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C Audio SRX3701 amp on a genny

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Sonic the hedge View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Sonic the hedge Quote  Post ReplyReply Direct Link To This Post Posted: 19 October 2021 at 4:20pm
Originally posted by Esc4pe Esc4pe wrote:

Unfortunately bar heater for freeparties won’t be too great haha! Maybe I could use filament lamp for a light to keep the decks visible. Would NON LED UV lamps have the same resistive load?

Filiment lamps e.g. halogen are ideal

For UV I'd say no, florescent strip/discharge type UV lamps are inductive loads but 'should' have a capacitor to correct the power factor, but the actual PF will vary with voltage so I wouldn't want to rely on it in this case.


Edited by Sonic the hedge - 19 October 2021 at 4:32pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 4D Quote  Post ReplyReply Direct Link To This Post Posted: 19 October 2021 at 11:22pm

static load add a few 300w par-cans
DMZ. "The bass was intense. Girls were literally running up to stand next to the subs"
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Sonic the hedge Quote  Post ReplyReply Direct Link To This Post Posted: 22 October 2021 at 10:27pm
Originally posted by Conanski Conanski wrote:

Originally posted by zigzagwanderer zigzagwanderer wrote:

Other than the above I have no knowledge or experience with PA related stuff , but as much as id like the practicality of light weight amps my gut feeling is older heavy weight amps as opposed to light weight switch mode amps will potentially fare better running on this genny.
Am I right thinking this ?

That isn't my experience. The problem with old school linear amplifiers is they are power hogs. They typically waste just as much power generating heat as they produce in audio output which means you need twich as much AC supply as a class D of the same output. So while a big boat anchor amp may deal with wonky generator power better(not shutdown) you're going to need a bigger generator to run it. 
The solution IMO is don't accept wonky generator power... the Honda isn't in that category, and buy better quality modern amplifiers not cheap things. 

That's all absolutely true. Good quality SMPS/class D are the ideal solution.

The problem is, you need to spend a lot more money (even second hand) to get good quality Class D/SMPS amps, with active PFC and good limiters. If you need 3-4 amps to run all your channels, it's likely going to work out much cheaper overall, to just get a bigger Genny, or use a second one.

So if you are on a tight budget, Toroidal amps (of any quality/price) are a probably a better bet, and certainly much less likely to cause problems than cheapo class D.


Edited by Sonic the hedge - 23 October 2021 at 12:09am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Andylaser Quote  Post ReplyReply Direct Link To This Post Posted: 23 October 2021 at 11:39pm
I always have a couple of 500w halogen floods powered when using a genny. Its useful just haviing one lighting up the genny itself so you can keep an eye on it.
"music so loud, that if we move in next door to you; your lawn will die" - Lemmy
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Boxes-R-Blue Quote  Post ReplyReply Direct Link To This Post Posted: 25 October 2021 at 3:36am
OK

Copper/Iron amps have a huge powerfactor issue ( you "6k" set is 6KVA, so @ 0.8 PF 4.8KW with the Amp pulling another 0.8 Drift that becomes 3.84KW, you see where this is going...)


But SMPS amps use 6 pulse inversion (massive current distortion) and often have leading power factors, which causes absolute HAVOC with, basically any Genset you can get you hands on upto about 500KVA, so that is thing...

Gensets ( all of them) are absolute crap in a 0> x% load aspect, if you want solid mains you need a full phase sensing AVR controlled unit working in a 15-X% load aspect...

Under 15% all sets exhibit shocking load regulation, so what the f*** might this mean en Anglias?

Always use an amp equal to or above the max wattage of you amps, (bear in mind 6K+4K+2K+2KW sat in a rack ain't EVER gonna pull 10KW let alone 14KW) so you have head room.

Use something stupid like a some HMI movers, a fan heater, some floods to give the genset some base load to chew on, for big shows I used to think nothing of a 30Kw load bank so when the LD bumped in 8 MolePhay (40Kw bump) the gensset didn't blink (some black smoke, sorry Greta!) but def keep like 1KW load on a 6KVA set solid...

Above all use proper cable, 4mm 32a is crap (and not allowed under XXXX blah blah regs) but even 6mm is only good for like 30m, so don't wreck you rig with shite cabling...

I have recently run 35mm2 for 32A feed, yep 35mm!!!

Yep I did make a 3PNE (I used 5G35 as 3G35 wasn't available easily) 125A plug to 32A single phase adapter (prob should have gone 70mm L + N, but I was walking away from the job for the duration  and, well, I didn't) but to get 2.6% voltage drop from supply to drain 35mm was required (I could even have used the spare pairs for a V-sense line) so never forget spending on speaker cable (yes you pricks that run 4mm to 2r instead of 2.5 to each driver @ 8r) is waste if you have JoJo reel feeding your rig!!!!!!!!

To be clear, bass (not a prob if you have Pioneer, no bass can come from here) drops and mains cable modulates, not drivers!!!!!

So make sure to have 800A PSC at you racks at all times!!!!

x



Edited by Boxes-R-Blue - 25 October 2021 at 3:37am
Kinda Been there, Kinda done that, YOU COULDN'T handle my bar bill!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Esc4pe Quote  Post ReplyReply Direct Link To This Post Posted: 25 October 2021 at 10:48am
I feel like every time a generator is brought up this information gets thrown up and scares people away! This and telling people they need a monster towable gen set for a mini rig. Albeit you’re not lying in what you’ve put, he’s only using 2 scoops and a couple of amps. Throw them on a gx390 Honda or similar and have a constant load then he’s away and laughing! I’ve used far far less ideal situations and the one and only time I have ever had a problem is running a SMPS amp. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Earplug Quote  Post ReplyReply Direct Link To This Post Posted: 25 October 2021 at 5:40pm
Originally posted by Esc4pe Esc4pe wrote:

I feel like every time a generator is brought up this information gets thrown up and scares people away! This and telling people they need a monster towable gen set for a mini rig. Albeit you’re not lying in what you’ve put, he’s only using 2 scoops and a couple of amps. Throw them on a gx390 Honda or similar and have a constant load then he’s away and laughing! I’ve used far far less ideal situations and the one and only time I have ever had a problem is running a SMPS amp. 



I have to say that I must agree. I have a 5kVA petrol generator that I use for small events, where I will run either 1 or 2 7001's off the thing. Mainly speech, background music - or a couple of times a duo o trio playing live.

Needless to say, no problems at all with the Crests, but ages ago I did try a QSC Powerlight 2 on the generator and it gave me all sorts of problems. I also recently had huge problems with 2 Lab Gruppen FP10000's off a large, hire generator.

So despite all the talk about PF issues with transformer powered amps, there definitely seems to be far more issues when using amps with SMPS.



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Post Options Post Options   Thanks (0) Thanks(0)   Quote csg Quote  Post ReplyReply Direct Link To This Post Posted: 25 October 2021 at 7:54pm
Yet we do it week in week out with SMPS amps without any issue whatsoever in nearly 20 years since we sold all our crest p series in favour of lab gruppens, and that’s probably 5 stock changeovers ago now. Don't blame the technology, get your temp power system design right.
“The fact is this is about identifying what we do best and finding more ways of doing less of it better”
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Earplug Quote  Post ReplyReply Direct Link To This Post Posted: 26 October 2021 at 7:59am
Originally posted by csg csg wrote:

Yet we do it week in week out with SMPS amps without any issue whatsoever in nearly 20 years since we sold all our crest p series in favour of lab gruppens, and that’s probably 5 stock changeovers ago now. Don't blame the technology, get your temp power system design right.


 
Off generators - or mains?

And I know that there are millions of lightweights doing the job day in and day out, no doubt, but I can only comment on my personal experiences. I do actually still have a couple of lightweights - a Chevin A1000 and Crest 9200. Both used regularly, but I'd think twice before powering them off a generator - especially a small petrol job.


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Post Options Post Options   Thanks (0) Thanks(0)   Quote Esc4pe Quote  Post ReplyReply Direct Link To This Post Posted: 26 October 2021 at 1:43pm
Just to add, SMPS amps won’t cause problems if using a huge gen set with huge floor heaters and the likes but those gensets also cost near on the same to hire as the amount I’m paid to do events so using such is not feasible for small scale events 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote csg Quote  Post ReplyReply Direct Link To This Post Posted: 26 October 2021 at 4:48pm
Originally posted by Earplug Earplug wrote:

Originally posted by csg csg wrote:

Yet we do it week in week out with SMPS amps without any issue whatsoever in nearly 20 years since we sold all our crest p series in favour of lab gruppens, and that’s probably 5 stock changeovers ago now. Don't blame the technology, get your temp power system design right.


 
Off generators - or mains?

And I know that there are millions of lightweights doing the job day in and day out, no doubt, but I can only comment on my personal experiences. I do actually still have a couple of lightweights - a Chevin A1000 and Crest 9200. Both used regularly, but I'd think twice before powering them off a generator - especially a small petrol job.



Majority of the time generators, any size from 20 to 2000kva often across multiple sets, loadsharing. But even a single 20Kva correctly specified with a reasonable ballast load and no issues resulting. Of course that is a different kettle of fish to a small petrol machine 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Earplug Quote  Post ReplyReply Direct Link To This Post Posted: 26 October 2021 at 6:28pm
" Of course that is a different kettle of fish to a small petrol machine "

Yes - which is where this discussion started! 3kVA Honda.  Smile


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