Powered cabs / power amps

[mmbongo]

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.

Those only work with GK amps though.

 

[Hasty]

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'm only quoting you because it reminded me of the following. Nothing whatsoever implied here, just using the statement for context.

In my time here I've learned two incontrovertible facts…

1. No matter how transparent your amp is said to be, it's never flat.

2. Watts are irrelevant. It's all about cab efficiency and that formula is just a single forum search away because I can't remember it.

 

[BlueTalon]

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

You have an unbelievable amount of patience for answering topics and questions from people who don't know what they don't know.

(Not intended as a slam against anyone. As a friend of mine says, "Learn comes before know.")

 

[ProbablyTooLoud]

Those only work with GK amps though.

And with the Plex.
But yeah good point.

 

[agedhorse]

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?)

The description is horribly unclear... a jack is the female "socket", what they really mean is a PLUG not a jack, and a shorting plug is a plug with tip and sleeve connected together. Do NOT plug this into the speaker output of an amp by accident, that's a quick way to ruin a solid state amp.

Most power amp inputs interrupt the signal, it's called an insert point and inserting into the input defeats the normal through connection.

The XLR DI out will probably not have the signal present, but it depends on the amp's architecture. The signal block diagram will tell you this information.

 

[agedhorse]

You have an unbelievable amount of patience for answering topics and questions from people who don't know what they don't know.

(Not intended as a slam against anyone. As a friend of mine says, "Learn comes before know.")

I think this one was an example of what he found rather than what might have been appropriate.

 

[BlueTalon]

I think this one was an example of what he found rather than what might have been appropriate.

That comment was only one of thousands. It just happened to be the one that triggered my thought.

 

[Michael Eisenman]

I like a Fender TMB as a core sound and then tweak it with a parametric.

What form does your Fender TMB take? The bass, a pedal?

 

[agedhorse]

What form does your Fender TMB take? The bass, a pedal?

Not going to be in the bass unless it's some custom active electronics.

 

[moon-bass]

What form does your Fender TMB take? The bass, a pedal?

Pedal mostly, but I also have a Mesa 400+ with a Fender style tone stack.

I've tried quite a few preamps with the Fender TMB over the years.

 

[JeezyMcNuggles]

I'm puzzled as to why there aren't more of these, particularly as a good number of players are moving to preamp pedal DIs / modelers, and as class D amps offer significant space and weight savings.

Even in the pro audio space, almost nobody is making a basic 1U rack power amp suitable for a bass rig anymore. Demeter have the Minnie, which is a tad pricey, and Orange make a small power amp aimed at pedal preamp users, and that's all.

Phil Jones Bass used to make powered cabs, but no longer. Outside the PA space, there's the Blackstar Unity 250ACT (15"), Wayne Jones' stuff, and… everything else seems rare or out of production.

I know amp makers know their markets, but one would think it'd be relatively easy to create a drop-in "power amp only" module for most combo amps, especially the ones with the amp mounted top rear.

(@agedhorse if you care to comment? Is this a niche market or a growing one?)

2u. Everyone makes 2u amps. Suitable for far more than just a bass guitar.

Also, powered PA speakers and monitors, are powered cabs.

Also, combo amps, are powered cabs.

 

[Michael Eisenman]

Pedal mostly, but I also have a Mesa 400+ with a Fender style tone stack.

I've tried quite a few preamps with the Fender TMB over the years.

Which pedals do you recommend?

 

[moon-bass]

Which pedals do you recommend?

My favorite is the SIB Fatdrive. Also really good are the Origin Bassrig 64, and it comes with a speaker sim and DI, it's great if you need an all in one solution (disclaimer: I have one for sale). Also up there is the SushiBox UA and the AMT A bass. The Master Effects Super 400 has a graphic EQ option (also selling one of those).

Out of all of the ones that I've tried those have been my favorite TMB preamps. Right now I have the SIB and A Bass on my board (if I had space I'd have the sushibox instead of the AMT). I use the SIB as a my main tone and the AMT to add a little dirt and a lot of thickness when needed. Check out my other thread:

My preamp journey

 

[Camarillo]

GR Bass, an Italian brand, makes this.
Pure amp – GRBass

 

[monsterthompson]

Seymour Duncan has been selling their "pedal amps" for a while now. These are power amps for use with pedals and preamps.

One version is sized for pedal boards and the other is rack mount capable. I don't know that they've been gettin rich selling them but they have yet to halt production.
Pedal Amps view All | Seymour Duncan

 

[brianrost]

I'm puzzled as to why there aren't more of these, particularly as a good number of players are moving to preamp pedal DIs / modelers, and as class D amps offer significant space and weight savings.

Ask the companies that offered powered cabinets and then dropped them...GK for starters. Of course, their cabs were designed to only be used with their combos. That limited the market. The Acoustic 360 and 260 (guitar) stacks were actually just preamp heads and powered cabinets...up to four of the 1-18 361 bottoms for an 800 watt rig. When they replaced the 360 with the 370, the power amp was in the head.

Check out the rear panels. Notice how there is only one AC outlet on the rear but four preamp outputs.

Each cab had it's own convenience outlet to power the next cab and you could also daisy chain to the next cabinet. Perhaps agedhorse could discuss why the "convenience outlets" that used to be standard on amps in the 1960s died out.

UNlike the GK and Acoustic designs, when you have to support many different preamps of unknown levels, you have to offer a lot more sensitivity at the input of the power amp. Go read up about people unable to use certain preamp pedals with the high powered amps due to sensitivity issues...there are many threads here, just a few:

QSC 1850hd & Sansamp RBI questions

Having trouble pushing power amp. Sansamp into Crown XLS1502 into Avatar 212.

Preamp into poweramp issues

Then there's the issue of multiple power cords. Users of powered PA cabinets are used to this. Instead of a single speaker cable to the cabinet, you need both an XLR cable and an AC cable. While the XLR connections can usually be daisy chained, the AC power cannot. More cables means more spare cables, too.

 

[monsterthompson]

Ask the companies that offered powered cabinets and then dropped them

Barefaced offered powered cabs for a bit but seems to have dropped them. I can only assume the demand for them at the price they sold for simply didn't work. Barefaced sells premium priced products that are focused on weight savings. I'd imagine the added weight of the power amp didn't make them terribly heavy, but the added cost boosted the sales price more than most were willing to pay. They also don't have huge promotion and distribution as a small company, so I'd assume many bassists didn't know these were even available.

 

[Killing Floor]

The first and second powered bass cabs I owned failed. One of them I liked enough that I removed the amp and rebuild the enclosure to function like a normal cab. It's a lot of cost and risk. Even now that amp quality is improving I still don't see a practical advantage unless you're in a light travel situation and have a backup plan.

 

[agedhorse]

Convenience outlets/receptacles have gone away due to how the safety certification process has evolved. Not that it couldn't be done, but it becomes more difficult and expensive to do and certify because it would require an additional circuit breaker, and may also require that the power cord be permanently attached. It would probably need to comply with the standard for power strips as well as for amplifiers.

 

[bherman]

I believe that there are many small class D amps that negate the market need for a 3-500 watt class D standalone power amp. I currently use a Quilter BB800; 8x7 inches, 3.7 lbs, 800 watts, balanced line in for preamp bypass. I use this amp both as a power amp only when needed as well as a full-feature bass amp. I'm sure that there are many others that can be used the same way with the effects loop to bypass the internal preamp if desired. I tried the Sumo and found it lacking (unbalanced input, so there was significant loss of signal level). i could maybe see the benefits if/when technology gets to the point where a 5-800 watt power amp can fit comfortably on a pedal board, but until that time I don't see the benefit. Even then I think that I'd prefer a standard bass amp for the occasional gig done without a pedalboard.

Others have already hit my reasons why I would not consider powered cabs. 1) I have two cabs that I mix and match depending on need, and it would be redundant to have them both powered - 2) weight