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Marantz Transistor/Diode/Trimmer Sub Guide

Jamie Starr said:
Steve. Thanks for all your work on this. No doubt it will be the go to list for the foreseeable future.
I also think it speaks to how much people are willing to help each other on this site. I have been on other sites where you ask a question and you completely flamed by the responses. Here, on AudioKarma, my experience has been that most people are willing to give their input and help you as much as they can. Great work again!! :music:
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Thanks! I agree about the warm reception given by AK members - especially in the Marantz forum. I came to this about four years ago with some decades old soldering skills, some basic knowledge of electronics, but no real hands on work or knowledge of audio repair/rebuilding. I was received with open arms by so many who patiently helped me gain experience and knowledge. I'm glad to be able to pay it forward a little bit with what I have learned from them. :D
 
Hello! I too will take a look at you list over the next few weeks. I rebuild around 50 1970's receivers a year, all makes and have my own list off all Mouser Supplied semiconductors. Cheers!
 
Good catch, Tom. I had that listed as a TO-220 case, but it's a TO-66. A bit of a bummer that Mouser or Digikey don't stock it. Do you know of a source that I could put along side the 2N4231?
 
The 2SC945s I have replaced in my 2235B had a hfe of 180-211.
The replacement KSC945CYTA all come in a bit lower, 156-171.
Maybe not an issue on the PSU board but the pre-amp board would be nice to match better. Ideas?
 
Magnus Back said:
The 2SC945s I have replaced in my 2235B had a hfe of 180-211.
The replacement KSC945CYTA all come in a bit lower, 156-171.
Maybe not an issue on the PSU board but the pre-amp board would be nice to match better. Ideas?
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According to the data sheet, the “Y” gain code KSC945 has an hFE range of 120-240. It should be a good sub. I don’t think a difference in an average hFE of 160 and 195 is going to have any practical ramifications. But a larger sample might get you a bit higher number. The next higher gain code “G” (200-400) does not appear to be readily available.
 
One more for the 2235B, 3386H-1-201LF works for R766 and R767, Idle Current Adjustment. The legs are short and you have to bend them exactly right but it works.
The old ones didn't work to deox, they still had spots with no connectivity and were difficult to adjust.
 
Magnus Back said:
One more for the 2235B, 3386H-1-201LF works for R766 and R767, Idle Current Adjustment. The legs are short and you have to bend them exactly right but it works.
The old ones didn't work to deox, they still had spots with no connectivity and were difficult to adjust.
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I noticed you had an F footprint on the DC Offset trimmer, and it looks like its pins are a little better positioned. Also, it was a suffix TLF, which looks like it has a knob. Did one of these work better than the other? We might want to make them the same footprint if it looks like that's what the original was.
 
The original trim pots are of different models and layouts. The DC bias doesn't have as much pin spacing as the Idle Current one and are in one line more or less, see below.
The silkscreen on the board is wrong for the Idle Current Pot. Pins need to be like I have drawn or the 0-200 Ohm will turn into 0-50 Ohm. That could work but the we need a larger resistance.
The one I used for the DC bias is a better pot I think.

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Steve,
Your listing shows the original 2SC945 (ECB basing) is replaced by KSC945. (EBC basing)
In order to match the original ECB basing, a "C" suffix needs to be added (KSC945C).
Thanks
Phil
 
I wanted to post this here in case anyone finds this useful.

Marantz 2010:
I replaced a 2SC536E (H112) for a KSC945C (YTA variant), which worked well. Not saying it's perfect, but it functions excellent in this particular application.
 
OsciloNope said:
I wanted to post this here in case anyone finds this useful.

Marantz 2010:
I replaced a 2SC536E (H112) for a KSC945C (YTA variant), which worked well. Not saying it's perfect, but it functions excellent in this particular application.
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Thanks for posting. I have updated the file to reflect that the "E" suffix can use the same sub as the "G" suffix.
 
Steven Tate said:
Well, I did another data dive and compiled a fairly comprehensive list of 99% of the transistors and diodes used in 70's era Marantz stereo integrated amps and receivers. I scanned threads until I was blue in the face, and scanned the internet for specs. I searched every Service Manual to pull a list of transistors and diodes. I looked for recommended subs throughout the threads, and collected the ones that were repeated often, or that someone had successfully used. I can't be sure of the appropriateness of any of the listed subs, but these are the ones I would start with if I were looking for a sub. I tried to search for availability, and only use subs I could find. Many recommendations that I came across turned out to be obsolete. I'm hoping the gurus will take a little time to scan for obvious problem suggestions, or to fill in blanks where I couldn't find any info. Please let me know if you find errors or have better suggestions for any sub. So, here is a link to the Excel spreadsheet on my Google Drive and I am attaching a PDF for those that don't have Excel handy. Give me suggestions on how to improve my list! Search for your transistor or diode in the left column (alpha order), and look for subs in the columns to the right.
Spreadsheet:
https://drive.google.com/file/d/1KENR38vb7bf0c2oqj-gFRVrDScrzIMSw/view?usp=sharing
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Just came across this, this is the best thing ever. Thanks Steve!
 
I’m trying to understand the ay and ays at the end of the part number. My 140 is frustrating me and I had to take a couple of days off. 2sa794=Ksa1220ay on h711 and h712 is 2sc1567=Ksc2690ay according to Steve’s awesome list. Well I ended up with ksa1220ays and ksc2690ays. Using these it stays in power protect and the relay won’t energize. If I put the OG 2sc1567 back in h712 comes up. I can’t figure out if the s at the end is the problem. Same problem with both amps. And it is possible I’ve over thought this also :)
 
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