ARRO with Aleph

[ruferto]

I have a Totem Arro speakers, they are 87 db / 4 Ohm
Can some one tell me witch Aleph should i build for this great speakers , now i have a 80W REGA AMP, but i want to try a class A amp.
I was thinking of a Aleph 5 but with more bias corrent, is it a good choise.

Best regards,

 

[Nelson Pass]

Whatever Aleph you build, figure on higher bias, as the stock Alephs are
really designed around 8 ohms, and you will want about 50% more
current. An Aleph 2 circuit with 32 volts rails would be a good example.

 

[Bakmeel]

Aleph 2+

I'm building a set of Aleph 2 amps for use with my Piega P5 LTD. They are also around 87dB/W and 3-4 Ohms (4 ohms according to spec, but the curve is more on 3 ohms for the mid-range frequencies).

I was planning to beef up my A2's by adding 2 sets of output devices, so 4 fets extra per amp, putting the bias up to 4A. The heatsinks and Power Supply should be able to take that extra dissipation without a sweat (PSU rails will probably be around +/-50). The increased dissipation will get around 400W per channel.

The only thing I'm not sure about is whether I need to modify the rest of the circuit as well?

Bakmeel

 

[Nelson Pass]

You might want to adjust the resistor which determines the gain on the
current source for 50% contribution. Also, as you pile up output devices
you may find that you need to adjust the values of the Drain-Source
compensation capacitor.

 

[ruferto]

thank you very much for the help.