100W amp: Leach amp or P101 ?

pwan · 15th April 2006, 03:34 PM

Hello,

I currently have 40-0-40 480VA and 6x 6800UF, I wonder which one ( Low-tim Leach amp, and P101) is suitable for my 88 db/w/m speaker and classic/pop music?

Thanks.

Leolabs · 15th April 2006, 04:20 PM

Depend on your DIY experience.

pwan · 16th April 2006, 03:06 AM

Quote:

Originally posted by Leolabs
Depend on your DIY experience.

P101 seems to be simpler, however, I found Leach kit available at reasonable price. As far as sonically concerns, which one is your recommendation?

AndrewT · 16th April 2006, 06:50 AM

Hi,
you are short of smoothing capacitance.
You will need a minimum of +-10mF/channel for 8ohm speakers. i.e. 4off 10mF or 8off 6m8F
If you have 4ohm speakers, you need to double the minimum requirement. This will also apply to 4 to 8 ohm speakers since it is the bass unit that tends to be the 4ohm part. 4ohm bass units need 8off 10mF or 12off 6m8F.

There are three ways to arrive at smoothing caps:
1. 2mF/Apk output current. (based on nominal impedance or DCR)
2. 1mF/10W output power. (40Vac will give about 140W)
3. PSU RC time constant >1.4*NFB>1.4*input hiPass. (aim for 1 to 2Hz on 4r or 8r)

pwan · 16th April 2006, 10:26 AM

Quote:

Originally posted by AndrewT
Hi,
you are short of smoothing capacitance.
You will need a minimum of +-10mF/channel for 8ohm speakers. i.e. 4off 10mF or 8off 6m8F
If you have 4ohm speakers, you need to double the minimum requirement. This will also apply to 4 to 8 ohm speakers since it is the bass unit that tends to be the 4ohm part. 4ohm bass units need 8off 10mF or 12off 6m8F.

My friend just offer to trade his 4x 10,000UF 63V with my 4x 6,800UF 80V. With 40-0-40 transfer produce ~ 58Vdc, Is it safe to use with 63V cap?

AndrewT · 16th April 2006, 10:38 AM

Hi,
allowing +5% for transformer regulation and a further +-6% for mains supply variation brings 40Vac right up to the 63Vdc limit.

So the answer is yes, use 63Vdc on 40Vac.

That gets you in the ballpark of about 130W to 140W into 8ohm.

pwan · 16th April 2006, 11:50 AM

I see. I will use 4x 10,000UF 63V for 40-0-40Vac traf then

Andrew, Many thanks.!

still4given · 16th April 2006, 02:43 PM

Actually Rod Elliot recomends 6X4700uf 80V for the P101.

I asked him when building mine if using 6X15000 whould improve things and he told me no. I used them anyway since that is what I had.

I think the Leach is a little more HiFi sounding than the P101 but it needs more heatsink than the P101. At least mine does.

Link to the PSU schematic at the bottom of the page.

Blessings, Terry

pwan · 16th April 2006, 03:12 PM

still4given,

Thanks for your comment. BTW, you might consider removing the schematic above as it's Rod's intelectual property. :-)

PS: I sending you an email. Could you check it out? Thanks.

djk · 16th April 2006, 04:37 PM

"you might consider removing the schematic above as it's intelectual property"

Looks like any other power supply to me.

15th April 2006, 03:34 PM	#1
pwan diyAudio Member Join Date: Apr 2006 Location: Earth	100W amp: Leach amp or P101 ? Hello, I currently have 40-0-40 480VA and 6x 6800UF, I wonder which one ( Low-tim Leach amp, and P101) is suitable for my 88 db/w/m speaker and classic/pop music? Thanks.

16th April 2006, 06:50 AM	#4
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Hi, you are short of smoothing capacitance. You will need a minimum of +-10mF/channel for 8ohm speakers. i.e. 4off 10mF or 8off 6m8F If you have 4ohm speakers, you need to double the minimum requirement. This will also apply to 4 to 8 ohm speakers since it is the bass unit that tends to be the 4ohm part. 4ohm bass units need 8off 10mF or 12off 6m8F. There are three ways to arrive at smoothing caps: 1. 2mF/Apk output current. (based on nominal impedance or DCR) 2. 1mF/10W output power. (40Vac will give about 140W) 3. PSU RC time constant >1.4NFB>1.4input hiPass. (aim for 1 to 2Hz on 4r or 8r) __________________ regards Andrew T.

16th April 2006, 10:38 AM	#6
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Hi, allowing +5% for transformer regulation and a further +-6% for mains supply variation brings 40Vac right up to the 63Vdc limit. So the answer is yes, use 63Vdc on 40Vac. That gets you in the ballpark of about 130W to 140W into 8ohm. __________________ regards Andrew T.

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
High Current Leach/leach super amp	bowdown	Solid State	41	2nd March 2011 02:15 PM
Esp P101....................	Gavinator68	Solid State	66	8th February 2011 05:44 PM
FS ESP P101 Amp	john65b	Swap Meet	3	26th February 2008 07:24 AM
esp p101	djronbxs	Solid State	2	6th January 2007 01:02 AM
Evolve Amps 100W+100W Stuff 4 Sale	WALTER BURKHARD	Swap Meet	4	8th June 2005 10:57 AM


	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

15th April 2006, 04:20 PM	#2
Leolabs diyAudio Member Join Date: Dec 2004 Location: Bukit Mertajam	Depend on your DIY experience.

16th April 2006, 11:50 AM	#7
pwan diyAudio Member Join Date: Apr 2006 Location: Earth	I see. I will use 4x 10,000UF 63V for 40-0-40Vac traf then Andrew, Many thanks.!

16th April 2006, 02:43 PM	#8
still4given diyAudio Member Join Date: Oct 2004	Actually Rod Elliot recomends 6X4700uf 80V for the P101. I asked him when building mine if using 6X15000 whould improve things and he told me no. I used them anyway since that is what I had. I think the Leach is a little more HiFi sounding than the P101 but it needs more heatsink than the P101. At least mine does. Link to the PSU schematic at the bottom of the page. Blessings, Terry

16th April 2006, 03:12 PM	#9
pwan diyAudio Member Join Date: Apr 2006 Location: Earth	still4given, Thanks for your comment. BTW, you might consider removing the schematic above as it's Rod's intelectual property. :-) PS: I sending you an email. Could you check it out? Thanks.

16th April 2006, 04:37 PM	#10
djk diyAudio Member Join Date: Feb 2001 Location: USA	"you might consider removing the schematic above as it's intelectual property" Looks like any other power supply to me.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

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