Best practice for power amplifier building ?

[drmaftoon]

I'm building a nap 250 clone. I'm going to keep toroidal transformer and rectifier board in one chassis.
I can't decide if the voltage regulator board should be installed in the same chassis as amplifier board or it should be in the same chassis as rectifier board?
Will it make any difference either way? Please guide me
Many thanks
Sajjad

 

[rayma]

I can't decide if the voltage regulator board should be installed in the same chassis
as amplifier board or it should be in the same chassis as rectifier board?

The safest bet is for the regulator to be in the amp chassis.
The regulator drives the entire amplifier, and you want to have
low impedance between the regulator and the amp circuit.

The regulator board also should have some added local decoupling at its input,
if it is separated from the main filter capacitors. How much decoupling is necessary
may need to be found experimentally, to keep the regulator stable.

 

[FauxFrench]

Fully agree with rayma.

 

[rayma]

Fully agree with rayma.

Personally, I'd just install a steel cover over the toroid if the precaution
is thought to be necessary, and keep it in the same box as the amplifier.
However, I don't recall hum ever being an issue in the Naim.

Good wiring practice goes a long way in making a quiet amp.
Twist those wires, and don't couple charging pulses into the grounding.

 

[FauxFrench]

I make modular amplifiers such that I can re-use the power supply (transformer + rectifier bridge + some decoupling) when I (soon after) want new experiments. Then I split up as you advice. If it is for long term use and to be put in the living-room, one cabinet may be appreciated by the spouse and a shielded toroidal transformer rarely causes problems.

 

[rayma]

I make modular amplifiers such that I can re-use the power supply (transformer +
rectifier bridge + some decoupling) when I (soon after) want new experiments.
Then I split up as you advice.

Good idea, especially for Pass type amps where most models use a similar supply.
If I'm going to have two boxes, I'd rather go with a pair of mono amps.

 

[drmaftoon]

Thank you so much both of you, I appreciate your guidance. I will do exactly as you both suggested.

 

[rayma]

Thank you so much both of you, I appreciate your guidance.
I will do exactly as you both suggested.

I'd say add at least 1000uF local decouping at the regulator input,
bypassed by a small film or ceramic 0.1uF capacitor. Twist together
tightly all leads going between the two boxes.

 

[drmaftoon]

Actually due to wrong measurements the case I've ordered is incorrect size hence I will have to split the components to make them fit

 

[drmaftoon]

I'd say add at least 1000uF local decouping at the regulator input,
bypassed by a small film or ceramic 0.1uF capacitor. Twist together
tightly all leads going between the two boxes.

Will do, thank you once again. Very informative.