Thurbs Posted July 31, 2011 Share Posted July 31, 2011 Hi all. I did a gig yesterday and I had a serious problem with my Peavey IPR 1600. My pedal board has 2 DI outs so one goes to the PA and the other goes to the Peavey and I use it to drive a BFB Midget-T for on stage monitoring mainly for the drummer. We did the gig on the back of a trailer running extension leads over from a nearby shed. This meant there was extension lead off extension lead and so on. The problem was there was nothing coming out of the amp at all. From full volume to quiet as a mouse there was no output (the lights were on).. Just before I left it worked and when I got home it worked, so my only conclusion is that there was something amiss with the power causing it not to work. Incidently, the band's bass player after us plugged in his Ashdown ABM EVO III 500 and it worked perfectly, as did the PA (not class D amps) and valve driven Blackstar & Marshall guitar rigs. Is there an inherent issue with Class D power? Is it just a Peavey issue? Anyone care to speculate what the issue was? Quote Link to comment Share on other sites More sharing options...
chrisd24 Posted July 31, 2011 Share Posted July 31, 2011 We tried to buy a pv ipr amp last year but the guy in shop told us they weren't making the big ones anymore as there es a manufacturing issue,can't recall the details but you might want to look into it. Quote Link to comment Share on other sites More sharing options...
franzbassist Posted July 31, 2011 Share Posted July 31, 2011 If it worked fine before and after, I'd assume it was the quality of the supply from the shed via the extension leads, rather than the amp itself. Quote Link to comment Share on other sites More sharing options...
guildbass Posted July 31, 2011 Share Posted July 31, 2011 [quote name='walbassist' post='1321983' date='Jul 31 2011, 10:16 AM']If it worked fine before and after, I'd assume it was the quality of the supply from the shed via the extension leads, rather than the amp itself.[/quote] Almost certainly a voltage drop issue on the supply. You can easily lose 40 volts down several cheap extension leads and the shed will have been fed from a house as well... Could have been more than 100 feet of thin supply cable... These switching amps use the input voltage level and chop it up to get the output... Like a switch mode power supply... That's why they weigh bugger all...No transformers... If the Input is low or drops significantly under load, they don't run well. They also pull a chunk of current to fire up if I recall... So if THAT demand squashed the supply even more, the amp would never have kicked on... What you could do next time is put a multimeter on the supply and see what it says... Your amp might have a switchable input level...240, 220.110... 220 would work... Jon Quote Link to comment Share on other sites More sharing options...
stingrayPete1977 Posted July 31, 2011 Share Posted July 31, 2011 [quote name='guildbass' post='1322001' date='Jul 31 2011, 10:52 AM']Almost certainly a voltage drop issue on the supply. You can easily lose 40 volts down several cheap extension leads and the shed will have been fed from a house as well... Could have been more than 100 feet of thin supply cable... These switching amps use the input voltage level and chop it up to get the output... Like a switch mode power supply... That's why they weigh bugger all...No transformers... If the Input is low or drops significantly under load, they don't run well. They also pull a chunk of current to fire up if I recall... So if THAT demand squashed the supply even more, the amp would never have kicked on... What you could do next time is put a multimeter on the supply and see what it says... Your amp might have a switchable input level...240, 220.110... 220 would work... Jon[/quote] I seriously doubt this guys as most if not all class D amps will happily run on 120v Dodgy lead or socket on the amp is far more likely, Often the sockets on extension reels can be iffy too so without trying the same lead from the same ext reel it's hard to say. Quote Link to comment Share on other sites More sharing options...
stingrayPete1977 Posted July 31, 2011 Share Posted July 31, 2011 Then again the lights were on?....still sounds more like a dodgy signal or something, is there a DI out of the peavey if so was that working? If it were mine I would still be double checking all my leads jacks and power cables before the next gig. Give everything a really good wiggle. I had the same fault which turned out to be a cheap Chinese made speakon plug on the speaker to head lead. OBBM one fixed it 110% Quote Link to comment Share on other sites More sharing options...
Thurbs Posted August 1, 2011 Author Share Posted August 1, 2011 Hi all, thanks for the replies. To clear up a couple of things... I tried plugging in to 3 separate extension leads. I changed every lead with a replacement. I tried changing every wire between the guitar and the amp, including plugging the guitar direct in to the amp. I put the guitar through a EQ with a meter which showed good signal going to the amp. It all worked perfectly before and after at home with the same leads. At the time I had the theory that it was the power supply effecting the amp also. Assuming this is the case, are all class D amps so sensitive? Quote Link to comment Share on other sites More sharing options...
alexclaber Posted August 1, 2011 Share Posted August 1, 2011 Sounds like an under-voltage issue due to the chained extension leads. Approximately how long was the total run of leads between mains sockets and power amp? Quote Link to comment Share on other sites More sharing options...
BigRedX Posted August 1, 2011 Share Posted August 1, 2011 From what I can tell from the PDF manual I found on line the PSU is not universal and this unit is sold in separate 120 and 240 volt versions depending on the territory. What does it say on the back panel of your amp below the mains socket? Quote Link to comment Share on other sites More sharing options...
Thurbs Posted August 1, 2011 Author Share Posted August 1, 2011 Cable run was probably 25 to 30 meters. Off of the single cable was: - 60w Blackstar 4x12 rig - 30w Blackstar 3x12 rig - Marshall 4x12 rig - 3Kw Pa with 4 tops & 2 subs - 4 pedal boards - Other things like wireless IEM & guitar stuff - My non functioning amp! Back of the amp says 220-240v 50/60hz 550 watts. There is no switch but there is a 4amp trip. Quote Link to comment Share on other sites More sharing options...
Adrenochrome Posted August 1, 2011 Share Posted August 1, 2011 Had similar problems with guitarists running Line6 amps from a generator that wasn't producing enough voltage at a bike rally. I don't know if the amps had class D power supplies but they switched off almost immediately, and worked fine from mains electric. Quote Link to comment Share on other sites More sharing options...
alexclaber Posted August 1, 2011 Share Posted August 1, 2011 It does sound like there isn't enough power (low voltage caused by the current draw down a long cable or even current supply issues) for the main SMPS to start up - there's usually a small power supply that powers up first and then regulates the powering up of the main SMPS. The 4A trip will be a slow blow to avoid problems from switching on or transients. Not much you can do other than bring a huge heavy gauge extension lead with you! Quote Link to comment Share on other sites More sharing options...
baixo Posted August 1, 2011 Share Posted August 1, 2011 I had a the same problem recently with my Orange Bass Terror amp!!! It was local festival and the organisers where let down by Southern Electric and had to resort to generators. The guitarist H&K tube head would not work either! We lost 15 minutes of our 45 minute set, very frustrating..... Quote Link to comment Share on other sites More sharing options...
stingrayPete1977 Posted August 1, 2011 Share Posted August 1, 2011 (edited) Thats the first make of class D amp anyone has mentioned on BC as not being able to run on 120v. So they do exist maybe its a bit of an old circuit compared to most then? Makes sense about the volt drop in that case. For future ref then there are UK voltage only class D heads out there which has come up concerning importing cheap amps from the states where general opinion here was that all SMPS class D heads would be fine and only SS or Valve amps needing confirmation before shelling out any cash, Turns out not to be true. The good old shuttle has run fine on 2 30M extension reels end to end and off various generators without any trouble Edited August 1, 2011 by stingrayPete1977 Quote Link to comment Share on other sites More sharing options...
BigRedX Posted August 1, 2011 Share Posted August 1, 2011 Peavey were one of the first mainstream manufacturers to offer high output low weight digital amplifiers. I can remember seeing them in the early 90s. The OP says that the lights on the amp came on so maybe there are two PSUs - one for some analogue circuits including the status lights and one for the actual class D amp? Quote Link to comment Share on other sites More sharing options...
stingrayPete1977 Posted August 1, 2011 Share Posted August 1, 2011 [quote name='BigRedX' post='1323391' date='Aug 1 2011, 06:53 PM']Peavey were one of the first mainstream manufacturers to offer high output low weight digital amplifiers. I can remember seeing them in the early 90s. The OP says that the lights on the amp came on so maybe there are two PSUs - one for some analogue circuits including the status lights and one for the actual class D amp?[/quote] Maybe, Its a bit of a worry if another outdoor gig comes up thats for sure. Quote Link to comment Share on other sites More sharing options...
LawrenceH Posted August 1, 2011 Share Posted August 1, 2011 [quote name='stingrayPete1977' post='1323360' date='Aug 1 2011, 06:29 PM']Thats the first make of class D amp anyone has mentioned on BC as not being able to run on 120v.[/quote] Not exactly, the Markbass F1 requires a jumper (and fuse of course) switching round when changing between 240 and 120v Quote Link to comment Share on other sites More sharing options...
stingrayPete1977 Posted August 1, 2011 Share Posted August 1, 2011 [quote name='LawrenceH' post='1323435' date='Aug 1 2011, 07:59 PM']Not exactly, the Markbass F1 requires a jumper (and fuse of course) switching round when changing between 240 and 120v[/quote] But it can be done. TC win with automatic matching to input voltage, Very good. Quote Link to comment Share on other sites More sharing options...
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