Favorite Practice/small group amp

[n9voc]

Good Day, Again!

Attached is the schematic of my favorite amplifier I have built and use regularily.  I call it the "Classy Lassy" because the speakers are "recycled".  The 8 inch and the tweeter were from an old Magnavox tube type console record player.  The 6 inch is a Bogen speaker that was used as a studio monitor at a now defunct radio station from a local college.

I use a lot of "recycled" speakers in my little amplifier projects - the sources are quite varied.  I have found that old televisions usually provide highly usable speakers, that also give it a neat tone.

I have found that multiple speakers, each driven by an amp chip provide a MUCH "bigger" sound punch per watt than a single speaker device.  Also, by mixing speaker sizes and shapes, one can shape the tone out of the amplifer.

Well, Here's the 'lassy:

[n9voc]

Attached are pics of the "Classy Lassy".  Behind the front grill cloth are the 8" and tweeter speakers, the round side grillcloth hides the 6" speaker.  I added the duplex outlets to the back - run fewer power strips that way!

[joecool85]

Did you make the enclosure?  That looks great!  Have you tried any circuits using a LM1875 ?  It's a really great sounding 20-30w poweramp chip.

[n9voc]

Yes, I did make the enclosure.  The wood for the case came from some scrap wood from a local construction site.  The grill cloth was from the same old console record player the 8 inch speaker came from, and the corners and handle were bought online.
I used the 1875 in my firsts amp rebuild (my son uses it now), didn't keep the schematic.  Information I had showed it needed a bipolar power supply, and most of the power supply resources I find lend themselves to single ended power supplies. I would use the 1875 again if I wanted to build a "beefier" amplifier.

[joecool85]

Yeah, I built a stereo LM1875 amp for a computer sound system.  It works really well.  I've hooked my guitar into it and it sounds awesome.  If I needed another 20w amp I'd build one for guitar usage, by my K-20X does fine for that.