Substitutes for McIntosh

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1

------Question for MJE350G Please Put your question below------

I am trying to match a substitute for a pair of complementary transistors in my McIntosh MC-7300 amplifier. The original pair are Sanyo 2SA1480D/E and 2SA3790D/E. I’m getting MJE340G and MJE350 as substitutes. Is this substitution equivalent or allowable? This pair is in the signal path of the Power Driver PCB.

Thanks for any help you can provide. I ordered and have received these parts, but want to ensure they’re appropriate.

2

Hi J_bose, welcome to the DigiKey TechForum,

Although the MJE340G/MJE350G pair has similar polarity, voltage ratings, and pinout, it is not an exact electrical equivalent. The main differences are the gain specifications and high-frequency characteristics of the Sanyo transistors, which could affect performance or stability in an audio application. The Sanyo datasheet calls out high frequency and low reverse capacitiance while the MJE are typically for general purpose so it’ll be important to verify that these characteristics will work for your application.

3

Thanks, Mitch, my research was giving me that answer, as well. Can you recommend a replacement equivalent for the originals for this application? Is there additional information I can provide? I have the schematic available if that helps.

Jon

4

Perhaps a better question first. My tester shows the old component with the following values:

hFE= 110

Vbe = 0.61V

Ic = 0.5uA

I believe these values are within spec tolerances. Can I infer that the component is still good and I should look elsewhere for the fault?

Thanks

5

Those reading do appear to be within specification. You should keep an open mind to considering the issue may be something else.

6

Thanks so much! I’ll keep looking.