Another Aleph finished!

[Edwin Dorre]

Hello,

Here 4 pictures of my almost finished Aleph 4. Is it an 4 which has a bit higher bias and a change in the current source gain, to get a bit more punce in the bass department!

The inside is still a bit of a mess, because I ordered some professional made PCB boards which I will build with blackgates and holco's in the future. So I did not put much effort in cable guiding and stuff like this!

I sounds wunderfull and an absolute minimal of hiss and hum.









Thanks,

Edwin

[BrianGT]

Congratulations, it looks good.

--
Brian

[stefanobilliani]

Very nice .

What is the VA rating of each transformer ?

Thanks.

[Peter Daniel]

Now that's a seriously good looking amp. Silver and black always look better than one colour. Have some questions:

I see you used thermistors in series, what's the reason?
What about those fans on a side?

I finally see properly done output stage wiring. No PCB and p2p, that's the best way to do it. Nice looking switch on front panel too. Where is it sourced from?

[fcel]

Nice looking amp!
Is that a current meter hanging on top of the heatsink? What reading do you have? Just curious.

[Peter Daniel]

It's more like a temperature meter. How those heat sinks behave, seem kind of small for Aleph 4 with incresed bias.

[Edwin Dorre]

I am in the process of typing a piece of text for the diypass website! But here are some battle stats ;-)

2x 1000VA 40-0-40
16x 22000uf 63V

which gives about + / - 49.8V of loaded voltage, 52V unloaded!

P2P done with silver wire. The other pieces of wire are not very good but will be replaced with silver when kristian's PCB's are ready. I still have to find a good source for holco's where I can buy with creditcard.

I could not find 10 ohm thermistors, so 2x 5 ohm in serie.

The fans are there for safety. It is about > 33 degree celcius here at the moment :-(

I am very very happy with the switch. It is a vandal prove RVS switch with a micro-switch behind it. I use a bi-stable relais to switch it on and off with each click. I bought both at www.conrad.nl ! It looks like the same switch ( I think ) Nelson uses for his X150 amps! :-)))

[Edwin Dorre]

Originally posted by Peter Daniel
It's more like a temperature meter. How those heat sinks behave, seem kind of small for Aleph 4 with incresed bias.

it is a temperature meter! They are fischer SK435 blocks. Four of them! 200mm x 215mm x 80mm with a 18mm base plate!

So they are not that small :-)

They behave good, but indeed a bit too hot. about 62C with a room temperature of 26C ..

Edwin

[Peter Daniel]

What kind of rectifying bridges are you using? I'm asking because I had some problems in the past when bridges blew because thermistors didn't provide enough inrush protection. I also tried puting them in series because of that. You seem to have a lot of capacitance to deal with thou.

[lieven]

how does it sounds compared to the luxman in the background?

Where did you get those trafo's and heat-sinks???

Verry nice, my complements!!!

As Peter mentioned, don't change output-stage wiring, it can't be nicer. (pcb is a way to have equal quality, not better...smd is even worse)

Got a ESS amp wired that way, even a Soundcraftsmen ma 5002a wire-wrapped, still working (both lightly modified)