2SC1328 [Hitachi?] is a low noise small signal transistor :
150mW 35V 100mA
hFE=180..1040@5V@2mA
Ft>150Mhz NF<4dB
BC550C may be an easy to find replacement, altough pinout may be different
2SA763 [Toshiba] is also a small signal transistor :
200mW 30V 50mA
hFE=250@6V@1mA
Ft>120Mhz
BC560C and BC556B may be easy to find replacements, but pinout may not be the same
150mW 35V 100mA
hFE=180..1040@5V@2mA
Ft>150Mhz NF<4dB
BC550C may be an easy to find replacement, altough pinout may be different
2SA763 [Toshiba] is also a small signal transistor :
200mW 30V 50mA
hFE=250@6V@1mA
Ft>120Mhz
BC560C and BC556B may be easy to find replacements, but pinout may not be the same
A quick look in the MCM catalog showed the 2SC1328 listed at 9 cents each and the 2SA763 listed at 53 cents each.
www.mcminone.com
If you stick with 2S numbers you should have no trouble with leg arrangements. Most any audio small signal transistors with reasonable noise figures will work here.
www.mcminone.com
If you stick with 2S numbers you should have no trouble with leg arrangements. Most any audio small signal transistors with reasonable noise figures will work here.
Hi EWorkshop1708,
I'll agree totally with Echowars here. They suck ! And that's at best. Plus, what are they? What are the ones you buy two months from now??
When I service an amplifier, any ECG / NTE is automatically on the need to replace list, or I don't service the amplifier.
I used to work in a place that sold ECG's. I HAD to use them in my service work. It was so bad, I would stick the leads through the bag and test them first. My rejects were still sold to customers. Once I refused to use these and went to original numbers, my return rate dropped to almost zero. Enough said.
Of course, my favorite has to be the "tech" that gets a cross ref #, and replaces the part with another orig. number that crosses to the same replacement #. These guys have no clue what they are doing, and the paying customer gets nailed. I hate techs like that. They give us all a bad name.
-Chris
I'll agree totally with Echowars here. They suck ! And that's at best. Plus, what are they? What are the ones you buy two months from now??
When I service an amplifier, any ECG / NTE is automatically on the need to replace list, or I don't service the amplifier.
I used to work in a place that sold ECG's. I HAD to use them in my service work. It was so bad, I would stick the leads through the bag and test them first. My rejects were still sold to customers. Once I refused to use these and went to original numbers, my return rate dropped to almost zero. Enough said.
Of course, my favorite has to be the "tech" that gets a cross ref #, and replaces the part with another orig. number that crosses to the same replacement #. These guys have no clue what they are doing, and the paying customer gets nailed. I hate techs like that. They give us all a bad name.
-Chris
Don't labor under the misconception that the NTE stuff is some sort of exact replacement - it's not. They make - or at least supply - a number of transistors, and they list the ones that most closely resemble your parts among those they make.
I work in pro audio, and this is especially important in high power amps. When I have a row of six power xstrs in an output stage, I need them to share current. They need to all be similar. I can't mix RCA and Moto xstrs even. If one xstr turns on a bit lower than the others it hogs current, and conversely if one turns on a bit higher, the others do its work. That NTE power xstr won't match up to anything. Might as well leave it out. The amp certainly won't meet its power specs or reliability.
And the NTE stuff costs more. In that MCM catalog, the 2SC1328 was 9 cents, while the NTE199 was $1.06.
I used to use 2SD870 in video monitor service - $4.10 at MCM and the NTE89 sub for it is $8.45. of course the more expensive the part, the more they can charge the customer for the repair. Stay away from NTE.
I work in pro audio, and this is especially important in high power amps. When I have a row of six power xstrs in an output stage, I need them to share current. They need to all be similar. I can't mix RCA and Moto xstrs even. If one xstr turns on a bit lower than the others it hogs current, and conversely if one turns on a bit higher, the others do its work. That NTE power xstr won't match up to anything. Might as well leave it out. The amp certainly won't meet its power specs or reliability.
And the NTE stuff costs more. In that MCM catalog, the 2SC1328 was 9 cents, while the NTE199 was $1.06.
I used to use 2SD870 in video monitor service - $4.10 at MCM and the NTE89 sub for it is $8.45. of course the more expensive the part, the more they can charge the customer for the repair. Stay away from NTE.
Hi Morgan
Those are for H705 and H706? The complimentary parts are H707 and H708 (2SA562Y) and these are the current limiting transistors - right?
Just making sure we are talking about the correct parts here.
A quick look with Google presents the following data for the 2SC371.
The following ratings are absolute maximum values except for gain and things like that, those will be typical values.
25 VDC C-E, 200mW (at 25° ambient), collector current is 100 mA maximum and a beta of approx. 80. The 2SA562 will be similar to that. Now you only need to select a replacement with the same pinout and similar ratings. That shouldn't be too difficult. Remember, you are not allowed to use the ECG or NTE parts, nor are you allowed to use either replacement "manual". I call them "the book of lies" and for good reason too.
Just a stab in the dark, 2SC1815. 50 VDC, 150 mA, 400 mW and gain from 70 to 700. Looks like a winner, how about 2SC945? 50 VDC, 150 mA, 250 mW and gain from 40 to 700. This does depend on the gain range denoted by the letter following the device type (not an A, B or C), they are commonly types R, O, Y, P and L. Look at this link to data sheets for 2SC945 to see what I mean. This is from a second source manufacturer, try to buy from the real manufacturer when you do buy.
I think the Toshiba site is better for looking up transistors they produced, Sanyo also has a search-able site.
Now, on to more important things. Normally this means shorted output transistors and possibly drivers as well. Also, inspect (measure!!) the 0.24 ohm resistors, a replacement would be 0.22 ohm, also 10 ohm and 220 ohm resistors in the driver / output circuit. There are also 470 ohm and 390 ohm parts that warrant inspection, and don't forget the four diodes (H715 ~ H718). All the output transistors should be the same in each channel, differences between channels are okay. Just make sure the parts in one channel are the same, matching would be nice.
-Chris
Those are for H705 and H706? The complimentary parts are H707 and H708 (2SA562Y) and these are the current limiting transistors - right?
Just making sure we are talking about the correct parts here.
A quick look with Google presents the following data for the 2SC371.
The following ratings are absolute maximum values except for gain and things like that, those will be typical values.
25 VDC C-E, 200mW (at 25° ambient), collector current is 100 mA maximum and a beta of approx. 80. The 2SA562 will be similar to that. Now you only need to select a replacement with the same pinout and similar ratings. That shouldn't be too difficult. Remember, you are not allowed to use the ECG or NTE parts, nor are you allowed to use either replacement "manual". I call them "the book of lies" and for good reason too.
Just a stab in the dark, 2SC1815. 50 VDC, 150 mA, 400 mW and gain from 70 to 700. Looks like a winner, how about 2SC945? 50 VDC, 150 mA, 250 mW and gain from 40 to 700. This does depend on the gain range denoted by the letter following the device type (not an A, B or C), they are commonly types R, O, Y, P and L. Look at this link to data sheets for 2SC945 to see what I mean. This is from a second source manufacturer, try to buy from the real manufacturer when you do buy.
I think the Toshiba site is better for looking up transistors they produced, Sanyo also has a search-able site.
Now, on to more important things. Normally this means shorted output transistors and possibly drivers as well. Also, inspect (measure!!) the 0.24 ohm resistors, a replacement would be 0.22 ohm, also 10 ohm and 220 ohm resistors in the driver / output circuit. There are also 470 ohm and 390 ohm parts that warrant inspection, and don't forget the four diodes (H715 ~ H718). All the output transistors should be the same in each channel, differences between channels are okay. Just make sure the parts in one channel are the same, matching would be nice.
-Chris
Hi Chris,
The 2SC371 was only one of the transistors taken out by a shorted output pair.
Replaced the outputs with OEM, several resistors, checked the drivers (OK), used an NTE 107 for replacement, but would prefer to use similar OEM type.
I have heard that using the 2SC945 in some audio circuits is not recommended since there is a tendency for noise.
I believe I read that on Audio Karma.
I have a 2A562 on hand I can use.
Thanks for your reply
The 2SC371 was only one of the transistors taken out by a shorted output pair.
Replaced the outputs with OEM, several resistors, checked the drivers (OK), used an NTE 107 for replacement, but would prefer to use similar OEM type.
I have heard that using the 2SC945 in some audio circuits is not recommended since there is a tendency for noise.
I believe I read that on Audio Karma.
I have a 2A562 on hand I can use.
Thanks for your reply
Hi Morgan,
Perhaps the writer got some renumbered parts(=fake)? The 2SC458 was a problem device.
NTE107 is good for 12 VDC C-E and 25 mA for IC and 200 mW dissipation. Now get this, it's and RF transistor, so the reverse E-B voltage is only 3 VDC instead of the normal 5 ~ 7 VDC for most transistors.
How did you come to see this as a good substitute? If you used the ECG or NTE Replacement Manual, you can see why I call them "the book of lies". I'm not kidding!
I used to do warranty service on these, and did them for years out of warranty. I'm trying to help you do a good job on this. Yank those transistors and test for gain and leakage (two modes). I'd say to simply replace them, the measuring is for your education in case something actually shows up. Leakage is in uA.
-Chris
False, completely false.
Perhaps the writer got some renumbered parts(=fake)? The 2SC458 was a problem device.
You're kidding me - right?
NTE107 is good for 12 VDC C-E and 25 mA for IC and 200 mW dissipation. Now get this, it's and RF transistor, so the reverse E-B voltage is only 3 VDC instead of the normal 5 ~ 7 VDC for most transistors.
How did you come to see this as a good substitute? If you used the ECG or NTE Replacement Manual, you can see why I call them "the book of lies". I'm not kidding!
No, they were the only transistors that actually failed. Some others were stressed and may fail later. The driver transistors in that channel should be replaced, as well as the bias control transistor. It was bad enough to blow a current protection transistor, so there may be more problems than you know about.
I used to do warranty service on these, and did them for years out of warranty. I'm trying to help you do a good job on this. Yank those transistors and test for gain and leakage (two modes). I'd say to simply replace them, the measuring is for your education in case something actually shows up. Leakage is in uA.
-Chris
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