hifi engine


Hello all. Stuck in virus isolation and thought I'd spend the time fixing my amp Marantz 1060.
I am replacing the transistors on the phonoboard:

the 2sc1000's with 2sc2240 bl

and 2sc 458's with 2sc1845.

Got the 2240's and the 1845's from china. Only problem is the data sheets for the 2240's gives the pin outs as e c b but by meter makes them ebc (not even the same base!), and for the 1845's data sheet says ecb and my meter says ceb.
When I say data sheet I mean something I got from google, all I got from China was a placcy bag.

With the old transistors my testing results agree with the respective datasheet, so though I'm a novice I think I'm using the meter correctly. The voltage drops are what you would expect and all the new transistors (10 of each) give consistent readings.

My questions are Is this common and should I just solder the pins according to my meter or just bin the transistors. (I dont think soldering them acording to the data sheet is an option as we seem to disagree as to which pin is the base!)
Jim Hallett

Re: marantz1060

It is not common. But if you wish to try them, do it according to your meter. Your Marantz 1060 will not go in fire if the transistors are not good. The 2SC2240BL is a very good transistor and as you know, for every good product there is a fake one from China. Some ten years ago I've bought the stock of 2SC2240BL from a local parts store. By chance they had only a few. When I tried to match them with an hFE meter, I got strange results. I put them on my venerable Tektronix 575 curve tracer, to find they were PNP, and very bad PNP. These were the last transistors I've bought from this store. You have better chances to find true original 2SC2240BL (or 2SC1845) in dual tray cassette decks of the 80's

Re: marantz1060

Depends on what 'meter' you are using. Is it a transistor tester that identifies basing or just an ohmmeter?

Re: marantz1060

Its digital multimeter. I just used the diode setting to measure the voltage drop between the base and both the emitter and the collector, the highest being the emitter.