That’s how important this transistor is to the TR-808’s unique sound. When he could not purchase any more of the transistors that was the end and the TR-808 could no longer be produced. He said that as semiconductor manufacturing improved he found that he could no longer source these unique rejected parts.
![tr 808 drum kit tr 808 drum kit](https://soundgas.com/wp-content/uploads/2019/02/Roland-TR-808-Rhythm-Composer-3_46210995-aaca-49c4-b887-a626fe48df00.jpg)
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.
#Tr 808 drum kit movie
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”. 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.
#Tr 808 drum kit Patch
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 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. 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. Several manufacturers made them including Toshiba and Panasonic. The “R” suffix indicates the DC gain rating of the transistor. They are a simple, general purpose silicon NPN transistor used for audio and switching applications. Though discontinued these are still available to buy at many electronics suppliers for less that 30 cents each. The part number on the front is that of a common transisitor, the 2SC828-R.
![tr 808 drum kit tr 808 drum kit](https://media.guitarcenter.com/is/image/MMGS7/1980s-TR-808-Drum-Machine/000000113418599-00-500x500.jpg)
The image above shows some very special transistors. And here begins a strange chapter in the story of the Roland TR-808 Rhythm Composer. They may not be bad, they are still functional transistors for example but they just don’t fit the characteristics of any part number the company’s catalogue and so were dumped. Some were so different than expected that they were rejected altogether and discarded. From any given batch several different transistor part numbers might emerge depending upon how they performed.
![tr 808 drum kit tr 808 drum kit](https://cdn-djifo.nitrocdn.com/LzlMtmpqrIJsucaVvfIaAYjYTIRtRTCM/assets/static/optimized/rev-442a74e/wp-content/uploads/2015/06/drum-kit-pack2-500x500.jpg)
Manufacturers tested each batch, graded the parts depending upon their electrical characteristics and marked them appropriately before shipping them out. Solid state electronic components were quite new when he started Acetone and then Roland, by the early 1980’s component manufacturing processes were becoming quite mature but each batch of semiconductors such as IC’s and transistors had a significant reject rate, perhaps due to uneveness in substrate materials, temperature differences across dies and so on. Mr Kakehashi was an excellent design engineer and he created Roland’s early products at the same time as building and running the company and travelling the world promoting it’s instruments. His story is worth reading as a lesson in indominable perseverence and strength of character. The TR-808 has an interesting story and that is no surprise as it’s designer, Roland founder Ikutaro Kakehashi had a life journey that is almost unbelievable – His early life was a story of extraordinary creativity, resilience and sheer determination, he faced and triumphed over challenges that would make most people give up and fold.