Transistor info...

[Bad silver]

Hi, I got a new amp for my collection Diamond Audio D7104 that blew one output transistor while bench testing. What transistor is this?

An externally hosted image should be here but it was not working when we last tested it.

 

[jol50]

I think it is this one on ebay (don't know the seller): http://cgi.ebay.com/2SA1303-A1303-P...936864QQihZ004QQcategoryZ109457QQcmdZViewItem

It is a Sanken, hit google and you can find a data sheet.

http://pdf1.alldatasheet.com/datasheet-pdf/view/37917/SANKEN/2SA1303.html

 

[Bad silver]

Yep, I also found 2sa1303/NTE2306, but just wanted somebody to confirm… Thanks

 

[Perry Babin]

I'd be careful buying those parts from ebay. There are a lot of fake parts and even those distributors with relatively good reputations seem to be selling questionable parts. I'd suggest buying them from mcm. I've never had any problems with any parts I purchased from them.

http://www.mcminone.com/

Remember, you have to replace all of the transistors that were running in parallel with the one that failed.

I've never seen one of those amps but it looks like it's related to some of the PPI amps.

 

[Bad silver]

Hi Perry, it was one of three transistors connected in parallel. Strangely enough, when I removed this transistor the channel continued to work but with little (almost unnoticeable) distortion. I remember that when I removed outputs form other amps, there was a lot more distortion... This Diamond amp is amassing.

 

[Perry Babin]

If an amp has 10 parallel transistors (20 total for the channel) and you remove 9 of the 10, it shouldn't change the way it sounds unless you drive it hard. Of course, it would not survive long at high power if it needed 10 and there was only one left to do all of the work.

The Diamond audio amps are supposed to be good quality amps but I haven't seen enough of them to know if they are.

It looks like they're using the same build house as ARC and Zapco.

 

[Bad silver]

Do you think this is original? It seems like someone added the resistor in series with the cap...

 

[jol50]

I bought some IRFZ44 off ebay, they looked like IR but how do you know? They worked fine but its not like I fully benched the amp and they were replacing another can't-find Sanken part that was $15 each+ship from good old Sony only. I have seen 44s in cheap China amps but they looked different.

I had a little amp with 2 TO-220 per channel, one smoked and I clipped it out. It sounded really bad, like I was powering it off a 9v battery. Most of the TO-220 amps sure are cheaper for parts, at $6ea plus shipping (depending on how much stuff you order at once) some of these smaller amps are not worth fixing. I need 2sa1694 for 5.79 at MCM and I guess I'll just wait for the next order....but I don't order that often and now it will be sitting around here .

Here is a cool chart for SK Transistors: http://www.ibselectronics.com/pdf/ac/Allegro/Allegro_Power_Transistors.pdf
Well actually a huge catalog for them, but it has a selection guide at the front. Certainly a broadband thing or don't click on it.

 

[marko]

sorry to bump this old thread but i have a d7056 that needs a couple of a1303 and would like to know if the 2sa1303 is a direct replacement or not? i'm struggling to find just a1303...

 

[Perry Babin]

Yes, that's a 2SA1303.

 

[jol50]

Perry is modest...

Look here. Scroll down to "Back to repair information...." then down six paragraph headings and Perry explains the naming prefixes for those in a Note there. With those types you add it to find them, the transistor # always leaves them off.