Hello everyone,
This early 70's amplifier of mine uses Hitachi drivers, 2SC708/2SA537 pair.
I'd like to be given some suggestions as to what would be an ideal replacement, these are also used in other Sansui models, the Eight being one example.
Suggestions for current available parts and obsolete parts are welcomed, I do like using well regarded Japanese transistors in my equipment if I'm fortunate to find them.
Previously I upgraded the 2SC871 to 2SC2240 and
CDC8002 to 2SC4793, there's no doubt of the improvement with those new parts in.
I'll do my best to upload the originals data sheet and the schematic of the amp.
Thanks in advance.
~Ben
This early 70's amplifier of mine uses Hitachi drivers, 2SC708/2SA537 pair.
I'd like to be given some suggestions as to what would be an ideal replacement, these are also used in other Sansui models, the Eight being one example.
Suggestions for current available parts and obsolete parts are welcomed, I do like using well regarded Japanese transistors in my equipment if I'm fortunate to find them.
Previously I upgraded the 2SC871 to 2SC2240 and
CDC8002 to 2SC4793, there's no doubt of the improvement with those new parts in.
I'll do my best to upload the originals data sheet and the schematic of the amp.
Thanks in advance.
~Ben
Attachments
What I'm looking for is a driver of aprox ~1A Ic and ~1W dissipation. Also one that shares a fT of ~200Mhz
I have also the 2SC5171/2SA1930 pair but never tried them as I assume something closer to the original specs might perform better.
The 2SD669/2SB649 would be another good option.
Any advice or suggestions for subs welcome. Thank you
I have also the 2SC5171/2SA1930 pair but never tried them as I assume something closer to the original specs might perform better.
The 2SD669/2SB649 would be another good option.
Any advice or suggestions for subs welcome. Thank you
The Sanyo ones are long gone already - C3902/A1507 used to be the good ones. Still available -sort of - in f***ing surface mount packages with different type numbers. Those Fairchild parts are on the chopping block now too.
The NTE/ECG 128 and 129 will work at these low voltages and are in the metal can. They probably already are pretty rare these days, and usually overpriced. A lot of NTE parts are still listed as active but no one has any stock.
When I posted the NTE (ECG) replacements, I did not say anything about them being rare, or overpriced.
NTE is still a major supplier of semiconductors.
And I've been using them to repair customer equipment for decades now.
Sorry, no intent to confuse, See post #7.
Thanks again, I appreciate all the advice.
I do think I'll eventually find some regarded pieces, that are known for their linearity, low noise and sonic goodness. At least that's what I discovered when using the audio spec'd Toshibas that I have.
The search continues..
Thanks again, I appreciate all the advice.
I do think I'll eventually find some regarded pieces, that are known for their linearity, low noise and sonic goodness. At least that's what I discovered when using the audio spec'd Toshibas that I have.
The search continues..
Again, if you can get them. NTE’s that are “equivalent” to parts that are in widespread use are commonly available. Ones that are “equivalent” to dinosaur parts are getting harder to find in stock. NTEs *are* industry standard parts, either from the original OEM or second sources that are labeled for them. Hence the price premium (can’t be done for free), and the availability issue. Obsolete parts will have to get made somewhere, and until someone orders a production run there can be a drought. That drought has gone on for many years on parts I used to use from NTE that disappeared from the regular makers (like GE and RCA). If they are selling enough 128/129 you’ll find them in stock, but when sales drop and supply runs out, there will be some MOQ and 20 week lead time. At the best case.
NTE still sells “equivalents” to things like the Sanken LAPTs in the MT200 case. They CANNOT get them from Sanken anymore, so they have to come from the likes of ISC. They’re not as good - nowhere near- they are considered fakes. So caveat emptor. The medium voltage TO-39’s are a lot easier to clone and there are other second sources offering the original 2N types, so your chances of getting a real one are much better. But the risk is not zero, and it may not be the exact original.
There is reason not to switch to More common TO-220 parts. Output capacitance being MUCH higher is number one. You may notice a difference on the sound, you might not. Depends on the circuit. The TO-126’s are a good compromise, as output capacitance tends to be about 20 or 30 pF. EF2’s can simply absorb that without much change. But they are going the way of the dodo. Awfully quickly.
NTE still sells “equivalents” to things like the Sanken LAPTs in the MT200 case. They CANNOT get them from Sanken anymore, so they have to come from the likes of ISC. They’re not as good - nowhere near- they are considered fakes. So caveat emptor. The medium voltage TO-39’s are a lot easier to clone and there are other second sources offering the original 2N types, so your chances of getting a real one are much better. But the risk is not zero, and it may not be the exact original.
There is reason not to switch to More common TO-220 parts. Output capacitance being MUCH higher is number one. You may notice a difference on the sound, you might not. Depends on the circuit. The TO-126’s are a good compromise, as output capacitance tends to be about 20 or 30 pF. EF2’s can simply absorb that without much change. But they are going the way of the dodo. Awfully quickly.