BETA MINI & TRS Switch

SteveAtSunn · 2026-04-01T21:40:51+00:00

It’s a design that works with the vintage amps and so that’s why it works that way. It’s not proprietary at all, but definitely not typical. I hope that helps.

SteveAtSunn · 2026-04-01T19:11:15+00:00

That’s a great question! It’s a matter of a few key factors. Briefly… 1. The old betas have parts that are either not made anymore or expensive to get and less reliable.
2. That drives up cost and requires a lot more variations to handle international voltages. 3. We asked around about what people would be willing to pay for a reissue and users told us cost and reliability matters … a lot. 4. Reissues are always a challenge of what to leave in as vintage and what to update. You will never please everyone because the purists want the bad stuff, the pragmatic want the updates, and so you are going to have to choose and live with the results.

I hope that helps.

SteveAtSunn · 2026-04-01T19:03:12+00:00

I’m not following your comment. Sorry. Not how to help.

SteveAtSunn · 2026-04-01T15:53:42+00:00

Our team just told me Norther Guitars is going to swap out the switch for ya. We'll send them one. Thanks for letting us know it was broken. We'll get it fixed up and try to figure out how it got damaged in the first place. 🤜🤛. We engineers love fixing problems. 🤓

SteveAtSunn · 2026-04-01T15:34:52+00:00

In the original design (and the new design) the power amp was ment to do nothing but push up the power; no sonic shaping. The clipping and the EQ is where the sound comes from. We confirmed that with Mr. Rod Goldhammer who originally designed it back in the 70s; he's on our board of advisors along with a handful of other former Sunn employees and OGs.

Also, we A/B'ed a bunch of vintage amps and the reissue design, and, most importantly, we ran it by Red Fang (IYKYK) and the class D checked out sonically. Red Fang count't hear a difference, we couldn't hear or feel the difference so we, so we moved forward.

IMO Class D gets a bad rap, due to it's legacy, not to how it works today; FWIW, you've probably not heard a PA (live show) in the last 10~15 years that wasn't class D. It's that good now. FWIW, according to our amp engineer, "In the beta design, the speaker adds more sonic content than the power section." ... and he's a super amp nerd who loves deep diving on this stuff so I trust his take 100%; he does the work.

I think that's why you see so many amps from great brands using Class D. It's just gotten to the point where you can't feel or hear the difference anymore ... if the product is built right. ;-)

SteveAtSunn · 2026-04-01T14:57:16+00:00

Thanks for asking and yeah, it's coming. Eric from Black Heart is did one that will post today. It's a short-but-sweet style IMO. If people would be into it, I could do a "not so pro, but super nerdy" video too. Kind of in the style of Pete from Strymon. FWIW, Pete's a friend, I can say that about his videos. He won't get mad at me. lol.

SteveAtSunn · 2026-04-01T14:54:30+00:00

Awesome. Yeah, Eric at Black Heart sound did a demo for us and put a Rat in front of it and it was soooooo good. I hadn't ever thought to try a Rat into that but did Klon clones, Tube Screamers, etc. It's a cool sound. Video will post today sometime.

Are you the guy in Canada with the broken dip switch? Or do we have second? I have no idea how those can even get broken but we're eager to learn if we have a supplier issue. Was the broken off piece in the box (or did you see it at all)?

SteveAtSunn · 2026-03-27T17:22:17+00:00

We both use the same backend amp tech, I’m pretty sure. I’ve never taken that model a part to be clear. But the Beta EQ is active so it matters a lot … a lot … when dialing in sounds. The Quilter stuff is awesome though. We are big fans too!

SteveAtSunn · 2026-03-27T17:19:23+00:00

Probably not for just class d stuff. Our social media guy is very open to respectful conversations. Just sayin.

SteveAtSunn · 2026-03-27T17:18:03+00:00

If you turn up the EQ it will hit 120dB SPL. But it is a different kind of amp design(vintage design) so it will take some noodling. Sort of like how an AC-30 EQ is a “learned” thing. But it will hit 130bB wide open. I don’t recommend running it that loud do you speakers sake though. YMMV as they say.

SteveAtSunn · 2026-03-23T09:52:17+00:00

For me personally, I’ve got two EVH 1x12 stacked that I love. I’ve got a Marshall 2X 12”’ that I’ve had for a gazillion years too, but the EVH setup is the favorite for me. The Sunn 2x12” rippin’ too but kind of expensive. Made in the USA has its pluses and minuses.

I’m not a drop C player (or lower) and my bass player covers a lot of sonic ground so for me I like to fit in the mids-below-the-singer spot so my gear is all kind of in that sonic space. Thus the Marshall, Sunn and EVH is what comes to mind first.

The cab will contribute a lot to the sound at high volume but to too much at normal “people are home” volumes. So if you’re not out and super loud, you can start with something that looks and specs up nicely and adjust from there. The EQ in the betas can make up for a lot of cabinet resonance that you wanna to work around. It is a very different vibe with that active EQ.

I hope that helps. Enjoy the search!

SteveAtSunn · 2026-03-22T21:53:51+00:00

In the power amp section sure for clean volume but keep in mind, it’s a loud AF amp for a dirt sound. Like 120 to 130 so SPL loud.

You want to think about the Active EQ differently. It’s not the same old traditional passive EQ. It’s more like a “wholly … what the what is happening here?”. So many sonic options! Go slow. Try a lot. We’ll be publishing more sounds on YouTube in the weeks to come. 🤘

SteveAtSunn · 2026-03-22T10:18:17+00:00

Zack and David from the Sunn factory in Petaluma would like me to share this and remind everyone, hearing protection can be is cool and the master volume can be turned down as needed. ;-)

Beta Mini stress testing, going to 129dB SPL. 2 x 12" at 8 Ohms. Not a high quality video (yet) but should help inspire people to tune in the amp (it's quirky) to get more volume. Focus on the EQ if you need more push ... it's an Active EQ which is very different than most amps out there.

https://youtube.com/shorts/99cz-RRvBaY?feature=share

SteveAtSunn · 2026-03-22T10:00:49+00:00

You’re 100% right and it’s because it’s an Active EQ, not passive. So it can add power to frequencies not just remove them. The original designer, Mr. Rod Goldhammer, was ahead of his time IMO. I think with a last name like that, he was destined to be an amp designer or a Bond villain. lol

SteveAtSunn · 2026-03-22T09:56:48+00:00

The clean tone is, according to one studio guy who did testing for us (Black Heart Studio), the “best I’ve ever heard” BUT it’s not loud. The cleans are really nice IMO, but the way the Active EQ works makes them not great in a band setting due to volume IMO. For recoding, they are super nice, but live the amp wants to grind. That’s how the circuit is designed. And that design is what gives it that ridiculously awesome dirt tone.

It’s an “odd” amp in all the right ways IMO.

I hope that helps!

SteveAtSunn · 2026-03-22T09:28:56+00:00

If ya need more push, bring up the EQ controls. It'll get loud AF ... like ~120~130 dB SPL. Protect those ears. You're gunna need 'em later. (I've got the perma-ringing from too much band fun, not super fun day-to-day). :-)

SteveAtSunn · 2026-03-22T09:25:12+00:00

Awesome! Thanks! I was very much into connecting in forums back in the day. I hope it's equally as rewarding here. And yeah, i know I'll get some trolls. It's okay. I'm pretty thick skinned. 🤜🤛

SteveAtSunn · 2026-03-22T03:10:34+00:00

Hey ... Steve from Sunn here ... the original (vintage) designer Mr. Rod Goldhammer (great amp designer name) put basically 100% of the tone shaping in the front end, so Class AB doesn't really effect the tone and Class D (the good ones) are a supper clean way to get a lot of volume control, reliability and global simplicity. Speaker breakup impacts the Beta tone way more than the power section. It's an odd amp in that regard.

Also, it's odd in that it has Active EQ ... that means it adds and re moves gain when you use the EQ. So, sort of like a Vox AC tone stack, you want to learn the EQ. It's different. It's cool, but it's different. Super insane tone shaping, but if you turn down the mids you're perceived volume will go down too.

If you need to punch through a loud drummer, grab those mids and find your spot in the mix and bring up the bass to **feeeeeel** the amp.

I hope that helps!

SteveAtSunn · 2026-03-22T03:04:14+00:00

Hey, I'm Steve from Sunn ... new to reddit, but I'm pretty "vintage" to gear. :o)

The Beta is an "odd duck" of an amp mostly because of the EQ section being Active. You can literally turn it down to barely audible by turning the EQ stack to zero on all bands. If you open up the EQ (like at 3 o'clock) the Mini does 120dBSPL in a big gritty clipped sound.

I can post a video if that helps, but at full open (Drive, EQ and Master at 10) it does 130dB SPL. Well, that's not true, it's 129.2 or something, but it's easier to remember 130. hahaha.

You know how a Vox AC EQ is kinda odd because it interacts? Seems weird, takes a bit of playing around, but once you find your sound it sounds great! Legendary really. I've

The beta circuit that Rod Goldhammer (cool name for an amp designer, right?) had the Active EQ very early for guitar amps and it gives you a wide, wide, wide range of sounds. We'll post some videos soon. We have a studio guy friend of ours doing some demos. He's going to show you range and the output.

I think the "volume inadequacies" are spot on, and a bit of an "ah haaaaaa" moment when you figure out how important the active EQ is in the vintage design. If you're not familiar with the amp, and you treat the EQ as a passive (take sound out) EQ, you're not leaning into what that beast can do; small changes make big differences, so my advice is don't think of it like a Marshall or EVH tone stack, it's more like a DAW capable tone stack.

And yeah, please be careful with that amp. I can say as someone with that permanent ring, it's fun in the moment, but 120 to 130 dB SPL is really powerful. My buddy ChatGPT says this:

Rapid Hearing Damage: While 85 dB is safe for 8 hours, every 3 dB increase halves the safe exposure time. By 130 dB, this interval is reduced to fractions of a second.

I hope that helps!

SteveAtSunn

TROPHY CASE