Aleph 5 playing...

[Lucas_G]

I have finally got some pictures of my two new Aleph 5 monoblocks.
They were taken some 10 days ago when I had just started to listen to them.
You will see them in their naked version.
Meanwhile I have added the wooden sides and the aluminium tops and bottoms. The frontplate will be professionally made in a later stage.

Lucas.

In this picture you see the side of it:
The Condis were still not fixed, but hey cvould not fall out...

[Lucas_G]

View on the top:

[Lucas_G]

Other side:

[Lucas_G]

View from underneath:

[Lucas_G]

Also upsidedown:

[Lucas_G]

Again from underneath you see the 30 VAC transformator (330 VA) with next to it a small heatsink on to which two rectifierbridges are attached.

[Lucas_G]

These PCBs are Kristijan's...

I attached folded brass dog-pennings for cooling the 9610s.
Under the PCBs you first get a nylon ring, then an alunminium stripe, then the IRFP 240, then Kapton (non-grease) isolation, then a 3 mm thick redcopperbar, then grease, and finally the Seifert Heatsink, measuring 216 x 150 x 84 mm.

[Lucas_G]

Here you can again see how the Mosfets were attached:
(Sorry for the badly focused photo...)

You also see the AC filter inlet, and the thermal 80 degrees Celsius clickson.

[Lucas_G]

Here is a final (rather dark) picture where you can see the wooden sidepanels in a still rough state and one of the aluminium grids for the tops and bottoms.
(They have been installed now but I don't have a digital camera. I will post them later...)

[Lucas_G]

Some remarks on the components used:

The toroids are 30 VAC 330 VA from Reichelt, Germany. Very cheap (33 Euro) and very silent.

The Condensators are 45 Volt (56 Volt surge) Marcon 16.000 uF. I used 2 sets of 4 pieces in each monoblock, divided by Intertechnik 3,9 mH 0,24 Ohm I-Point chokes.

I use two rectifierbridges for each channel.
The 30 VAC result in a 39 VDC under load.

One channel delivers appr. 30 mV DC offset, the other one is around zero!

I matched all mosfets, and I also matched the 550BC on HFE.

I used 0.25 Watt 0,1% precision resistors made by Welwyn, and 5 Watt MOX resisters made by Intertechnik.

Since I too have 4 Ohm speakers I decided to use the resistorvalues of WuffWaff that he has posted in another thread. This leads to a higher bias.

The Seifert heatsinks reach a temperature of about 47 degrees Celsius at a roomtemperature of 20 degrees. The redcopperbar on which the mosfets are attached reaches 53 degrees.
We can therefor conclude that the redcopperbar is a good solution.


Now on to the sound:

I have borrowed a lot of commercial products in the 1000 up to 4000 Euro segment from a befriended Hifi-shop.

Most sounded horribly clean and sterile with a narrow spacing.
Only a Classé Audio amp was a bit more natural but its bass was weak.

The Aleph 5 is in another class: it lets you hear detail and space in recordings without ever getting harsh.
It is the most natural sound that I have heard.
Thank you Nelson Pass!

Regards to all,

Lucas.