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C'mon... 34-Cent Stereo Amp 2x3W? 29-Cent Battery Savior? - Page 2 — Parallax Forums

C'mon... 34-Cent Stereo Amp 2x3W? 29-Cent Battery Savior?

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Comments

  • My Russian electronics purchases have been limited to things like:

    *ferrite cores
    *seven-segment incandescent displays
    *wound paper capacitors
    *low-esr pulse discharge capacitors

    They were all serviceable. No rip-offs. No junk.
  • I was wondering where you could find batting - thought about ripping open an old pillow.


    We have a furniture manufacturing company nearby called "Norwalk Furniture", they sell big bags of remnant batting for a couple of bucks, some large pieces involved, maybe you have something similar near you.
  • kwinnkwinn Posts: 8,697
    User Name wrote: »
    My Russian electronics purchases have been limited to things like:

    *ferrite cores
    *seven-segment incandescent displays
    *wound paper capacitors
    *low-esr pulse discharge capacitors

    They were all serviceable. No rip-offs. No junk.

    Don't know if it's still the case, but they also made some pretty good RF power tubes a few years ago. Used to buy them for the 1.5KW and 3KW rf generators used on the ICP spectrometers.
  • Try some batting in that enclosure. In an odd counter-intuitive way, the batting actually increases the apparent space of the enclosure as "seen" by the drivers, and you get a better sound (at least in the midrange, which is what those speakers are built for).

    Though fiberglass is better, you can use white polyfill from Joann's -- costs something like a buck for a sheet, and you'll only need one sheet to try it out. Worth a shot for the non-ported cabinet you've made (without a CNC...).

    Got some poly fill at Hobby Lobby. It seems like it sounds a little bit better and lessens distortion at higher volume

  • Hey Erco!
    Would you sell me one of these amps? I have no use for 10 of them but really could use one or two.
    Jim
  • ercoerco Posts: 20,244
    RS_Jim wrote: »
    Hey Erco!
    Would you sell me one of these amps? I have no use for 10 of them but really could use one or two.
    Jim

    Sure, PM me your address.

  • Thanks,
    Check Messages
    Jim
  • ercoerco Posts: 20,244
    @Jim: Two going out in today's mail. Enjoy and get amped!

  • 2x3W isn't going to cut it for me on my radio/RPi streamer.

    This seems like a decent deal:
    http://www.ebay.com/itm/1pc-PAM8610-2-15W-Dual-Channel-Stereo-Class-D-Amplifier-Board-12V-/272318922517?hash=item3f6778ff15:g:CaMAAOSw-YVXlfqz

    1pc PAM8610 2*15W Dual Channel Stereo Class D Amplifier Board 12V $2.59

    Would this be of similar output quality to the one Erco mentioned as OP, better, worse?

    This'll probably be my workshop machine, so I don't need audiophile quality, however for a buck or two more I'd spring for something of better quality.
  • Ron CzapalaRon Czapala Posts: 2,418
    edited 2016-07-27 14:13
    koehler wrote: »
    2x3W isn't going to cut it for me on my radio/RPi streamer.

    This seems like a decent deal:
    http://www.ebay.com/itm/1pc-PAM8610-2-15W-Dual-Channel-Stereo-Class-D-Amplifier-Board-12V-/272318922517?hash=item3f6778ff15:g:CaMAAOSw-YVXlfqz

    1pc PAM8610 2*15W Dual Channel Stereo Class D Amplifier Board 12V $2.59

    Would this be of similar output quality to the one Erco mentioned as OP, better, worse?

    This'll probably be my workshop machine, so I don't need audiophile quality, however for a buck or two more I'd spring for something of better quality.

    This datasheet says the PAM8610 is 10W at 8 ohms- the eBay description says 15W at 24 ohms but still sounds like a good deal!
    http://www.datasheetspdf.com/PDF/PAM8610/642172/1

    Also says it has "32 steps DC volume control has a +32dB to -75dB range". I wonder what this board does with the volume pin...
  • Ron CzapalaRon Czapala Posts: 2,418
    edited 2016-07-27 19:31
    Here is another PAM6810 board with a volume control, power jack, 3.5mm input jack and speaker terminals for $5.21

    http://www.ebay.com/itm/311602010347

    A similar one with a heatsink

    http://www.ebay.com/itm/291792721354
  • Here is another PAM6810 board with a volume control, power jack, 3.5mm input jack and speaker terminals for $5.21

    http://www.ebay.com/itm/311602010347

    A similar one with a heatsink

    http://www.ebay.com/itm/291792721354





    Well documented.
  • Thanks, since I am looking at upgrading power, considering one of the 2020a Class T now.

    But they're $20, so Off-Topic...
  • Has anyone had any luck with getting erco's original units to work? I soldered 1/2" wires into each f the holes so that I could put them onto a breadboard, supplied power from a USB port connected an 8 ohm speaker, and no joy. Today I will pick up a 1/8" jack at work and try an aux cord from my phone and see if that works. any other suggestions?
    Jim
  • RS_Jim wrote: »
    Has anyone had any luck with getting erco's original units to work? I soldered 1/2" wires into each f the holes so that I could put them onto a breadboard, supplied power from a USB port connected an 8 ohm speaker, and no joy. Today I will pick up a 1/8" jack at work and try an aux cord from my phone and see if that works. any other suggestions?
    Jim
    You said you connected an 8 ohm speaker (singular) - I hope you didn't connect the left and right channels together - you can't even connect the speaker negatives together as a common ground. I think it will damage the amp...

  • I wired up three boards and they all work perfect - I used an in-line stereo jack here:

    Class%20D%20amp.jpg
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  • Ok,I had 2 issues, 1 power supply related and 1 bad speaker. Fixed power supply problem and tried new speakers. They work great. I am a little suprised at how much drive they seem to need. Ran them off of an old cell phone running Pandora from wifi. Phone indicated volume in the danger zone for headphones.
    Jim
  • ercoerco Posts: 20,244
    Here's a 10-cent 4-tone "alarm" chip (10 fer 99 cents shipped!) for anyone who can't figure out what to amplify with their 34-cent amplifier:

    http://www.ebay.com/itm/10PCS-KD9561-CK9561-Alarm-Chip-Four-Alarm-Tones-Chip/191106113304

    Doesn't even say what it is, but I found more info at

    http://www.ebay.com/itm/Voice-Module-KD9561-CK9561-Alarm-Module-4-Kind-of-Sound-DIY-Kit-/381754558228?hash=item58e2584714:g:J8EAAOSwaB5XphJ9

    Gotta be the same cheesy beepy 8-bit sounds we've heard in cheap toys since 1980.

    At that price, every project we build should include one!

    Alarm.png
    350 x 500 - 79K
  • Just got me 10 amplifiers. Your bad erco, but at 2.80 I can play!
  • ercoerco Posts: 20,244
    edited 2016-09-07 02:46
    Shawn Lowe wrote: »
    Just got me 10 amplifiers. Your bad erco, but at 2.80 I can play!

    There's one born every second! Welcome to my hoarder's club. We have another forum for self-help and self-control.

    NOW THIS MUST BE A TYPO: Shawn made me look for a better deal (did he really get ten for $2.80?) and I found THIS:

    10 pieces amp with volume control for $1 ($1.29 can)! Likely they meant 1 piece, but I ordered one just to see. Still a bargain at $1 with that volume control!

    http://www.ebay.com/itm/10PCS-PAM8403-5V-Power-Audio-Amplifier-Board-2-Channel-3W-W-Volume-Control-/142101024643

    Edit: I just emailed the seller through Ebay for confirmation on that qty 10, so if it's a mistake he may change the listing. IOW, order now! :)

    PAM8403.jpg
    500 x 500 - 32K
  • I've used the PAM 8403 amps (the red ones you can see on some ebay listings) on a couple of projects. They're surprisingly good for the price.
  • ercoerco Posts: 20,244
    edited 2017-05-02 23:17
    Dollar Tree has these amplified speaker balls for a buck (duh) in their hardware section. Roughly baseball-sized, flat bottom, 2xAAA batteries, nice old-school 1-7/8" steel frame PM speaker. Certainly not Veho quality nor hi-fi but plenty good enough for many projects. A fair amount of room inside for some extra gizmos & circuitry. 3.5mm input jack, no cable. Amplifier chip stamped LM4871, which if authentic is a decent chip from TI: http://www.ti.com/lit/ds/symlink/lm4871.pdf

    I only bought one today but I'll hoard a few more next trip.
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  • ercoerco Posts: 20,244
    Even better is this Veho semi-clone at 99 cent stores. The "bomb speaker" by Vibe Sound. Internal rechargeable battery. Comes with USB charge cable, unusual small diameter coaxial plug. Works fine, I'm going to build one inside a robot project with an MP3 player.


    1550 x 1000 - 363K
  • ercoerco Posts: 20,244
    I hoarded a few more of those Dollar Tree ball amps, since they have worked well in several projects. Most recently the amp drove a 6x9" 4-ohm car speaker and was LOUD powered by 5V.

    There are a few changes in the new stock. Good news, there's now a short stereo plug included (see package). Meh news, the speaker got cheaper, it's not a giant PM type anymore, but it still works surprisingly well.
    750 x 900 - 204K
  • I picked up one of those Dollar Tree ball amps. The chip inside is stamped YX1613, which Google translates into 8002, and it brings up a surprisingly detailed data sheet:
    https://thaieasyelec.com/downloads/EFDV308/HXJ8002_Miniature_Audio_Amplifier_Datasheet.pdf

    Erco, you're right - giving it 5V lets it put out a lot more volume! I even hooked it up to one of the speakers from an old Sony bookshelf stereo, and it drove it quite well. Quite a bargain.


  • These amps aren't at any Dollar Tree in my area. Am I being suppressed by the Illuminati?
  • ercoerco Posts: 20,244
    How many do you require?
  • Gordon,

    Try one of the more secluded, hard to find, or hard to get to locations.
    I found a few recently at a store that was surrounded by blocks and blocks of residential.
  • Unfortunately, in my area all of the DT's are in fairly busy commercial areas -- the one closest to me has residential around and behind it, but is on the main commuting thoroughfare leading to the towns to the north. I'll keep checking as there's one I haven't hit for a few weeks.

    I plan on getting one or two. Xanadu and I shop at the same stores and I want to leave him some!
  • ercoerco Posts: 20,244
    Plenty here, I can grab you guys some if you can't find any. We're overdue for a lunch this year to discuss the human condition of robotics... We'll have to pick a place within range of my Leaf that has an EV charger. Looooong lunch to recharge.
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