boyz , but moi no ...... my curls are natural ..........
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