New build of Aleph X amplifier

t3447ml · 15th November 2006, 05:16 PM

For your consideration, my Aleph X mono blocks built to G. Rollins original design, 15V rails, 4A total bias, 4IRFP044 devices per channel. I would like to thank Grey Rollins for the design, Nelson Pass for the concept and Carondimonio (Bruno) for the boards.

t3447ml · 15th November 2006, 05:17 PM

Front Panel

hc167 · 15th November 2006, 05:22 PM

look nice, did you make your own chassis or you purchase somehwere else? and where did you purchase it?

t3447ml · 15th November 2006, 05:23 PM

Rear Panel

moe29 · 15th November 2006, 05:51 PM

does it run cool enough? heat sinks look a bit small.

The build quality looks excellent though

CJ900RR · 15th November 2006, 07:17 PM

Nice looking

What is the power in watt in 8 and 4 omhs from the original schematic?

t3447ml · 17th November 2006, 01:10 PM

The chassis is a Bud 17x12x3 from Digi Key. The sides have been cut off to mount the heat sinks.

The output power, when calculated using wuffwaff's AXE 1.2 spreadsheet, at 4amps bias into 8 ohms is 42 watts and into 4 ohms is 26 watts.

Moe29 you are correct this unit does run too hot. After about 1 hour I can still hold my hand on the heatsinks, after another half hour the heatsinks are too hot to touch.

The amplifiers are driving back loaded Fostex 108EZ horns rated at 24 watts. At my listening levels the volume control on my Aleph P1.7 64 step relay attenuator is set about step 25.

My next step will be to rework the unit to 2.5 amps bias, again from the spreadsheet this comes out to 21 watts into 8 ohms. This should cut the power dissipation for each channel from 148 to 92 watts.

hc167 · 17th November 2006, 01:49 PM

t3447ml:

do you mind to give me the part number of the chassis from digikey? thanks a lot.

hifimaker · 17th November 2006, 02:00 PM

Hi t3447ml,

I built an Aleph30 earlier this year that consumes 100 watts of power per channel. It has one 151x350mm heatsink per channel. After about 2 hours the heatsinks still pass the 5 second touch test. I've run the amp for as long as 6 hours on a warm summer day and the amp still passed the touch test.

My 1st Aleph Amp

You may need larger heatsinks even with the reduced power.

Something to consider.

-David

t3447ml · 17th November 2006, 02:18 PM

hc 167, the Digi Key PN# for the chassis is 377-1025ND

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15th November 2006, 05:22 PM	#3
hc167 diyAudio Member Join Date: Oct 2006	look nice, did you make your own chassis or you purchase somehwere else? and where did you purchase it?

15th November 2006, 05:51 PM	#5
moe29 diyAudio Member Join Date: Dec 2002 Location: Florida	does it run cool enough? heat sinks look a bit small. The build quality looks excellent though

15th November 2006, 07:17 PM	#6
CJ900RR diyAudio Member Join Date: Jan 2006	Nice looking What is the power in watt in 8 and 4 omhs from the original schematic?

17th November 2006, 01:10 PM	#7
t3447ml diyAudio Member Join Date: Oct 2005	The chassis is a Bud 17x12x3 from Digi Key. The sides have been cut off to mount the heat sinks. The output power, when calculated using wuffwaff's AXE 1.2 spreadsheet, at 4amps bias into 8 ohms is 42 watts and into 4 ohms is 26 watts. Moe29 you are correct this unit does run too hot. After about 1 hour I can still hold my hand on the heatsinks, after another half hour the heatsinks are too hot to touch. The amplifiers are driving back loaded Fostex 108EZ horns rated at 24 watts. At my listening levels the volume control on my Aleph P1.7 64 step relay attenuator is set about step 25. My next step will be to rework the unit to 2.5 amps bias, again from the spreadsheet this comes out to 21 watts into 8 ohms. This should cut the power dissipation for each channel from 148 to 92 watts.

17th November 2006, 01:49 PM	#8
hc167 diyAudio Member Join Date: Oct 2006	t3447ml: do you mind to give me the part number of the chassis from digikey? thanks a lot.

17th November 2006, 02:00 PM	#9
hifimaker diyAudio Member Join Date: Oct 2003 Location: San Jose	Hi t3447ml, I built an Aleph30 earlier this year that consumes 100 watts of power per channel. It has one 151x350mm heatsink per channel. After about 2 hours the heatsinks still pass the 5 second touch test. I've run the amp for as long as 6 hours on a warm summer day and the amp still passed the touch test. My 1st Aleph Amp You may need larger heatsinks even with the reduced power. Something to consider. -David

17th November 2006, 02:18 PM	#10
t3447ml diyAudio Member Join Date: Oct 2005	hc 167, the Digi Key PN# for the chassis is 377-1025ND

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