New Amp Day! Sunn Beta Mini!

[junderwood]

So far I love it, with some minor reservations. Essentially it's a solid state preamp into an off-the-shelf Icepower power amp. I've been playing a Hilbish beta for a while now which is very similar - in fact they share the same exact power amp. But the Hilbish is many many times louder at the same settings. So the preamp circuit in the Mini is definitely a little off somewhere. You can get massive volume out of it, don't get me wrong, but not quite the same way - I'm still exploring it and figuring out how it wants to be played.



This approach with the preamp mounted to the front and the power amp situated in the center is cool. I've seen this style of enclosure for sale before so I think it could be a good form factor for DIY. It gets warmish, but not at all that hot. These tiny Icepower power amps are truly marvels.



Here's the preamp PCB! Doing something like this DIY would probably necessitate a couple layers sandwiched, but there's plenty of room in the case to make that work.



And the knob side.

It's a pretty cool little amp, and definitely an inspiration for building similar DIY projects.

 

[Band of Dans]

Interesting! I’m a little familiar with those ice power amps from building a few speakers and boomboxes but haven’t seen one in a guitar amp before. Now you’ve got me thinking my sunn beta pedal needs a power amp to go with it.

 

[Harry Klippton]

Great read. The demo I heard sounded good and the price is reasonable

 

[gonzo]

Those old amps were great! This looks cool too.

 

[Passinwind]

Interesting! I’m a little familiar with those ice power amps from building a few speakers and boomboxes but haven’t seen one in a guitar amp before. Now you’ve got me thinking my sunn beta pedal needs a power amp to go with it.

I've done several bass amps with a similar format (which is very popular commercially, of course), mostly with the 700 watt mono ICE modules:





^^^ Preamp boards ^^^



^^^ 700AS1 module mounted to Heatsink USA finned sink, then 3 mm aluminum case lid with powder coating masked off for sink contact area.



The 700AS1 has regulated +/- 15 V supplies built in with plenty of current for a pretty full featured preamp.

I also did a dedicated 700 watt power amp using the same heatsink, this is bottom-up view: :



And with matching bass/utility preamp:



The newer 200 and 300 watt modules have pretty robust built in heat sink plates and will work as is in many applications without a fan.

I did one with tubes in the preamp for a customer as well, but it's under an NDA and I can't post pictures of it.

 

[Passinwind]

View attachment 113696

So far I love it, with some minor reservations. Essentially it's a solid state preamp into an off-the-shelf Icepower power amp. I've been playing a Hilbish beta for a while now which is very similar - in fact they share the same exact power amp. But the Hilbish is many many times louder at the same settings. So the preamp circuit in the Mini is definitely a little off somewhere. You can get massive volume out of it, don't get me wrong, but not quite the same way - I'm still exploring it and figuring out how it wants to be played.

View attachment 113697

This approach with the preamp mounted to the front and the power amp situated in the center is cool. I've seen this style of enclosure for sale before so I think it could be a good form factor for DIY. It gets warmish, but not at all that hot. These tiny Icepower power amps are truly marvels.

View attachment 113700

Here's the preamp PCB! Doing something like this DIY would probably necessitate a couple layers sandwiched, but there's plenty of room in the case to make that work.

View attachment 113701

And the knob side.

It's a pretty cool little amp, and definitely an inspiration for building similar DIY projects.

A friend of mine was the first CTO of this newest version of Sunn, but unfortunately he had a falling out before they actually started shipping product. I use to be a warranty service provider for the company just before the Fender buyout, nice to see the name in play again!

The other bassist in my mid-80s Seattle band used an OG Beta Bass, it worked great for the Flea-ish thing he was mostly going for at that time.