EHX Magnum 44 Pedal Amplifier

[bifurcation]

I try not to post pedals without having a schematic, but I'm not finding much on this. I'm mostly curious if it's possible to recreate a DIY pedal-sized amplifier.

Apparently the Magnum 44 is based around this amplifier chip: http://www.ti.com/lit/ds/symlink/tpa3106d1.pdf

And here's another variation: http://www.aresaudio.com/uniamp.html



(The above page has schematics for everything)

They also make one that has more wattage, but doesn't have a DI: http://www.aresaudio.com/uniamp-v2.html



Schematics on the page.

 

[bifurcation]

Oh, I realized they actually have one that's very close to the Magnum 44: http://www.aresaudio.com/nanoamp.html
(though it'd be nice to have a solution that contained a preamp as well.)

 

[the_grumpy_gnome]

Oh, I realized they actually have one that's very close to the Magnum 44: http://www.aresaudio.com/nanoamp.html
(though it'd be nice to have a solution that contained a preamp as well.)

View attachment 920View attachment 921View attachment 922View attachment 923View attachment 924View attachment 925

I own one of these, love it and have found it to be my main amp. But, let me warm you- this thing is LOOOOOOOOOOOOOOOUD. You have no idea how loud this is. I have NEVER gotten to 9 o'clock for fear of breaking my windows (really). I wish I'd gotten the 22, but even that would be enough to play a large venue.

There are some other projects available in the 10-12W range that you can make.

I definitely want a PedalPCB power amp, but maybe 15W.

 

[bifurcation]

let me warm you- this thing is LOOOOOOOOOOOOOOOUD. You have no idea how loud this is. I have NEVER gotten to 9 o'clock for fear of breaking my windows (really).

Heh, ever since we talked about the TC Mimiq I've been thinking running one into a couple Magnum 44s out into a couple 2x12s...

...it sounds like people might literally die.

There are some other projects available in the 10-12W range that you can make.

Ohhh... do you have links?

 

[the_grumpy_gnome]

10W Power Amp – PCB – TH custom effects

diy.thcustom.com

Expect it to take 3 weeks to arrive and I've never gotten a response from their customer service, but there you go. The built has a few tricky spots, but nothing bad. lmk if you have questions

 

[bifurcation]

I own one of these, love it and have found it to be my main amp.

Oh speaking of which, do you like how it overdrives? That was my only concern, that it wouldn't open up like an amp when I slam it.

 

[the_grumpy_gnome]

If there's an effect, I haven't noticed it. I use pedals to shape my sound, then just amplify it with this and it's exactly what I want.

It's certainly not going to react like tube amp.

 

[the_grumpy_gnome]

hey @bifurcation, i just tried it with a regular TS (drive at zero) and a 20dB clean boost; the TS produced little effect beyond the EQ change, but the clean boost produced a noticeable difference in the form of even-order distortion. (audibly, it sounds like warm clean).

it's always best to test and measure. I wish I had a working o-scope.

 

[the_grumpy_gnome]

i should add, the TS does add a slight clipping effect, but I'm not hearing any change in the EHX's op-amp.

also, the combination doesn't resort in more even-order harmonics.

finally, halfway through writing this second post i tried setting the clean boost at unity gain. it's clear that the even-order distortion is originating there, not from the EHX. this makes sense as I'd not have expected the EHX to break up: it's just a clean power amp.

 

[bifurcation]

...this makes sense as I'd not have expected the EHX to break up: it's just a clean power amp.

Dig. I think I'll have to play with tone-from-effects more. Thanks for sharing your test!

 

[the_grumpy_gnome]

you're welcome.

despite having several tube amps, i've always found good quality, clean solid state amplification to be the most satisfying amplification method to enjoy most pedals.

 

[the_grumpy_gnome]

@bifurcation, i'm just finishing building one of these and...it doesn't have a way to control the volume: it's 10W all the time. This makes me REALLY grumpy. I can tell you though, this one

Tiny Giant Amp (PCB only) — MusicPCB

The Tiny Giant is a very small, simple 20 watt solid state amplifier. It allows you to build a very loud, great-sounding amp that’s about as easy to build as an overdrive pedal. The best part is that it’s powered by a cheap, easy-to-find readymade power supply, which avoids the issues of working wit

www.musicpcb.com

is great AND has a damn volume control. Hope you haven't ordered the other yet.

 

[bifurcation]

@bifurcation, i'm just finishing building one of these and...it doesn't have a way to control the volume: it's 10W all the time. This makes me REALLY grumpy.

That's... insane. Who designed that? Do they expect you to use a preamp like an attenuator?

I can tell you though, this one

Tiny Giant Amp (PCB only) — MusicPCB

The Tiny Giant is a very small, simple 20 watt solid state amplifier. It allows you to build a very loud, great-sounding amp that’s about as easy to build as an overdrive pedal. The best part is that it’s powered by a cheap, easy-to-find readymade power supply, which avoids the issues of working wit

www.musicpcb.com

is great AND has a damn volume control. Hope you haven't ordered the other yet.

Nice, thanks! (Nah, I have an engineer friend who's excited about designing a circuit/PCB around the TPA3116D2, but I'm about a week away from just ordering something...)

 

[the_grumpy_gnome]

That's... insane. Who designed that? Do they expect you to use a preamp like an attenuator?

yeah, i think so. i'm going to try to figure out how to stick a volume pot in there though. What a pain (if I can get it to work). I may have to get a Tiny Giant amp.

Nice, thanks! (Nah, I have an engineer friend who's excited about designing a circuit/PCB around the TPA3116D2, but I'm about a week away from just ordering something...)

Oh cool!

 

[the_grumpy_gnome]

I think I figured out how to do this. I think.

 

[bifurcation]

I think I figured out how to do this. I think.

Go Gnome Go!

 

[Nostradoomus]

I just bought one or two of those cheap aliexpress TDA31152 amps on eBay, work like a charm

 

[the_grumpy_gnome]

Yeah, it may come to this. I would just get and build another Tiny Giant Amp, but it needs 15-20V and I need a small amp that runs on 9V. I'm fairly confident I can insert a volume pot right at the beginning of the circuit and effectively control the volume. The amp will still be running at full power, but at least it won't be loud.

Still, WTF TH Custom? What a stupid oversight.

 

[the_grumpy_gnome]

Oh, I realized they actually have one that's very close to the Magnum 44: http://www.aresaudio.com/nanoamp.html
(though it'd be nice to have a solution that contained a preamp as well.)

View attachment 920View attachment 921View attachment 922View attachment 923View attachment 924View attachment 925

This is neat, but I definitely have reservations (language warning for those at work)

 

[Nostradoomus]

TDA3116D2 High Power Digital Amplifier Board TPA3116 Dual Channel Amp 12-24V | eBay

Find many great new & used options and get the best deals for TDA3116D2 High Power Digital Amplifier Board TPA3116 Dual Channel Amp 12-24V at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Thats pretty similar to the ones I have, I run it off the 12v tap on my pedal power ISO thing, or you can get a laptop adapter to run at 24v. It works off 9v too but just not as loud obviously