dly66
Addicted Member
Sometimes. Old caps can lose their films and reform. Was looking at a fix and repair Sony STR-7065 being sold with bad tuner section was checking out the amp part had switched to FM which tuning meters seemed like it was tuning but no output. Some reason left it on in that state put the headphones down was looking at something else and after couple minutes picked up the headphones heard faint audio coming from them put the headphones back on FM section slowly was coming back to life but with some distortion. After that experience after redoing the power supply and part of the amp section of a 3000A testing it out switched to AM tuner seemed dead. After the Sony experience let it sit a few minutes and after a time the AM section did slowly come back to life.
But then again old caps can blow up. The SX-1500TD (1971) currently in the living room is of similar vintage and after rebuilding the amp card (new transistors, caps, trimmers) and recapped the power supply, I usually test a unit at that point for a bit at each stage of doing the recaps before continuing the recapping process. Sounded pretty good at first but then started declining in sound. Continuing the recap when I got to a tone control board a pair of 3.3 uf caps had blown their bottom seals and were looking baked. Read something like 5.5 uf and I forget what loss value I was getting with my $20 Amazon tester. After recapping the rest and upgrading the output caps from the 1000 uf I originally put in to 2200 uf Nichicon fine golds it sounded really good. May not be the most accurate by test numbers but a pleasing one to listen too.
Somebody gave me a Technics SA-5170 (~1977) they had been using as a garage system. Really dirty inside so cleaned it up and gifted it to a friend with a pair of speakers to a friend to use as the office background music system. Originals seems okay but after a year of use walking by it you can see the pair of filter caps through the top screen and I noticed one was much taller than the other. Surprised the filter cap they used in it could expand that much without blowing its seal. I got them to let me recap it has seen a number of years of weekday use since then.
Recapped mine. Used Silmic II and did Conrad's mods to it can see what some people complain about an "air brushed sound" to them. Others love them. For the most part on units I have used Nichicon UPW an UKL mix with either Wima MKS2 or Kemet R82 films sometimes some Panasonic polyester but they can be huge. Have used some others like Panasonic FMs and FCs and with axials often used the Nichicon VX series but those seem to be in the process of being obsoleted. Also like old Pioneers some noise/failure prone transistors good to replace them too.
If I remember right, the third digit of the Sansui serial number is the year, next two digits the month. But you also need to know the approximate vintage of the unit so you can recognize 9 is 1969 and 0 is 1970.
I have seen posts you need to check board numbers in a unit using the service manuals as a guide. The 2000A and X are very similar and production may have overlapped have seen posts you can have one unit with some boards in it that go with the other unit. On cap values always check the boards and take an inventory of what was installed to verify things. Sometimes what got produced has some differences from what is shown in the service manuals.
Cost partly depends on what you need to buy to do it, if you need to buy some tools and other supplies to start. Would guess in the $60 - $80 range. If you mess with the output transistors you have thermal paste and mica washers or the silicone silpads.
On the big caps used the one Conrad suggested as his go to for these unist, the Nichicon LGU2A272MELC, 2700 uF, 100 VDC which fit my 2000A clamps. Lower value in the same line can be used to the other smaller clamped snap in type capacitor. Usually screen filter caps by the original diameter (to fit the clamps) and voltage. Usually step voltage ratings by at least one increment, say 50 replace with 63, 63 with 80. With that screen often not many choices left, hopefully all the choices are not more than I want to pay. Then may consider using a smaller cap with a wrap to hold the smaller cap in the clamp.
But then again old caps can blow up. The SX-1500TD (1971) currently in the living room is of similar vintage and after rebuilding the amp card (new transistors, caps, trimmers) and recapped the power supply, I usually test a unit at that point for a bit at each stage of doing the recaps before continuing the recapping process. Sounded pretty good at first but then started declining in sound. Continuing the recap when I got to a tone control board a pair of 3.3 uf caps had blown their bottom seals and were looking baked. Read something like 5.5 uf and I forget what loss value I was getting with my $20 Amazon tester. After recapping the rest and upgrading the output caps from the 1000 uf I originally put in to 2200 uf Nichicon fine golds it sounded really good. May not be the most accurate by test numbers but a pleasing one to listen too.
Somebody gave me a Technics SA-5170 (~1977) they had been using as a garage system. Really dirty inside so cleaned it up and gifted it to a friend with a pair of speakers to a friend to use as the office background music system. Originals seems okay but after a year of use walking by it you can see the pair of filter caps through the top screen and I noticed one was much taller than the other. Surprised the filter cap they used in it could expand that much without blowing its seal. I got them to let me recap it has seen a number of years of weekday use since then.
Recapped mine. Used Silmic II and did Conrad's mods to it can see what some people complain about an "air brushed sound" to them. Others love them. For the most part on units I have used Nichicon UPW an UKL mix with either Wima MKS2 or Kemet R82 films sometimes some Panasonic polyester but they can be huge. Have used some others like Panasonic FMs and FCs and with axials often used the Nichicon VX series but those seem to be in the process of being obsoleted. Also like old Pioneers some noise/failure prone transistors good to replace them too.
If I remember right, the third digit of the Sansui serial number is the year, next two digits the month. But you also need to know the approximate vintage of the unit so you can recognize 9 is 1969 and 0 is 1970.
I have seen posts you need to check board numbers in a unit using the service manuals as a guide. The 2000A and X are very similar and production may have overlapped have seen posts you can have one unit with some boards in it that go with the other unit. On cap values always check the boards and take an inventory of what was installed to verify things. Sometimes what got produced has some differences from what is shown in the service manuals.
Cost partly depends on what you need to buy to do it, if you need to buy some tools and other supplies to start. Would guess in the $60 - $80 range. If you mess with the output transistors you have thermal paste and mica washers or the silicone silpads.
On the big caps used the one Conrad suggested as his go to for these unist, the Nichicon LGU2A272MELC, 2700 uF, 100 VDC which fit my 2000A clamps. Lower value in the same line can be used to the other smaller clamped snap in type capacitor. Usually screen filter caps by the original diameter (to fit the clamps) and voltage. Usually step voltage ratings by at least one increment, say 50 replace with 63, 63 with 80. With that screen often not many choices left, hopefully all the choices are not more than I want to pay. Then may consider using a smaller cap with a wrap to hold the smaller cap in the clamp.
