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Transistor Substitutions

Dutch9600 said:
Looking for a replacement for 2SC1846R for my Carver TFM-25 can anyone help. Thank in advance.
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www.bdent.com

2SC1846

2SC1846
www.bdent.com www.bdent.com

Suffix Q , R and S gain ranks will all suffice.

Datasheet Archive: 2SC1846 datasheet by Panasonic

Preview and download the 2SC1846 datasheet by Panasonic on Datasheet Archive.
www.datasheetarchive.com www.datasheetarchive.com

Get them while you still can. These are the genuine Panasonic transistors. Grapevine says that B+D Enterprise is closing down for business soon.
 
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Dutch9600 said:
Looking for a replacement for 2SC1846R for my Carver TFM-25 can anyone help. Thank in advance.
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I assume you mean for Q205, Q206? Temperature compensation for the bias circuits. Looks like Onsemi KSC2690AYS should be a pretty good sub.
 
GlasgowGrip said:
I assume you mean for Q205, Q206? Temperature compensation for the bias circuits. Looks like Onsemi KSC2690AYS should be a pretty good sub.
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Thank you for the info, I am having trouble getting the getting the idle current down on the left channel, it read 4.2 mV and should be 1mV. any suggestions.
 
Dutch9600 said:
Thank you for the info, I am having trouble getting the getting the idle current down on the left channel, it read 4.2 mV and should be 1mV. any suggestions.
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I would not start with that transistor (Q205 for left channel), there are other more likely culprits. I will say that if Q205 is actually bad, then you likely have bigger problems/other damage in that amp and I would suggest you start a new thread for it to get help (either here on AK or over on "thecarversite".)

So, would you say the amp is generally working okay and you just have a problem setting bias? If so, then I'd jump straight to the Service Bulletin for the TFM-22/24/25 - have you done that yet? I would absolutely take care of that Service Bulletin before beginning to suspect Q205 (or trimmer VR201).

That service bulletin has you replace 14 resistors and 8 transistors that are prone to heat damage. It specifies replacement/upgrade of R209-R212, R229-R230, R235-R238, R243-R244, R245-R246 (pay attention to values called for in the bulletin). It also calls for replacement of Q201-Q202, Q209-Q210, Q203-Q204, and Q207-Q208 if heat damage is evident. My advice is just replace all of those for peace of mind. High chance that bulletin includes the source of your bias problem. Substitutes for the 2SA1370 / 2SC3467 are the Onsemi KSA1381ESTU / KSC3503DSTU.

Also note that the TFM-25 Service Manual floating around the internet (I think i found it on thecarversite) has Service Bulletin #TFM-25-2 included in the back, shouldn't be too hard to find.

Finally, there is this thread on AK (not much detail, but it's something): Recapping a Carver TFM25 for Dummies
 
Dutch9600 said:
Will KSB1366GTU work to replace 2SB1375 and is there a direct sub for 2sc2878-A,B? Thanks in advance.
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Looks like KSB1366G is an excellent sub for 2SB1375 based on the datasheets.

The 2SC2878 is a "muting transistor" and so it has some very unique properties. From a quick search it looks like there are no drop-in replacements available anymore, unless you find new old stock somewhere (bdent.com is out of stock). There is a "direct" replacement in production in terms of electrical properties, but it is SMD so you'd need to use an adapter. See this thread.
 
GlasgowGrip said:
Looks like KSB1366G is an excellent sub for 2SB1375 based on the datasheets.

The 2SC2878 is a "muting transistor" and so it has some very unique properties. From a quick search it looks like there are no drop-in replacements available anymore, unless you find new old stock somewhere (bdent.com is out of stock). There is a "direct" replacement in production in terms of electrical properties, but it is SMD so you'd need to use an adapter. See this thread.
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Consolidated Electronics (United States) has Toshiba 2SC2878 in stock for a good price https://www.ebay.com/itm/293692034095
 
I'm working on a Sansui G-5500 with one pair of bad output transistors. I want to replace both pairs. The originals are 2SC2578 and 2SA1103. I've searched this thread and haven't found any reference to these. BD Enterprises shows 2SC4467 and 2SA1694 as suitable (and in-stock) replacements. Can anyone please verify that these are suitable replacements and, if not, suggest other replacements?

Many thanks in advance for any help you can provide,
Joe
 
Joe Nardy said:
I'm working on a Sansui G-5500 with one pair of bad output transistors. I want to replace both pairs. The originals are 2SC2578 and 2SA1103. I've searched this thread and haven't found any reference to these. BD Enterprises shows 2SC4467 and 2SA1694 as suitable (and in-stock) replacements. Can anyone please verify that these are suitable replacements and, if not, suggest other replacements?

Many thanks in advance for any help you can provide,
Joe
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Yes the ones you quote are a very similar replacement to the originals. Another option with slightly better SOA are the Sanken 2SC4468/2SA1695. They are cheap and also in stock in the same vendor.
 
JoseHH said:
Yes the ones you quote are a very similar replacement to the originals. Another option with slightly better SOA are the Sanken 2SC4468/2SA1695. They are cheap and also in stock in the same vendor.
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@JoseHH ,

Thank you very much for the quick reply. I am once again amazed at the collective wealth of knowledge and willingness to share information here on AK!

Thanks again,
Joe

P.S. Went to BD Enterprises site to order and the site was having issues. I couldn't add items to cart or checkout. I checked DigiKey and they had the 2SC4468/2SA1695 in stock for slighty more money. I ordered two of each with no issues.
 
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Joe Nardy said:
@JoseHH ,

Thank you very much for the quick reply. I am once again amazed at the collective wealth of knowledge and willingness to share information here on AK!

Thanks again,
Joe

P.S. Went to BD Enterprises site to order and the site was having issues. I couldn't add items to cart or checkout. I checked DigiKey and they had the 2SC4468/2SA1695 in stock for slighty more money. I ordered two of each with no issues.
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“Hold a small basket”with Digikey , they move their warehouse and some things are not “functioning” . A month now
(3 shipments)they are keep on sending me the wrong part.
The website at DB Enterprises is not working for outside US customers.
If you need something from them write directly to Bud with the parts you need,explain the reason and he will send you a PayPal invoice , they ship the same day.

Edit:
Buds email : bud.funari@bdent.com
 
HI all i am working on an Onkyo DC power supply board and need replacements for 2sa816 and 2sc1626.
I am thinking i can use MJE15033 to replace the 2sa816, same goes with the MJE15032 for 2sc1626.
Overkill i assume, but should be good, just hoping someone can help me confirm
 

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JoseHH said:
May be the toshiba TTA004 are sufficient (TO126 isolated). Check them out
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Thanks for that very much appreciated, i will use those then, (I have some of the ksa1220ays and KSC2690 left)
I was ideally looking for a To220 case as the originals are tied directly into a heatsink with no mica, not that it matters i suppose as the collector leg still gets soldered.
 
PTL-Pioneer said:
I have some of the ksa1220ays and KSC2690 left
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Is really up to you and what you have available, but hose are actually too nice to be used in the power supply. If I were in your situation, I would keep the KSA1220/KSC2690 for use in VAS stage and use something more available in the power supply. As you said, overkill, but will work also the MJE15028/29, or MJE15030/31 as well as MJE15033/33. In my previous suggestion, I assumed that you needed to order the parts.
 
Hi what would be a good replacement for an M10 j fet. When testing on peak atlas says drain and gate can’t be identified. Thanks
 
Does the tester say tat the part is faulty? For many JFETS drain and soiurce are interchangeable. M10 is the complete denomination of the part? Is is a TO-92 or is it in a different package?. If it is in SMD package it would be a J310 like the MMBFJ310. If you can you privide a little more information it would be appreciated.
 
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Which would be a better replacement for 2SC3329-GR, a KSC1845 or a KSC1815. Thanks in advance for any help.
 
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