Aleph 5 tower power finished

[vossie]

Here is my completed Aleph 5 in tower form. It measures in at 36Kgs (about 80lbs) and yes, yer can cook on it if the stove or Weber is not working...

I use a X-BOSOZ to drive it balanced. The speakers are Mission 702. Cables are diy CAT5 nw cable with twisted pair method. On the inside you will notice I've bolted the fets to the heatsinks using aluminum angle-iron with two stainless steel screws each. I decided to use the IRFP250 fets as they have even higher ratings
than the 240/244 - the sound is definitely excellent and I'd recommend these puppies without hesitation. BTW, the biggest difference between 12 of these fets during the vgs matching was 0.04V - I bought 12 and did not have to bother further. (Seems like manufacturing tolerances are becoming better and better...)

The transformer is 625VA (28-0-0-28) giving out 36.1V on the rails when all connected. Capacitance is 120000uF. Two 5Ohm 5A thermistons in series controls inrush current. LED supply is taken from the negative rail with a 10KOhm resistor in series (sorry boys, I don't hear the difference if connected across plus and minus ). The triangular nameplates of the X-BOSOZ and Aleph 5 is mounted 5mm away from the faceplate so that the LED reflects off the back of the plate while at the same time shining through a smaller hole in the nameplate. This makes for a nice backlit (and not directly-in-the-eye) blue power indicator. We should make a law that no other color LED are to be used in this gear...

Only thing I want to change is the power switch. In these pics I used a double 15A switch in parallel for lack of a nice flat push-button-type switch. (I searched for 5 months for a bloody switch to my liking without luck.) Here in Cape Town the only one I could get was at RS but they want more than 20$ for it - ha ha ha!!!

Sound is amazing and once it has warmed up (takes at least and hour) the sound becomes even better! The Aleph 5 compares well with the original Aleph 30 (top shelf in the pics). So much has been said about different sounding amps that it is sometimes neglected to take into consideration the differences between variables like source components, speakers, interconnects and weather conditions and even time of day listening is performed - here I can say that under the same conditions these two amps are both extremely good music machines. Even my cats love them...

I consider the Aleph 30 a better fit to my X-BOSOZ for the simple reason that the small listening room does not want too much bass. I used 47uF NP caps on the output of the X-BOSOZ. These large-value caps lets through much more lower frequencies with the result that the Aleph 30 (having half the output power than the Aleph 5) does not overdo the bass for such a small room size (4.5m X 6m).

Nevertheless, The Aleph 5 has huge hands on the lower frequencies and reproduce them with absolute excellence. The higher frequencies are unmistakably crystal clear as well (a nod to Nelson ). I have decided that these caps must be swapped for smaller ones - 10uf to 20uf max which I'll do soon.

Oh yes, I did mention to Nelson that I will buy a decent CD player but my current one must do for now...

Vossie

[vossie]

The back

[vossie]

Inside from front

[vossie]

Close-up of the electronics

[vossie]

Nametag close-up

[vossie]

Aleph 5 with X-BOSOZ and Aleph 30 on top

[vossie]

Oh yes, I had to re-design the pcb layout - I have gerber files if anyone is interested... (dimensions is 24cm X 9cm)

[vossie]

Another pic - before pbc and other wiring...

[vossie]

Close-up of my X-BOSOZ front plate...

[Jarno]

Hello Vossie,

Looks very nice indeed, how's the sound quality?
How does the Alep 5 compare to the 30?

Regards,

Jarno.