Hiraga Transistor Substitutes

I was planning to build Hiraga 8w amp but was having trouble finding the substitutes. My local electronics (RS and Farnell) don't seem to have this substitutes. Can anyone recommend some good replacements hopefully not japanese type. Seems to always run out of production. I found awebpage from http://www.gmweb.btinternet.co.uk/hiragatrans.htm and the transistor substitutes but still the recomended replacements can't be found here. The transistors are
2sd1063 and 2sb825
2sa1124 and 2sc2229
2sc1775 and 2sa872
2sk147 and 2sj72
COuld anyone recommend replacements please


2002-03-12 7:46 am
I am going to build the 8W Hiraga too. And I am having problems finding some of the transistors also. I know you can get the 2SK147, 2SJ72, 2SC1775, and 2SA872 from borbelyaudio.com in matched pairs from Germany. I deal with him all the time. As for the other transistors I have other electronics catalogs to try to find them but have not had time to look.


2002-03-12 7:46 am
Snice you don't have a location under your name. I am not sure were to tell you to look. Anyway, Mouser has a few of the other transistors listed in their catalog 608 for the 8W but the best source I have found on the internet (haven't ordered yet) is www.mcmelectronics.com. Every transistors I put in their parts search came up for the 8W, 20W Hiraga, and JLH amps.
At their home page click on guest which will take you their parts search and just call the 800 number to order.

I builted several Hiraga Monster amplifier with the transistors
shown below, and did not have any problems.
Do not mix original and suggested new transistors in amplifier.
Use only ALL original or ALL substitute parts, as otherwise the
amplifier might not be stable.

Best regards,
Kristijan Kljucaric


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substitutes for Monstre: especially for sk/sj couple

More than 10 years back I built 5 times the original Monstre amplifier. At the time the transistors were obtainable though not easily. After I heard another Monstre a few months ago I decided that I wanted to built me another one from scratch, just for fun. But indeed: the transistors are a problem now. Therefore I just tried several alternatives and found no problems at all (but could hear differences in sound quality and character).

As the previous reply stated: using bc550/560, tip's etc is no problem, you will get a good working amplifier. I also tried bd139/140 and some other sa/sc pair and everything works okay. So I even mixed the original parts and their substitutes without problems.

The only challenge for the forum here is to find (just to have maximum flexibility and fun) European or American substitues for the SK/SJ pair (at this place I used the original sk170/sj74 couple) and I have not a clue what could be used in this place instead (not talking about sj72 and the like of course).

So start building it on a breadbord and for a very modest sum of money you get yourself a special amp and a lot of fun.


(Why this thread is under video .. i don't know).