Sneezed, and the part dissapeared!

Started by jkrienert, September 24, 2010, 08:06:19 PM

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phector2004

Quote from: jkrienert on September 25, 2010, 08:08:28 PM
wow. no takers on the free-bee chip.

I really must have made a mistake ordering em. ;)

thanks for the help you guys.
You'll likely see an upcoming new topic disusing my amp, but seeing how many of them come or go, I am debating not bothering anyone on here with the 'same old same old...'

jmk

Thanks for the offer, but I've got too many projects and too many circuits to breadboard and mess with. They'd just hibernate for a couple of years in my parts box!

If you get tired of small amps, plenty of cool fx projects here involving LM386 (they even double as headphone practice amps!)
Have fun, play nice!

PRR

Aside from electric and thermal hurdles....

That chip is intended to take signal from a "sound card" chip with 3V output signal. It has no or no Voltage gain, it just boosts Current.

For guitar you want to take a 0.02V signal and bring it up near the 3V level. The '386 was made to take fairly weak signals and give a large Voltage gain (as well as current gain).

Wired per the datasheet schematic, you are going to need a 20-gram pick and put your ear in the speaker to hear any faint sound. You need to build a voltage-gain preamp to put in front.

You can pick any of many chips, DIP and SMT, or go discrete, to make a preamp. It's really just a high-gain booster pedal. Ya know what's one of the more popular boosters? A '386. It's kinda over-kill, its current delivery is wasted, but it is dead-simple and cheap, easier to build than about anything else.

We are going to have to face problems like this. Chips now cost as much as the circuit board they are on. To reduce board costs, mass-producers need smaller chips to get more functions per dollar per board-cost. This is so pervasive that non-SMD chips have gone out of style. There's thousands of most parts in warehouses, and that may last for years, but when slow-selling chips finally run out there's little reason to run another batch of slow-sellers when there's other hot-selling chips to be made.

Of course in 1980 we said there would be no new vacuum-tubes ever. And a few of the slow- but steady-selling audio-focus chips orphaned by the big makers have been adopted and produced by smaller makers like CoolAudio.
  • SUPPORTER

jkokura

I want to see it. I don't care how many end up displayed here, I will look at just about every one. There's no such thing as same old here I think. Be creative! Even if your creativity looks like everyone else's, I will still appreciate it and offer (hopefully) constructive suggestions. I like it when I get good suggestions and love to show my fairly boring, run of the mill pedals still.

Jacob

Quote from: jkrienert on September 25, 2010, 08:08:28 PM
wow. no takers on the free-bee chip.

I really must have made a mistake ordering em. ;)

thanks for the help you guys.
You'll likely see an upcoming new topic disusing my amp, but seeing how many of them come or go, I am debating not bothering anyone on here with the 'same old same old...'

jmk

I agree, and what's cool is the Cool Audio is now cheaper than the original NOS parts! I know it might be a bit expensive, compared to when the originals were in production, but I'm glad they're available at all.

Jacob

Cliff Schecht

The little SMD to through hole boards are called Surfboards. Digikey sells a few and they are available in other places.

I've built all kinda of stuff using floating SMD parts. There was one year where I was doing a lot of RF stuff for school and built a few 450 and 900+ MHz oscillators (Colpitts with SMD ceramic resonator elements) by floating surface mount parts over copper clad board. They worked well and got the students I was helping out A's.

jkrienert

Thanks for the tip cliff!
checking it out now....

jmk

jkrienert

http://www.sparkfun.com/commerce/product_info.php?products_id=570

I wonder if I could make this work.

It looks like the measurements line up.
oh.  dang it... heat sink...
hmm.

Pigyboy


These are available from BrownDog
http://cimarrontechnology.com/
You can see the 8 inline pin to DIP adapter I made from a flat cable and a strip of pin sockets. I originally did this to swap op amps inside of a newer DS1

I found a bunch of CoolAudio SMD opamps in a broken Behringer mixer and used the adapters to be able to use them elsewhere
And you'll have to admit, I'll be rich as shit
I'll just sit and grin, the money will roll right in....
                                                            - FANG

lowend

??? how does he solder the adaptor to his chip that has no pins?

Pigyboy

Quote from: lowend on September 28, 2010, 09:46:42 AM
??? how does he solder the adaptor to his chip that has no pins?
Very carefully ;D
And you'll have to admit, I'll be rich as shit
I'll just sit and grin, the money will roll right in....
                                                            - FANG

Pigyboy

And you'll have to admit, I'll be rich as shit
I'll just sit and grin, the money will roll right in....
                                                            - FANG

puretube

"Never sneeze while SMD-ing"...

(and cloze doorz`n`windowze)  :icon_wink: