Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: Gwymember on December 18, 2018, 11:54:23 AM

Title: Speedball Big Board TIP-50 insulator cracked
Post by: Gwymember on December 18, 2018, 11:54:23 AM

Hi there,

Today I got around preparing the big board from the speedball upgrade. When assembling the TIP-50 transistors to the heat sinks I noticed one of the insulators was cracked. I'm not sure if it's safe to move on with the upgrade, as I'm positive it is vital that the backplate of the TIP-50 is not supposed to make electrical contact with the heat sink. The crack is not all the way through so it might still be okay. But I wanted to have a second opinion from you guys. I sent a picture so you can have a look at it if you find the time. I really appreciate your dedication to the products and the ongoing support you guys provide!
 Unfortunately I cannot post links yet, the picture: https:// imgur.com/Qed7ddu

Happy DIY'ing,

Title: Re: Speedball Big Board TIP-50 insulator cracked
Post by: Paul Birkeland on December 18, 2018, 12:00:35 PM

That is extremely unlikely to present you with any problems, I would use it. 

Title: Re: Speedball Big Board TIP-50 insulator cracked
Post by: Gwymember on December 18, 2018, 12:02:40 PM

Cool! Thanks for the amazingly swift reply  ;)

Title: Re: Speedball Big Board TIP-50 insulator cracked
Post by: Vonkrumm on January 18, 2019, 12:15:21 AM

Hi Guys, I think I have a similar problem.

Although I can't see the above picture of the OP, the plastic bit that comes between the transistor and the heat shrink, I no longer can find the part and need to replace them with something.

Is there anything similar, material wise, when it comes to the plastic insulator?
What could someone use instead?

Any help is much appreciated.  :)

Title: Re: Speedball Big Board TIP-50 insulator cracked
Post by: Paul Birkeland on January 18, 2019, 04:39:37 AM

If you have a local electronics retailer, they will likely carry NTE parts.  An NTE198 will come with another insulator.

Title: Re: Speedball Big Board TIP-50 insulator cracked
Post by: Vonkrumm on January 18, 2019, 04:42:38 PM

Can I use heat shrink?

Title: Re: Speedball Big Board TIP-50 insulator cracked
Post by: Vonkrumm on January 18, 2019, 10:48:47 PM

I found some 'Mica' thermal insulators, they look/feel  plastic and clear. Think they will do :)

Title: Re: Speedball Big Board TIP-50 insulator cracked
Post by: Paul Birkeland on January 19, 2019, 05:37:49 AM

Mica insulators are the proper item to use.  Heatshrink is not so good though.