solid state power amps for bass

[iriegnome]

I am looking to go to a tube preamp and power amp setup. however what amp to choose? class a, b, a/b, d, h? i mean how do you tell what is best for bass and what are the differences in bass power amps, pa amps and guitar amps?

[RickenBoogie]

By playing them, and using your ears.

[Plstrns]

There isn't an ounce of sound difference between various PA poweramps when used for bass. Class D is light, and doesn't require a ton of AC to operate to it's fullest potential.

SS poweramps labeled as a bass poweramps are either substandard for PA, labeled as bass power for marketing reasons, or have additional tone controls.

[mowburger]

Going to a preamp-poweramp setup can give your fav sounding pre a ton of headroom so yous don't have to push alot of gain on your signal =very clean bass tone. It also lets you run a modular setup with diff cabs, even if thier different impedances. The new lightweight class D amps looked so good I just ordered a Crown XLS 2000 my link
Just pulled the trigger on a Crown XLS 2000!
I can't wait to get this new toy in the mail! I will be posting my results, as I try it out with several cabs and various volume/playing situations.

All the good brand name poweramps out there will provide you with pure clean power, to let the sound of your bass and tube pre come thru at any volume without too much output stage coloration.

Did you have any in mind?
What cabs do you plan to run?
what styles(tones) do you wanna comp?


good luck to you in your quest!

[BurningSkies]

With power amps and amp heads, people love to throw generalizations around about how they sound. The problem is that its the execution of the amp rather than its classification that matters. Also, remember, just because it's small and light, doesn't necessarily make it 'class D', it may just have a switching power supply.

[craig.p]

Make sure you pay attention to the fine print when it comes to power-output ratings, especially around duty cycle relative to load impedance.

Put warranty length at or near the top of your list.

Check for features that might be of value to you: channel paralleling, low-cut filtering, and so on.

Make a hard distinction between what you CAN carry and what you're WILLING to carry week after week, to job after job. A forty-pound QSC AB sled sounds great (I own one), but maybe not so great after six months of schlepping it from job to job. Each person has a different tolerance level for that sort of thing.

Pay attention to airflow direction if you're going to rack mount your amp. Stacked equipment should have same-direction airflow, and that includes stacked racks as well as units stacked in the same rack. Also check specs for required free space above and below the unit in the rack itself.

Consider unit depth, relative to available racks and the other equipment you plan to rack with it. If your other gear is deep but your amp is shallow, you may have to go hardware-store hunting for extra-long brackets for the amp's rear supports.

Finally, consider resale value and (in that same vein) warranty tranferability. For the high-quality AB sleds, even though they're built like tanks and there's warranty left on them, you may take a hit simply because they're heavy and almost no one wants that any more. The flip side is that you might be able to pick up a quality used AB sled for cheaper today than, say, five years ago. And they're out there.

[BurningSkies]

Originally Posted by craig.p

Make sure you pay attention to the fine print when it comes to power-output ratings, especially around duty cycle relative to load impedance.

Put warranty length at or near the top of your list.

Check for features that might be of value to you: channel paralleling, low-cut filtering, and so on.

Make a hard distinction between what you CAN carry and what you're WILLING to carry week after week, to job after job. A forty-pound QSC AB sled sounds great (I own one), but maybe not so great after six months of schlepping it from job to job. Each person has a different tolerance level for that sort of thing.

Pay attention to airflow direction if you're going to rack mount your amp. Stacked equipment should have same-direction airflow, and that includes stacked racks as well as units stacked in the same rack. Also check specs for required free space above and below the unit in the rack itself.

Consider unit depth, relative to available racks and the other equipment you plan to rack with it. If your other gear is deep but your amp is shallow, you may have to go hardware-store hunting for extra-long brackets for the amp's rear supports.

Finally, consider resale value and (in that same vein) warranty tranferability. For the high-quality AB sleds, even though they're built like tanks and there's warranty left on them, you may take a hit simply because they're heavy and almost no one wants that any more. The flip side is that you might be able to pick up a quality used AB sled for cheaper today than, say, five years ago. And they're out there.

(bolded sections)

I agree with these things. You know, it seems like a great idea to have a big heavy amp sometimes...I know that a few years back I thought "I'll be happy to make the sacrifice for the tone" and ended up with a 100+ pound 5 space rack. After 6 months of gigging and rehearsals, I was much less happy about taking the rack out of my car trunk and upstairs to my apartment at 3am several times a week (or loading it in to my car from my apartment,etc.), or in and out of our practice walk-up.

I found myself taking my 20-something pound backup amp instead many times. Then I realized that I liked the tone of EITHER rig (once the honeymoon period had worked its way out on the heavy rig)...And now I'm down to a shoulder bag with a 6lb integrated mini.

I agree that it's also important to check that the amp does what you want. Can you bridge into the correct impedance for your cab setup? Does it provide enough power for your cabs if you're running off of each side of a stereo amp if you're working a couple 8ohm cabs? Think about possible scenarios...I'm looking at a power/pre setup that depending on the gig may turn into a monitor amp or a front end amp or maybe both...

[craig.p]

Yikes. I can't imagine lifting a hundred-pound rack. Or going up and down stairs with one.

I'll probably rack-bag my QSC, eventually. But alone. Maybe have a separate rack bag for the other junk so the "carry" is balanced.

[ThrashMaster]

Originally Posted by craig.p

Yikes. I can't imagine lifting a hundred-pound rack. Or going up and down stairs with one.

in one of my old bands i was the guitard, and the bassists rack was probably over 200 pounds

Ampeg SVT 2 pro
lead sled power amp
rack tuner
power distributer
compressor
crossover
drawer full of cables etc

cabs were a ampeg sealed 4x10 pushed by the svt, and then some mammoth sub pushed by the power amp

Sounded absolutely godlike...but holy hell was it awful to move, even on wheels

[iriegnome]

My whole thing is to get lighter not heavier. My SWR Bass 750 weighs 34 pounds. With a preamp weighing 6 pounds and something like a QSC PLX2500 weighing in at 11 pounds, I can cut my rig weight down 17 pounds. Also it would give me 750w to my under rig cabs and like 450w back to my drummer cabinet and that would work.

[BurningSkies]

Originally Posted by iriegnome

My whole thing is to get lighter not heavier. My SWR Bass 750 weighs 34 pounds. With a preamp weighing 6 pounds and something like a QSC PLX2500 weighing in at 11 pounds, I can cut my rig weight down 17 pounds. Also it would give me 750w to my under rig cabs and like 450w back to my drummer cabinet and that would work.

How do you feel about the new Peavey IPR series? They list a weight of ~7 pounds, for big power.

[iriegnome]

No. Peavey probably would not work for me..

[Balog]

Originally Posted by iriegnome

No. Peavey probably would not work for me..

Just idle curiousity, but why is that? Lack of bridged mono without jumpering?

[iriegnome]

Not to be a snob, but I am a snob. Peavy is too entry level and not clean. Not that I absolutely have to have botique, but in my experience, peavey just would not give me ultra quiet performance that I require from my rig. I was thinking more of a Stewart 1.2 or something like that. I would love a 1 space amp, but most of those are only 100w and I am currently using 850w and need to stay about the same or go more. That is why I was considering the QSC PLX2502, but again, I would like to find a 1 space amp.

[projectMalamute]

Originally Posted by iriegnome

Not to be a snob, but I am a snob. Peavy is too entry level and not clean. Not that I absolutely have to have botique, but in my experience, peavey just would not give me ultra quiet performance that I require from my rig.

Then you should look at the Crest Pro 200 series stuff.

[Balog]

Originally Posted by iriegnome

Not to be a snob, but I am a snob. Peavy is too entry level and not clean. Not that I absolutely have to have botique, but in my experience, peavey just would not give me ultra quiet performance that I require from my rig. I was thinking more of a Stewart 1.2 or something like that. I would love a 1 space amp, but most of those are only 100w and I am currently using 850w and need to stay about the same or go more. That is why I was considering the QSC PLX2502, but again, I would like to find a 1 space amp.

Do you have any experience with the IPR line?

[seamonkey]

Peavey IPR with DSP which includes MaxxBass, is an incredible bargain.

[BurningSkies]

Originally Posted by seamonkey

Peavey IPR with DSP which includes MaxxBass, is an incredible bargain.

Have any of the DSP versions be released to date?

[RedLeg]

Alembic Fx-1 + QSC PLX1804
its high end and light. Fx-1's Sound greeeeaaaattttt

[iriegnome]

The 1804 is a "stereo amp" (non-bridgeable) only correct? Now with that, can I through a 8Ohm load on 1 side and a 4Ohm load on the other? Actually, can that be done with any amp? Currently I run my SWR Bass 750 into 3-8Ohm cabinets MONO, for a total of 2.6Ohms and just about 850w.