The image above shows some very special transistors. The part number on the front is that of a common transisitor, the 2SC828-R. Though discontinued these are still available to buy at many electronics suppliers for less that 30 cents each. They are a simple, general purpose silicon NPN transistor used for audio and switching applications. The “R” suffix indicates the DC gain rating of the transistor. Several manufacturers made them including Toshiba and Panasonic. In a sense the numbers printed on the transistors in these particular photos aren’t technically correct, they are not actually 2SC828’s, they are basically a rejected transistor with a 2SC828-R part number still printed onto them from their production but that didn’t qualify as 2SC828’s during testing.

The transistors pictured in this article are some of the small batch of transistors that were rejected as “out of specification” by the manufacturer and purchased by Roland. The little patch of paint that you can see on the top of each transistor marks them as being very special and very, very rare indeed. The paint mark was applied at the Roland factory in the late 1970’s to identify these transistors as having a unique characteristic to be used as the noise source for Roland’s new drum machine, the TR-808 Rhythm Composer.

How exactly Mr Kakehashi found these specific parts is not known, he would have had a relationship with the manufacturers that supplied parts to Acetone and Roland but you can hear him tell some of the story himself right at the end of the excellent 2015 documentary movie “808”. In the documentary he says that of a production run of 10,000 transistors for example maybe 2-3 percent were “defective” and he purchased these rejected parts which became intgregral to the “sizzling” sound in the TR-808. He said that as semiconductor manufacturing improved he found that he could no longer source these unique rejected parts. When he could not purchase any more of the transistors that was the end and the TR-808 could no longer be produced. That’s how important this transistor is to the TR-808’s unique sound. After a production run of 12,000 units the TR-808 was no more. There has been a lot of discussion about these transistors since the documentary came out and there is a lot of folklore around them so we thought that we would fill in some details and show you some close up photos of some of the few remaining transistors from the original lot. Click on the photos for a larger view.