F5 power amplifier - Page 191

ashaw · 19th October 2008, 11:48 AM

Would the following PSU be okay for The balanced F5 posted by Patrik a while ago?

I was thinking 4 Jenson 47000uF caps per rail per channel, could i get away with less?

stein2 · 19th October 2008, 12:00 PM

Quote:

Originally posted by ashaw
Would the following PSU be okay for The balanced F5 posted by Patrik a while ago?

I was thinking 4 Jenson 47000uF caps per rail per channel, could i get away with less?

Look at SM, it can't be much simpler. I have 2x22.000uF followed by 2x 25W R22 and 4x 33.000uF per channel. Across the 22.000 caps additional 1u/250V and the 2k2 5W resistor as well. Hope the simulation is just for one of two required rails per channel.

ashaw · 19th October 2008, 12:12 PM

SM? so like this - per rail?

(note steped load 5 than 10A)

stein2 · 19th October 2008, 12:53 PM

Quote:

Originally posted by ashaw
SM? so like this - per rail?

(note steped load 5 than 10A)

Something like that. 18VAC before the bridge but twice, meaning 18-0-18VAC to get rectified 24VDC per rail, plus and minus 24VDC measured from the center tap. SM is service manual downloadable from passdiy site ...
There's a full schematic drawing of the suggested PSU, but really not critical. Across each 22.000uF goes one 2k2 5W (can go with less power but I had these at hand)

I have a single 500VA transformer (toroid) with four 18VAC secondaries. Go back a few posts and pages and check it out. Very simple, very stable, completely silent... I suggest you get one NTC TH with around 6-10 Ohms for the primary that will act as a soft start and two more to ground the signal's ground. But it's all in the manual...
Here's the direct link to the service manual for F5
http://www.firstwatt.com/downloads/F5-om_sm-080527.pdf

ashaw · 19th October 2008, 01:11 PM

Note i said Patrick's Balanced F5, IE this one,

stein2 · 19th October 2008, 01:42 PM

Ok, then, sorry for talking about higher rail voltages. Still, adding the drain resistor across the first pair of caps and being wise about the grounding plus adding the thermistor in the primary remains a valid recommendation. I guess you have the service manual at hand and that you have checked how it was done.

jameshillj · 19th October 2008, 02:09 PM

Patrick's balanced Cct uses just 4 amps per channel (2A per side).

Suggest smaller caps in R-C-R-C configuration if using Jensens - not the usual setup but very effective - 1st cap (ripple) = 10,000 (maybe 22) and 2nd cap (power)= 22,000 (maybe those 47s) and R = 0.1R - 0.12R.

Not sure about those 1N5828 diodes on design spec - studs?
Avoid the cheap Jaycar, etc trannie - better to spend some $s.

ashaw · 20th October 2008, 05:58 AM

Really, Jest 4A,

so it will do only about 10W?

The diodes are just that, Ones the program has in it's memory bank

Wasim · 23rd October 2008, 04:28 AM

Hi All,

This amplifier seems to be very good. Those who have built this ... How does it sound? Which transformer did you use?

Reg

Babowana · 23rd October 2008, 02:02 PM

Quote:

Originally posted by Wasim
Hi All,

This amplifier seems to be very good. Those who have built this ... How does it sound? Which transformer did you use?

Reg

Many F5 builders confirm that the F5 sound is great.
You could use any good quality of transformer.

Cheers,

19th October 2008, 01:42 PM	#1906
stein2 diyAudio Member Join Date: Feb 2007 Location: Subotica	Ok, then, sorry for talking about higher rail voltages. Still, adding the drain resistor across the first pair of caps and being wise about the grounding plus adding the thermistor in the primary remains a valid recommendation. I guess you have the service manual at hand and that you have checked how it was done. __________________ "Calculations? We don't need no stinkin calculations! We just make them really big!" - Papa

19th October 2008, 02:09 PM	#1907
jameshillj diyAudio Member Join Date: Feb 2005 Location: Melbourne, Aust	Patrick's balanced Cct uses just 4 amps per channel (2A per side). Suggest smaller caps in R-C-R-C configuration if using Jensens - not the usual setup but very effective - 1st cap (ripple) = 10,000 (maybe 22) and 2nd cap (power)= 22,000 (maybe those 47s) and R = 0.1R - 0.12R. Not sure about those 1N5828 diodes on design spec - studs? Avoid the cheap Jaycar, etc trannie - better to spend some $s. __________________ ... jh

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Rockford Fosgate Power 20001 bd amplifier power rating??	pachoorion	Car Audio	8	8th May 2011 10:49 PM
Power transformers versus amplifier output power..what is your option?	destroyer X	Solid State	38	9th May 2009 05:23 PM
McIntosh Power Amplifier Power Guard	johnnyrt	Solid State	2	23rd August 2007 10:22 PM
Output power for a power amplifier	Progg70	Solid State	33	10th September 2006 08:44 AM
Amplifier 3000 Wats Rms Power + Smps Higcht Power Bestiality	MARAVILLASAUDIO	Class D	1	5th November 2004 04:06 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

20th October 2008, 05:58 AM	#1908
ashaw diyAudio Member Join Date: Jul 2006	Really, Jest 4A, so it will do only about 10W? The diodes are just that, Ones the program has in it's memory bank

23rd October 2008, 04:28 AM	#1909
Wasim diyAudio Member Join Date: Aug 2007 Location: Lahore	Hi All, This amplifier seems to be very good. Those who have built this ... How does it sound? Which transformer did you use? Reg