Another Aleph finished!

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Edwin Dorre

Member
2002-04-12 12:25 pm
Netherlands
  • #1
    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.

    [IMGDEAD]http://www.xs4all.nl/~edwind/aa.jpg[/IMGDEAD]

    [IMGDEAD]http://www.xs4all.nl/~edwind/bb.jpg[/IMGDEAD]

    [IMGDEAD]http://www.xs4all.nl/~edwind/cc.jpg[/IMGDEAD]

    [IMGDEAD]http://www.xs4all.nl/~edwind/dd.jpg[/IMGDEAD]

    Thanks,

    Edwin
     
    Peter Daniel

    Peter Daniel

    Member
    Paid Member
    2002-07-27 5:20 am
    Toronto, Canada
    www.audiosector.com
  • #4
    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?
     
    E

    Edwin Dorre

    Member
    2002-04-12 12:25 pm
    Netherlands
  • #7
    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! :)))
     
    E

    Edwin Dorre

    Member
    2002-04-12 12:25 pm
    Netherlands
  • #8
    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
    2002-08-11 4:42 pm
    Belgium
  • #10
    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)
     
    E

    Edwin Dorre

    Member
    2002-04-12 12:25 pm
    Netherlands
  • #11
    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
    2002-05-09 4:35 am
    Canada
  • #12
    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.:)
     
    E

    Edwin Dorre

    Member
    2002-04-12 12:25 pm
    Netherlands
  • #14
    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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