I have buit SOZ with 10w output power,the sounds very nice and nature.I plan to build the F1 power amplifier with 30W output. Anybody can help me modify the schematic with 30W power outpu?thanks in advice
Per Nelson's request not to publish schematics but rather link to his site I removed the picture and added the link to the manual
/Netlist
Per Nelson's request not to publish schematics but rather link to his site I removed the picture and added the link to the manual
/Netlist
As the F1 is intended to use with very high efficiency loudspeakers in the range of +90dB/watt, cranking up the volume to as high as 8 watts will result in 99dB of headroom. Perhaps there’s a way to make the amp deliver more power but I presume we will deviate from the original idea of simplicity and thus will be penalized soundwise. The F1 was designed to work only well with a limited amount of speakers, being high efficiency and full range as their most important parameters.
Not wanting to temper your enthusiasm, could you tell us what speakers you have in mind?
/Hugo
Not wanting to temper your enthusiasm, could you tell us what speakers you have in mind?
/Hugo
I think ~20watts would be possible without resorting to more devices with oodles of cooling and flogging it hard.
Reliability would suffer, burning FETs is one thing, just dont burn any fancy drivers. 
F1 in qualifying trim?
Reliability would suffer, burning FETs is one thing, just dont burn any fancy drivers. F1 in qualifying trim?
Adams_Leo said:
Adams_Leo, the input power of the 1st_w is 100W/one ch. - i.e efficiency=10% (@ 8 Ohm load).
If you built 30W you need 300W per channel, you are ready ? 🙂
If yes, you should increase the voltage from 24v up to 45-50v, and increase the current (decreasing R27 & R28)
I think 30 watts would mean ~75w/device using the stock overall layout and efficiency. You might be able to drop it some by tailoring it to a specific load, either sacrificing voltage for low impedance or current for high.
Adams
High power F1 . . . ?
If we have a wild horse, who has a good potential character but is too sensitive, nervous in a way and afraid of tough control, we might need a horseman to lightly stroke and calm her down. Then, we could manage to get her shining character. If we have a speaker behaving like the wild horse, we might need F1 as the horseman—i.e. the current source amp of the first watt.
As far as I understand, Nelson likes F1 just for such first watt . . .
Good luck and Regards
jH
High power F1 . . . ?
If we have a wild horse, who has a good potential character but is too sensitive, nervous in a way and afraid of tough control, we might need a horseman to lightly stroke and calm her down. Then, we could manage to get her shining character. If we have a speaker behaving like the wild horse, we might need F1 as the horseman—i.e. the current source amp of the first watt.
As far as I understand, Nelson likes F1 just for such first watt . . .
Good luck and Regards
jH
Re: Re: First Watt F1 with 30W output power
altor,thanks,I will try it.I have purchased the heatsink for this.
yeah,I think 20W power output would be better.Tweeker said:I think ~20watts would be possible without resorting to more devices with oodles of cooling and flogging it hard.
F1 in qualifying trim?
altor said:
altor,thanks,I will try it.I have purchased the heatsink for this.
jh6you said:
I use SOZ with 10w power output driver Harbeth P3,the sounds very good.now I plan to use F1 with 20~30w output to driver Dynaudio counter 1.3 SE.
altor said:
Try 🙂
And don't forget to tell us the results
P.S. I send you a private message.
Ok,I will.
I don't know how to get the private message.pls send it to my mail box.lxiaojun@cn.ibm.com
You could try an ISOTOP type device.
http://www.elfa.se/pdf/71/07112881.pdf
They can take a lot of dissipation without any problem.
Thermal resistance case/heatsink 0,05 C/W!
Johannes.
http://www.elfa.se/pdf/71/07112881.pdf
They can take a lot of dissipation without any problem.
Thermal resistance case/heatsink 0,05 C/W!
Johannes.
Adams_Leo said:
Toda I've sent 2 e-mails, from 2 of my account.
One return back - you server said that "user is unknown", second - maybe reach you.
Of course you can bypass the dissipation limits of the gain
devices by cascoding them with larger and/or parallel devices.
devices by cascoding them with larger and/or parallel devices.
had anyone ever used these ISOTOP mosfets
how about them.
if i use normal mosfet , for instance irfp140, as gain device , and use big packet mosfet as cascode device , so can i make huge
power class-A single ended amplifier?
if it is feasible , how is the sound quality ? and i think i can use single mosfet to build powerful single ended amplifier.
how about them.
if i use normal mosfet , for instance irfp140, as gain device , and use big packet mosfet as cascode device , so can i make huge
power class-A single ended amplifier?
if it is feasible , how is the sound quality ? and i think i can use single mosfet to build powerful single ended amplifier.
Re: had anyone ever used these ISOTOP mosfets
Either that or some parallel devices for the cascode and current
sources, and you can make it quite big if you want. As a practical
matter, probably about a 10 amp output peak. I would expect
quite good performance.
john-china said:
Either that or some parallel devices for the cascode and current
sources, and you can make it quite big if you want. As a practical
matter, probably about a 10 amp output peak. I would expect
quite good performance.
altor said:
sorry,I still do not receive you mail,I don't know why,pls send again to lxiaojun@cn.ibm.com
thanks
Leo
Re: Re: had anyone ever used these ISOTOP mosfets
I want to use IRF140 to replace the IRFP9240&IRF240,does it can work well?
Nelson Pass said:
I want to use IRF140 to replace the IRFP9240&IRF240,does it can work well?
Adams_Leo said:
Yesterday sent 2 times to you hotmail account, in a few minutes will try to send to this.
Re: question
The primary spec on a cascode device is whether it will break or
not.
😎
john-china said:
The primary spec on a cascode device is whether it will break or
not.
😎
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