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NAD - Blackstar Unity ACT250 and Darkglass B7K

I posted a little while ago asking for any user experiences with this powered cabinet running a preamp pedal into it, and I guess no one on here has used one for this, so here’s a little review for any interested:

Background info: I was running heads into cabs, combos, and recently tried a PA speaker setup. My goal was to be able to run a couple preamp pedals while monitoring myself for practice in my room, but using the same rig to play with my daughter (high school jazz drummer). I didn’t like a head and cab as it wasn’t very portable. Didn’t like combos because while being portable, I wasn’t really using the preamp section and felt too many were boomy sounding in my practice space. PA Speaker sounded great, but couldn’t do the high frequency hissing self-generated noise from the power amp section.

So, I decided to take the plunge on the Blackstar Unity 250ACT powered cabinet. As far as I can tell, this is really the only powered bass cab out there now at a reasonable price. I know GK was doing this for a bit, but seems they’re no longer in production.

I was a bit hesitant due to the only speaker available in this is an Eminence 15” and no compression driver/horn/tweeter. I’ve only ever played through 10” and 12” speakers and had issues with 112 setups being boomy.

First, this thing is kind of heavy. Not overly heavy, but not light. The size is nice; fairly decent size cabinet with 2 ports at the bottom of the front baffle.

The “controls” are all on the rear panel. There’s ventilation near the top of the panel, but I have yet to hear any fan noise at all, even when very close to the cab. There is a ground lift button, XLR out (comes with a XLR cable) and a 1/4” input. From reading the manual, since these are powered at 250w, you can daisy chain these together infinitely. There is also a very small volume “knob” on the back… this thing gets really loud and moves a ton of air.

I’m not sure about how the signal is processed or whatever, but plugging my basses (MIM Precision w/ flats and a Spector NS Pulse II) directly into the 1/4” input sounds fantastic. No EQ control of course, but it’s definitely a usable tone and I’d be perfectly happy running straight in.

I also purchased a Darkglass B7K V2 preamp pedal. This is a very, very transparent preamp. Lots of awesome and well thought out EQ options (selectable low mid and high mid frequencies, toggles for treble and bass shaping). When the blend is set all the way towards the clean side, I hear almost no difference to the inherent tone of the Blackstar Unity 250ACT aside from some more top end emphasis. This is a very good thing to my ears because the tone from the cab already sounds really great, flat, and clear. The EQ adjustments allow me to shape this already great base tone into whatever I can think of. The drive on the pedal is also really great sounding. It’s hard to describe and really sounds nothing like what I hear in most of the demos. With moderate EQ settings, it’s very usable all the way through the sweep. It never becomes “too much”, but skirts the edge when maxed. It’s a very organic, grinding distortion sound that feels really responsive to playing dynamics. I owned an Alpha-Omega a while ago and while that distortion circuit is glorious sounding, it really kind of covered up dynamics. Everything just sounded the same. I don’t think that’s a bad thing, just might not be applicable for everyone’s needs. The B7K is more of a tube-ish grind, though very hi-fi sounding in a way. Very high quality tones and I have yet to find a bad setting.

So, overall, I think this is a great way to run a preamp pedal or simply go direct into the cab, and if anyone hasn’t tried a B7K yet… you’re missing out.
 
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Interesting cabinet without mid driver or tweeter. Is this marketed as a powered sub?
What's the weight?
It’s probably 35-40lbs. It’s supposed to be an extension speaker for their bigger Unity combos, but they market it as being a good platform for running preamp pedals into, so that’s what piqued my interest.

Edit: no, it doesn’t have a tweeter or anything, but I honestly can’t tell the difference. Not sure if that’s indicative of a wide frequency response from the speaker and cab or of my lack of an ear for nuance
 
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debating getting one of these, are you still using yours? hows it pair with preamps? could you go DI straight in or it needs that preamp level?

hows the cab sound? its a little heavier than a i like, and it's a ported 15 which to me spells boomy, but i'm interested to hear how it is.
 
Been looking for some end user thoughts towards the U250ACT and preamp pedals, glad I found this thread...

Plan is for this powered cabinet to be paired with my Punchline and a HX One, using the four cable method...
One thing I’ve learned is get this up off the floor. It couples really easily and can get really boomy. Get it up off the floor and it’s perfect.
 
One thing I’ve learned is get this up off the floor. It couples really easily and can get really boomy. Get it up off the floor and it’s perfect.
I'm still using mine. I've run a B7K, MXR M-80, Sansamp BDDI and now an Ampeg SGT-DI into them. All pedals have gone pretty well. I have also used a signal attenuator (cut) to control the amp volume so as to avoid having to use the tiny knobs on the back. What is the four cable method?
 
I'm still using mine. I've run a B7K, MXR M-80, Sansamp BDDI and now an Ampeg SGT-DI into them. All pedals have gone pretty well. I have also used a signal attenuator (cut) to control the amp volume so as to avoid having to use the tiny knobs on the back. What is the four cable method?
4 cable method with the pedals he’s using will basically allow some of the line 6 effects to go into the punchline before the power amp, some bypass the punchline and go directly to power amp. Basically a way of using a multi-fx unit in a more flexible way.
 
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One thing I’ve learned is get this up off the floor. It couples really easily and can get really boomy. Get it up off the floor and it’s perfect.

Very good to know, and this will bring the speaker up closer to the ears...!

I'm still using mine. I've run a B7K, MXR M-80, Sansamp BDDI and now an Ampeg SGT-DI into them. All pedals have gone pretty well. I have also used a signal attenuator (cut) to control the amp volume so as to avoid having to use the tiny knobs on the back. What is the four cable method?

Four cable method...

Cable #1 - Bass > HX Stomp In
Cable #2 - HX Stomp Out > Punchline In
Cable #3 - Punchline Out > HX Stomp Return
Cable #4 - HX Stomp Send > U250ACT

This allows one to place a filter effect before the preamp, and a modulation effect after the preamp; obviously, since the HX One is only one effect at a time, a choice is made...

Hey Line 6, how about a HX Two, Three, or Four...? ;^p

The four phases of the Punchline are in the following order, Compression > Drive > Amp Sim > EQ, the Compression can switched to be between the Amp Sim and the EQ; the EQ is always on...
 
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Very good to know, and this will bring the speaker up closer to the ears...!



Four cable method...

Cable #1 - Bass > HX Stomp In
Cable #2 - HX Stomp Out > Punchline In
Cable #3 - Punchline Out > HX Stomp Return
Cable #4 - HX Stomp Send > U250ACT

This allows one to place a filter effect before the preamp, and a modulation effect after the preamp; obviously, since the HX One is only one effect at a time, a choice is made...

Hey Line 6, how about a HX Two, Three, or Four...? ;^p

The four phases of the Punchline are in the following order, Compression > Drive > Amp Sim > EQ, the Compression can switched to be between the Amp Sim and the EQ; the EQ is always on...
Waaaaaaaay better explanation than what I gave! 🤣
 
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LOL, I just realized I had "HX Stomp" in there, when it should be "HX One"...!

And I also realize that folks might think "why not just get a HX Stomp" when I say Line 6 needs to make a variant of the HX One that allows multiple effects at one time; but the answer there is that I already have the Punchline, so no need for all the amp sims and such...

Although the new Darkglass Anagram is pretty compelling, and I love that it is a bass-focused offering; if I had the cash and the realistic need, I would throw five grand at it, a MIDI footswitch, an expression pedal, and a pair of powered 12" Barefaced cabinets; run a "dual amp" wet/dry rig...

And the HX One is 300 bucks, and has a tuner; a Peterson Strobostomp HD is 150 bucks, and most of the viable filter & modulation pedals out there start around 100 bucks and up; so the HX One seems a good value and makes for a compact board...
  • Pedaltrain Nano
  • CIOKS Sol
  • HX One
  • JHS Punchline
Thanks for coming to my TEDx Talk...! ;^p
 
It’s probably 35-40lbs. It’s supposed to be an extension speaker for their bigger Unity combos, but they market it as being a good platform for running preamp pedals into, so that’s what piqued my interest.

Edit: no, it doesn’t have a tweeter or anything, but I honestly can’t tell the difference. Not sure if that’s indicative of a wide frequency response from the speaker and cab or of my lack of an ear for nuance
it is also an extension powered cabinet for all of the smaller Unity combos in the range.
 
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