twitchie said:Thank you ZM
Actually what I meant to ask was how much bias can the 510/9510 take? Should I just let the heatsinks decide?
(previous post should have been bias adjustment, not gain)
presuming that your hphones aren't too hungry - 150 to 200mA will suffice .
Magura said:
Let your ears/heatsinks decide
Magura
always nutty Metaldanske
but - speaking wise ......
there are limits to even my own stupidity
it's alive!
Currently running at 125mV or about 250mA and the heatsinks don't actually feel very hot until you squeeze them between your fingers for about 5 seconds and then they are hot, but not too hot to continue holding.
Had them hooked up to LM317/337 regulated supply at first, but it was unstable so I suspected it was drawing more than the regulators could handle.
Right now, it's running on super-overkill psu held down to 15V with a variac
I need to figure out a permanent solution for the psu since I don't have any 'appropriate' transformer.
Anybody have a good recommendation on minimum VA for the transformer? 10VA enough? I was thinking of a 12V (AC) through hole Pulse transformer from digikey
http://www.pulseeng.com/products/datasheets/LT2006_27.pdf
What would the min VA recommendation be? I have a few of the 15V 2.3VA ones:
http://www.pulseeng.com/products/datasheets/LT2006_10.pdf
Here's what it looks like so far:
with the psu:
Currently running at 125mV or about 250mA and the heatsinks don't actually feel very hot until you squeeze them between your fingers for about 5 seconds and then they are hot, but not too hot to continue holding.
Had them hooked up to LM317/337 regulated supply at first, but it was unstable so I suspected it was drawing more than the regulators could handle.
Right now, it's running on super-overkill psu held down to 15V with a variac
I need to figure out a permanent solution for the psu since I don't have any 'appropriate' transformer.
Anybody have a good recommendation on minimum VA for the transformer? 10VA enough? I was thinking of a 12V (AC) through hole Pulse transformer from digikey
http://www.pulseeng.com/products/datasheets/LT2006_27.pdf
What would the min VA recommendation be? I have a few of the 15V 2.3VA ones:
http://www.pulseeng.com/products/datasheets/LT2006_10.pdf
Here's what it looks like so far:
An externally hosted image should be here but it was not working when we last tested it.
with the psu:
An externally hosted image should be here but it was not working when we last tested it.
Supply trannie
Twitchie,
Go nuts and really do it right - won't cost the earth.
Suggest a 30V centre tap, 100VA to give you a "raw" rails about +/-20 volts, and then simply reg it down to the 15V rails - a couple of Toole shunts (boards available soon) look to be perfect for this, or any other GOOD supply. (317/37 will take more than 1/4 amp, but easy to slave as Teddy-Power Reg for example)
Phones are much more critical, long term, than speakers.
[... then you can also try it on the DOA, just for fun!]
Twitchie,
Go nuts and really do it right - won't cost the earth.
Suggest a 30V centre tap, 100VA to give you a "raw" rails about +/-20 volts, and then simply reg it down to the 15V rails - a couple of Toole shunts (boards available soon) look to be perfect for this, or any other GOOD supply. (317/37 will take more than 1/4 amp, but easy to slave as Teddy-Power Reg for example)
Phones are much more critical, long term, than speakers.
[... then you can also try it on the DOA, just for fun!]
I am building a pair of SE Mono F4's and would like opinions.
I have 2 pair of the Conrad Heatsinks from the group buy.
Would mounting 3 Mosfets per heatsink and running a higher bias current to get 50 deg C be better than all 6 Mosfets on 1 heatsink at a lower current?
What bias current would each allow for.
rigma
I have 2 pair of the Conrad Heatsinks from the group buy.
Would mounting 3 Mosfets per heatsink and running a higher bias current to get 50 deg C be better than all 6 Mosfets on 1 heatsink at a lower current?
What bias current would each allow for.
rigma
Starting to stuff my boards and realized:
I ordered FQA12P20-ND but received FQAF12P20-ND
There are differences according to the spec sheets (links below)
Could someone with more knowledge than me let me know if the FQAF12P20-ND is OK in F4
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=FQA12P20-ND
http://parts.digikey.com/1/parts/1018029-mosfet-p-ch-200v-11-5a-3pf-fqaf12p20.htm
I ordered FQA12P20-ND but received FQAF12P20-ND
There are differences according to the spec sheets (links below)
Could someone with more knowledge than me let me know if the FQAF12P20-ND is OK in F4
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=FQA12P20-ND
http://parts.digikey.com/1/parts/1018029-mosfet-p-ch-200v-11-5a-3pf-fqaf12p20.htm
rigma said:
The FQAF12P20 is TO3PF package, will dissipate 70W and the FQA12P20 is TO3P will dissipate 150W -- see
http://mouser.com/catalog/637/513.pdf
The FQAF12P20 isn't on Fairchild Semi's website, or at least it isn't this Saturday morning.
ND just means "number digikey"
jacco vermeulen said:
Naah Grünschnabel, I think you made a typo, no?
The P in TO-3P is as opposed to a regular TO-3, which is a metal can.
So, we have TO-3P(lastic).
The F is as you describe the designation for "Fullpack", as in fully insulated.
For the F4, I would not worry too much about it, 70W per device is still plenty.
Magura