G'day everyone,
I am currently working on a Sanyo DCA 200 amp. I'm comfortable ordering replacement capacitors but have never worked on transistors before. I want to replace the 4 main output stage units but am a bit unsure how to go about getting suitable equivalents.
The transistors are marked:
I usually use DigiKey to ship here in Australia so if they stock something that would be good.
If anyone can help me I'd appreciate it.
Cheers
I am currently working on a Sanyo DCA 200 amp. I'm comfortable ordering replacement capacitors but have never worked on transistors before. I want to replace the 4 main output stage units but am a bit unsure how to go about getting suitable equivalents.
The transistors are marked:
- SANYO B514D 91
- SANYO B514D 91
- SANYO D330D 60
- SANYO D330D 60
I usually use DigiKey to ship here in Australia so if they stock something that would be good.
If anyone can help me I'd appreciate it.
Cheers
Use KSD526/KSB596. They are now EOL, but last I looked at Digikey two weeks ago they still had some. The original 2S Toshiba version was the go-to for replacing most TO-220 outputs used in Jap receivers. When those are finally gone, we’ll be stuck using TIP41/2 for this sort of amplifier. There are also several series of 2N devices that are similar, and many would work fine. Most are not that much different from the TIPs and they do make some that are bigger if you were looking to make it more robust at 4 or less ohms. All are higher capacitance than the originals or the recommended replacements so they could scrub off some performance.
Higher speed devices like MJE15030/31 would work. Different problems than TIP41/2 - hard to say which is better. I see 25V rail caps. If the actual voltage is +/-20V or less the D44H8/D45H8 pair can be used as an upgrade. They do not tolerate higher operating voltages, especially if 4 ohm loads are ever used. Very poor second breakdown capability, but work exceptionally well at low voltages.
Higher speed devices like MJE15030/31 would work. Different problems than TIP41/2 - hard to say which is better. I see 25V rail caps. If the actual voltage is +/-20V or less the D44H8/D45H8 pair can be used as an upgrade. They do not tolerate higher operating voltages, especially if 4 ohm loads are ever used. Very poor second breakdown capability, but work exceptionally well at low voltages.
Thanks so much for the quick reply. It's much appreciated.
Great! I have found the KSD526/KSB596 transistors you mentioned in the form of: KSD526Y (NPN) and KSB596YTU (PNP). These are in stock at DigiKey so I'll be ordering them. I'll keep in mind the other options you listed if I'm looking to improve or change again later down the track.
I'm also going to replace the smaller transistors seated below the main output transistors (can be seen in the photo).
Those are 'C536 E5L' - I used https://alltransistors.com/ and did a cross search and found many equivalents that are available on DigiKey - this search process didn't really help when I was trying to track down the Sanyo B514D/D330D equivalent units. Do you just know what to replace them with or is there another way you can manually look up replacements?
Great! I have found the KSD526/KSB596 transistors you mentioned in the form of: KSD526Y (NPN) and KSB596YTU (PNP). These are in stock at DigiKey so I'll be ordering them. I'll keep in mind the other options you listed if I'm looking to improve or change again later down the track.
I'm also going to replace the smaller transistors seated below the main output transistors (can be seen in the photo).
Those are 'C536 E5L' - I used https://alltransistors.com/ and did a cross search and found many equivalents that are available on DigiKey - this search process didn't really help when I was trying to track down the Sanyo B514D/D330D equivalent units. Do you just know what to replace them with or is there another way you can manually look up replacements?
Q17 and Q18? Those are probably the bias transistors (aka the Vbe multiplier) and are nothing special. My guess is the cross ref’s pointed you to a KSC945 (the Korean 2N3904) or KSC/2SC1815 (the most popular Asian transistor ever produced).
The D526/B596 we’re a bog standard Japanese low power output device, used in receivers up to about 30 wpc and as drivers or voltage regulator pass transistors. They will work in place of 99% of the TO-220 or TO-66 silicon outputs from the 70’s, 80’s and 90’s - as long as the originals are not darlingtons. Most of the time they were not. If you can identify complementary driver transistors in between that C536 and the outputs, those Fairchild parts are good to go. Alternatively, measure the voltage between the bases of the two outputs. If it is about 1.1 volts, then they are normal transistors. If it is close to or over 2 volts, then they are darlingtons and another type would be required.
The D526/B596 we’re a bog standard Japanese low power output device, used in receivers up to about 30 wpc and as drivers or voltage regulator pass transistors. They will work in place of 99% of the TO-220 or TO-66 silicon outputs from the 70’s, 80’s and 90’s - as long as the originals are not darlingtons. Most of the time they were not. If you can identify complementary driver transistors in between that C536 and the outputs, those Fairchild parts are good to go. Alternatively, measure the voltage between the bases of the two outputs. If it is about 1.1 volts, then they are normal transistors. If it is close to or over 2 volts, then they are darlingtons and another type would be required.
Just reporting back.
I have completed the capacitor replacement along with replacing the main output stage transistors and the accompanying smaller transistors nearby to them.
Enjoyed the job and replaced the pilot light too. The Sanyo sounds terrific and is nice and clear.
Thanks again for your help with suggesting the replacement parts.
I have completed the capacitor replacement along with replacing the main output stage transistors and the accompanying smaller transistors nearby to them.
Enjoyed the job and replaced the pilot light too. The Sanyo sounds terrific and is nice and clear.
Thanks again for your help with suggesting the replacement parts.
Looks like the NPNs are on one heat sink and the PNPs on the other. Probably so they could get by with NO insulators, collectors of NPN would be on the + supply, and PNPs on the -. That improves heat dissipation capability A LOT, especially with the TO-220. Thermal compound is a good idea. In this case you can use the conductive stuff for CPUs, which is better than the white stuff when you can use it.