HELP! ( MJ 2955- 2N 3055 )--( MJ15015- MJ15016) Transistors

[runruncamaro]

Hello everyone.My 80's vintage stereo receiver has to have the following transistors replaced MJ2955 and 2N3055. There is a pairs of these on each channel. Someone has told me that I can replace those transistors with a MJ1 5015 and MJ1 5016. Could this be done?Is that a better equivalent or would it be best to replace with originals? I will appreciate all your help since I will be doing the replacement. Thank you very much everyone.

[Pete Schumacher]

Re: HELP! ( MJ 2955- 2N 3055 )--( MJ15015- MJ15016) Transistors

Hello everyone.My 80's vintage stereo receiver has to have the following transistors replaced MJ2955 and 2N3055. There is a pairs of these on each channel. Someone has told me that I can replace those transistors with a MJ1 5015 and MJ1 5016. Could this be done?Is that a better equivalent or would it be best to replace with originals? I will appreciate all your help since I will be doing the replacement. Thank you very much everyone.

The original parts are still being made and are fairly common.

I even have some on hand. How many do you need?

[runruncamaro]

Re: HELP! ( MJ 2955- 2N 3055 )--( MJ15015- MJ15016) Transistors

mj2955(2 of these) and 2n3055( 2 of these). but i would please like to know the difference between the mj15015-mj15016 and the originals if you know.

[runruncamaro]

Re: HELP! ( MJ 2955- 2N 3055 )--( MJ15015- MJ15016) Transistors

Thank you very much Pete for answering. For how much would you sell them transistors Pete?

[Pete Basel]

Re: HELP! ( MJ 2955- 2N 3055 )--( MJ15015- MJ15016) Transistors

Look at the current 2N3055s to see who the manufacturer was, often an M for Motorola, RCA, or ...?

[AJ]

Re: HELP! ( MJ 2955- 2N 3055 )--( MJ15015- MJ15016) Transistors

The MJ15015/MJ15016 pair is a selected 2N3055/MJ2955 for higher voltage applications. They will be drop in replacements. I would stick with OnSemi. You can get samples direct from them, up to 5 of each.

http://www.onsemi.com/pub_link/Collateral/2N3055A-D.PDF

[Pete Schumacher]

Re: HELP! ( MJ 2955- 2N 3055 )--( MJ15015- MJ15016) Transistors

Thank you very much Pete for answering. For how much would you sell them transistors Pete?

Are these the full TO-3 metal case?

Even brand new ones are only a couple bucks each.

Mouser.com and Newark.com

http://www.newark.com/on-semiconductor/2n3055g/bipolar-transistor-npn-60v-to-204/dp/98H1011

http://www.newark.com/on-semiconductor/mj2955g/bipolar-transistor-pnp-60v-to-204/dp/26K4526

Might be simpler/cheaper to order via those guys.

There might even be an electronics store within driving distance that would have those in stock.

[Pete Basel]

Re: HELP! ( MJ 2955- 2N 3055 )--( MJ15015- MJ15016) Transistors

The 15015/16 are not really selected, rather they are an improved type of the same family and you should use them if they are known to work well in the design. They are rated for the same speed but sometimes they actually do better and faster devices can hurt stability.
Note here that nearly every specification is improved, and in particular the Safe Operating Area is improved:

http://www.onsemi.com/pub_link/Collateral/2N3055A-D.PDF

Better SOA might help the amp not fail again.
What is the amp and does it have a reputation for failure?
In any particular way if so?

And by the way, the 2N3055 was really the first widely used Silicon high power device with the early ones fabricated in a slow single diffused process by RCA:

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=960371&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F16%2F20748%2F00960371.pdf%3Farnumber%3D960371

http://semiconductormuseum.com/Transistors/RCA/OralHistories/Meisel/Meisel_Index.htm

The later ones were really a different part and used a triple diffused process. Given that your amp used the compliment also, they were of the later triple diffused variety.

[tyger23]

Re: HELP! ( MJ 2955- 2N 3055 )--( MJ15015- MJ15016) Transistors

I had a NAD amp fail on me recently (7220PE, based on the old 3020 design). I used MJ15003/MJ15004 transistors, and I added base and emitter resistors to help stabilize the design while using faster transistors. The MJ15015/MJ15016 and the MJ15022/MJ15023 would also work well.

I'd post what your original schematic is, so that we can check to see if stability might be an issue when using newer, faster transistors.

[runruncamaro]

Re: HELP! ( MJ 2955- 2N 3055 )--( MJ15015- MJ15016) Transistors

The original transistors have an M Pete.Thanks for your response.

[runruncamaro]

Re: HELP! ( MJ 2955- 2N 3055 )--( MJ15015- MJ15016) Transistors

Thanks AJ!

[runruncamaro]

Re: HELP! ( MJ 2955- 2N 3055 )--( MJ15015- MJ15016) Transistors

Yes Pete they are TO-3's Thnx.

[runruncamaro]

Re: HELP! ( MJ 2955- 2N 3055 )--( MJ15015- MJ15016) Transistors

Pete I now have a better understanding at what options I have. Thank you very much.

[runruncamaro]

Re: HELP! ( MJ 2955- 2N 3055 )--( MJ15015- MJ15016) Transistors

tyger23 unfortunately the only ''schematic'' that came with the unit is a very basic one. What I mean is that it is a not detailed schematic. I don't know that maybe if I take a close up picture of the audio output module section where those 4 transistors are might help?

[tyger23]

Re: HELP! ( MJ 2955- 2N 3055 )--( MJ15015- MJ15016) Transistors

tyger23 unfortunately the only ''schematic'' that came with the unit is a very basic one. What I mean is that it is a not detailed schematic. I don't know that maybe if I take a close up picture of the audio output module section where those 4 transistors are might help?

No - a picture won't really help. Just post the make/model of the amp and hopefully we can find a service manual somewhere.