Caps for RGB amp - Page 1
Forum section: electronics / beginners

author: Legion
author_rank: Frequent Contributor
timestamp: June 15, 2014, 08:42:01 pm
content: I'm making this RGB amp for the TG-16 (schematic below). I already have a bunch of caps that match the specs but they're cheap ones (ChongX). There's no low ESR requirement that I'm aware of. Can't really find anything with better than 20% tolerance. It'll be through hole mounting. Since it's an analog circuit and fidelity is important, should I use better caps? Should I use caps meant for audio for the L/R channels?

author: thejamesclan
author_rank: Newbie
timestamp: June 15, 2014, 09:32:30 pm
content: I cannot see any problems with the use of cheap caps in this circuit , Just build it.

author: Legion
author_rank: Frequent Contributor
timestamp: June 16, 2014, 12:19:20 am
content: So I opened up the console to scout out a good location to add the amp. I don't what the previous owner did to this thing but it's disgusting in here. Full or rust, corrosion and stink. I'm surprised it still works.

author: theatrus
author_rank: Frequent Contributor
timestamp: June 16, 2014, 12:41:28 am
content: Thats terrible.

author: Legion
author_rank: Frequent Contributor
timestamp: June 16, 2014, 01:05:18 am
content: Judging from the smell, I'd say it's the work of cheesers.

author: peter.mitchell
author_rank: Super Contributor
timestamp: June 16, 2014, 01:10:23 am
content: get some acetone and a toothbrush and clean that up asap, then rinse the acetone off with isopropyl alcohol...

author: N2IXK
author_rank: Frequent Contributor
timestamp: June 16, 2014, 01:32:31 am
content: Definitely looks like mouse piss damage.Be somewhat careful cleaning that mess up if you live in an area where Hantavirus is found.

author: Legion
author_rank: Frequent Contributor
timestamp: June 16, 2014, 02:08:38 am
content: I don't have acetone. But I sprayed it with IPA and used a toothbrush. It kinda works. It looks really clean while wet but when it dries you're left with this white residue. Will the acetone take care of that residue?

author: peter.mitchell
author_rank: Super Contributor
timestamp: June 16, 2014, 02:12:45 am
content: Quote from: Legion on June 16, 2014, 02:08:38 amIt will take care of the most of it, and then the IPA will wish the acetone with the rest of it dissolved in it off.

author: Legion
author_rank: Frequent Contributor
timestamp: June 16, 2014, 02:14:09 am
content: For the acetone can I just use the stuff from the nail polish section of the drug store? Or does that have adulterants in it?

author: Legion
author_rank: Frequent Contributor
timestamp: June 16, 2014, 02:19:49 am
content: Quote from: N2IXK on June 16, 2014, 01:32:31 amI hope not. I sprayed it down with about half a can of IPA. Hopefully anything that was alive is now dead.

author: Rigby
author_rank: Super Contributor
timestamp: June 16, 2014, 03:24:36 am
content: Find 99% IPA. The 91% stuff found commonly might be the source of the "white stuff" that is left behind.

author: Zad
author_rank: Super Contributor
timestamp: June 16, 2014, 03:48:52 am
content: WD40 can be good for removing assorted yuckiness too.

author: Legion
author_rank: Frequent Contributor
timestamp: June 16, 2014, 01:36:51 pm
content: Any potential negative consequences to me submerging the board in a bath of acetone followed by a bath of 99.99% IPA? Or could that damage board components?

author: miguelvp
author_rank: Super Contributor
timestamp: June 16, 2014, 01:43:41 pm
content: wouldn't acetone melt the pastic?

author: Legion
author_rank: Frequent Contributor
timestamp: June 16, 2014, 01:52:05 pm
content: Quote from: miguelvp on June 16, 2014, 01:43:41 pmTrue. There are a couple plastic connectors on the board. Perhaps some strategic acetone scrubbing with a brush followed by an IPA bath?

author: ConKbot
author_rank: Super Contributor
timestamp: June 17, 2014, 01:39:17 am
content: Fyi, its generally not good form to mix IPA and acetone (or other ketones) It likes to make peroxides. Its nothing violent or sudden, and if youre just letting it evaporate off immediately after use, its probably not the end of the world. But store IPA/acetone mixed for later use, and let it get warm and you could be bursting containers.Also, for those etching boards with hydrogen peroxide and HCl, be wary of acetone and hydrogen peroxide mixing... Not as mild mannered as IPA/Acetone.

author: SL4P
author_rank: Super Contributor
timestamp: June 17, 2014, 02:27:19 am
content: Clean off ALL hydrogen peroxide - it is corrosive.Also aside fopr anyone building RGB projects.Remember tomake all the R/G/B wire lengths as close as possible to the same length.Skew/slew in the arrival of RGB at high frequencies will present themselves as LR color fringing on your display!

author: Rigby
author_rank: Super Contributor
timestamp: June 17, 2014, 03:24:59 am
content: And if you wind up with fringing, you may be able to tune it out by tweaking individual signal lengths.

author: Legion
author_rank: Frequent Contributor
timestamp: June 17, 2014, 03:25:20 am
content: Quote from: SL4P on June 17, 2014, 02:27:19 amGood to know.