MARANTZ 2330B Power Board P700 Choke induction

[angcast74]

Hello i need to replace the 2 Choke induction (L701/L702) on my Marantz 2330B P700 Power Board .
For the manual the value are 2,2uh. Seems a small value compared to the size.
I hope it is not a mistake in the Manual.
Can someone advise me where to find an alternative component for the L701 / L702 inductor?
How many amps should the inductor have?
Thanks from Italy.

 

[AE Bob]

Those chokes are to decouple high frequencies from the speaker system, so capacitive loading will not kill the high frequency negative feedback. Without them it would likely be possible to put the amplifier into oscillation (likely at hundreds of kHz) when a capacitive speaker load is connected. I doubt that the actual value is very critical. You could likely make your own with some enameled wire. Just use the same or larger gauge wire, and wind the coil with the same diameter and number of turns. You can use shellac or epoxy glue to make the coil hold it's shape.

 

[angcast74]

Those chokes are to decouple high frequencies from the speaker system, so capacitive loading will not kill the high frequency negative feedback. Without them it would likely be possible to put the amplifier into oscillation (likely at hundreds of kHz) when a capacitive speaker load is connected. I doubt that the actual value is very critical. You could likely make your own with some enameled wire. Just use the same or larger gauge wire, and wind the coil with the same diameter and number of turns. You can use shellac or epoxy glue to make the coil hold it's shape.

Thanks Bob,
and if i use SMD Power Inductors HCI2114-2R2 2.2uH; Ioper: 39A; 1.5m?; ±15%; Isat: 50A?
What do you think about?
Thanks

 

[AE Bob]

I don't know if I would go to a ferrite core inductor. It may be OK, but the originals were air core, which tend to have the same characteristic regardless of frequency range. Ferrite core devices have varying characteristics depending on frequency range. I believe that is why many speaker manufactures use coreless coils in their crossovers.