ALEPH-X - The Monster

[kristijan-k]

Hello,

Here is also one approach

The picture is too big to upload, and this smaller below is little fuzzy.
This is the link to the full size : http://web.vip.hr/pcb-design.vip/aleph-x.html

Hopeing to build this as my next DIY audio project

[MikeW]

Shouldn't the twice as many output resistors as sourse resistors? The Aleph 2 has 1 ohm source resistor and half ohm output resistors.

[Nelson Pass]

Originally posted by MikeW
Shouldn't the twice as many output resistors as sourse resistors? The Aleph 2 has 1 ohm source resistor and half ohm output resistors.

The ratios are arbitrary, but you might have to adjust the current
gain of the current source.

[john-china]

why use 50k resistor connecting output

[jh6you]

The monster looks strange in the active current source complex.
Do you think it will work as wanted?

[GRollins]

Since you've chosen to cap-decouple the front end from the output, you no longer have to use 392 ohm resistors for the front end load resistors. Given that you seem to be going for power you might consider using a higher value. Particularly if you intend to use the circuit in a bi-amp setup with a different amp that might have a lower power output. The idea being that it would be nice if both amps (the higher powered one and the lower powered one) reached full power about the same time, which will take more gain on the part of the big amp.
Which I'm assuming is this one...
Now, assuming that you intend to use this as a tweeter amp with an X-1000 driving the woofers, ignore the above.

Grey

[kristijan-k]

Hello,

Thank you for the response.

Mike, the source resistors are fine, but you can use even 1 Ohm,
but than the amplifier would run at much lower bias.
I plan to use 1000 VA (2x22 V) transformer, and the 0,47 Ohms
seems to be the optimum on the little tight side.
This circuit above normally would require around 1200 VA,
or even better 1500 VA (per channel) if you would like to be on a
very safe side.

'The one and only', thank you for the advice.
I planned to use 16 Ohm speakers with this amplifier, but now I
would probably use ones with 8 Ohms impedance.

John, this layout must have these resistors to function properly.
The overall gain would go little down, but there would also be
much less distortion at the output.
They also serve for the setting the gates of the gain transistors
at the 4 V, together with the 15 K and 10 K trimmer.
It is recommended to use multiturn trimmers, as the setting the
output offset would be far more easier and precise.

ih6you, it is not that strange as it looks at first look.
It should work just fine.

Grey, the 392 resistor would be left in the circuit to safely test the
amplifier, but it could be replaced with the some similar value.
I plan to use this amp together with the Aleph 5 and with the
active crossover.

Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip

[grataku]

If I understand it correctly, this design is pretty bizarre, and utterly un-buildable.
All this current dissipated for a 16 ohm load? Are you sure you want 3 100 ohms resistor in parallel going to -26V and not to ground?
In any case you would be circulating as much current in these resistor as in your speakers.

[Netlist]

Looks very elegant to me.
A few questions: Why do you decouple the front end?
There must be a good reason, as these caps are in the signal path.
Can the protection circuit still be added? (Q4, Q9 in the original AlephX) ? And why the 100ohm resistors to -V? Isn't that a waste of power as Grataku states?
Does this work similar as R1, R4 and R44, R45 in AlephX V1.0?
Nice job nevertheless.

/Hugo

[grataku]

If my calcs are correct we are talking about 13 Amps/channel
with 700 W/channel dissipated. It is going to be as elegant as an elephant at Tiffany. The trafo itself is going to be dissipating 25 watts.
But it's just the usual A-hole me.