F4 and DAC?

Flecko · 22nd February 2008, 07:12 PM

Hi,
I would like to know if the 1,8V my DAC delivers is enough to drive my 8Ohm 105dB fullrange driver with the F4? How many watts I achieve with that?
Are PCB's available somewhere?
Thank you
Adrian

yggdrasil · 22nd February 2008, 08:05 PM

It will most likely not deliver enough.

You will get 1.8^2 / 8 = 0.4W

Flecko · 22nd February 2008, 08:18 PM

That is not much

but for 100dB it should be ok. The F4 looks REALY interesting. Will I just lose outputpower or would it also sound weak?

vitalstates · 22nd February 2008, 11:18 PM

Hi Flecko

These are the output figures I got from my F4 when fed with my dac-ah......I didn't include the wattage calcs but the ooutput voltages shown are into ariel mk6c which average about 6ohms...

the spl from the F4/Ariels is more than enough for me in average room conditions, especially considering the ariels are no more than 93db.

Ed

ps .... ran the f4 at a friends recently - fed by beresford dac (no pre, just cd into dac)into lowther ex4s OBs and couldn't run with the volume right up. He has an above average size room, at least 6m square.

Flecko · 23rd February 2008, 06:13 PM

The 1,8V I messured were not pp. So it should be 2,6VPP. The Speaker has also a impedance of 6Ohm -> 1,266W This should be enough. If you can listen with 93dB speaker at normal levels, then with 105dB it shouldn't be no problem. I think I will build one pair. It looks easy and the amp is very attractive

Thanks
Adrian

vitalstates · 23rd February 2008, 06:42 PM

Hi Adrian

Your DAC gives 1.8v my DAC gives 1.4v
Your speakers are 100db my speakers are 93db

my system is adequate in terms of spl, your system will be OTT(rolls royce philosophy)

what is stopping you?...have you read a negative report about F4....if you have I would suggest the author is certifiable!

regards

Ed

Flecko · 23rd February 2008, 07:05 PM

Quote:

Hi Adrian

Your DAC gives 1.8v my DAC gives 1.4v
Your speakers are 100db my speakers are 93db

my system is adequate in terms of spl, your system will be OTT(rolls royce philosophy)

what is stopping you?...have you read a negative report about F4....if you have I would suggest the author is certifiable!

regards

Ed

Perhaps a misunderstanding, your post encouraged me to build the f4.

I have looked around and the first problem is that I couldn't find the diodes 2n4736 at mouser, digikey and rs-components at all. The other semiconucters I could find but they should be matched somehow.Has somebody a link where I can read about this matching?
I searched for GB but there are no...

Has anybody an ieda where I can get the matched semiconductors for this project?
thanks Adrian

Yunick · 23rd February 2008, 07:25 PM

This place have what you need.. He offers complete kit's for F4.

http://www.tech-diy.com/hexfets.htm

The 2n4736 is a typo.. should be 1n4736.

Regards
David

Flecko · 23rd February 2008, 08:06 PM

thank you very much for this link, this is so great!
I will finish this amp very soon.

vitalstates · 23rd February 2008, 09:57 PM

Hi Adrian

no misunderstanding...I was just reinforcing the idea.......

good luck with the build, I'm sure you won't be sorry

Ed

22nd February 2008, 07:12 PM	#1
Flecko diyAudio Member Join Date: Apr 2006 Location: Hessen	F4 and DAC? Hi, I would like to know if the 1,8V my DAC delivers is enough to drive my 8Ohm 105dB fullrange driver with the F4? How many watts I achieve with that? Are PCB's available somewhere? Thank you Adrian

23rd February 2008, 07:25 PM	#8
Yunick diyAudio Member Join Date: Mar 2006 Location: Timrå	This place have what you need.. He offers complete kit's for F4. http://www.tech-diy.com/hexfets.htm The 2n4736 is a typo.. should be 1n4736. Regards David __________________ http://www.blogotheque.net/-Concerts-a-emporter-

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22nd February 2008, 08:05 PM	#2
yggdrasil diyAudio Member Join Date: Sep 2005	It will most likely not deliver enough. You will get 1.8^2 / 8 = 0.4W

22nd February 2008, 08:18 PM	#3
Flecko diyAudio Member Join Date: Apr 2006 Location: Hessen	That is not much but for 100dB it should be ok. The F4 looks REALY interesting. Will I just lose outputpower or would it also sound weak?

23rd February 2008, 06:13 PM	#5
Flecko diyAudio Member Join Date: Apr 2006 Location: Hessen	The 1,8V I messured were not pp. So it should be 2,6VPP. The Speaker has also a impedance of 6Ohm -> 1,266W This should be enough. If you can listen with 93dB speaker at normal levels, then with 105dB it shouldn't be no problem. I think I will build one pair. It looks easy and the amp is very attractive Thanks Adrian

23rd February 2008, 06:42 PM	#6
vitalstates diyAudio Member Join Date: Jan 2006 Location: uk	Hi Adrian Your DAC gives 1.8v my DAC gives 1.4v Your speakers are 100db my speakers are 93db my system is adequate in terms of spl, your system will be OTT(rolls royce philosophy) what is stopping you?...have you read a negative report about F4....if you have I would suggest the author is certifiable! regards Ed

23rd February 2008, 08:06 PM	#9
Flecko diyAudio Member Join Date: Apr 2006 Location: Hessen	thank you very much for this link, this is so great! I will finish this amp very soon.

23rd February 2008, 09:57 PM	#10
vitalstates diyAudio Member Join Date: Jan 2006 Location: uk	Hi Adrian no misunderstanding...I was just reinforcing the idea....... good luck with the build, I'm sure you won't be sorry Ed

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