• Please note that there are a few updates and clarifications made in the Audiokarma Rules, mostly relating to advertising and the addition of the new "Paying it Forward" & "Giving back" forums in the AudioKarma Audio Marketplace section.

McIntosh MC2125 - BC416C (132-096) and BC239C (132-092) replacement

Porthos

Porthos

Active Member
I am recapping my McIntosh MC2125 and am planning on changing some of the transistors too. Basically SMD chips are becoming more and more common and I want to make sure it'll be good to go for many years to come.

I have been able to gather that at some point in the 1980's McIntosh swapped these transistors with the following:

BC416C > 2SA970BL = KSA992
BC238C/BC239C > 2SC2240BL = KSA1845

The BC550CTA and BC560CTA seem to match fT far better than the recommended transistors. Would these be better replacements? They are 50MHz faster than the originals. While the KSA and Toshiba replacements are around 150-200 MHz slower.
 
Register to hide this ad
McIntosh chose the original Toshiba parts, 2240 and 970. I think the current Fairchild devices are closest to those Toshiba parts as I believe they were NEC designs.

DOB confided that the Toshiba sourced product was much tighter to spec than the BC devices they replaced and did not have the reject rate and the needed color coding the originals needed.

I have no idea how well the current BC devices stack up.....I have found that the current 2240s and 970s ( not labeled Toshiba) I have obtained are not the same as the few original Toshibas I have kept around for reference
 
Hello

I really don't understand why people want to replace working components .....
I read every day people making "recap" ....What for ?
Do you think that repair or restoration is replacing everything ???
Explain us why you want to replace working transistors
You don't do that if you know how electronic components works
I do have original Toshiba and they work flawless
 
Porthos said:
I am recapping my McIntosh MC2125 and am planning on changing some of the transistors too. Basically SMD chips are becoming more and more common and I want to make sure it'll be good to go for many years to come.

I have been able to gather that at some point in the 1980's McIntosh swapped these transistors with the following:

BC416C > 2SA970BL = KSA992
BC238C/BC239C > 2SC2240BL = KSA1845

The BC550CTA and BC560CTA seem to match fT far better than the recommended transistors. Would these be better replacements? They are 50MHz faster than the originals. While the KSA and Toshiba replacements are around 150-200 MHz slower.
Click to expand...

I am trying to read between the lines what you are questioning?

I believe that a half dozen or do Asian OEM manufacturers made devices to compete with each other and supply their own "captive" in house manufacturing arms.

These devices were similar and direct copies or competitive products to American and European sourced devices that they were interchangable.

In the 80s Mac engineering chose the Toshiba devices.....I believe that later they started to use Sanyo sourced semiconductors.

I do not believe Mac parts has ever shipped the Fairchild modern parts; many of us have chosen these parts because they work and are readily available and are useful in most brands of vintage audio units.

If you are trying to stockpile a cache of parts for future repair needs that is one thing, trying to sub in new parts for old semiconductors is foolish as most semiconductors if heatsinked properly do not have a built in life span.

Electrolytic caps do have a given life span and if you add to that many report a positive improved sound experience it can make real good sense to do a major recap.

Lastly, faster does not make a device better, in fact it can cause greater issues due to rampant oscilation problems.

So recap if you wish, stock pile parts if you want, but don't bank on huge sound improvements, certainly if you swap out semiconductors
 
Please look into this other forum. You will find current Toshiba SMD low noise parts that are a close match to the 2sc2240 and the 2sa970. The posts by user name "Celestial" contain a couple of tables that are woth looking at.
 
I have to agree with the masses here!

Buy the replacement parts and stock pile sure ...but I wouldn't replace anything that isn't faulty ATM. The circuit board mounted stock/factory transistors are fine, and most likely will perform just as good as (or better than) the 992/1845's anyway ...for another 40years maybe!

I'll be updating my 2125 thread later this weekend :smoke:
 
You must log in or register to reply here.
Back
Top Bottom