TB-303 internal images

[MartinDidymus]

I while ago someone was asking about the position of the thermistors in TB-303 in relation to the accuracy of their x0x build. I stumbled across these images on the Matrixsynth Blog and thought they would be useful reference for x0x bulders and TB cloners.








































































Images found via: http://matrixsynth.blogspot.com/2010/07/inside-roland-tb-303.html

[Brassteacher]

MartinDidymus,
It was me that had asked about the thermistor mounting, I hope I thanked you for finding the photos! In case you are interested, based on the photos you sent I decided upon the following solution for mounting the thermistors on the board:

P7300017.jpg (377.65 KiB) Viewed 1585 times

[MartinDidymus]

Hi,

I can’t take any credit for the pictures in response to your post, that was another forum member (sorry I can’t remember who either). But your initial request sprung to mind when I saw these pics.

Interesting thermistor arrangement, has it made any difference?

[SubStyler]

MartinDidymus,
It was me that had asked about the thermistor mounting, I hope I thanked you for finding the photos! In case you are interested, based on the photos you sent I decided upon the following solution for mounting the thermistors on the board:

P7300017.jpg

hmm..isn't that 1583 mounted backwards?

[Brassteacher]

MartinDidymus,
It was me that had asked about the thermistor mounting, I hope I thanked you for finding the photos! In case you are interested, based on the photos you sent I decided upon the following solution for mounting the thermistors on the board:

P7300017.jpg

hmm..isn't that 1583 mounted backwards?

Well, with a 1583, or a 2291, it really doesn't matter, as they are both symmetrical from the center pin. The C1583 is: B-C-E-C-B . In other words, 'tis a palindrome, you can't put it in backwards! I turned it that way so the thermistor would have more surface area to contact.

[Luap]

MartinDidymus,
It was me that had asked about the thermistor mounting, I hope I thanked you for finding the photos! In case you are interested, based on the photos you sent I decided upon the following solution for mounting the thermistors on the board:

P7300017.jpg

hmm..isn't that 1583 mounted backwards?

Well, with a 1583, or a 2291, it really doesn't matter, as they are both symmetrical from the center pin. The C1583 is: B-C-E-C-B . In other words, 'tis a palindrome, you can't put it in backwards! I turned it that way so the thermistor would have more surface area to contact.

Ugh, I wish I had known that earlier! I had a hell of a job unsoldering one I had accidentally installed backwards.. I thought I was lucky at the time, as I caught it before it ever got powered up