Alphasonik PMA-2300 zobel

[picco76]

Hello,i need to know resistors value of output zobel on pma-2300 old amplifier. Thanks

 

[picco76]

Are R42 and R142 (picture attached)

 

[Perry Babin]

What's the value of the series capacitor in the Zobel?

 

[HumbleDeer]

Can you take a picture from further away? I'd like to see what type of board revision this is, so I can find it on another board for you.

Edit: A similar amplifier from the same series has 2.2 ohm resistors (red-red-gold-gold, fusible) in series with the PET caps at the outputs. That sounds like an entirely reasonable value to me.

 

[picco76]

What's the value of the series capacitor in the Zobel?

220nf

 

[Perry Babin]

If you don't get any more reliable information, compare the values of the parts in your amp to those in the attached image. The inductor in the output makes this seem like a Zeff design. The attached clarion is also a Zeff design.

 

[HumbleDeer]

2.2 ohms huh! Although this is in parallel with the capacitor 👀

 

[picco76]

Can you take a picture from further away? I'd like to see what type of board revision this is, so I can find it on another board for you.

Edit: A similar amplifier from the same series has 2.2 ohm resistors (red-red-gold-gold, fusible) in series with the PET caps at the outputs. That sounds like an entirely reasonable value to me.

In attached board picture

 

[Perry Babin]

Seeing that the network appears to be on the speaker side of the inductor, see attached.

 

[picco76]

Ok, 5.1ohm resistor. I change also the capacitor with 120nf?

 

[Perry Babin]

These amplifiers are so stable that it won't make much difference. Many amp designs use 0.1uf and 4.7 ohm so 5.1 and 0.12uf would seem perfectly OK.

 

[picco76]

Ok, thanks Perry!