Mono 160W Aleph-X towers

[Wes Marquenie]

Mono 160W (16Ohm) Aleph-X towers



One Tower:


1*800VA 2x30V toroid (I'll buy a second one when I have enough money)

CLC filtering
2-3mH air core chokes (still have to wind them from pairs 1mm wire)
4x 37000uF
4 (maybe 6)x 68000uF

16 output devices

Outer dimensions:
250mm x 250mm x 820mm




front

[Wes Marquenie]

back

[Wes Marquenie]

inside

[steenoe]

1*800VA 2x30V toroid

Whooohoooo, you intend to ride the A-X at 1,4*30 volts? 42 volts?? You better check Wuffwaff's excell page

Steen

[Wes Marquenie]

The alephx will be optimised for a 16 Ohm load so the current draw isn't as high if it's optimised for 8 or even 4 Ohm.

And if the toroids runs to hot I'll use my variac for the time being.

[wuffwaff]

Hi,

2x30V really is a bit too much. 2x18V primaries will give you 200 watts in 16 ohms so even if the bias isn´t that high you will be wasting quite a lot of power.........

William

[EUVL]

One comment from a mechanical engineer, if I may.

You would find that long and narrow heatsinks are not effective for natural convection. The fins are too long and hence resistance to air flow too high. This is why power amplifier heatsinks tends to be wide and short. After 150mm length, the thermal impedance of almost all heatsinks levels off (i.e. no further gain for any additional length). Increasing the spacing between fins helps, but then you loose area in turn given the same width.

Of course this is not the case if you use force convection -- i.e. fan.


Patrick

[Wes Marquenie]

Originally posted by wuffwaff
Hi,

2x30V really is a bit too much. 2x18V primaries will give you 200 watts in 16 ohms so even if the bias isn´t that high you will be wasting quite a lot of power.........

William

Are you sure?

2x18v secondaries gives 50V rail to rail. With some power-supply and mosfet losses this leaves about 45V. 45^2/16=127W


Still 30V is probable a little too high. Maybe I should consider LCLC or LCRC power supply filtering. or buy a new pair of toroids.

[Wes Marquenie]

Originally posted by EUVL
One comment from a mechanical engineer, if I may.

You would find that long and narrow heatsinks are not effective for natural convection. The fins are too long and hence resistance to air flow too high. This is why power amplifier heatsinks tends to be wide and short. After 150mm length, the thermal impedance of almost all heatsinks levels off (i.e. no further gain for any additional length). Increasing the spacing between fins helps, but then you loose area in turn given the same width.

Of course this is not the case if you use force convection -- i.e. fan.


Patrick

Could you elaborates on this with some calculations?

[pinkmouse]

Originally posted by Wes Marquenie
2x18v secondaries gives 50V from rail to rail. With some power-supply and mosfet losses this leaves about 45V. 45^2/16=127W

Remember, by the nature of its topology, the AX is bridged!