Page 1 of 1
Increase the output of your amps!??
Posted: Sat Sep 28, 2013 6:18 pm
by escapemcp
Saw this
http://www.prosoundweb.com/article/figh ... elivered_/ and the theory seems good, along with the author (Dave Rat... he knows a thing or two

). It all seems to makes sense... I am going to have to rejig how I run my amps!
Thought it worth sharing with you guys.
Re: Increase the output of your amps!??
Posted: Sat Sep 28, 2013 6:36 pm
by escapemcp
On second thoughts, would this create more 'stress' on the amp??
I am OK for power on the tops, so I don't think I'll need this until I run 2 subs per channel (coming soon!!

). The iNuke's power rating of 625W into 4ohms is right on the 50V limit (and that's probably only measured with one channel loaded), so any extra little benefit will help (as long as it doesn't blow the amp due to an 'uneven' load).
Re: Increase the output of your amps!??
Posted: Sat Sep 28, 2013 7:01 pm
by Grant Bunter
Well, rather than try it on cabs, grab a tone generator, oscilloscope etc and use the same method Mr Ratt did.
I only say this, because, I'm not sure that the Crest amp mentioned is in the same configuartion as the Inuke.
The Inuke is Class D and switch mode power supply right?
I think that's different to the Crest.
You'd want to know exactly what's going on...
Re: Increase the output of your amps!??
Posted: Sat Sep 28, 2013 8:28 pm
by escapemcp
Grant Bunter wrote:Well, rather than try it on cabs, grab a tone generator, oscilloscope etc and use the same method Mr Ratt did.
I only say this, because, I'm not sure that the Crest amp mentioned is in the same configuartion as the Inuke.
The Inuke is Class D and switch mode power supply right?
I think that's different to the Crest.
You'd want to know exactly what's going on...
Yeah, Class D & SMPS. I'd be happy to test, but it's really got to be done under load... how do I emulate that? I don't have an oscilloscope either. I could just run 50Hz @ 50V through my cabs and listen for distortion
I don't think the iNuke has massive caps... if that's the case then it may well run out of energy stored in the caps quite quick. Hence this possibly working. I dunno... I understand all the principles of how all this works, but I'm not too good on the details when it's time to investigate closely! I DO know that a little knowledge is a dangerous thing though, so I'm treading carefully!
Re: Increase the output of your amps!??
Posted: Sat Sep 28, 2013 8:58 pm
by BrentEvans
I believe that the Peavey IPRs do this already. If you look up bridging these amps, the method is to feed both channels the same signal, setting the attenuators the same, and connect to the positive out of both terminals. This would have to mean that the second channel is polarity reversed internally, which is neat.
Gotta say again how much I love these amps!
Re: Increase the output of your amps!??
Posted: Sat Sep 28, 2013 9:11 pm
by Bill Fitzmaurice
There's nothing new there. It's called a push-pull circuit, and it's how virtually every amp is made, the main exception being SET (Single Ended Triode). With a two channel amp you don't have to jump through hoops to do it, you just push the 'bridge' button.
Re: Increase the output of your amps!??
Posted: Sat Sep 28, 2013 10:10 pm
by Radian
IMO, if someone is truly fussing over coaxing an extra 0.8 dB of gain out of a power amp at its bleeding edge, perhaps it's time to step up to the next sized chassis or improve the sensitivity of the rig elsewhere.
Nothing against Dave Rat. When he speaks, I listen....but the practicality of this tip has me a little baffled.

Re: Increase the output of your amps!??
Posted: Sat Sep 28, 2013 10:40 pm
by Grant Bunter
Radian wrote:IMO, if someone is truly fussing over coaxing an extra 0.8 dB of gain out of a power amp at its bleeding edge, perhaps it's time to step up to the next sized chassis or improve the sensitivity of the rig elsewhere.
Nothing against Dave Rat. When he speaks, I listen....but the practicality of this tip has me a little baffled.

Well put Radian.
For me, the absolute worst thing about following this route, as described in the article, would be the PITA that comes from changing x amount of my speaker leads, or making adaptors, and storing them in yet another box.
Especially after the time I have spent over the last 6 months or so making sure every amp output and cab is now speakon (as well as every XLR in the entire system now being pin 2 hot).
Re: Increase the output of your amps!??
Posted: Sun Sep 29, 2013 8:05 am
by escapemcp
Radian wrote:IMO, if someone is truly fussing over coaxing an extra 0.8 dB of gain out of a power amp at its bleeding edge, perhaps it's time to step up to the next sized chassis or improve the sensitivity of the rig elsewhere.
I DO need to get more amps/speakers, but another amp isn't a luxury that I can afford at the moment.

I AM building another pair of T30s, so that should help somewhat

As for the PITA that is adaptors/specalized leads, I was just going to mark an XLR and a speakon with a bit of my luminous yellow gaffa tape and I'd know they are the reversed cables.
I admit that for 0.8dB, it's hardly a massive increase, but the free party crowd like it as loud as possible! I'll report back here IF I do ever try this.
Re: Increase the output of your amps!??
Posted: Sun Sep 29, 2013 1:23 pm
by slyslam
I started using this method for my subs about two years ago. No complain so far. I run a EP2500 with 4 T39 and and I see a bit more headroom when pushed to maximum. Could be a placebo effect but didn't cost me anything to try. I have my amp bridged, channel A speaker connected with a speakon and I used a banana plug for the reversed channel B.
Re: Increase the output of your amps!??
Posted: Sun Sep 29, 2013 3:15 pm
by Grant Bunter
slyslam wrote:I started using this method for my subs about two years ago. No complain so far. I run a EP2500 with 4 T39 and and I see a bit more headroom when pushed to maximum. Could be a placebo effect but didn't cost me anything to try. I have my amp bridged, channel A speaker connected with a speakon and I used a banana plug for the reversed channel B.
Glad to hear real world results.
AFAIK, using a brick wall limiter means no headroom when pushed to maximum.
When you're up to maximum limited voltage, that's it.
What limiter are you using?
Re: Increase the output of your amps!??
Posted: Sun Sep 29, 2013 4:26 pm
by Bill Fitzmaurice
escapemcp wrote:
I admit that for 0.8dB, it's hardly a massive increase
To say the least, since you can't hear a 0.8dB increase.
Re: Increase the output of your amps!??
Posted: Mon Sep 30, 2013 3:10 am
by Charles Jenkinson
I watched one of Dave Rat's videos once, after hearing of him on here. It was about setting up a system with subwoofers. I was surprised that horns were passed off as 'no-one uses them anymore' - exit stage left and wheel in your twin 18's approach. I didn't get to the end of the video. I concluded he probably isn't a closet BF fan and whilst he might know his stuff, I was disturbed by what he said, when horn subs make more sense from a performance perspective. I'm not meaning to be critical, just to make the point that I feel i have a small mountain to climb on credibility with Dave, and thats probably more my issue.
Monday morning confessional over.
Re: Increase the output of your amps!??
Posted: Mon Sep 30, 2013 7:00 am
by Bill Fitzmaurice
Charles Jenkinson wrote:I watched one of Dave Rat's videos once, after hearing of him on here. It was about setting up a system with subwoofers. I was surprised that horns were passed off as 'no-one uses them anymore' - exit stage left and wheel in your twin 18's approach.
Since you bring it up, he also hung onto cluster arrays long after they'd been abandoned by every other major tour sound operator. Kind of like Function1 he claimed the superiority of his cluster arrays because that's all that he had, and he tried milking them long after they'd gone dry. When finally forced to go to line arrays or go out of business he embraced them wholeheartledly. In short, Dave promotes what Dave uses. That doesn't diminish his capabilities as an FOH engineer, but you do have to take many of his recommendations with respect to gear as being subjective rather than objective.