Aleph J illustrated build guide

From what I can tell, the store chassis come are shipped from Europe
via fedex. So another thing I would be worried about are the brokerage
fees, bond fees, delivery fees, fees to collect fees, HST on fees. :(

All this on top of the legitimate HST on imported items.

Last September I ordered a Slimline 1U for a different project. There was a $2.22USD shipping fee added to the DIYaudiostore price. No brokerage fees or taxes added. Fast delivery from Italy to my door. Because the total cost was about $100 I think I stayed below the GST radar.

I would not hesitate to order again.
 
My shipping quote for 2 of the 400mm deep 4u dissipante chassis with the thick Al front panel was 11$. A real bargain. GST is hit and miss. Sometimes you pay and other times you don't. Depends on the values the seller puts on the product among other things.
Staying with the UMS heatsinks will save you lots of work.
 
What a most enjoyable day I`ve had.
I finished the basic assemble of my first Aleph last night.
Have spent most of the day hovering around checking this and that and listening to some incredible sounds.

Its not pretty, but now it runs I have a better understanding of what sort of box I am going to have to build to house the unit.

300 vac with 2X18v trans, bridge rectifier 35A 1000V (from a welder I pulled apart), 4 x 33000uf caps running through a pair of Peter Daniel boards. Luckily the boards cam with a genuine matched pair of SJ109`s.



Have had nothing to do with class A before I was surprised by how much heat this puts out. 58-60 deg C on the gauge with an ambient room temp of approx 26 C . After running all day it still passes the 5 second touch test but only just. Think I will go bigger on the heat sinks than the four 300mm x 75mm I put together for testing.

Rails are a pretty constant 21.6 volts, R7=4.7v, R8=8.4v which according to the schematic should be 4.3, 8.3.
DC at the speaker terminals is running approx. 5.9 mv RHS and 1.2 mv LHS.
Volts across the source resisters is runs 0.57 to 0.59 on most with one down to 0.52. The IRFP240 were put in as they came from Mouser so not matched properly.



A long way to go yet on this one but I cannot help myself I have all these boards to populate. Mini, A5?,A30?, or go the whole hog and build a 60.Better start saving.





Tony
 
Tony
congratulations
you idle Total of 2.2A per channel, Is that correct
how hot are heatsink after 1 hr
did you measure ripple
I think you have to add more caps or cap multiplier
I don't understand why pcb designers always put dissipating devices so close 2 x 2 Instead of In one row
 
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Tony
congratulations
you idle Total of 2.2A per channel, Is that correct
how hot are heatsink after 1 hr
did you measure ripple
I think you have to add more caps or cap multiplier
I don't understand why pcb designers always put dissipating devices so close 2 x 2 Instead of In one row

Thanks samoloko,

I don`t know if I have got the maths right but I figured the amps per channel was about 2.5.

Take`s between 50 to 60 minutes to get to approx. 58 deg C with room temp of 26C. Have been running it today for about 5 hours through my 1.5 magies (4 ohms) and temps have not moved from 58 no matter how hard I have pushed it.

Ripple, I don`t know. Only have multimeters to work with at the moment. Venturing more into this diy a scope is something I have added to the wish list.

I have set t up with some of my other diy bits. Valve pre-amp on top with phono pre and dac in the box.



I cannot get over how great this amp sounds.
I have been thinking of selling off some of my other gear to finance some more diy. Seems to be a no brainer know.
 
I would not worry too much about 58 degree C. I would call it acceptable. It would probably be cooler if the mosfets were spread out instead of being stacked and positioned on the lower 3rd of the heatsinks. Something to consider on the next build. If the temp rises when the case is finished a nice quiet fan will solve the problem without messing with the layout. I say enjoy.
 
OK, Aleph is up and running, warming up for final bias and offset adjustments. Plain Jane, using the Deluxe 4U, PSU board from the store (actually just the filter board, with separate bridge rectifiers), Antek 18V 18V 400VA, parts kit from the store, amp boards from the store, matched JFETs from a trusted (I think) ebay seller, matched MOSFETs from a different ebay seller (ditto), and stuffing courtesy of Mouser and Digikey. Once again, I need to express my gratitude to Papa and 6L6, as well as Didiet for the boards, and ZenMod for all his input on this thread. I'm going back to read a few more posts while I let it warm up.
 
Which toroidal transformer to use?

Hi all, I am a Dutchman living in Australia and I ordered the Aleph J + power supply when there was a group buy last time.
Now I have most of the parts, excluding the case, but my question is:
I have two toroidal transformers available, both 2x18 Volts secondary, both 8.3 Ampere. One label states 300 VA (Watts), the other does not state a wattage, but is probably also 300 Watts (2x8.3x18). They look quite different. Which one would be best to use in the Aleph J amp, or can I use both, one for each channel? Cheers, Wouter.
 

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New Aleph J build

My Aleph J is finally done. I used the DIY store 4U aluminum chassis, and a dual power supply, also from the DIY Audio store. Bias was set at 420mV (~0.89A), and I probably could go higher - the heat sinks reached 55º when separate but only get to 45º or so with the case assembled. Very pleasing sound - softer edges than the F6, not as "big" a sound as the M2, but very easy to listen to.
 

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