traw said:
This is well documented on this forum, but be aware that you have to check
the parts.
As I understand it, Fairchild bought Samsung's Mosfet fab, and we suddenly
experienced some P channel parts marked Fairchild but exhibiting the "IR"
P channel distortion. Wayne pointed out to me that the Samsung parts
had previously behaved this way, and it was logical to assume that these
were Samsung parts now made by Fairchild.
We relegated these to relay switches and bought a different Fairchild part #
that was fine.
Mind you, the Samsung P channel Mosfets meet all the published specs and
do indeed work, but they have more distortion at midband and above. None
of this stuff is documented on simulator device models as far as I know.
😎
F4 and others
Andrzej,
Now that you have developed a taste for "optomising" your circuits, perhaps another look at your power supply MAY also produce a noticeable improvement. ( May not, too!!)
With these "simple" circuits, the supply directly effects the sound - no news, here - but, many of us don't spend much thought/effort/cost on what type of caps, diodes, trannies, to use in the supply. Pity, really - much lost performance.
I have made a "bumpy ride" from Block bridges to Freds, Panas caps to Roe, Phillips, Mundorf, Rifa and now "Sikorel", Torroid transformer to EI frame, micron wire, etc - it's getting better!
A constant surprise (the improvement of) is to "tune" the transformer. The link is to the "Prometheus Audio" website (tuning a power transformer ...) and is simple, really, but not so easy to get good caps like propylene or styrene in 400v range for the primary side, although you have better access over there.
It does require MUCH patience (what doesn't, in audio!) and you learn how to listen to the DIFFERENCES of the sound - it's only for folks that don't mind lots of frustration!
It works with everything that uses a transformer, with or without regulators. (ie. how to get Clean base and crystal clear treble from a 1541A based NOS dac cd player, etc).
Suggest a look at the article.
Incidently, try a small filter around that TL431 and those IN4736's- hmm!
(Sorry, how do you add the links and things here? Can somebody advise this computer dummy!)
... jh
Andrzej,
Now that you have developed a taste for "optomising" your circuits, perhaps another look at your power supply MAY also produce a noticeable improvement. ( May not, too!!)
With these "simple" circuits, the supply directly effects the sound - no news, here - but, many of us don't spend much thought/effort/cost on what type of caps, diodes, trannies, to use in the supply. Pity, really - much lost performance.
I have made a "bumpy ride" from Block bridges to Freds, Panas caps to Roe, Phillips, Mundorf, Rifa and now "Sikorel", Torroid transformer to EI frame, micron wire, etc - it's getting better!
A constant surprise (the improvement of) is to "tune" the transformer. The link is to the "Prometheus Audio" website (tuning a power transformer ...) and is simple, really, but not so easy to get good caps like propylene or styrene in 400v range for the primary side, although you have better access over there.
It does require MUCH patience (what doesn't, in audio!) and you learn how to listen to the DIFFERENCES of the sound - it's only for folks that don't mind lots of frustration!
It works with everything that uses a transformer, with or without regulators. (ie. how to get Clean base and crystal clear treble from a 1541A based NOS dac cd player, etc).
Suggest a look at the article.
Incidently, try a small filter around that TL431 and those IN4736's- hmm!
(Sorry, how do you add the links and things here? Can somebody advise this computer dummy!)
... jh
There is a serie of article (5, started in August) on XpressAudio about cleaning the power, upstream the transformer. So far, I've found this very interresting and I'm planning to incorporate the ideas in my new PS (for F5 amps)
Arnaud
Arnaud
Re: F4 and others
JH,
I remember long time ago you mentioned Prometheus, I found an article, and according to that I add some capacitors around f4 transformers. I got some very old polistyrene (probably) caps used in tube TV-sets. But I did not detect any result, no change is sound, probably my old configuration of C1/C1 + 47nF bypass did not fit to trafo/caps solution. Now, after change of C1/2 + bypass, I am delighted in ambience, discovering more subtle differences between dry and life studio, for instance.
What do you mean „try a small filter around that TL431 and those IN4736's- hmm” – ? - try to attach a simple draft, link or photo. Adding photo remember must be small. I take a photo with my digital camera and next I use PhotoShop software to play with quality and size of the picture, but maybe there are other ways to make the picture small enough to reach max 100kB capacity, can somebody advise?
a.
JH,
I remember long time ago you mentioned Prometheus, I found an article, and according to that I add some capacitors around f4 transformers. I got some very old polistyrene (probably) caps used in tube TV-sets. But I did not detect any result, no change is sound, probably my old configuration of C1/C1 + 47nF bypass did not fit to trafo/caps solution. Now, after change of C1/2 + bypass, I am delighted in ambience, discovering more subtle differences between dry and life studio, for instance.
What do you mean „try a small filter around that TL431 and those IN4736's- hmm” – ? - try to attach a simple draft, link or photo. Adding photo remember must be small. I take a photo with my digital camera and next I use PhotoShop software to play with quality and size of the picture, but maybe there are other ways to make the picture small enough to reach max 100kB capacity, can somebody advise?
a.
Yeah Andrzej,
The early days of ham radio, the "rigs" needed a much "grunt" as possible, being so far away to everyone else, so all sorts of crazy ideas were used.
The problem with the tuning cap is the precision required - the F3, for example, is much more critical with the primary cap of 88.94nF +/- 20pF (Rifa 216 styrene) for the 240v, 50Hz AFTER power line conditioning! Each secondary is 46.05nF +/- 20pF !!
The natural variation of each value (s) gives the final precision - as I mentioned, much patience required!
As for the 431's, if you go to the TNT website, I think from memory, there is some information about theTL431 and how to clean it up a bit - for more detailed info, I suggest a good look at the Wenzel Associates articles about "Finesse the Voltage Reg".
Good stuff to play about with - simple, low cost "tweaks"!
The IN4736 should read 2N - sorry - about 1 nF across each should help to bring out upper-mid details, particularly for "brass music" - not sure about this, but so simple to try under the pcb.
It's been awhile since I built the F4 and fed it from the PL X2.5, so the results I look for may not suit your requirements at all.
This is so much fun,easy stuff, particularly compared to speakers where it's measure, check, now measure it again properly, where did THAT come from, etc, etc, - always a hard, slow progress.
Arnaud,
thanks for your info - anything to do with power conditioning is very much worth reading as none of our mains power supplies are staying clean - I've been toying with the idea of trying an isolating transformer with a "balanced power" setup - it still surprises me how much difference that the power cords make.
The early days of ham radio, the "rigs" needed a much "grunt" as possible, being so far away to everyone else, so all sorts of crazy ideas were used.
The problem with the tuning cap is the precision required - the F3, for example, is much more critical with the primary cap of 88.94nF +/- 20pF (Rifa 216 styrene) for the 240v, 50Hz AFTER power line conditioning! Each secondary is 46.05nF +/- 20pF !!
The natural variation of each value (s) gives the final precision - as I mentioned, much patience required!
As for the 431's, if you go to the TNT website, I think from memory, there is some information about theTL431 and how to clean it up a bit - for more detailed info, I suggest a good look at the Wenzel Associates articles about "Finesse the Voltage Reg".
Good stuff to play about with - simple, low cost "tweaks"!
The IN4736 should read 2N - sorry - about 1 nF across each should help to bring out upper-mid details, particularly for "brass music" - not sure about this, but so simple to try under the pcb.
It's been awhile since I built the F4 and fed it from the PL X2.5, so the results I look for may not suit your requirements at all.
This is so much fun,easy stuff, particularly compared to speakers where it's measure, check, now measure it again properly, where did THAT come from, etc, etc, - always a hard, slow progress.
Arnaud,
thanks for your info - anything to do with power conditioning is very much worth reading as none of our mains power supplies are staying clean - I've been toying with the idea of trying an isolating transformer with a "balanced power" setup - it still surprises me how much difference that the power cords make.
Here is the link for the article- part1
http://www.audioxpress.com/magsdirx/ax/addenda/media/simon2943.pdf
http://www.audioxpress.com/magsdirx/ax/addenda/media/simon2943.pdf
Hi,
I like this power amp and would love to make it. Is there anyone who tells me how much power does it deliver in 4ohm and what about the quality?
Regards
I like this power amp and would love to make it. Is there anyone who tells me how much power does it deliver in 4ohm and what about the quality?
Regards
flg said:
Hi Flg,
I have seen the the first post. there is link there but it's not working!!
Regards
Wasim,
New link - http://www.firstwatt.com/downloads/f4_om.pdf
The Pass Labs/PassDIY/First Watt sites have been rebuilt recently.
Cheers,
New link - http://www.firstwatt.com/downloads/f4_om.pdf
The Pass Labs/PassDIY/First Watt sites have been rebuilt recently.
Cheers,
Finished F4 Module
I've Finished build F4 Module, all component in right position.... double check already.
Tomorow i will try to turn on my F4 and i hope I don;t have any trouble.
Jopie
I've Finished build F4 Module, all component in right position.... double check already.
Tomorow i will try to turn on my F4 and i hope I don;t have any trouble.
Jopie
I was thinking ... would it be possible to remove the output capacitors on the venerable Pumpkin and stick in a TVC between the 
and the F4? Assuming you only used balanced output from the Pumpkin into the F4 ... dunno much about transformers, but seemed like an interesting idea.. to me at least.
and the F4? Assuming you only used balanced output from the Pumpkin into the F4 ... dunno much about transformers, but seemed like an interesting idea.. to me at least.
Maybe more interesting for a preamp that could do with a little extra gain to push an F4.
Unless you hate output caps but are in love with transformers, the F4 will not mind.
Unless you hate output caps but are in love with transformers, the F4 will not mind.
jacco vermeulen said:
am I right in thinking any sort of AVC (autoformer) wouldn't work in between the source and the Pumpkin, due to SE -> balanced conversion problems (floating ground)?
yes, it's probably a tradeoff of sorts, you're correct. I'm not super concerned about the caps, but it seems that this solution both provides for attenuation and cap removal, so many would jump at that opportunity..I'm still not sure if I'm one of those people 🙂
Re: Finished F4 Module
so, jopie of indonesia
you turned on your F4 on the 25th August 2008
now is 17 days later
i hope you were not killed by some explosion, when turned F4 on
or maybe you are at hospital
and can not post no results here
😀
Pocoyo said:
so, jopie of indonesia
you turned on your F4 on the 25th August 2008
now is 17 days later
i hope you were not killed by some explosion, when turned F4 on
or maybe you are at hospital
and can not post no results here
😀
Re: Re: Finished F4 Module
I'm fine... my F4 is working good and produce a wonderful sound but i can't post some picture maybe later after enclosure thing.
at this time i'm try to anodized my F4 enclosure by my self. I'm still learn and study doing this.
btw, Jeffry is a good friend of mine and he usually using my computer and he's always forgot to logout.
Regards
Jopie
Thanks lineuplineup said:
I'm fine... my F4 is working good and produce a wonderful sound but i can't post some picture maybe later after enclosure thing.
at this time i'm try to anodized my F4 enclosure by my self. I'm still learn and study doing this.
btw, Jeffry is a good friend of mine and he usually using my computer and he's always forgot to logout.
Regards
Jopie
I know Pocoyo
We posted a lot in aussieamplifiers NX150 Spyder topic
here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=101948&perpage=50&pagenumber=8
glad you got your F4 working
it is one simple style amplifier .. but very good design, by Nelson Pass
regards
Lineup
We posted a lot in aussieamplifiers NX150 Spyder topic
here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=101948&perpage=50&pagenumber=8
glad you got your F4 working
it is one simple style amplifier .. but very good design, by Nelson Pass
regards
Lineup
lineup said:
Indeed....
and thanks to Mr. Pass for sharing this to us and allow me to have this wonderful amps.
F4 Bias
This may have been posted previously.
The older schematic from '06 states 250mv across the source resistors. The '07 schematic I got states 200mv. It runs stable for hours at 200mv currently, but unsure if I am getting ideal sound. The IRF's casings run at 60 degrees C and the heatsinks 48 degrees C.
Any reason for this change? I am assume putting a little more juice may make it sound more better.
Thanks!
This may have been posted previously.
The older schematic from '06 states 250mv across the source resistors. The '07 schematic I got states 200mv. It runs stable for hours at 200mv currently, but unsure if I am getting ideal sound. The IRF's casings run at 60 degrees C and the heatsinks 48 degrees C.
Any reason for this change? I am assume putting a little more juice may make it sound more better.
Thanks!