Power amp options for a kemper profiling amp.

[cliffyspliff]

I've been gigging with a power rack kemper into a Barefaced BB2 with PA support for about a year now .... And it sounds awesome.

However .... We have been doing recently some festival multi band gigs ... With more coming up ....just using our own back line .....and my set up is underpowered as we have to push the volumes up a bit .... Becomes worse when I add a 2nd 8ohmn speaker ... In fact it clips the output section of the amp ... Which cuts out the sound .... Which is not good in front of a room full of people.

So I am prepared to invest in a poweramp... Hopefully 2nd hand .... That I could use in these situations.

I've been looking at the Matrix GT 800 and GT 1000 amps but I was wondering are there any alternatives to these for bass?

It must be light and preferably 1u.

Many Thanks,

Sean.

Edited June 7, 2016 by cliffyspliff

[chevy-stu]

Crown BF6000 if you can find one

[Dan Dare]

Always a load on evilBay. Any of the decent makes - Crown, Crest, QSC, Peavey, etc - will do the job. Avoid El Cheapo disco makes and you'll be fine.

Edited June 7, 2016 by Dan Dare

[Happy Jack]

[quote name='cliffyspliff' timestamp='1465289625' post='3066733']

It must be light and preferably 1u.

[/quote]

You don't mention whether it must also be cheap. Light + powerful + 1U + good performance + cheap is hard to achieve.

If you're not shaving the pennies, then the Powersoft Digam range are pretty much as good as it gets, and tick every box you can imagine.

[EBS_freak]

[quote name='Happy Jack' timestamp='1465297682' post='3066850']
If you're not shaving the pennies, then the Powersoft Digam range are pretty much as good as it gets, and tick every box you can imagine.
[/quote]

Powersoft is where it's at... although you will be paying a pretty penny for it.

[alexclaber]

I'd avoid 1U, it's so much harder (i.e. more expensive or worse performance) to package an amp in such a shallow casing. 2U gives much more internal space (not just twice as much!)

[Dood]

[quote name='EBS_freak' timestamp='1465300537' post='3066886']
Powersoft is where it's at... although you will be paying a pretty penny for it.
[/quote]

The Powersoft is indeed a beast. I have used and owned one and they are pretty exceptional. The only downside I can see of *very good* 1u racks is that they tend to be very deep physically. Mine only just fitted in a deep gator rack, but some are longer.

You will also find that 2u power amplifiers that are more than capable will be a bit cheaper vs the 1u form factor. I'm currently using a QSC shallow 2u power amplifier which I've been pleased with when I need stereo or big watts. - I'm comparing like for like here, not the cheaper 'unknown brand' 1u units that suggest 1 million watts output from a standard wall socket lol.

[Dood]

[quote name='alexclaber' timestamp='1465301122' post='3066893']
I'd avoid 1U, it's so much harder (i.e. more expensive or worse performance) to package an amp in such a shallow casing. 2U gives much more internal space (not just twice as much!)
[/quote]

Ahh! ha ha - which is what I meant though said more eloquently!

[Happy Jack]

[quote name='alexclaber' timestamp='1465301122' post='3066893']
2U gives much more internal space (not just twice as much!)
[/quote]

Is this a Zen thing?

[cliffyspliff]

That's interesting the 2u being superior to the 1u .... I wanted 1u as I wanted to keep the rack case size as small as possible ... I'm on a 4u case already ... With the kemper and wireless iems.

Thanks for the info though everyone ... That's great.

[charic]

Cut out the middleman and get a powered pa speaker?

[Dood]

[quote name='charic' timestamp='1465303513' post='3066921']
Cut out the middleman and get a powered pa speaker?
[/quote]

Or upgrade the BB2 to an FR800 which would be even better!

[cliffyspliff]

[quote name='dood' timestamp='1465303680' post='3066925']


Or upgrade the BB2 to an FR800 which would be even better!
[/quote]

A speaker upgrade was the other option 🙋🏻

Trouble is I really like the kemper but with the power section only going to 8 ohms it can be found lacking for bass .... A trade up on the BB2 could be another option I guess .... 😕 .... I do already have an rs212 that I can pair with the BB2 though ....so thats why I was thinking the amp route.

[charic]

[quote name='dood' timestamp='1465303680' post='3066925']
Or upgrade the BB2 to an FR800 which would be even better!
[/quote]

That was my next suggestion

[Passinwind]

[quote name='alexclaber' timestamp='1465301122' post='3066893']
I'd avoid 1U, it's so much harder (i.e. more expensive or worse performance) to package an amp in such a shallow casing. 2U gives much more internal space (not just twice as much!)
[/quote]

Yep. For me the QSC PLX1804 was the sweet spot for power and form factor when I was doing separates in racks..

Edited June 7, 2016 by Passinwind

[chevy-stu]

If you can find a shallow 2u amp, why not mount it in the rear of the rack, as the Kemper and wireless stuff isn't too deep, and it's unlikely you'll need to see the front..

[fretmeister]

Do you actually run stereo?

If not - then a Tecamp Puma 900 would have plenty of beans and be 1u and light.

The rack ears are now unavailable, but the Eich versions for the T series amps fit.

[Wooks79]

Has anyone tried using an Orange Terror Bass 500 as a poweramp, with the Kemper through the effects loop? Would this idea be good or bad?

[HazBeen]

QSC PLX would indeed be good. 1804 or 1104. Powersoft is great but twice the price or so.

Or a 300 watt full tube Aggie power amp.....

Edited October 25, 2016 by HazBeen

[NancyJohnson]

Sorry about weighing in late here.

My signal path is (in the main) a Sansamp RBI into a stereo 2U Matrix GT1000. I've been playing for years and years and bar none this is the best poweramp I've ever used. It's loud, transparent, lightweight and runs very cool with little or no fan noise. It comfortably fits into a shallow Gator rack.

I spoke to the Matrix guys and they said the 1U version is a bit noisier, but performance is similar.

Take a bit of advice from an old soldier; spend a little more and buy a 2U Matrix. It's a wonderful bit of kit.

[Chienmortbb]

[quote name='NancyJohnson' timestamp='1477480721' post='3162473']
Sorry about weighing in late here.

My signal path is (in the main) a Sansamp RBI into a stereo 2U Matrix GT1000. I've been playing for years and years and bar none this is the best poweramp I've ever used. It's loud, transparent, lightweight and runs very cool with little or no fan noise. It comfortably fits into a shallow Gator rack.

I spoke to the Matrix guys and they said the 1U version is a bit noisier, but performance is similar.

Take a bit of advice from an old soldier; spend a little more and buy a 2U Matrix. It's a wonderful bit of kit.
[/quote][i] looked at at Matrix when I\ considered going rack mounted. The designs are target at modelling preamps. They are almost unique in that the use a SMPS power supply and a mosfet Class AB output power amp. The other amps mentioned are fine amplifiers but the Matrix power amps are designed for MI use.[/i]

[stevie]

It's worth bearing in mind that the Matrix was designed with a very low damping factor specifically for the electric guitar.

[EBS_freak]

[quote name='stevie' timestamp='1477574981' post='3163097']
It's worth bearing in mind that the Matrix was designed with a very low damping factor specifically for the electric guitar.
[/quote]
I'm no expert but wouldn't the damping factor be less significant because we can assume the amp is going to be sat right next to the speaker? And the fact that it's importance is more empahsised under frequencies of say 150Hz - meaning that it's significance for electric guitar is even less?

Edited October 27, 2016 by EBS_freak

[stevie]

I'm sure one of our amp specialists will chime in, but I don't think the low resistance of a speaker cable makes much difference to the amp's damping factor.

The first time I came across a variable damping option was in the Duncan Convertible combo (although it had been around for decades before that). It was a simple knob that allowed you to vary the damping factor from high to low. Lowering the damping factor gives a pleasant "bloom" to the sound together with slightly more warmth, which apparently makes the electric guitar sound better. The effect was certainly audible. Whether it's appropriate for bass depends on what you're after, I suppose.

[EBS_freak]

I found this from the EAW site -

[color=#7F7F7F][font=myriad-pro, sans-serif][size=3]Amplifier damping factor (DF)is defined as “the ratio of the load impedance (loudspeaker plus wire resistance) to the amplifier internal output impedance.” This basically indicates the amplifier’s ability to control overshoot of the loudspeaker, i.e., to stop the cone from moving. It is most evident at frequencies below 150 Hz or so where the size and weight of the cones become significant. A system where the damping factor of the entire loudspeaker/wire/amplifier circuit is very low will exhibit poor definition in the low frequency range. Low frequency transients such as kick drum hits will sound “muddy” instead of that crisp “punch” we would ideally want from the system[/size][/font][/color][color=#7F7F7F][font=myriad-pro, sans-serif][size=3].[/size][/font][/color]

I suspect that I have read this before - this is probably why the frequency 150 Hz is stuck in my head and associated with damping factor.

The summary from that page is this -

[b] In Summary…[/b]
[color=#7F7F7F][font=myriad-pro, sans-serif][size=3]
So what have we learned? In live sound reinforcement systems, damping factor is really driven by the length and size of our wire and the impedance of the loudspeakers we connect at the other end. Since damping factor mostly affects low frequency, we should endeavor to keep our subwoofer loudspeaker lines as short as possible and/or use larger gauge wire. We should keep the impedance of the connected load as high as possible by connecting only one transducer per wire instead of two.[/size][/font][/color][color=#7F7F7F][font=myriad-pro, sans-serif][size=3]
So is more amplifier damping factor better? As one of my colleagues recently said, “Sure! If the loudspeaker terminals are welded to the amplifier output terminals!” Well, maybe he overstated it a little bit, but yes, as long as the loudspeaker wire is really short, then by all means![/size][/font][/color]

Anybody interested in that page -
http://eaw.com/amplifier-damping-factor-more-is-better-or-is-it/