[djdigital]

That's my question because for my very first amp I want to get all the parts locally and just try this stuff out. If I'm sacrificing a little sound quality that's okay because this is just a project to learn the ropes of building amps. A cmoy or mint would be prefered. I would also not like to spend more then 30$ on parts. I would also have to get a soldering kit right? Any help is appreciated.

Thanks,

dj_digital

P.S. I know about the tangentsoft website and those are the layouts and plans that I would follow. I hope that I could build the 20$ cmoy soon. (if I can get all the parts at radioshack)

 

[jeffreyj]

The only single op-amp available from Radio Shack is the very unhelpful uA741. I recommend the TL082/LF353 dual op-amp. It doesn't have very high output current, though, so don't expect any miracles. If you use a socket for the op-amp, and I highly encourage you to do so, then you'll be able to try out all sorts of other op-amps easily.

 

[Budgie]

Do you have any dead electronics laying around, or any you can sacrafice. A dead cd player for instance, would have all the parts in it to build a cmoy, including the opamps. If it is a few years old, it will likely be dip size chips instead of surface mounts, inside.

 

[tangent]

My first CMoy used all-Radio Shack parts. It encouraged me to keep going, but in retrospect it wasn't very good sounding. Be prepared to replace it.

 

[KTpG]

You could use the TL082.... yes...

I will open a can of worms here and sugges it... the HeadBanger. It uses all RS stuff... it was the first amp that I ever built, and I built it for the same reasons you are... RS is easy to get stuff from. Dare I say it would probably sound a little better than a CMOY with TL082 when using a single 9V battery? As much as people put it down all the time, it really doesn't sound THAT bad.

 

[jeffreyj]

KTpG - yeah, the LM386 will probably do a better job into sub-32 ohm cans than the TL082, but there isn't exactly an easy upgrade path if you use the LM386, eh? That was my rationale for suggesting the TL082 - upgrading will be as easy as swapping chips later on.

 

[djdigital]

Thanks for the help so far guys. The headbanger looks like a good option because it has all the parts numbers for radio shack.

On a side note, I found an old koss 2045series cd player in my basement and it doesn't work. I opened it up and all the insides are in good condition. Here is a parts inventory:
3x----330uf 10v
5x----220uf 10v
5x----47uf 16v

Then there's a bunch of even smaller ones like that that I can barely even read. Any chance I can use those in an amp design?

So which one should I build: cmoy, mint, or headbanger?
(I'm leaning toward the headbanger)

dj_digital

 

[Voodoochile]

The On-Semi MC33178P is a pretty boring amp, but it is still far and away better than the RS chip. If you send me your mailing address, I give you one for free (in the USA).

You can still put in a Burr-Brown OPA later, or and Analog chip. It's a dual amp witht he same pinout as the bulk of the popular chips. Sounds decent in a cmoy.

 

[djdigital]

I'm just wondering: Can the headbanger amp fit in one of those mint tins that the mint and cmoy amp go in?

thanks,

dj_digital

 

[KTpG]

Yes... it can.... my first attempt didn't fit very well, but if you don't use as much wire, you will do fine. (see attached file for my 2nd attempt- note, on this attempt, I still knew basically nothing about soldering or building circuits) This one fits much better than the first.

As others have said, it is not very upgradeable, so if that is important to you, it may not be the option. It doesn't sound too bad, though, and would be pretty nice for a first amp. (it was mine, and I enjoyed it, until my battery wire fell off the switch

). I was using 22-ohm cans at the time, and it drove them to ear splitting levels and was quite clear while doing it.

(I apologize for the poor image.... my scanner is wierd.)

EDIT: Oh, ya... there are more caps there than was necessary... I was trying an experiment (note, again, I didn't know what I was doing at the time) that didn't work, so I just left the cas on there.

EDIT again: I just remembered... this amp was done with non-RadioShack parts... with the RS stuff, some creative mounting was needed for the rather large 470uF caps. Have them angled off the board, almost flat against it.

 

[djdigital]

Thanks again for your responses so far. On the advice of Voodoochile I guess I'll just build a cmoy. I picked up a pack of altoids that'll be the case for the amp. I also went to radio shack with the parts list for the headbanger and they only had a few parts. Mostly the ones I wouldn't want to use(AC adaptor, rechargeable battery etc.) The lady there said that they were discontinued or just out of stock. She said that I might be able to find some parts at hobby shops. Something like a hobby shop that sells remote control cars, model planes etc. Do you think I would find any parts there? I also picked up a book today on how to solder and about electronics in general. One last question: those parts from the old cd player, are they useless or could I use them if I found nothing better?

dj_digital

 

[tangent]

The parts you've listed are just the electrolytic capacitors. It's not wise to re-use old 'lytics because they don't last very long, compared to semiconductors. It's best to buy new ones, which Radio Shack certainly should have.

What we're interested in seeing is what DIP-8 chips you see in the amp: black with white lettering, square-ish, 8 silver pins, 4 on each side.

 

[djdigital]

I can't find any of those. The closest I can find is a little square chip on the bottom that has 5 pins on each side. It has the numbers 4533 written on it and has another row below that says either DP6 or OP6(can't tell). That's weird...

dj_digital

 

[Budgie]

If it is a portable, the chips will all be super small sized and surface mounted. (Pain in the ass to work with.) Full sized home units from about 5 years ago or more used a larger size chip usually called a DIP package. They are much easyier to work with.

 

[Tomo]

Hey,

I built Szekeres' amp with Radio Shack Parts. Later I installed better caps.

(Then later I fried my MOSFETs so I redone the whole lot with parts from digikey.)

T