Sex on a stick: Clear resin encased amp - Page 1
Forum section: electronics / general

author: Wartex
author_rank: Frequent Contributor
timestamp: April 14, 2012, 11:15:25 pm
content: http://runawaybrainz.blogspot.co.uk/2012/04/audio-crystal-cmoy-freeform-headphone.html

author: olsenn
author_rank: Frequent Contributor
timestamp: April 14, 2012, 11:38:28 pm
content: I think soldering the pieces directly on to a copper wireframe and encapsulating it in resin is a bit much. A simple printed pcb in an altoids tin would have sufficed. Furthermore, I don't think that op-amp is the best; a AD8620 would probably be better.

author: slateraptor
author_rank: Frequent Contributor
timestamp: April 14, 2012, 11:54:35 pm
content: @olsenn: Picky picky.That resin isn't thermally conductive, is it?

author: Psi
author_rank: Super Contributor
timestamp: April 15, 2012, 12:18:24 am
content: Quote from: olsenn on April 14, 2012, 11:38:28 pmna the wireframe and clear resin is what makes it look cool.oh right, you were joking.

author: IanB
author_rank: Super Contributor
timestamp: April 15, 2012, 12:28:56 am
content: It looks beautiful, but I do wonder about the required heat dissipation of the components? I think this construction method could only work for very low power circuits.

author: olsenn
author_rank: Frequent Contributor
timestamp: April 15, 2012, 12:29:54 am
content: QuoteIt's a headphone amp... it won't get hot

author: Mint.
author_rank: Frequent Contributor
timestamp: April 15, 2012, 01:55:44 am
content: That is amazing. However imagine trying to carry around something like that in your pocket

author: graynomad
author_rank: Regular Contributor
timestamp: April 15, 2012, 04:27:53 am
content: Not practical for various reasons, but one of the best things I've seen in a long time.______Rob

author: Psi
author_rank: Super Contributor
timestamp: April 15, 2012, 04:56:32 am
content: Probably not the best thing to try and take onto a plane in the USA.Ironically if it was panted black so you couldn't see the components it would probably be fine.Being able to see what's inside should be a good thing but somehow i doubt they would see it that way.

author: elliott
author_rank: Regular Contributor
timestamp: April 15, 2012, 06:50:50 am
content: Quote from: Psi on April 15, 2012, 04:56:32 amIt would still look very strange going through the x-ray.

author: siliconmix
author_rank: Frequent Contributor
timestamp: April 15, 2012, 07:15:20 am
content: i love it.

author: amyk
author_rank: Super Contributor
timestamp: April 15, 2012, 07:36:58 am
content: Looks very stylish, but if something breaks you're out of luck.Potting an electrolytic cap sounds dangerous; they have vents for a reason.

author: AntiProtonBoy
author_rank: Frequent Contributor
timestamp: April 15, 2012, 08:22:32 am
content: Quote from: olsenn on April 14, 2012, 11:38:28 pmHahah, missing the point much?Quote from: amyk on April 15, 2012, 07:36:58 amI probably wouldn't worry about that too much. I doubt those caps would build up enough pressure the blast the resin apart - worst case maybe crack it. But yeah, you are shit out of luck if something breaks down.

author: Bored@Work
author_rank: Super Contributor
timestamp: April 15, 2012, 09:18:13 am
content: Quote from: AntiProtonBoy on April 15, 2012, 08:22:32 amNot much different from a lot of modern consumer electronics.

author: chrome
author_rank: Regular Contributor
timestamp: April 15, 2012, 10:35:59 am
content: Can somebody explain me why sex on a stick is supposed to be a good thing?Sex is great.Sticks are great too (I guess)Having sex on a stick sounds probably the worst thing ever.And the project looks nice but for this thing, where you basically have this in your pocket, it's a bit overdone, he/she should have made it smaller.

author: SeanB
author_rank: Super Contributor
timestamp: April 15, 2012, 12:49:41 pm
content: Nicely done, I have had similar amplifiers that were encased in resin ( made by OpAmp Labs) which were rather difficult to open to fix them. The steel case did not survive, and a lot of grinding and epoxy solvent eventually got the board inside out, enough to trace the circuit ( basically a LM709 with a output stage and little else really) and replace the 2 dead output transistors with new ones ( 2n2219 and 2N2905 wearing little heatsinks instead of the 2 plastic devices it had) and get it working again.

author: saturation
author_rank: Super Contributor
timestamp: April 15, 2012, 12:58:57 pm
content: Its an English expression "XXXX ... on a stick" means the XXXX is pleasurable and/or easy to obtain and often cheap. It probably has roots from getting treats like hot dogs, candied apples, cotton candy, etc., "on a stick" from carnivals.Quote from: chrome on April 15, 2012, 10:35:59 am

author: olsenn
author_rank: Frequent Contributor
timestamp: April 15, 2012, 01:32:24 pm
content: If anyone is interested, here is a headphone amplifier that I put together; I've included the gerber files and eagle board/schematic files along with some other useful resources such as datasheets and photos.I didn't have any dual pots at the time so this one doesn't include volume control in the device itself, but feel free to add it if you'd like. It sounds better than my JDS Labs Cmoy amplifier by a long shot, but I didn't bother with bass boost in this one... once again it is easy to add if you desire.Download Link:http://www.freefilehosting.net/headphoneamp

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 15, 2012, 01:43:31 pm
content: Quote from: saturation on April 15, 2012, 12:58:57 pmMore specifically I think it's that "XXX on a stick" is an improvement on/better than plain old "XXX".

author: koogar
author_rank: Contributor
timestamp: April 30, 2012, 12:39:03 am
content: Quote from: olsenn on April 14, 2012, 11:38:28 pmWhat a uninspiring comment.maybe the cMoy will jump inside the tin after reading your commentand the use of which opamp is best is subjective.It clearly states in the Analog Devices data sheet that the AD8620 should not be encapsulated

author: koogar
author_rank: Contributor
timestamp: April 30, 2012, 12:41:44 am
content: Quote from: Mint. on April 15, 2012, 01:55:44 am@MintI never intended it for portable use as the plug on the wallwart would be harder to imagine in your other pocketRegardsRupert

author: steve_w
author_rank: Regular Contributor
timestamp: April 30, 2012, 01:32:36 am
content: That stuff can be repaired, there was some stuff like that that I have worked on that was installed in an aircraft.it was part of the flight controls and lived near the afterburner. The potting solved a lot of environmental problems, repair was difficult but not impossible. The OEM made them as throwaway modules, but tightwad aussies said repair them so we did.

author: SeanB
author_rank: Super Contributor
timestamp: April 30, 2012, 06:22:34 pm
content: Yes, I know those modules. most common problem was the Socaplex sockets wearing out the pins from vibration, and getting so thin they would snap off in the socket, giving an intermittent pin. After around 20 pin changes the actual body of the unit would wear out and require replacement. A big pain as they were not the standard 19-9 keying, but were an alternate with the same basic part number, and were hard to order as most suppliers would only give the standard part without realising the special keying.

author: M. András
author_rank: Super Contributor
timestamp: May 01, 2012, 06:07:57 pm
content: where can you get this clear resin in europe? or any epoxy resin without an insane price

author: koogar
author_rank: Contributor
timestamp: May 01, 2012, 07:20:22 pm
content: Quote from: M. András on May 01, 2012, 06:07:57 pmI actually got it fromhttp://www.mbfg.co.uk/casting-resin/1453.htmlIt was very reasonable I think I paid around £12 delivered for 500g of resin including the catalyst they also sell on EbayRegardsRupert