Aleph 2 build questions

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ok let`s try:


I had the same questions. looked in the Service Manuals & some members told me that:


Aleph 3 & 30 pretty much the same
-both mosfet frontend
-aleph 3 -unbal Input, -2 Output pairs, -2.1A bias
-aleph 30 -Bal/unbal Input, -3output pairs, -1,6A bias


Aleph J
-jfet frontend -bal/unbal Input, -2output pairs, -bias in schematics not specified but 1,6A-2A bias should be ok.


The most difference in Sound is because the use of jfets / mosfets
in the frontend.


Mosfets- darker, more dynamic, Little bit more bass than J,
Jfets -more detailed, better top end, not so good bass.


Never heard a mosfet frontend Aleph, so not my own experience.


Hopefully i could help you
 
I need your advice please about power supply for aleph 3. I intend to build it as bridge-CRC-voltage stabilizer. So i plan to output 35 V from CRC filter and than to decrease it by tl431+Mosfet in order to obtain +-25V. What are the disadvantages of this approach except power dissipation of 10 watts? Which electrolytic capacitors (model, brand) for the reasonable price will be ok in this power supply (22 000 uf) as it tends to be the most expensive part overall?
 
Official Court Jester
Joined 2003
Paid Member
how you got to power dissipation of 10W ?

skimming - using (existing?) power transformer then caps with increased voltage, then decreasing voltage is recipe for bigger expenses than using proper xformer and caps from the start

18Vac secondaries will give you something as 22V5dc at caps , loaded onditions

to shave 35V to 25V , there is difference of 10V , multiplied with Iq ( at least 3A for two channels) and that's 30W per rail , 60W for both rails

that , not disputing way how you got starting figure of 35Vdc

don't get me wrong - I certainly tried more than zillion times either to skim expenses or simply to be smartjack , but sometimes most effective and most rewarding way is to do things as smarter guys are doing it
 
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Official Court Jester
Joined 2003
Paid Member
first you need to chosse between snap-in and computer grade caps

first one are in economic range , second in expensive range

brands - usual suspects and you choose by availability ( price and level of complication)

Panasonic , Philips , F&T etc.

just go to mouser , digikey, Buerklin , TME ....... choose electrolytic caps , put 25V or 35V in filter , capacitance of your liking ( I prefer 33mF) .......say 15mF to 47mF (mF being miliFarad) then observe

according to these information you get there , you can look more locally , or buy from there

if in doubt , post here
 
Official Court Jester
Joined 2003
Paid Member
not so simple

room - speakers - how much watts and what type of amp

then - dissipation , so what case , what xformer , what caps , what bridges , what wires

can't have approach as with icecream - 2 or 3 or 4 spoons , big cornet or small one

there is a huge difference in hardware (kilos , money , size) between Aleph 3(0) and Aleph 60
 
Hi. Some wrong when i try test aleph 2 with load 8 Ohm, look the sine wave form is not good. Did some one get problem like that ? what wrong with circuit?
 

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