woody said:I wonder what the distortion and damping factor would be
if I used lateral mosfets. I know both would suffer but how
bad would these figures be.
Why would you say that distortion would be worse?
Re: Powering F5 fans
Do not modify them unless you can ensure that any thing connected to them cannot be touched when the chassis is closed. And similarly nothing else should be able to come loose and touch the bared innards.
are/were the wallworts double insulated.steveleen said:The modules, after removal from their wall wart cases, are small and they will be easy to mount in a corner of the amp case, fed by the incoming line AC.
Do not modify them unless you can ensure that any thing connected to them cannot be touched when the chassis is closed. And similarly nothing else should be able to come loose and touch the bared innards.
Not to mention that a lot more wall-warts theses days are switching supplies -- and they will really screw up your results.
If you are going to deploy a fan, make sure that you have some protection/warning system to circumvent catastrophic events if the fan fails.
If you are going to deploy a fan, make sure that you have some protection/warning system to circumvent catastrophic events if the fan fails.
jackinnj said:Why would you say that distortion would be worse?
An F5 made with laterals will sound quite good, but should measure more
distortion because of the lower transconductance.
😎
Safety concerns noted.
I just read up on switch mode power supplies and the contamination via the AC line using these types of power supplies is a cause for concern. I knew the ones for computers do contaminate, but was not aware that the charger sized units cause problems. Will do a listening test with and without to determine if there is an audible difference.
Thanks,
Steve
I just read up on switch mode power supplies and the contamination via the AC line using these types of power supplies is a cause for concern. I knew the ones for computers do contaminate, but was not aware that the charger sized units cause problems. Will do a listening test with and without to determine if there is an audible difference.
Thanks,
Steve
I need help in identifying whether my Nokia cell phone charger units (to be used to power the F5 fans) are switch mode or linear -- I just don't have the electronics background, and have exhausted a web search on this. They are the older, fatter ones, and I think they are linear, but not sure. Here are the main parts I've identified:
on the PCB are:
NEC 2501 opto coupler
S1NC60 N-channel MOSFET
SB9471 (can't identify what this is)
Z625 (can't identify what this is)
rising above the PCB are:
1 small transformer (FM 6722)
4 small electrolytic caps
2 resistors, one of which is a 1 watter
If they are linear, they should be fine, and I will use them.
If they are switch mode, then their use is doubtful.
Can anyone help on which type they are?
Thanks,
Steve
on the PCB are:
NEC 2501 opto coupler
S1NC60 N-channel MOSFET
SB9471 (can't identify what this is)
Z625 (can't identify what this is)
rising above the PCB are:
1 small transformer (FM 6722)
4 small electrolytic caps
2 resistors, one of which is a 1 watter
If they are linear, they should be fine, and I will use them.
If they are switch mode, then their use is doubtful.
Can anyone help on which type they are?
Thanks,
Steve
properly designed switched mode power supplies can be an excellent choice for size/weight/power saving... it is a pity that alot of switched mode power supplies are poorly designed using cheap parts and minimal filtering / shielding.
having said that there are plenty of linear supplies out there which are a junk too
the reason there are probably less "junk" linear power supplies is their design tends to be less complex.
like everything it is a trade off.....
my ten cents.
-Dan
having said that there are plenty of linear supplies out there which are a junk too
the reason there are probably less "junk" linear power supplies is their design tends to be less complex.
like everything it is a trade off.....
my ten cents.
-Dan
For anyone that wonders here's a quick way to tell.
1. If it works with no adjustment over 110 to 240volts it's switch mode.
2. Bring an unterminated scope probe close to it, again if switchmode you will see all the HF hash.
I would imagine HF contamination by electromagnetic radiation is more of an issue than any contamination of the actual mains supply.
1. If it works with no adjustment over 110 to 240volts it's switch mode.
2. Bring an unterminated scope probe close to it, again if switchmode you will see all the HF hash.
I would imagine HF contamination by electromagnetic radiation is more of an issue than any contamination of the actual mains supply.
You could possibly "swamp" all problems with a largish X - type capacitor across your mains. Possibly close to this regulators input.
R-K Rønningstad said:You could possibly "swamp" all problems with a largish X - type capacitor across your mains. Possibly close to this regulators input.
X and Y perhaps, and a choke on the mains and a ferrite on the output. The problem remains that the little booger is in a plastic case.
I haven't seen a linear supply for any consumer device in many years. So pretty much everything you find will be a switcher. And I don't imagine you'll find a properly designed one from a consumer product.
If you lived in USA you could go to Home Depot and buy a doorbell transformer.
If you lived in USA you could go to Home Depot and buy a doorbell transformer.
Lateral MOSFET F5
I am going to try this out (again) during the weekend. I really didn't push the ball very far along when the design first showed up as the results with the IRF/Vishay and Fairchild devices was so good right out of the box.
I am going to guess that 2 (matched) taste better than one.
Getting back to fans for the moment. You do need some protection in case of fan failure if you aren't going to invest in more aluminum.
I am going to try this out (again) during the weekend. I really didn't push the ball very far along when the design first showed up as the results with the IRF/Vishay and Fairchild devices was so good right out of the box.
I am going to guess that 2 (matched) taste better than one.
Getting back to fans for the moment. You do need some protection in case of fan failure if you aren't going to invest in more aluminum.
labjr said:I haven't seen a linear supply for any consumer device in many years. So pretty much everything you find will be a switcher. And I don't imagine you'll find a properly designed one from a consumer product.
If you lived in USA you could go to Home Depot and buy a doorbell transformer.
What voltages and currents are in question?
Do you have some secondary present on a transformer you could use that and e.g. a TO220 can LM317 set to your correct voltage. I mean, use one of the F5 rails and drop it to 5V or whatever it was with a LM317. Or 7805 for that. Or a NPN and a zener or something simple. Depends on the power this thing are using....
http://sound.westhost.com/power-supplies.htm
Just get a transformer and build one. It will be quicker and not hard to do. What if you used two fans where you need one so that they are sharing the power and when one dies the other gets full power?
Uriah
Just get a transformer and build one. It will be quicker and not hard to do. What if you used two fans where you need one so that they are sharing the power and when one dies the other gets full power?
Uriah
R-K Rønningstad said:
What voltages and currents are in question?
Do you have some secondary present on a transformer you could use that and e.g. a TO220 can LM317 set to your correct voltage. I mean, use one of the F5 rails and drop it to 5V or whatever it was with a LM317. Or 7805 for that. Or a NPN and a zener or something simple. Depends on the power this thing are using....
I thought he wanted to isolate the fan circuit and any noise it generates from the audio power. The stock toroids don't have an extra secondary winding for this. Seems just as easy to use a small transformer for the purpose.
Just tested the F5 using the Nokia charger units to power the fans, with a switch attached to compare sound with and without. The magical see-through clarity of the F5 disappears when the charger units are engaged.
I will build a simple dedicated power supply for the fans, using a small transformer.
Thanks,
Steve
I will build a simple dedicated power supply for the fans, using a small transformer.
Thanks,
Steve
Altmann's SPLIF topology:
Uff! Another one that came late to the F5 party. I started reading the entire thread when you were at page 140 and look now we are on page 154! 😡
Anyway, I came to know simultaneously the SPLIF feedback topology, the Selectronic Triphon amp and the F5 and obviously I went tempted to try the SPLIF on (both) amp(s):
http://www.altmann.haan.de/splif_page/
I think that maybe the Selectronic, with its lower bias (+/-260mA...) will be safer to try this. Apart that F5's feedback looks more complex and I don't have a clue about if SPLIF will work here...
The good thing is that the power supply can be used for both, just swapping amplifier modules 😎 to compare. The SPLIF can be selected with a switch to perform ABAB comparisons.
😎
What do the wise think?
Is there anybody who has tried this mod?
Regards,
M
Uff! Another one that came late to the F5 party. I started reading the entire thread when you were at page 140 and look now we are on page 154! 😡
Anyway, I came to know simultaneously the SPLIF feedback topology, the Selectronic Triphon amp and the F5 and obviously I went tempted to try the SPLIF on (both) amp(s):
http://www.altmann.haan.de/splif_page/
I think that maybe the Selectronic, with its lower bias (+/-260mA...) will be safer to try this. Apart that F5's feedback looks more complex and I don't have a clue about if SPLIF will work here...
The good thing is that the power supply can be used for both, just swapping amplifier modules 😎 to compare. The SPLIF can be selected with a switch to perform ABAB comparisons.
😎
What do the wise think?
Is there anybody who has tried this mod?
Regards,
M
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