Marantz 1030 Heat Sink

[n4buq]

The PA board on my Marantz 1030 does not have heat sinks on H711 and H712. I notice many examples on the web where these two transistors do have heat sinks on them.

I'd like to have them on mine; however, the transistors appear to be TO-44 form factor and I don't find heat sinks for those.

Are these indeed TO-44? Anyone know a source for heat sinks for these two transistors?

Thanks,
Barry

 

[catrafter]

I have seen TO-92L in those locations, but never TO-44. The ones that have heat sinks usually use TO-39 style transistors with press on heat sinks.

Tom

 

[ruesselschorf]

Hello,

the 1030 amp-board is a downsized 1060 and really does not need a heat sink on the driver transistors.
These are TO-92L transistors, either search for TO-92 heatsink or fold them yourself form a thin sheet of aluminum

Helmut

 

[n4buq]

The transistors on my board seem a bit odd. They look like TO-92L, but they are slightly larger in diameter (~0.230" versus ~0.190" for a TO-92). I'm pretty sure these are factory originals but just don't see heat sinks for this size body.

 

[Tom B]

I have tons of heatsinks that are used for this type of transistor if you want. although if they were really needed, they should have been there

The heatsinks I have were used by electro voice. They are circular aluminum fin type sort of spring loaded where they are easily mounted onto the transistors

 

[n4buq]

I have tons of heatsinks that are used for this type of transistor if you want. although if they were really needed, they should have been there

I can't figure why some have them and some don't. I suppose if the drivers have lasted this long, then they probably don't really need them but seeing them on other units makes me wonder if those transistors might get pretty warm. I plan to monitor them when I get this all back together.

Thanks,
Barry

 

[Tom B]

Looking at your board and the service manual, this is what I see.
The drivers have big black heatsinks on them (H710, 711, 712, 713)

Transistors H703, H704 are not drivers are in the early part of the amplifier, and don't usually develop a lot of heat. But looking at the service manual the original transistors did have a type of heatsng on the (2SC853), so assume that someone has replaced them along the line. If they don't get hot, i wouldn't worry. If the unit is working, and they do get a little hot, either try to find original 2sc853 replacements, or send me a PM and I can get you some acceptable heatsinks.