Powersoft

[fincaman]

Hello all, I am in Spain using a Crown XTI 4002, it's a great amplifier but when I work out in the country the mains voltage can often drop and the amp cuts out. I have been looking at a Powersoft K2 which seems to work on anything down to about 160 v . Is powersoft rated as a good make ? and are there any other amplifiers that will work on low voltages ?

[fincaman]

Can someone help ?

[Stuart91]

Powersoft will be absolutely fine for this.

 

I've not used the K2 series, but we've got some Q-series amps which have coped with all sorts of inadequate generators etc. without complaint.

 

They are not cheap, so you may want to make sure that you're not going to simply move the problem to the next bit of vulnerable kit.

[fincaman]

Thanks for your help

[csg]

The K2 is now quite an old model. I would encourage you to have a look at the T series - these have a full set of modern specs such as universal power supplies, Dante, superior DSP and superior sound quality. I can clearly hear the difference between K and T series.

 

powersoft is a top tier amp manufacturer used globally in touring and premium quality installations.

[sunray]

Mid 90's I did a year or so installing nightclubs. We settled on Eclar PAM series amps - no silly SMPS's to throw a hissy fit, they powered up & carried on working on some horrible underpowered generator supplys.

 

In that summer I borrowed hire stock from work on 2 occassions when hired in systems at local events failed to power-up due to under volts.

 

[csg]

Interesting, I used to find the PAM amps particularly unreliable !

 

Good SMPS with PFC are the way to go on modern systems and are far kinder to generator / temporary power systems, not to mention the fact that they can operate on a much wider range of voltage and frequency compared with any linear PSU.

[timsabre]

Good SMPS with PFC are the way to go on modern systems and are far kinder to generator / temporary power systems,

 

They aren't really very kind - they have a massive inrush when switched on. And in amps they are a very similar load to a conventional PSU which rectifies the mains and feeds big DC capacitors, so all the power is drawn at the peak of the mains cycle which is not a happy thing for a generator

Edited December 2, 2020 by timsabre

[sunray]

Interesting, I used to find the PAM amps particularly unreliable !

 

Good SMPS with PFC are the way to go on modern systems and are far kinder to generator / temporary power systems, not to mention the fact that they can operate on a much wider range of voltage and frequency compared with any linear PSU.

I'm amazed you found them unreliable. I worked for the company who had the contract to repair for one of the two official importers to the UK. In the year I was there I worked on 7 of their amplifiers, 2 of which were full of smoke fluid [mounted adjacent to smoke machine and fan drew the smoke into amp] and one had mains fed into speaker O/P, in contrast we purchased O/P transistors for the Crown's by the 100 . In that same year we refitted the whole of the Club UK chain, replacing CVA with PAM's [circa 200 amplifiers] and as a rough estimate that was 1/3 of our installations.However one club seemed to be knocking out amps and tweetwers quite regularly but once we installed cctv in the rack and started invoicing for repairs when the resident DJ bypassed the compressor and EQ the problems stopped.

As to SMPS's their inrush generally exceeds that of linear supplies and the current waveform is horrendous, I find we need to spec much bigger generators for SMPS amplifiers and provide a substantial fixed load than is ever needed for transformers/big capacitors amplifiers.

As I mentioned before at 2 events in mid 90's I rushed in to work to borrow PAM's when some well respected amplifiers [truly can't remember which] would not work, simply wouldn't power up. One on generator, the other on long cables [supplied by PA company].

The really annoying thing is they insisted on both occassions it was the first time it had ever happened.

 

I fully accept the reduction of power on lower volts and if too low the biasing is wrong and distortion becomes apparent but that is waaaaay down below 200V.

 

 

Good SMPS with PFC are the way to go on modern systems and are far kinder to generator / temporary power systems,

 

They aren't really very kind - they have a massive inrush when switched on. And in amps they are a very similar load to a conventional PSU which rectifies the mains and feeds big DC capacitors, so all the power is drawn at the peak of the mains cycle which is not a happy thing for a generator

A couple of years ago I helped with providing site tempories at an event, the stage PA system quoted as 6KW. We provided a 32A feed for the PA and a 16A for the backline from a 63A distro as the exclusive load on one phase of a 60KVA generator. They took out the 32A breaker twice when initially powering up and twice more during the event.

The rack was about 18-20U and maybe 8 1U amps. If it was 6KW it really shouldn't have tripped a 32 like that.

Edited December 2, 2020 by sunray

[Jivemaster]

Remember that a KW of amp will draw more at times and will draw a higher current at lower voltages leading to needing bigger wires and breakers.

[csg]

I can only go on my 30 years providing PA systems run on substantially temporary / generator based power systems. Early days were Crest P001 series ( mostly 8001's and 9001's), then moving to Lab Gruppen and more latterly Powersoft. The current models ( we are mostly X series based) have PSU's that will run on SPN+E, 2P+E or 3P+E with a very wide range of voltage acceptance without a loss of headroom on the audio side. We have FAR fewer issues with mains systems now then back in the Crest days of the 1990's - this may be in part due to better temporary supply design, but looking at metering on our racks inrush is a fraction of what it used to be, power factor and harmonics are also much reduced and general reliability is far improved. I certainly wouldn't wish to move back to linear PSU's, and being able to hang these large amplifiers ( 8 channels, 40Kw on a 12 dB crest factor) over 3 phases is a real advantage on larger systems, makes balancing much easier.

 

Im quite sure this is not likely the case with cheap and cheerful SMPS units, but that's not the fault of the technology, just poor design.

 

The PAM's were mooted as a possible replacement to the crest amps. along with RAM audio from spain ( they sounded great as did the Ecler's, but were very prone to failure, worse than the PAM's) but in the field the Labs proved much more reliable - and to be fair the Ecler's were likely more suited to installation use.

Edited December 2, 2020 by csg

[DrV]

Good SMPS with PFC are the way to go on modern systems and are far kinder to generator / temporary power systems,

 

They aren't really very kind - they have a massive inrush when switched on. And in amps they are a very similar load to a conventional PSU which rectifies the mains and feeds big DC capacitors, so all the power is drawn at the peak of the mains cycle which is not a happy thing for a generator

Tim, I'm intrigued by the second assertion here. Surely the point of a properly designed PFC circuit (I'm talking about the type which is essentially a boost converter, not just a cap across an inductive load) is that it draws more current at the lower part of the input waveform and less at the peak. This being done by altering the mark/space ratio of the high frequency switching waveform in sync with the a.c. Can't argue with the first one of course, unless there's an active surge limiter in the way.

Dave

[sunray]

I can only go on my 30 years providing PA systems run on substantially temporary / generator based power systems. Early days were Crest P001 series ( mostly 8001's and 9001's), then moving to Lab Gruppen and more latterly Powersoft. The current models ( we are mostly X series based) have PSU's that will run on SPN+E, 2P+E or 3P+E with a very wide range of voltage acceptance without a loss of headroom on the audio side. We have FAR fewer issues with mains systems now then back in the Crest days of the 1990's - this may be in part due to better temporary supply design, but looking at metering on our racks inrush is a fraction of what it used to be, power factor and harmonics are also much reduced and general reliability is far improved. I certainly wouldn't wish to move back to linear PSU's, and being able to hang these large amplifiers ( 8 channels, 40Kw on a 12 dB crest factor) over 3 phases is a real advantage on larger systems, makes balancing much easier.

 

Im quite sure this is not likely the case with cheap and cheerful SMPS units, but that's not the fault of the technology, just poor design.

 

The PAM's were mooted as a possible replacement to the crest amps. along with RAM audio from spain ( they sounded great as did the Ecler's, but were very prone to failure, worse than the PAM's) but in the field the Labs proved much more reliable - and to be fair the Ecler's were likely more suited to installation use.

I can't dispute any of your experience, other than in my very limited experience I've found the opposite is true. To put this into perspective my typical systems are village/school fetes and auction/conferences sort of work. However being a one man band I find I get to work with others in the same boat, just like any other SE subby.

My experience in big music systems is limited to:

1 year of nightclubs 1995 during which time we installed many hundreds of Eclar and serviced many more,

 

assisting at a couple outdoor events a year since then, although it's varied considerably over the years the main aspects of these two events I assist with is temp power, assisting the bands on and off the stage and micing up.

So no I'm not the expert with big portable systems but I've dealt with getting a number of them up and running and interfacing with the main PA for the event etc.

 

Yes I agree the PAM series did lend themselves to fixed systems as they required 4U [although I always disputed the benefit of (and proved wrong!) a vent panel for each one] and the shape and lack of rear mounts made mobile mounting difficult. And of course the weight.

But the funny thing I have noticed is the S/H linear powered amps have always seemed to hold their price better than SMPS types.

 

I'm sure it seems like it but I'm really not knocking either style, I have a selection of SMPS's used for a range of applications and love them and generally agree with the advantages mentioned above.

 

[gyro_gearloose]

Just wanted to add what little experience I've had with Powersoft amps.

 

A few years ago I was helping a friend service a local clubs sound system. They had a 1U/4 channel Powersoft amp (can't remember the model) that wasn't working, so we took it to a local electronics engineer who we've used for years to repair other amps. It turned out that the capacitors Powersoft used were custom items which our engineer couldn't find suitable replacements for. I don't know if that issue still persists with newer Powersoft amps, or if its just limited to their 1U amps.