Sanyo Plus 75 Project continues. - Page 1
Forum section: electronics / repair

author: Arty30
author_rank: Regular Contributor
timestamp: December 16, 2022, 07:30:39 pm
content: Hello all, It's been a while since I've been here, I've been busy with college, but now that it's Christmas break I have time to continue working on my temperamental Sanyo Plus 75 receiver. some may remember as this is my third thread since acquiring this unit, that I've been fighting an intermittent popping/thumping noise through the output. sometimes it's mild, other times I have to just stop using the amp because its so bad. I have gone through the electrolytics on this thing, so now what's left is transistors. I have experienced a similar fault on my Pioneer SX-737 and fixed it with a new set of silicon, it's now my favorite daily driver. My game plan is to replace transistors in the tone/volume controls and phono/aux preamp section of the Sanyo. There are a total of 24 transistors of 7 types that I would like to replace, and while I'm not big on replacing a load of components all at once, I had to surgically remove the boards to access them, Sanyo wasn't big on ease of serviceability. My goal with this thread is to figure out the best approach to this, I don't know the best way to properly match replacement transistors, I don't know what specs are important for the application. Datasheets are readily available for the transistors in question and I'm sure there are an number of threads about transistor replacement and cross-referencing, if anyone knows of any, a link would be appreciated.

author: Arty30
author_rank: Regular Contributor
timestamp: December 16, 2022, 07:46:52 pm
content: This is a list of the transistors I want to change, maybe someone has replaced some before and had success.1) 2SC1570(G)2) 2SA929(G)3) 2SA1083(E)4) 2SC2362K(G) assuming the suffix is G, it wasn't printed, there is a 2362 and 2362K, not sure of the difference.5) 2SA1016(G)6) 2SD438(E)7) 2SB560(E)All of these are ECB according to the silkscreen on the boards and my transistor tester, however Sanyo's datasheets all say BCE, I'm not sure what's going on there. The datasheets have a short header describing the goal, for example the 2SC1570 and 2SA929 which are a complementary pair are described as suitable for very low noise amp applications, others are high voltage low noise amp applications, and low frequency power amp applications. I'm not sure if this affects how I spec out transistors, but in case it's important, I have that information along with all the other transistors on this list in a word document to keep track of it all. By the way, I don't know if it's setting any records, but there are 81 discreet transistors in this thing, and 28 different types.

author: Arty30
author_rank: Regular Contributor
timestamp: December 22, 2022, 03:47:21 pm
content: I've done a bit of cross referencing on mouser and having no idea if I'm doing it right, I've come up with these substitutes:for 2SC1570G substitute BC546Bfor 2SC929G substitute BC556Bfor 2SA1083 substitute BC556Cfor 2SC2362K(gain code G) substitute KSC1845FTAfor 2SA1016G substitute KSA992FBUfor 2SD438E substitute BD139Gfor 2SB560E substitute BD140GOf course there were no perfect or definitive matches to be had so I just tried to find things with the same or higher specs that were in stock, if anyone can help me with this I would be very thankful, I really don't want to mess up my Sanyo Plus 75 by putting incompatible transistors in it or something. ThanksArthur.