Marantz 2330 driver subs

[ocdecio]

I have a 2330 on the bench with driver subs I never saw before. Instead of 2SA839/2SC1669 I see 2SB596/2SD526. The spec sheets say these subs can take half the voltage as the originals.

Pretty sure I should replace them - even if working?

 

[Matt Giarra]

Does the service manual show the predicted voltage at that component’s location in the schematic? Perhaps the component you were expecting is rated for 2x the voltage it needs to be?

 

[ocdecio]

Does the service manual show the predicted voltage at that component’s location in the schematic? Perhaps the component you were expecting is rated for 2x the voltage it needs to be?

Fortunately the SM lists the expected voltages at Q710/Q709, the transistors in question:





Installed are as such:



Originals are:



I think 80V (as max rating) may not be safe.

 

[Matt Giarra]

Looks like you have about 65V across the emitter/collector and collector/base, right? So why wouldn’t a component rated to 80V_CE and 80V_CB work? It looks like your current part can handle more power as well (30W vs 25W).

 

[ocdecio]

Looks like you have about 65V across the emitter/collector and collector/base, right? So why wouldn’t a component rated to 80V_CE and 80V_CB work? It looks like your current part can handle more power as well (30W vs 25W).

It would and it does work. I am worried about safety and reliability.

 

[Matt Giarra]

It would and it does work. I am worried about safety and reliability.

Based on those specs, it seems like you’re good. But curious to hear other opinions.

 

[ocdecio]

Based on those specs, it seems like you’re good. But curious to hear other opinions.

Maybe I am, and I would love to hear other opinions. One thing that happens different on this side is that the pre-drivers get a lot hotter than the other side, 20F+ difference, and I am trying to find out what could cause that.