Output power
Hello!
Can any body say me how is the output power with 16 Ohms speakers?
Thank you very much.
José Humberto
Hello!
Can any body say me how is the output power with 16 Ohms speakers?
Thank you very much.
José Humberto
15W RMS? I´m not sure the power output of F5.
I hope will be enough for my speakers with 97dBWm
Thank you Andrew
I hope will be enough for my speakers with 97dBWm
Thank you Andrew
You could always look at OTL amplification as those generally increase their power as impedance increases.
I´ve never been ear the Otl, but with the F3 and F4 run ok with more of 20 db of gain in the pream. I understan the F5 is more independient of F4, my favorite, to the preamplifier.
Excuse me for my bad English.
Excuse me for my bad English.
Power supply schematic
Hi
Where can I find the schematic for the F5 power supply?
I've seen folks make reference to it here on this thread but the F5 article that I downloaded from Mr pass's site does not show the PS schem.
I also looked to see if there was a Service Manual for the F5 with no luck..
I would just feel more comfortable using the proper PS schem..
Thanks for the help
Sean
Hi
Where can I find the schematic for the F5 power supply?
I've seen folks make reference to it here on this thread but the F5 article that I downloaded from Mr pass's site does not show the PS schem.
I also looked to see if there was a Service Manual for the F5 with no luck..
I would just feel more comfortable using the proper PS schem..
Thanks for the help
Sean
Re: Power supply schematic
http://www.firstwatt.com/downloads/F5-om_sm-080527.pdf
dionisio said:Hi
.......
Sean
http://www.firstwatt.com/downloads/F5-om_sm-080527.pdf
transformer!
The piltron I salvaged from my unfinished gainclone is more than is required.
input: 2x 115vac
output: 2x 24vac
va:160
(model # 200428)
The transformer in the PS 0 R1 is 2x18vac out.
So, I guess I'm good to go?
The piltron I salvaged from my unfinished gainclone is more than is required.
input: 2x 115vac
output: 2x 24vac
va:160
(model # 200428)
The transformer in the PS 0 R1 is 2x18vac out.
So, I guess I'm good to go?
AndrewT said:Hi,
the F5 works the transformer pretty hard.
A transformer for a ClassAB chipamp would need to be mighty oversized to suit the F5, even though the voltages are similar.
Hi,The plitron I salvaged from my unfinished gainclone is more than is required. input: 2x 115vac output: 2x 24vac va:160
no way. The voltages aren't even similar.
A 160VA 24+24Vac transformer has a maximum continuous AC current output of 3.33A into a resistive load.
When fed into a capacitive input filter the maximum continuous DC current draw is reduced to ~1.67A.
This continuous current draw will make the transformer run at maximum temperature. It will be HOT inside.
The maximum continuous DC current is recommended @ ~50% of rating.
This reduces your 160VA to just 800mA of continuous DC output current.
What is the quiescent current of a single channel F5?
Edit,
divide by two error corrected.
AndrewT said:Hi,
no way. The voltages aren't even similar.
A 160VA 24+24Vac transformer has a maximum continuous AC current output of 1.67A into a resistive load.
When fed into a capacitive input filter the maximum continuous DC current draw is reduced to ~ 0.8A.
This continuous current draw will make the transformer run at maximum temperature. It will be HOT inside.
The maximum continuous DC current is recommended @ ~50% of rating.
This reduces your 160VA to just 400mA of continuous DC output current.
What is the quiescent current of a single channel F5?
Shucks, I guess I'll have to get a bigger transformer.
What should I be looking for then? besides 2x 18vac?
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=122-620
Is 250va enough? The price is right, and it comes with a mounting kit.
merlin2069er said:
Shucks, I guess I'll have to get a bigger transformer.
What should I be looking for then? besides 2x 18vac?
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=122-620
Is 250va enough? The price is right, and it comes with a mounting kit.
Looks like a good trany, buuuuuut! Great googly moogly, I guess you've missed the tranny in one of these F5 threads about the supplier right in your back yard. Antek ..........
....Antek of this group buy and asked if there might be any preferential pricing available for his AN-4218 torroid. That is 2 x 18, 400 VA. John replied: "I can offer the individual (transformers)... at $37 each for your group. Please use this discount code GN8128 "shipping not included" http://www.antekinc.com/
This is the baby to use and it's larger (VA) and cheaper. Great service too.🙂
Antek Trannies
I concur with Ichiban - John's Antek toroids are beautiful and half the price of a Plitron. His service is excellent also.
Someone else on the forum is building a test set-up to "listen" for transformer sonic differences, but I think the Antek's will work just fine. Cap, resistor and rectifier (standard vs. soft-recovery) selections will probably have a greater impact, IMHO. (BTW, Papa is not overly enamored with soft recovery rectifiers, even though they have become pretty cheap to use.....)
I concur with Ichiban - John's Antek toroids are beautiful and half the price of a Plitron. His service is excellent also.
Someone else on the forum is building a test set-up to "listen" for transformer sonic differences, but I think the Antek's will work just fine. Cap, resistor and rectifier (standard vs. soft-recovery) selections will probably have a greater impact, IMHO. (BTW, Papa is not overly enamored with soft recovery rectifiers, even though they have become pretty cheap to use.....)
labjr said:
His question was why does Nelson use the 25V caps then?
would anybody who has build their F5 measure the rails
also tell us what are your mains and do you use 2,2 mH Inductor In power supply
samoloko said:
would anybody who has build their F5 measure the rails
also tell us what are your mains and do you use 2,2 mH Inductor In power supply
Salamoko,
Please notice that the setup of a pi filter (Cpar-L-Cpar) not only depends on the inductor (L). I build my F5 with the amplimo 2x18V (650VA), Cpar1=30.000uf and Cpar2=0,1F per channel!!
Using these high capacities made it able to use an R of 0,9 Ohm instead of an L, with the benefit of coupling the very low output impedance of the transformer to the Fet's. My mains voltage is 230V, rail voltage=24.5 V, voltagedrop over R=120mV dc. As you can imagine I reduced the current limitation and the value of R11 and R12 to 0.39 Ohms.
If you have a oscilloscope and a tone generator with a nice square wave output you can clearly see the influence of the design of the pi filter especially with a low impedance load.
Have fun testing!
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