#143022  by zambiland
 Thu Nov 27, 2014 11:31 am
Jon S. wrote:New from Carvin. That's $1.23/watt!
I'm skeptical of Carvin's power ratings. When they give a rating, they don't tell you at what bandwidth, nor at how much THD, nor the measurement technique (RMS? Peak power? Something else?). The THD they do mention is fairly high (.5%). I'm thinking it's more like $2/watt.

They need to supply more meaningful specs. I'll stick with QSC or Crest.
 #143024  by Jon S.
 Thu Nov 27, 2014 4:22 pm
The Class D DCM200L is commonly used as a guitar amp which is how I use mine. It's f- loud. I've never come close to having to push mine hard. Ourdoors, live, I've set mine just below half up. So I'm not sure what to make of your post (are you thinking of it as a PA amp? if so, choose a different model).
 #143025  by zambiland
 Thu Nov 27, 2014 6:17 pm
Jon S. wrote:The Class D DCM200L is commonly used as a guitar amp which is how I use mine. It's f- loud. I've never come close to having to push mine hard. Ourdoors, live, I've set mine just below half up. So I'm not sure what to make of your post (are you thinking of it as a PA amp? if so, choose a different model).
I'm just responding to your statement of dollars vs. watts. My experience with Carvin is that their specifications are misleading. But, if it's loud enough, then the specs don't matter, which means that that should be the focus of your assessment of the amp. I'm not really thinking of it in any particular context, although my perspective as a bass player triggers my response to call out specification BS when I see it, as for bass players, if an amp claims to have a certain amount of power but can't deliver it at 40hz, then it's a fraudulent claim. Guitarists obviously don't care about 40hz, so the 1khz rating is fine, although still misleading.

As far as settings on the volume knob of a power amp goes, that's pretty meaningless because it's just an attenuator, so it depends on what the preamp is throwing at it. You might have plenty loud at halfway up, but if you turn it up all the way, you might just be going into overload territory. With an SMS preamp, you can set the preamp output at 100% and the power amp at 50% or you can set the preamp at 50% and the power amp 100%. It's a matter of gain structure, not how much headroom you have in reserve.
 #143027  by Jon S.
 Fri Nov 28, 2014 6:23 am
OK, I see what you're saying. Also, a bassist needs more power than a guitarist, often much more. As for my preamp, in the rig where I use the Carvin, it's an SMS Classic Preamp that I run with the rear trim pot on full and the front gain control a little over half (I used to run the gain lower but then replaced the stock 12AX7 with a less powerful 5751).

Oh, and to repeat my main point for why I posted this as a PSA: $249 for a 2X100W, bridgeable, 4 lb., toneful-sounding Class D 1U power amp? You can't buy a decent boutique pedal for that price these days.

Image
 #143028  by mkaufman
 Fri Nov 28, 2014 7:29 am
I see that the Carvin has two channels. Can one run two separate cabs based on one input signal? In that scenario, is it two channels or bridged mono? If so, can the cabs have difference ohms?

I'm currently doing this with my Rocktron 300.

tx,
mk
 #143029  by Searing75
 Fri Nov 28, 2014 7:53 am
You could, but the difference in ohms would not be ideal. The amp runs in stereo or bridged, so one input will give you two outputs at 100w each at 8 ohms, or one output, bridged, with 200w at 8ohms.

I have this amp, and it is great! Second only to my MC50.
Last edited by Searing75 on Fri Nov 28, 2014 1:23 pm, edited 1 time in total.
 #143030  by Jon S.
 Fri Nov 28, 2014 10:11 am
In case you were asking about this, there is a parallel switch by the inputs that allows you to drive both inuts with one signal, no Y-cord needed.
 #143415  by zambiland
 Thu Dec 18, 2014 10:04 pm
Jon S. wrote:In case you were asking about this, there is a parallel switch by the inputs that allows you to drive both inuts with one signal, no Y-cord needed.
Exactly. And the channels need not be driving the same impedance. I do this all the time with my QSC CX1202v.