Hi, I have an old Yamaha A-520 amplifier. It isn't working since my mate blew it up somehow. I opened her up and there is a transistor split intwo, black marks everywhere, obviously it bit the dust
A1306A it reads, did a search on google. http://www.epanorama.net/wwwboard/messages/181.html was the only page that I could find that was useful. So I checked up the 2SA1306A as the page recommended and found a bunch of results, however I can't seem to find anything that says where I could buy another one, or even enough details for myself to find an appropriate match. Then again I am not very experienced so I am not sure if I can find a replacement.
There are as much details as I can find
2SA1306 SI-P 160V 1.5A 20W
Can anyone suggest a replacement if possible, or maybe someone knows where I can find hard to get transistors.
Mikey
A1306A it reads, did a search on google. http://www.epanorama.net/wwwboard/messages/181.html was the only page that I could find that was useful. So I checked up the 2SA1306A as the page recommended and found a bunch of results, however I can't seem to find anything that says where I could buy another one, or even enough details for myself to find an appropriate match. Then again I am not very experienced so I am not sure if I can find a replacement.
There are as much details as I can find
2SA1306 SI-P 160V 1.5A 20W
Can anyone suggest a replacement if possible, or maybe someone knows where I can find hard to get transistors.
Mikey
There is only one transistor of that type. There are some other ones, but they seem all fine (physically).
Do you have any other suggestions for a replacement outside of the 2SA family that is a little more easier to get? Would I just have to match the volts (160), amps (1.5) and frequency (?) or would other specs of the transistor be important?
If there is no other suitable chip it is fine, since I found a lot of the transistors I am after now while searching for those transistors you gave me, under the name 2SA1306 without the last A. They are all just in other countries and the postage costs and/or minimum orders are pretty high.
Do you have any other suggestions for a replacement outside of the 2SA family that is a little more easier to get? Would I just have to match the volts (160), amps (1.5) and frequency (?) or would other specs of the transistor be important?
If there is no other suitable chip it is fine, since I found a lot of the transistors I am after now while searching for those transistors you gave me, under the name 2SA1306 without the last A. They are all just in other countries and the postage costs and/or minimum orders are pretty high.
Complementary pair I assume is the chip closest, I am not that great with electronics at th design stage yet, but it is C3298A which I assume is 2SC3298A.
There are two others in the same line on the circuit board (about 8-10cm apart) They are
(2S)C2238 and (2S)A958
The main driving pairs per channel are
(2S)C3182 and (2S)A1265.
I ordered a few MJE15031 transistors anyway, even if I don't use them, might come in handy one day.
-Mike
There are two others in the same line on the circuit board (about 8-10cm apart) They are
(2S)C2238 and (2S)A958
The main driving pairs per channel are
(2S)C3182 and (2S)A1265.
I ordered a few MJE15031 transistors anyway, even if I don't use them, might come in handy one day.
-Mike
Mike,
The 2SC3298A indeed is the complementary transistor.
You must know that you can't judge a transistor if you didn't measure it.
If you have a DMM (multimeter), it's fairly easy to do.
Here's a good link:
http://www.eatel.net/~amptech/elecdisc/ampfail.htm
You will have to take them out of the circuit to measure accurately.
So definitely check the other transistors as well.
I predict that the one you found blown-up will not be the only one broken.
/Hugo
The 2SC3298A indeed is the complementary transistor.
You must know that you can't judge a transistor if you didn't measure it.
If you have a DMM (multimeter), it's fairly easy to do.
Here's a good link:
http://www.eatel.net/~amptech/elecdisc/ampfail.htm
You will have to take them out of the circuit to measure accurately.
So definitely check the other transistors as well.
I predict that the one you found blown-up will not be the only one broken.
/Hugo
I imagine the complementary FET in my amp is an N channel so I did those tests according to the N-Channel tests.
2S3298A -
Diode test (probe polarity in brackets):
Gate(+) to Drain(-): 200
Gate(+) to Source(-): 0
source(+) to Gate(-): 0
Drain(+) to Source(-): 198
Source(+) to Drain(-): 200
I assume the values are in mV, since that site mentions 0.4-0.5V
so I guess this transistor is fudged.
Should I test the 2SA958 and 2SC2238? Or are they different? I can't find anything online to tell me what type of transistors they are.
Mike
2S3298A -
Diode test (probe polarity in brackets):
Gate(+) to Drain(-): 200
Gate(+) to Source(-): 0
source(+) to Gate(-): 0
Drain(+) to Source(-): 198
Source(+) to Drain(-): 200
I assume the values are in mV, since that site mentions 0.4-0.5V
so I guess this transistor is fudged.
Should I test the 2SA958 and 2SC2238? Or are they different? I can't find anything online to tell me what type of transistors they are.
Mike
I checked the 2SA958 as a PNP Bipolar Junction Transistor and the results were consistent with those assumed for a healthy transistor by that website.
Base to Collector - 543
Base to Emitter - 557
I checked the 2SC2238 as an NPN bipolar junction transistor and results were also consistent.
Base to Collector - 595
Base to Emitter - 600
I also talked to my mate, who gave me the amp, he blew it up by putting both left and right channels into one speaker. HEHEHE
Mike
Base to Collector - 543
Base to Emitter - 557
I checked the 2SC2238 as an NPN bipolar junction transistor and results were also consistent.
Base to Collector - 595
Base to Emitter - 600
I also talked to my mate, who gave me the amp, he blew it up by putting both left and right channels into one speaker. HEHEHE
Mike
Mike,
Basically you have 2 kinds of devices.
The bipolar transistor and the Fet.
Bipolar transistors pins are called Base, Emitter and Collector.
Fet pins are called Source, Gate, Drain.
All devices in you amp are bipolar transistors.
So forget the fet's for the moment.
Scroll down to the bottom of that Eatel page and you'll find how to measure bipolars.
Basic measurements on a transistor (I'm only talking bipolar from now on) are very easy.
You switch your DMM to diode test and a cross measurement on all 3 pins should only measure 0.6V between 2 of them. From the moment on you measure more (or less) than two times average 0.6V between different pins, the transistor is broken.
Some very old transistors measure only 0.2V, but none of them will be in your amp.
Indeed, 0.6V = 600mV
All 2SA and 2SB Japanese transistors are PNP-types, all 2SC and 2SD's are NPN's
Here's a short data of your transistors:
2SA1306A:NF/S-L, 180V, 1,5A, 20W, 100MHz
2SC3298A:NF/S-L, 180V, 1,5A, 20W, 100MHz
2SA958:NF/S-L, 200V, 2A, 30W, 20MHz
2SC2238:NF/S-L, 160V, 1,5A, 25W, 100MHz
NF=Audio frequency
S = Switch
L = power
Again, you definitely should check all of them.
/Hugo
Basically you have 2 kinds of devices.
The bipolar transistor and the Fet.
Bipolar transistors pins are called Base, Emitter and Collector.
Fet pins are called Source, Gate, Drain.
All devices in you amp are bipolar transistors.
So forget the fet's for the moment.
Scroll down to the bottom of that Eatel page and you'll find how to measure bipolars.
Basic measurements on a transistor (I'm only talking bipolar from now on) are very easy.
You switch your DMM to diode test and a cross measurement on all 3 pins should only measure 0.6V between 2 of them. From the moment on you measure more (or less) than two times average 0.6V between different pins, the transistor is broken.
Some very old transistors measure only 0.2V, but none of them will be in your amp.
Indeed, 0.6V = 600mV
All 2SA and 2SB Japanese transistors are PNP-types, all 2SC and 2SD's are NPN's
Here's a short data of your transistors:
2SA1306A:NF/S-L, 180V, 1,5A, 20W, 100MHz
2SC3298A:NF/S-L, 180V, 1,5A, 20W, 100MHz
2SA958:NF/S-L, 200V, 2A, 30W, 20MHz
2SC2238:NF/S-L, 160V, 1,5A, 25W, 100MHz
NF=Audio frequency
S = Switch
L = power
Again, you definitely should check all of them.
/Hugo
Sweet, well the 2SC2238 and 2SA958 are both the results I gave earlier. The 2SC3298A gives:
Base to Collector - 199
Base to Emitter - 1
in reverse polarity it gives the same results. Collector to Emitter in either polarity gives 199-200. So this one definitely seems fried.
So it is pretty much stuffed it seems.
I know that I don't have a schematic, but would it be possible to suggest a replacement, even if it means replacing all of them?
One last question, I noticed the main drivers mounted on the heatsink, have a pair of two chips. So 2x2SC3182 and 2x2SA1265, I assume so the left and right have one of each and are the same.
How come there are four different transistors here and no matching pairs? I am assuming that these transistors are driving the main ones, so why are they different?
Base to Collector - 199
Base to Emitter - 1
in reverse polarity it gives the same results. Collector to Emitter in either polarity gives 199-200. So this one definitely seems fried.
So it is pretty much stuffed it seems.
I know that I don't have a schematic, but would it be possible to suggest a replacement, even if it means replacing all of them?
One last question, I noticed the main drivers mounted on the heatsink, have a pair of two chips. So 2x2SC3182 and 2x2SA1265, I assume so the left and right have one of each and are the same.
How come there are four different transistors here and no matching pairs? I am assuming that these transistors are driving the main ones, so why are they different?
Let's see:
For the 2SA1306A you could try MJE15031
The 2SC3298A will of course be replaced by the MJE15030
The MJE15032/33 combination is good also, even better. They have a higher voltage rating.
The 2SC2238 and 2SA958 can also be replaced by MJE15030/31 or MJE15032/33.
2SC3182:BD 245D, 2SC2706, 2SC2837, 2SD1047
2SA1265:BD 246D, 2SA1146, 2SA1186, 2SA1227(A)
Obviously you should try to find as much originals as possible to maintain the original specs of the amp.
The reason for using both PNP and NPN devices is mainly because the supply consists of a plus and minus side.
/Hugo
For the 2SA1306A you could try MJE15031
The 2SC3298A will of course be replaced by the MJE15030
The MJE15032/33 combination is good also, even better. They have a higher voltage rating.
The 2SC2238 and 2SA958 can also be replaced by MJE15030/31 or MJE15032/33.
2SC3182:BD 245D, 2SC2706, 2SC2837, 2SD1047
2SA1265:BD 246D, 2SA1146, 2SA1186, 2SA1227(A)
Obviously you should try to find as much originals as possible to maintain the original specs of the amp.
The reason for using both PNP and NPN devices is mainly because the supply consists of a plus and minus side.
/Hugo
Hehe, yeah when I get enough money (I just started a casual job yesterday since starting uni) I want to build her a gainclone with some nice bookshelf speakers.
She has an old stereo. An old Pioneer SA-9500-II, cost her $800 AUD back when she was 18!!! Quite a lot of money back then... it is an awesome amp. The speakers are LD or something, 15inch bass, a pair of 5 inch paper mids and 4 ich tweeter, like mostly metal case with a little spike in the middle, not sure what you would call them. The speakers certainly make nice party boomers though
Anyway, that stereo is in the backroom, her computer is in the front, so I want to make her a nice one to complement the lounge room.
Wouldn't mind making her a turntable either... she has a decent collection of vinyl!
She has an old stereo. An old Pioneer SA-9500-II, cost her $800 AUD back when she was 18!!! Quite a lot of money back then... it is an awesome amp. The speakers are LD or something, 15inch bass, a pair of 5 inch paper mids and 4 ich tweeter, like mostly metal case with a little spike in the middle, not sure what you would call them. The speakers certainly make nice party boomers though
Anyway, that stereo is in the backroom, her computer is in the front, so I want to make her a nice one to complement the lounge room.
Wouldn't mind making her a turntable either... she has a decent collection of vinyl!
Mmm got the transistors
cleaned up all the tracks
soldered them in nicely
Replaced
2SC3298A and 2SC2238 with MJE15032
2SA1306A and 2SA958 with MJE15033
When I turn it on, there are two small transistors, one went up in smoke (on the same side as the blown transistor originally)
I suspect there is more to this than just the blown transistors for the left channel :/
Without a schematic I think I am pretty much stuck ey?
I could salvage the parts though, got two 12,000uF/56V capacitors, 36-0-36 240VAC transformer, 6 MJE15032/33 pairs, and 2 2SC3182/2SA1265 pairs.
What do you think?
-Mikey
cleaned up all the tracks
soldered them in nicely
Replaced
2SC3298A and 2SC2238 with MJE15032
2SA1306A and 2SA958 with MJE15033
When I turn it on, there are two small transistors, one went up in smoke (on the same side as the blown transistor originally)
I suspect there is more to this than just the blown transistors for the left channel :/
Without a schematic I think I am pretty much stuck ey?
I could salvage the parts though, got two 12,000uF/56V capacitors, 36-0-36 240VAC transformer, 6 MJE15032/33 pairs, and 2 2SC3182/2SA1265 pairs.
What do you think?
-Mikey
shyfx said:
Did you check all the transistors as I suggested?
Indeed, if the amp only has to serve for PC amplification, it would be better to buy a cheap small amp somewhere.
Keep the parts you have and start looking for a nice decent schematic and try to build something.
But that's another story...
Good luck
/Hugo
Gainclone it is I got some 4xLM3875's too, just need a different tranny.
I checked all the transistors, even the one that blew and it's other. They were fine. I suspect perhaps another component is shorting or damaged. The PCB isn't symmetrical and is hard to tell what is what.
Thanks heaps for your help. It has been very much appreciated.
-Mike
I got some 4xLM3875's too, just need a different tranny.I checked all the transistors, even the one that blew and it's other. They were fine. I suspect perhaps another component is shorting or damaged. The PCB isn't symmetrical and is hard to tell what is what.
Thanks heaps for your help. It has been very much appreciated.
-Mike
