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6L6 3rd December 2012 03:16 PM

Aleph J for Universal Mounting Spec
This is a thread to discuss the Aleph J PCB on the Universal Mounting Scheme from the DIYaudio store.

Link to UMS -


Originally Posted by 6l6
As for the board, I was envisioning the same basic layout as the F4, F5c, etc... The longer board with the outputs all on the lower edge.

Also, I would love to see R7 replaced with a trimmer pot, as that's where you will be able to dial out any DC offset on the outputs... Maybe put pads for a parallel resistor there as well...

J109's are basically impossible to get anymore, so most people will be using a matched pair of J74's... it would be handy if they were face to face so their cases can be zip-tied together for better thermal tracking.


Originally Posted by GKU
May I suggest some additional design proposals:

- Lead pitch for the use of 1/4W audiophil resistors as Dale or PRP
- Space for an - input foil capacitor as f.i. 1uF ClarityCaps PWA or ESA

didiet78 4th December 2012 02:55 AM

Aleph J PCB
2 Attachment(s)
My first try, double layer. C1 using Electrolit Cap, Q1 2SJ74. :D


6L6 4th December 2012 03:14 PM

Didiet - That looks very nice!

How much lead spacing is there for the 'small' resistors? It would be nice to fit a PRP or dale RN60, as those are about as big as most 'audiophile' resistors. Some people will want to use them.

Great to see the pair of J74 - could you put a pot at R7 as a variable resistor?

If possible, the 0v traces should be bigger, and another wire pad added near the input to connect signal ground, psu ground and speaker ground at one place. See the F4 or F5 pcb in the store for an example.

Thank you so very much for your efforts!

AudioSan 4th December 2012 05:03 PM

why not make it a long board. all outputs on a line. thats what folks want. so they kan make use of the 400mm wide sinks.

6L6 4th December 2012 06:29 PM

I agree! But the 400mm sinks would be more than enough for an Aleph J. The 300mm would be fine.

AudioSan 4th December 2012 06:52 PM

yes. 400mm was just a option:) its the same for 300mm. let's say board lenght of 240mm
and spacing between the to center fets of 120mm (center to center) and 40mm between center and outher fets (center to center) thats 200mm center to center between the outher fets.

6L6 4th December 2012 09:43 PM

So what you are saying is that you would like to see the basic form factor of the cviller F5x boards?

I agree that it's a great idea, as it is the 'standard' form factor for the DIY audio boards. And if someone has a F5c or F4, etc... they could just plug the Aleph J pcb in with minimum trouble.

AudioSan 4th December 2012 10:58 PM

i don't remember how the F5X boards look like. but the F5c/F4 style. only with bigger space between the 2 center outputs.
or make it posible to use some standar ouput boards with it. i have the peter daniels board's. but if i want to use them, i need to use output boards from my aleph30 boards. just to get the heat spread over my sinks.

AudioSan 4th December 2012 11:07 PM

or just make it as the chipamps boards. with breakable output boards.
that will suit everyone.

6L6 5th December 2012 01:15 AM


Originally Posted by AudioSan (
i don't remember how the F5X boards look like. but the F5c/F4 style.

I meant F5c -- sorry.

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