NAD 3130 Output Transistors

[Kevin Atkins]

Hello all,

I've got a NAD 3130 amplifier on the bench at the moment with blown output transistors, one of the drivers has gone too..

I'm looking for suitable 2N3055 / MJ2955 replacements, and in the back of my mind I seem to remember some issues relating to correct devices (for 3020 amplifiers) - homotaxial vs epitexial if memory serves..

The 3130 output stage looks pretty close to the 3020, no emitter padding resisters etc.. So, is the 3130 similarly sensitive to getting the correct replacements? I'd have thought that by the mid 1980s, the old RCA homotaxial devices were long obsolete so modern 3055s should be fine in the 3130?

All comments welcome - meantime I'm going through the rest of this dead amplifier with a fine toothcomb before I risk powering it up..

 

[stillspin'n]

Search for a power envelope model on here, there is a mod to use epitexial transistors. Basically it's just cutting the foil on the board and adding emitter resistors and some resistors to the base as I remember.

 

[Kevin Atkins]

Search for a power envelope model on here, there is a mod to use epitexial transistors. Basically it's just cutting the foil on the board and adding emitter resistors and some resistors to the base as I remember.

Thanks - I've had a hunt and found the info.. I think I'll be adding emitter resistors