1. avatar Eamonn BASIC
    Anyone using laptops live might have found the same problem as me: a nasty buzz through the whole PA when connected to the mains, which disappears when the computer is unplugged to run on battery. It permeates the system whether the computer channel is turned up on the mixer or not, so an external soundcard won't solve this.

    My battery is currently knackered and dies after about 5 minutes, so it seems to be:

    1. Put up with the buzz (no)
    2. Buy a new battery and trust it to last the guts of an hour, while powering usb hardware, high processor plug-ins and the realtime manipulation of soft synths (no thanks if possible)
    3. Find some magical way of running it off the mains without generating a subdued hairdrier effect (yes please)

    I'm off to do some Googling on the subject, but thought I'd check in here first.

    Thanks! Edited by: Eamonn BASIC at: 3/12/03 4:22 pm
  2. avatar Eamonn BASIC
    Please be patient, I'm genuinely ignorant when it comes to electricals: but what is a power conditioner? and if you reckon a UPS can help (cool - cheaper than a £100+ battery I take it?), what is the exact nature of the problem?

    Needless to say, when I went to Micron (geographically convenient) to ask advice, they answered me in yes/no/dunno grunts, with a mixed expression of pity and contempt... and I expect from experience that PC World will be a similar barrel of laughs, only they seem to want custom. Edited by: Eamonn BASIC at: 3/12/03 5:33 pm
  3. avatar Pete
    Right, well the noise will probably stem from an unclean power supply in the venues. Due to bad earth, constant fluctations in voltage, surges in power, electromagnetic radiation, power harmonic spikes and all sorts of weird and wonderful power phenomena. So the power supply itself has a "noise" inherent in it. This is often made 10 times worse when lighting rigs are run off the same power supply.

    Computers are especially vunerable to poor power supplies and its a common source of headache in studios and all sorts of labs.

    Power Conditioners will take the power source and smooth the whole thing out, like a combined compressor and noise reduction for electrcitiy. They'll limit any surges as well, there for protecting your gear from being fried. They range in quality, power rating... and therefore price.

    A UPS (uninterruptable power supply) is like a big battery constantly on the charge. It will act as a surge protector and has the advantage that if power is for some reason cut then it switches to be a battery source, so your computer won't instantly shut down and potentially damage itself.

    There are some UPS which have conditioning built in (or conditioners with UPS built in.... chicken or egg??)

    Furman make power conditioners that seem to be heavily recommended by a lot of live engineers... [url="http://www.furmansound.com/pro/pwr_cond_seq/"]Stuff like this[/url]

    A UPS may be slightly cheaper, but I reckon a conditioner is a way forward... if you get one with a big enough power rating then everyone in the band can be put through the one conditioner.

    Digital Village have [url="http://www.dv247.com/invt/10968"] an eight way Furman one...[/url] its on our shopping list for our keyboard rack after we've had our leslie cab blown twice and our rack mounted PC keeps crashing because of unsteady power. Edited by: morphsville at: 3/12/03 6:02 pm
  4. avatar Pete
    Buy a power conditioner or UPS??
  5. avatar Eamonn BASIC
    Wow... amazing the stuff I didn't used to know I needed. I think that big fella is out of my price league, but I'll phone about. Much appreciated!
  6. avatar feline1
    Morphsville, I don't wish to "pooh pooh" ewer sage advice on mains conditioning (which is perfectly valid in and of itself),
    but Eamonn's prob sounds much more like the clawwsick Earth Loop to me..... passing his laptop's audio output through a DI box with the "earth lift" button engaged should surely cure matters.

    Meanwhile, I'd advise all readers and power-conditioning fetishists to consult [url]http://www.russandrews.com[/url] without further delay.
    Their helically-woven mains cables do *wonders* for keeping your fields orthogonal.... :-)
  7. avatar Pete
    I suppose the earth lift might have some effect, but I do remember seeing another band have similar problems one time and the earth lift didn't really help... I had assumed that the lovely person dealing with sound on the night had tried that.

    On another note.. do you reckon that [url="http://www.russandrews.com/product.asp?lookup=1&region=UK&currency=GBP&pf_id=1403&customer_id=PAA0694126803826DUOFWVWDXPFTINJT"]these things[/url] actually work? Might be a worth while investment for anyone with a situation where their hi-fi/studio monitors are surrounded by loads of other electrical gubbins...
  8. avatar feline1
    Auch, I bought a Silencer myself for £45 or sthg,
    and have never noticed *ANY* difference whatsoever!

    I have bought LOADS of their helically woven RFI-cancelling "Yello" mains cables and 6-way strips, and I find they give a *noticeable* improvement - my metal werker pedal's background noise is no longer louder than the actual audio signal, my clavinet no longer picks up Delia Smith and Leslie Crowther, and even feline2's Laney keyboard amp sounded better.....

    It all depends where your pollution is coming from, y'see - some fixes may be unnesscessary
  9. avatar numbnut31
    i'd say dont use a laptop live - not the most reliable.

    And you may as well just put a CD on - i know you can use various programs for "on the fly" novelties - but there is nothing else LESS inspiring than somebody on stage with a laptop.
  10. avatar Pete
    How many people have you seen use laptops live then?
  11. avatar numbnut31
    OK - i realise there will be exceptions (i think you guys use em live).

    Generally Laptop musicians are 1/2 guys and a laptop - and thats it!

    What i was getting at is that its difficult integrating a laptop into a "proper" live setup (ie extra musicians...drummers in particular) due to unreliability etc

    Using an MPC for example is much much better as they are dedicated Live equipment.

    I wasnt being confrontational - just speaking from experience
  12. avatar Pete
    We don't actually, we have a rackmounted computer and monitor, but we very rarely use it in a live situation at the minute.

    It depends what you want to do with the computer. We use it as a softsynth and as a sampler/fx processor but until we can get a proper midi control surface it's too fiddly live.

    Basic are one band that integrate sequenced stuff into a "proper" live setup. I suppose it's made easier by having no live drummer (and therefore no click) but they put on a fantastic show.

    I do know what you mean about laptop only shows though, I saw FourTet support Radiohead and while the music was great there was just no atmosphere to a bloke with an afro hunched over two laptops on a huge stage.
  13. avatar EPK
    Oh, I dunno..I've heard Iso 9 not only do wonderful things live with a laptop, but also mangling a DJ set with same and a few MIDI controllers.
  14. avatar feline1
    Yeah but on the other hand, I've seen bloody DOZENs of bands "play" live with laptops, and they were generally all rather dull. Including Kraftwerk (not that this has stopped me buying a ticket to see them again this March, mind ewe... :-)

    The only person who I really have enjoyed with a laptop was DJ Shïtmat here in Brighton - he's a real quickspoon.
  15. avatar EPK
    Aye..but they've been dull for twenty-five years now...like, how much time can you give someone, even out of kindness?
  16. avatar feline1
    Well the good thing about a Kraftwerk gig is that you can watch the amazing visuals or have a wee dance as well.

    But mostly I just sit glued watching Florian Schneider to see if he ever looks up.... :-)
  17. avatar RosettaBelfast
    You need a ground loop isolator.......

    Nuthin to do with bad electrics. Its like a kind of mains feed back (a form of Electro Magnetic Compatability).

    I use two Laptops in The Rosie both different, both needing the isolator.

    These can be found in Car Stereo suppliers.
    Maplin should help.

    You connect it in line with your RCA cable. They cost about a fiver.

    Though I could send you a diagram and you could make one.

    Some Di boxes do this with the ground lift OFF.... Go for a stage line cheap as chips £20. But you will need two for stereo.
  18. avatar feline1
    That's what I said in the first place!!

    But I wouldn't advise using the cheapeast DI box you can find, as it will just have a crap passive transformer and be designed for geetars or summat.
    If you wish to pass thru the full 20Hz - 20kHz glory of your laptop's output with maximum fidelity of phatness and freshness, I'd suggest getting a pleasing mains-powered active DI rackmount thing (eg like Behringer's 4-way one) which will be splendid have wee lights on it and everything.
  19. avatar Pete
    Yeah, but eamonn had said that the sound guy at the gig in question had tried groundlift on the DIs and it made sod all difference.
  20. avatar RosettaBelfast
    Some Di boxes with the groundlift switched OFF will do the trick. Groundlift is used for a completley different beast altogether.

    It is to do with the Choking of Magnetic Compat not Mains Compat.

    I would often use this approach but use a couple of dedicated isolators from an old car stereo install.

    Passive DI's are more likely to do this for you but if you switch the ground lift ON it will return.

    The laptop isn't grounded only the mains adapter.
  21. avatar Pete
    But i I remember correctly, Eamonn said the engineer at the time had tried different DIs with different configurations (lift on and off) and nothing made a difference.... its actually a problem that a lot of people have reported over at the Sound on Sound forum.
  22. avatar RosettaBelfast
    Not all DI boxes work for this you need a dedicated isolator in the signal line....

    The reason not all Di boxes work is to do with the way they "Balance the signal" cos that is what a di box is for. The Groundlift is for correcting problems with different Earthing points.

    It is because the laptop is not earthed.

    We use 2 laptops in the
    Rosie. Same problem.

    An Archer Realistic (Tandy) Car stereo ground loop isolator currently works for me as does a passive "stageline" Di Box with the ground lift OFF the Bheringer Active does not work at all.
  23. avatar feline1
    Arfle barfle gloop?!?

    Sometimes even invoking a ground-lift with a DI box won't deliver the goods cos the ground path is still getting connected via other leads of cos the cable screen of the XLR lead has been connected to the shell of the XLR plug or whatever fiendish other thing has happened etc etc etc it's rather difficult to know without actually being there with a multimeter and examinging the laptop in question and how it's being wired up.
  24. avatar What About Octo
    My first post!
    Performing with laptops is hit or miss:
    Aphex Twin (Boring visually, but supposed to b in anti roc way)
    Manitoba and Capitol
    (managed to be
    visually and sonically interesting).
    and two bands I saw while ago, Clone quartet (musically, made you forget about any visual aspect).
    The blac Supremos (unpredictable nd more exciting live than some roc band)

    As for your problem, go with the groundlift as said or try different power outlet than the rest of your equipt. (not always poss. tho) specific to laptop. Edited by: What About Octo at: 26/1/04 2:57 am
  25. avatar Eamonn BASIC
    Aye, typically me, I forgot about this thread and wandered off after the event. Turns out I bought a Soundblaster USB Audigy NX a few days before the gig, and whether that solved it or the hum just didn't arise in the Mandela will remain a mystery for now. I'll tell youse if it happens anywhere else. But I have this accursed laptop with a very strange power configuration whose AC mains won't power it unless the battery is installed and has some life in it. Surely not a great machine for live work.

    Also, thanks for the "give up" advice, whoever it was up there, but I have no intention of standing on my own with a laptop onstage [i]ever[/i] unless it's part of a satirical revue, as I just can't pull a serious enough face to let on I'd need to be there at all. I've turned down a lot of gigs for this reason, and in fact I've pretty much stopped being asked. There just isn't enough interactive functionality available to a laptop to [i]not[/i] be miming a vast amount of the set, or risking severe memory fck-ups by playing about switching loops on and off in real time on something as variably realiable as Fruity Loops or similar.

    All of which all applies, I hasten to add, to my own habits in making music, it's not an automatic judgement in the least on anyone else who does choose to do it solo, and when I encounter such an artist I always give them the benefit of the doubt. But I will admit I've also often find it a kind of dull, uncomfortably "private" thing to watch where the guy behind looks like he'd have prefered to send the performance from his bedroom (the worst laptop performance I ever saw was whoever supported Sigur Ros in The Empire - insufferable. The best was Antipop Consortium).

    So it's soft synths, samples, sequences and only being usually a quarter of the band for me.