ronzo56
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Post by ronzo56 on Jan 10, 2013 3:21:33 GMT
My Advanced Placement physics students are interested in building a very basic CMOY amp. The ones I have found on the web so far are too expensive or too complicated for them (and me ). Does anyone have a design for a really simple CMOY in an Altoids can? Not looking for audiophile sound, just some sound. American teacher = (no budget) 2. Thanks for any help, Ron PS-from what I've heard a Grado design would be close.
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mrarroyo
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Post by mrarroyo on Jan 10, 2013 11:49:28 GMT
How much do you want to spend per unit?
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Post by PinkFloyd on Jan 10, 2013 14:19:17 GMT
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Post by pandapops on Jan 10, 2013 14:23:19 GMT
The basic circuit is a chip and a few capacitors and resistors, plus input/output sockets, volume control + PSU. The components you can do more cheaply could be the case and chip: the case could be any box, metal is actually a pain to drill and risks unintended electrical connection. The various chip manufacturers do free samples, each person can request a certain amount it varies between companies and the chip( they don't like to give away their best stuff), they might be nice enough to give an educator some additonal freebies or even have a policy of doing so.
Resistors cost very little if bought by the hundred, the capacitors could be done for maybe a $1, audio people will spend a $2 where a 5 cent item is functional. Sockets, rail splitter, battery and connector and volume control will cost a few dollars, theres not a simple cheaper alternative to batteries. The bits could be wired togther directly to save the cost of stripboard or pcb.
Could it be done as a club with the students making a contribution?
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Post by PinkFloyd on Jan 10, 2013 14:34:55 GMT
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Post by PinkFloyd on Jan 10, 2013 14:42:39 GMT
You're cheaper going for the ready made $19.99 shipped one!
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Post by PinkFloyd on Jan 10, 2013 14:52:16 GMT
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Post by PinkFloyd on Jan 10, 2013 14:53:56 GMT
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Post by PinkFloyd on Jan 10, 2013 14:54:42 GMT
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Deleted
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Post by Deleted on Jan 10, 2013 15:22:11 GMT
.....or, if you really want to make these from scratch on blank boards, here's my very fugly effort from a while ago. It's based on this layout (I think Mike sent it sent to me) If you reorganised and compacted my mess here (but at least you see what's going on) you will have a working cmoy. It sounds fine and was made from whatever I could find in the box-a-bitz.
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Post by PinkFloyd on Jan 10, 2013 21:08:05 GMT
That looks familiar Chris
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ronzo56
Been here a while!
All you need is love. But money helps too.
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Post by ronzo56 on Jan 11, 2013 0:40:43 GMT
Wow! Thanks for all the great replies. Budget is probably at most $20 USD, if we can even get it approved. Spending money on education is a controversial political topic right now. Last year most of us had to buy paper out of our own pockets to make it through the year. Many elementary teachers spend 2 to 3 thousand USD out of their own pockets so their students can have supplies. I am working with another teacher to see what funds we might be able to find in terms of $$$. I'll have to take a look at all the links this weekend. Keep the ideas coming. The kids are really excited about actually building something instead of just drawing circuits and calculating resistance capacitance etc. Plus maybe it might get them into listening to their music with some better SQ. Maybe they might go into a tech field. Thanks for all your help with this. RG rocks! Ron
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Post by PinkFloyd on Jan 11, 2013 11:41:37 GMT
Hi Ron, I'd be happy to donate the parts... that's not a problem
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mrarroyo
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Our man in Miami!
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Post by mrarroyo on Jan 11, 2013 14:11:58 GMT
I too would be happy to donate some funds, send me a PM with your PayPal address and I will see how much I can send. Cheers!
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XTRProf
Fully Modded
Pssst ! Got any spare capacitors ?
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Post by XTRProf on Jan 12, 2013 1:52:31 GMT
Hi Ron,
I suggest you get the circuit diagram and the bom and buy in bags of the parts if this is a continual educational module. Overall, will be cheaper for your educational needs. Sure will be approved by the head of department for physics.
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Post by PinkFloyd on Jan 12, 2013 21:29:36 GMT
I too would be happy to donate some funds, send me a PM with your PayPal address and I will see how much I can send. Cheers! X2
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XTRProf
Fully Modded
Pssst ! Got any spare capacitors ?
Posts: 5,689
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Post by XTRProf on Jan 13, 2013 0:32:07 GMT
Yeah, forget to reiterate. Do approach the op amp manufacturers for the op amp part. They do donate op amps for educational purpose in the hope that you and any future engineers from your class will buy from them in quantity later.
Er, tell your students tin cans and boxes for the cmoy not provided to entice their creativity. Also, that's what industrial engineers will have to do to ingrain in them the work of an industrial engineer. No spoon feeding in that area. But please tell them don't steal it from their parents' closet. Do give a prize for the best looking cmoy as voted by the class.
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ronzo56
Been here a while!
All you need is love. But money helps too.
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Post by ronzo56 on Jan 13, 2013 20:49:38 GMT
Many thanks to all of you. Sorry my reply is so late, but work was completely crazy this week. I'm taking a break from grading to check in. I am overwhelmed with the generosity shown here. What a great group of people you are. I truly appreciate your willingness to help out the next generation. I always tell my wife, take care of the younger generation, and they will take care of you. Let me talk to the other physics teacher I am working with on this and see what the status of the order is. I teach at a high school that has about 3000 students. It's like living (working) in a small town. So we may need to pool resources to pull this off as I am not sure yet how many students would want to be part of the build. Wish I could ask the kids to put in some money, but it's against state law here. Don't get me started or I may get going on a "Mike" rant about dumb arses ruining education and treating it like shite. ;D Mike feel free to give your thoughts however. I will get back to all of you next week and we can figure out how to make this happen. You guys have helped to restore my faith in humanity. (well at least the part that appreciates good sounding music, played on great sounding gear ). My very best wishes to all of you, here's to the next generation! Ron
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Spirit
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Post by Spirit on Jan 27, 2013 13:30:08 GMT
Where'd you get to with this Ron?
Also happy to donate some $$.
Cheers, Phil
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ronzo56
Been here a while!
All you need is love. But money helps too.
Posts: 316
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Post by ronzo56 on Jan 27, 2013 20:13:03 GMT
Trying to work it out with the "powers that be" at school, and the other physics teacher. He and I have to pick a design and last week I had maybe 5 minutes to talk with him. Thanks greatly for your offer. I am hoping this week we can finish planning it out. Right now there are about 20 students who are really serious about building one. If you know teens, they can be really on about something and two weeks later they have moved on to something else, so we always give a little time between proposing something and then wait to see who is still interested. Thanks again for your support, Ron
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