Powered cabs / power amps

[darwin-bass]

In the PA world, powered speakers have an advantage of reducing the length of wire between the amp and the speaker. The FoH hixer is 100 (or more) feet from the speakers and you don't want to run power-level over that distance. So put your amps on the stage or better yet, put them right in the speaker cabs themselves.

This problem doesn't exist for a bass amp.

 

[agedhorse]

Good question! If we are talking a TC electronics version like in my hypothetical then I'd basically pay the same as for the one with the preamp built in, maybe a little more. Those go new for about 180 so yeah I'd pay about that. That's not much less than the Jay Genz Straight ahead goes for and that's 500 watts. I think that price point is pretty fair, straight ahead just can't mass produce them like say ampeg or fender could.

tho I do understand that it isn't just as simple as take the knobs off an already existing micro-amp and charge the same or even less for it (less features, less dough) cause the manufacture would have to go thru the already mentioned R&D and safety cert stuff to mass produce it which sounds like a costly process for the market share that would want it….I just really want it!

Safety certification is ridiculously costly and resource consuming after the destruction of the power supply/power amp section (of sometimes several units) in the overload and fault testing.

 

[Passinwind]

Essentially just want a company to do what fender/SWR did with the amplite…it was ahead of its time and they don't go for cheap, because folks like them and are looking for them!

If it actually worked business wise they'd still be making them, no? Acoustic Image made a killer one that never sold 60 units; not a year, ever. A few of us at NAMM 2020 tried to interest Temple Audio in doing a higher powered version of the cool little ones they optionally build into their pedalboards, my guess (and theirs apparently) is that the market demand still isn't solid enough just yet but we may well get there sooner than later.

 

[agedhorse]

Essentially just want a company to do what fender/SWR did with the amplite…it was ahead of its time and they don't go for cheap, because folks like them and are looking for them!

They weren't much less expensive than the HeadLite either, which is why they weren't nearly as popular.

I use a Radial Bassbone, original version, primarily as a nerve center/signal router on my pedalboard; I like the fact that it has the effects loop(missing on many pedal pre's), before the xlr/DI, and the dual switchable imputs, for the occasion where I have fretted/fretless. The levels of the two instruments are balanced, and with very judicious EQ tweaking, only as needed. I don't overdrive the input of the amp with any kind of dimed output on the pre, I've got stomps for that. Now, if I had an onboard preamp with some sort of sweepable mid, or active EQ in my bass, doesn't that potentially(if misused)thwart/fight the amp's tone controls? Wouldn't that be the same thing as a box?

Anything misused can become problematic.

 

[moon-bass]

I use a Radial Bassbone, original version, primarily as a nerve center/signal router on my pedalboard; I like the fact that it has the effects loop(missing on many pedal pre's), before the xlr/DI, and the dual switchable imputs, for the occasion where I have fretted/fretless. The levels of the two instruments are balanced, and with very judicious EQ tweaking, only as needed. I don't overdrive the input of the amp with any kind of dimed output on the pre, I've got stomps for that. Now, if I had an onboard preamp with some sort of sweepable mid, or active EQ in my bass, doesn't that potentially(if misused)thwart/fight the amp's tone controls? Wouldn't that be the same thing as a box?

Yes and no ... I tend to think of EQ in terms of distinct purposes - Bass, pedal board, and amp. I use the EQ on the bass to set a "base" sound and for fine tuning for songs - some like a little more treble, slap like a mid scoop, etc. The majority of my tone comes from preamp on my board. I like a Fender TMB as a core sound and then tweak it with a parametric. I also like having a few EQ options set on my boards for different songs and different basses. For instance, I like a bump around 800 for fretless, plus some songs like a little dirt, etc.

I use the EQ on my amp for character and to balance the room. For the most part the EQ on my amp is set relatively flat.

I tend to play a lot of variety on my gigs, so I like to have a lot of tonal control and options.

Probably overkill for sure, but I am real particular about my tone.

 

[hooky_marr]

I deeply agree, luckily I've been seeing more sumos and straight aheads in the classifieds but I would love for someone to start mass producing a 300 watt class D power amp that is under 5lbs. Basically id take a tc bam200 with just a volume knob.

These things sort of exist in the car audio space, whenever I search for "class D bass power amp" I get a ton of Invalid Link Removed intended for subwoofers.

But yeah, exactly that, a little module like an Elf or TC that's just a little power amp designed for bass, maybe a dual amp version with a crossover for bi-amping.

 

[hooky_marr]

I talked to GK on the phone last week and production of their MBP powered cabs is supposed to restart, when they have the available parts, sometime mid-year or earlier. RAG also said the same in a thread last fall.

Yeah, I expect supply chain issues are affecting everyone. (I presume RAG is Bob Gallien?)

 

[sawzalot]

I have a question about this, if you don't mind weighing in. I see people say they run an external preamp through an amp's instrument input and then set the amp's preamp to flat. Maybe I'm missing something, but doesn't doing that essentially negate the tone shaping work done by the external preamp?

Setting the amp's preamp to flat doesn't negate any of the shaping done by an external preamp. In theory, if the amp's preamp section were truly neutral, you would get exactly/only the tone shaping done by the external preamp. In reality, bass amps' preamps are not neutral, so you still get some kind of additional shaping by the amp's preamp section.

Most of the time an amp's effects return IS pretty much neutral, so you wind up with only the external preamp's tone shaping at the speaker outputs.

 

[hooky_marr]

Most powered speakers seem to use "plate amps".

The (uneducated) impression I've gained is that cooling design is a bit of a challenge with 1U form factor. I remember seeing a recommendation that 1U servers in server rooms should be spaced 1U apart for cooling reasons, which I thought rather defeated the object!

Rackmount servers have blower fans to keep them cool. You don't have to space them that far apart unless you're doing high-intensity compute tasks (like a scientific computing cluster). And server rooms / data centers are also heavily air-conditioned and the waste heat is usually taken out by HVAC manifolds. More modern centers recapture the waste heat and send it to ground loop heat pumps or re-use it elsewhere.

In this photo from AMD, this 1U dual Epyc server has eight small but high-RPM blower fans mounted just behind the front section where the redundant RAID removable drives are.

Data centers are LOUD. I remember our server room at work, it was heavily padded, at peak it sounded like a jet engine.

Link Removed

 

[hooky_marr]

For those who may not get this point, Andy just explained that many of the Class D amps are Class D power amps, which happen to have a preamp built into them. So, pedalboard preamps can go right in through the Aux In / Efx return. I have the Demeter Minnie, and it works really well; but, honestly many of the 800W Class D amps would be equally great.

Thanks for the clarification. As a note, I did check out the manual for the Blackstar U500 and they mention you can do this via the FX return, but it has a protection feature that turns off the amp if there isn't a plug in the main input jack. So all you need is a cable plugged in, or a "shorting plug" (i.e. a 1/4" plug wired to short to itself, I believe).

 

[57pbass]

Bag End has a few powered cabinets in their product line.
I have a powered 15 that I use with an Alembic F1-X.
They pair together beautifully.
I can plug my active bass directly into this cabinet without using a preamp if I choose. I can adjust the level control on the cabinet.
It also works both powered and passive with an upgrade.

 

[ProbablyTooLoud]

Yeah, I expect supply chain issues are affecting everyone. (I presume RAG is Bob Gallien?)

Yup, they say parts are the limiter.
And yes - that's his tb name.
Maybe it's lowercase though.

 

[bucephylus]

Thanks for the clarification. As a note, I did check out the manual for the Blackstar U500 and they mention you can do this via the FX return, but it has a protection feature that turns off the amp if there isn't a plug in the main input jack. So all you need is a cable plugged in, or a "shorting plug" (i.e. a 1/4" plug wired to short to itself, I believe).

Don't know that amp. I'd check with the amp maker before plugging in a shorted plug.

 

[logdrum]

Rackmount servers have blower fans to keep them cool. You don't have to space them that far apart unless you're doing high-intensity compute tasks (like a scientific computing cluster). And server rooms / data centers are also heavily air-conditioned and the waste heat is usually taken out by HVAC manifolds. More modern centers recapture the waste heat and send it to ground loop heat pumps or re-use it elsewhere.

In this photo from AMD, this 1U dual Epyc server has eight small but high-RPM blower fans mounted just behind the front section where the redundant RAID removable drives are.

Data centers are LOUD. I remember our server room at work, it was heavily padded, at peak it sounded like a jet engine.

Link Removed

Correct - 1U servers do not need 1U spacing. And some places used liquid cooling solutions as well. I used ear protection in the lab I was working in and our compute servers was at least 20 yards from where I was. That was not even a proper data-center but we ran our systems at full blast some days and it was unbearable without ear protection. The heavy compute stuff use mezzanine design for the GPUs and the airflow is designed properly. Those rooms kept cold though.

 

[ProbablyTooLoud]

Setting the amp's preamp to flat doesn't negate any of the shaping done by an external preamp. In theory, if the amp's preamp section were truly neutral, you would get exactly/only the tone shaping done by the external preamp. In reality, bass amps' preamps are not neutral, so you still get some kind of additional shaping by the amp's preamp section.

Most of the time an amp's effects return IS pretty much neutral, so you wind up with only the external preamp's tone shaping at the speaker outputs.

I found a preamp pedal I love, which I plug into the aux in on a 500w gk combo - because I was concerned about redundant preamps. But I guess everyone with an active bass already has redundant preamps anyways, and I should have figured running into the regular amp input wouldn't negate the first preamp.

 

[Smokey P]

for those looking for a cheaper (tho dumb heavey for what it is option) the ampeg PF500 and 800 have a "power amp in" input on the back that sounds really good. For some reason it sounds better when i use it than when i use the effects return these amps also feature, i guess its a headroom thing, i do both depending on how loud i need to be. The power amp in makes everything on the front of the amp useless, the fx return leaves the fx blend and master volume. Only problem is its a class D head that weighs 15lbs and is not known for being reliable.

I use an arkham oracle all the time as my "amp" essentially and just plug it into a combination of things depending on the gig.

 

[agedhorse]

These things sort of exist in the car audio space, whenever I search for "class D bass power amp" I get a ton of Invalid Link Removed intended for subwoofers.

But yeah, exactly that, a little module like an Elf or TC that's just a little power amp designed for bass, maybe a dual amp version with a crossover for bi-amping.

Car amps don't have an AC mains supply, nor does it have the safety approvals for AC supply powered amps.

 

[hooky_marr]

Car amps don't have an AC mains supply, nor does it have the safety approvals for AC supply powered amps.

Yes. I wasn't recommending them, I was just noting that when you Google those terms or try to find something on Amazon, that's what comes up.

 

[hooky_marr]

Don't know that amp. I'd check with the amp maker before plugging in a shorted plug.

I'm going by what they say in the FAQ. Maybe it just needs any kind of 1/4" plug there, if the lack of one disables the amp. There doesn't seem to be a good description of what "shorting jack" means. I'll contact them and ask. (FWIW the Boss Katanas have a power amp in, that disables the front input - I wonder if the XLR out will carry that signal if I want to daisy chain it?)

 

[J Wilson]

The manufacturers are missing the boat:

Powered cabinets would have to have TUBE amps built in and a MOJO Off/On switch! I'm trying to visualize something like a Bag End that weighs an extra 60# and the guy that bought it is complaining about the fan noise and the funky smell of hot tolex.

Well, NAMM's coming. Who knows?

Back on Earth, Bag End actually offers built-in 700w amps in most of their cabinets with a 5# weight gain, but as @agedhorse points out above, these would not be voiced for bass, but for overall FOH use, so you'd be very dependent on whatever preamp or preamp pedal or mic strip to voice some warmth back into it as needed.

This powered cab model has been a huge leap for touring sound, as you eliminate literally thousands of pounds of heavy copper speaker wire and racks and racks of stereo power amps, plus the control offered is a big advantage. But those commercial budgets haven't trickled down to instrument amps yet, and I'm convinced the average guy wouldn't have a clue.