Meridian 103 - bdy56 Transistor Alternatives?

[Thomo]

Hi. I have an old Meridian 103 which has four BDY56 as output transistors. Unfortunately two of these are bad and the only replacements I can find are £12 each.

Could I use any of these instead?

mj21194

2n3773

bdy56

Any help greatly appreciated, thanks.

Lee

[poynton]

Can't you use the plastic TO220 versions ?
A lot cheaper.

[Thomo]

Hi Andy. I don't think that it would be possible to mount them on the heatsink. They're mounted in a similar way to a Quad 405.

I have stuck the 2n3773's in just to see if they work but I have a problem with one channel. I don't have a scope so I can't check for oscillations etc though. Any ideas as to whether they're suitable? They seem to have very similar specs looking at the datasheets, but then I am a bit of a noob.

Lee.

[burbeck]

hi Lee,
have a look at
BUV20
MJ15003

[Thomo]

Hi Bob. Thanks for that. Do you think that the mj15003 will have as good a sound as the originals? I have them in my Quad 405 but I am told they're not as good as the 2n3773's.

Lee.

[burbeck]

hi Lee,
the MJ15003 are nice and cheap try them out.
the BUV20 are better but expensive.

why not give meridian service a call and ask there advice on the sub of these?
i repaired one of these amps a while ago which had one set of output devices already replaced (by meridian) for the life of me i cant remember the type number they used, it may have been BDY95 not sure. i was only replacing the speaker sockets.

let me know if you do call them

[Thomo]

I rang them yesterday, and they told me that they would be ringing back today, as they guy I need to speak to wasn't there. Aparently he worked there when the 103's were in production!

Meridian customer service has been outstanding I must say. How many companies would go out of their way to provide service information and help about a product they marketed nearly thirty years ago?

Lee.

[burbeck]

hi Lee,
i agree meridian are one of the few companies left with great back up.

[burbeck]

hi Lee
did you get an answer from them?

[Thomo]

Not yet, I will have to try again I think. Whilst waiting for a reply I ordered four MJ21194G transistors. I got them for $15 shipping which works out at around £7.50. Not bad I thought.

In the mean time, I fitted 2n3773's but I still have no joy at getting the thing to work. How accurately can you tell a transistor is faulty by testing? I have a fairly standard multimeter and used the diode test function.

I removed all the transistors and tested them, they all seemed ok, so I put them back with the new output trannies and still read -1.2v & -2.3v offset. I'm thinking of sending it to Meridian but don't want to, as I wouldn't learn anything out of it.

Lee.