Another Aleph finished!

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Edwin Dorre

Member
Joined 2002
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.

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


Thanks,

Edwin
 
Peter Daniel

Peter Daniel

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Joined 2002
audiosector.com
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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?
 
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Edwin Dorre

Member
Joined 2002
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! :)))
 
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Edwin Dorre

Member
Joined 2002
Peter Daniel said:
It's more like a temperature meter. How those heat sinks behave, seem kind of small for Aleph 4 with incresed bias.;)
Click to expand...

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
 
lieven

lieven

Member
Joined 2002
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)
 
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Edwin Dorre

Member
Joined 2002
lieven said:
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)
Click to expand...

The amp on the back is a Denon AVR3801. Only used for DVD movies which drives my back and center speakers. I use pre-out to my Aleph P for the front speakers.

My precious amp was a Classe CAP-151 integrated. The Aleph P + Aleph 4 wins ... ;-)

I bought the heatsinks from Texim, haaksbergen and the trafo's from Amplimo.

Edwin
 
trigon

trigon

Member
Joined 2002
Excellent job.

All compliments. Very impressive and I hope as well excellent sounding engine?

I have PCB's for Aleph 4 (mono block version) which I have ordered from PCB-Design (Kristijan) and they really look excellent.

Slowly completing my Aleph 4 but way far from finishing. May I ask you kindly if you can measure Voltages on 220uf capacitors, just curious as I have asked in an earlier post if I can use FK Series Black Gate capacitors 220uf/25V. ;) Thank you in advance.

Congratulation one more time, looking forward to see DIYPass web site with additional Aleph 4.

Trigon.:)
 
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Edwin Dorre

Member
Joined 2002
Peter Daniel said:
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.
Click to expand...

I used 2 times 25A 600V bridges. One for each channel, with all diodes of the bridges bypassed with a .47uf MKP. They are bolted to the floor of the amp.

Edwin
 
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