Pigdog MiniAmp

beedotman · Post by **beedotman** » 14 Jul 2011, 13:21

Hi!

Does anybody know and can share schematic for something like Pigdog MiniAmp (with and without speaker)?
It looks like really simple build....

Thanks!
b

JOHNO · Post by **JOHNO** » 14 Jul 2011, 13:32

Kind of looks like a "ruby amp" but with mojo parts. Very nicely built.

RnFR · Post by **RnFR** » 14 Jul 2011, 15:47

its hard to believe somebody put that much effort into a 386 chip amp. I would think this kind of attention to mojo/detail would be spent in better ways than a crappy sounding 1/4w amplifier. those curly q's are pretty funky though! I guess to each his own...

yes, look up the ruby or little gem. there might even be a tagboard layout somewhere. of course for the mojo parts yer on yer own.

btw- what kind of pots are those??

(edit: okay I see he makes very nice vintage fuzz "replicas" a la DAM. now it makes sense. sort of.

)

JOHNO · Post by **JOHNO** » 14 Jul 2011, 16:26

You could make a ruby twin, it's got 1/2 a watt of power.

I'd like to see the asking price for one. It looks like alot of work for something that is just a crappy little amp.

PokeyPete · Post by **PokeyPete** » 15 Jul 2011, 03:43

beedotman wrote:Hi!

Does anybody know and can share schematic for something like Pigdog MiniAmp (with and without speaker)?
It looks like really simple build....

Thanks!
b

Here's the data sheet: Scroll down for some amp ideas.

http://www.datasheetcatalog.org/datashe ... 006976.PDF

Use an output jack like a Switchcraft 12A with a switched tip. Connect a small speaker between the switch
connector and ground, or just use a small value resister of a few watts rating as a dummy load in case you
forget to connect that external speaker.

beedotman · Post by **beedotman** » 15 Jul 2011, 08:52

Thanks guys, looking on part values, indeed that his Ruby Amp.
http://www.runoffgroove.com/ruby.html

What small (which will fit small enclusre like 125BB) speaker You can recomend?

RnFR · Post by **RnFR** » 15 Jul 2011, 10:45

there looks to be an extra transistor in there as well. mil bypass? extra gain stage?

Greg · Post by **Greg** » 15 Jul 2011, 11:21

Neat.. but silly.

The bends and coils do nothing but impress the uninformed.

RnFR · Post by **RnFR** » 15 Jul 2011, 11:24

even sillier cuz it's a 386 chip amp! not exactly high grade. it's kind of a waste of those expensive parts. pretty though, almost to the point of OCD.

JOHNO · Post by **JOHNO** » 15 Jul 2011, 11:28

RnFR wrote:there looks to be an extra transistor in there as well.

I can't see it. I can only see one transistor for the input buffer. Which pic are you looking at?

RnFR · Post by **RnFR** » 15 Jul 2011, 14:00

ok, that's the one. haven't seen the schem in a while, didn't remember the buffer.

JOHNO wrote:You could make a ruby twin, it's got 1/2 a watt of power.

I'd like to see the asking price for one. It looks like alot of work for something that is just a crappy little amp.

totally. he shouldve made a cool little Ge tranny amp. that's my plan. it'll probably sound cooler, too. maybe I'll have to put it on tagboard and use up some of these mojo parts I've got lying around. hehe.

JOHNO · Post by **JOHNO** » 18 Jul 2011, 08:14

beedotman wrote:What small (which will fit small enclusre like 125BB) speaker You can recomend?

Hey, i think i just found the exact speaker used in these amps. It was in a "Tsunami" branded pair of old computer speakers. They measure 90mm by 50mm. Made by DACO.

Photo 12.jpg

DrNomis · Post by **DrNomis** » 18 Jul 2011, 08:51

beedotman wrote:Hi!

Does anybody know and can share schematic for something like Pigdog MiniAmp (with and without speaker)?
It looks like really simple build....

Thanks!
b

I really dig the way those parts are wired in TRUE point-to-point style....very retro there...

ppluis0 · Post by **ppluis0** » 19 Jul 2011, 01:51

The extra transistor may be equal to the first stage employed in the Marshall MS2, and it´s a normal gain stage intended to overdrive the amplifier chip:

http://www.diyitalia.eu/forum/download/file.php?id=6346

The speaker viewed in the previous post can be purchased at your local TV repair shop (or also rescued from an old TV set found into a dumpster...

)

These models have the magnet fully shielded in order to be placed near the picture tube and to not affect the reproduction of colors.

Cheers,
Jose