Rumple Posted November 8, 2009 Share Posted November 8, 2009 (edited) I have an old 60's Selmer valve head that was given to me many years ago and I have never turned it on, I'm curious to see if it works but I seem to remember that it's not a good idea to turn valve amps on without having a speaker attached, is this correct? I only have my EBS cab and don't fancy plugging it into that. Any advise would be appreciated. R. [attachment=35961:PICT0018.JPG] [attachment=46620:PICT0023.JPG] [attachment=46619:PICT0021.JPG] Edited April 6, 2010 by Rumple Quote Link to comment Share on other sites More sharing options...
obbm Posted November 8, 2009 Share Posted November 8, 2009 Do not power it without a speaker attached. If you are unsure about it then take it to a responsible amp tech to have it checked over. or give it to me. Quote Link to comment Share on other sites More sharing options...
Rumple Posted November 8, 2009 Author Share Posted November 8, 2009 Nice try For the purpose of seeing if it powers up would any speaker be OK to use to create a load? Quote Link to comment Share on other sites More sharing options...
henry norton Posted November 8, 2009 Share Posted November 8, 2009 A 2" speaker from a portable radio probably won't do but if you've got a reasonably sized speaker you know the resistance of (probably a 4, 8 or 16 ohm), the power handling isn't such a big deal so long as you don't turn it right up. I used a 100 watt Marshall valve head into a pair of HI Fi speakers once, and it sounded pretty good! Valve amps are actually quite tough (electronically), but it won't have all the safety features you'd find in a modern transistor based amp and no, you should never start one up without a speaker loading. Quote Link to comment Share on other sites More sharing options...
Rumple Posted November 8, 2009 Author Share Posted November 8, 2009 Thanks for the advice, much appreciated. Weirdly I think it's seeing the words 'not suitable for bass' on the back that got me wanting to try it out Quote Link to comment Share on other sites More sharing options...
Mr. Foxen Posted November 8, 2009 Share Posted November 8, 2009 [quote name='Rumple' post='648681' date='Nov 8 2009, 12:05 PM']Thanks for the advice, much appreciated. Weirdly I think it's seeing the words 'not suitable for bass' on the back that got me wanting to try it out [/quote] You might get distortion, heaven forbid. Anyway, where are the gutshots? Quote Link to comment Share on other sites More sharing options...
Rumple Posted November 8, 2009 Author Share Posted November 8, 2009 [quote name='Mr. Foxen' post='648799' date='Nov 8 2009, 02:30 PM']You might get distortion, heaven forbid. Anyway, where are the gutshots?[/quote] It would be awful if it distorted in that warm and lush way valves tend to do when pushed Nicest amp I have used was back in the 80's when I borrowed our guitarists Sound City valve amp, lovely tone when the volume was on 10. Quote Link to comment Share on other sites More sharing options...
Rumple Posted April 6, 2010 Author Share Posted April 6, 2010 Some more advise/thoughts please folk. Finally got hold of an old speaker and wired this beasty up and it's really not very well! Only one of the two EL34's glow and only for a short while then the HT fuse blows, just before it goes there is sound (humming) from the speaker though. I guess my question is does this sound like a typical problem with a valve amp that could be cheaply repaired by someone who knows what they are doing or should I assume it's beyond repair? Cheers R. Quote Link to comment Share on other sites More sharing options...
Bloodaxe Posted April 6, 2010 Share Posted April 6, 2010 [quote name='Rumple' post='797619' date='Apr 6 2010, 02:54 PM']Some more advise/thoughts please folk. Finally got hold of an old speaker and wired this beasty up and it's really not very well! Only one of the two EL34's glow and only for a short while then the HT fuse blows, just before it goes there is sound (humming) from the speaker though. I guess my question is does this sound like a typical problem with a valve amp that could be cheaply repaired by someone who knows what they are doing or should I assume it's beyond repair? Cheers R.[/quote] [i][b]Nothing[/b][/i] is beyond repair, just depends how much ££ you're willing to throw at it. PM'd. Pete. Quote Link to comment Share on other sites More sharing options...
Rumple Posted April 6, 2010 Author Share Posted April 6, 2010 Added a couple more pics Bloodaxe Quote Link to comment Share on other sites More sharing options...
Ancient Mariner Posted April 7, 2010 Share Posted April 7, 2010 If it'll do that much then it's certainly repairable, and provided the tech is good it shouldn't be ridiculously expensive (probably need the caps replacing amongst other things). It probably warns against using it for bass because the output transformer can't cope, and while it'll give you that distortion for a while, you may find that one day it lets the magic smoke out. Quote Link to comment Share on other sites More sharing options...
Rumple Posted April 8, 2010 Author Share Posted April 8, 2010 It's good to hear that it's probably repairable. I have no idea what I would use it for, probably not a lot but I feel it needs to be revived. As it's meant for keyboards and has some buttons for Leslie effects etc. I was wonering if it would be best to have that section wired out. not sure if that's a simple thing or not. Thanks for the advise so far. R. Quote Link to comment Share on other sites More sharing options...
4 Strings Posted April 9, 2010 Share Posted April 9, 2010 These old Selmers are quite sought after, you could flog it and buy something you actually want. Its definitely worth fixing, this place would certainly enthusiastic about it [url="http://www.chambonino.com/"]http://www.chambonino.com/[/url] though I've never had cause to use them. If it was mine I'd like to see it fixed and try it to see if I would like it, if not, send it to a welcoming home. Quote Link to comment Share on other sites More sharing options...
Rumple Posted April 10, 2010 Author Share Posted April 10, 2010 Wise words and my thoughts exactly, I'll get it repaired, try it out with guitar and if I don't fall in love with the sound I'll think about selling it. Thanks for the link, I like the look of those all white heads and cabs their sister company make. Quote Link to comment Share on other sites More sharing options...
Mikey R Posted April 11, 2010 Share Posted April 11, 2010 [quote name='Ancient Mariner' post='799161' date='Apr 7 2010, 08:11 PM']It probably warns against using it for bass because the output transformer can't cope, and while it'll give you that distortion for a while, you may find that one day it lets the magic smoke out.[/quote] Hey, Ive just started looking at valve schematics, could you tell me a little more about the problems with output transformers and low frequencies? What causes the problem, primary or secondary, or does it do something to the power valves? Sorry for the stupid questions, Im just learning about these things! Quote Link to comment Share on other sites More sharing options...
Ancient Mariner Posted April 12, 2010 Share Posted April 12, 2010 I'm a little vague on it myself, but I believe that the lower frequencies of a bass stress the transformer more than the higher frequencies of a guitar. Producing bass frequencies requires much more power than higher frequencies. This become apparent when you play a guitar amp with a valve rectifier cranked hard: notes on the A and especially E string below the 8th fret tend to sag - dip in volume after the initial pluck and then gradually recover - because the rectifier and caps can't sustain the current required to power the note. Many guitar amps were built with expensive parts like OTs close to the edge of spec or even slightly undersized. Sometimes this was for tonal reasons (a smaller OT will saturate sooner, providing compression and distortion) but most often for financial reasons, just to keep costs down, and know most users would never run it flat out. Using this amp in anger with a bass could be just too much for the OT - the label may be there because they had a string of failures in just this situation. Quote Link to comment Share on other sites More sharing options...
Rumple Posted April 13, 2010 Author Share Posted April 13, 2010 Am I right in thinking then that it would be OK with bass at a low practice volume but not when pushed hard and the label is just Selmer covering their r's? it's a keyboard amp so it must have to handle a certain amount of bass notes. Quote Link to comment Share on other sites More sharing options...
umph Posted April 13, 2010 Share Posted April 13, 2010 [quote name='Rumple' post='805098' date='Apr 13 2010, 05:35 PM']Am I right in thinking then that it would be OK with bass at a low practice volume but not when pushed hard and the label is just Selmer covering their r's? it's a keyboard amp so it must have to handle a certain amount of bass notes.[/quote] transformers in that amp will be more than fine with bass and so will the rest of the components. Sounds like you've got a duff valve. My advice is get a new set of WELL matched valves stick them in it and pluck away since these amps have a set bias anyway so you can't adjust it. Quote Link to comment Share on other sites More sharing options...
Rumple Posted April 13, 2010 Author Share Posted April 13, 2010 [quote name='umph' post='805133' date='Apr 13 2010, 06:07 PM']transformers in that amp will be more than fine with bass and so will the rest of the components. Sounds like you've got a duff valve. My advice is get a new set of WELL matched valves stick them in it and pluck away since these amps have a set bias anyway so you can't adjust it.[/quote] Many thanks umph I'll give that a go, where would be a good place to get hold of a pair of matched valves? Watford Valves any good? Quote Link to comment Share on other sites More sharing options...
umph Posted April 13, 2010 Share Posted April 13, 2010 [quote name='Rumple' post='805304' date='Apr 13 2010, 08:21 PM']Many thanks umph I'll give that a go, where would be a good place to get hold of a pair of matched valves? Watford Valves any good?[/quote] i've no experience with them but i hear there quite good. I've always used Hotrox for valves and they've always been fairly decent and the chap that runs them is quite a nice guy. Quote Link to comment Share on other sites More sharing options...
Ancient Mariner Posted April 14, 2010 Share Posted April 14, 2010 Hotrox are probably cheaper than WV. You could also try Edicron. [url="http://www.edicron.com/"]http://www.edicron.com/[/url] Quote Link to comment Share on other sites More sharing options...
Rumple Posted June 19, 2010 Author Share Posted June 19, 2010 Well I'm back in Worcestershire home of the Selmar and have replaced the old valves with a pair of Electro Harmonix EL34's and this beast is alive again I have it hooked up to an old 8ohm B&O hi-fi speaker for testing purposes so can't give it a good test yet but it sounds ok. it's a bit smelly but I expect that's 30 years of dust burning off, next time I'm up here I'll bring a proper cab and my old Squier guitar and give it a good work out with a bass and a 6 string. Thanks to everyone who gave help an advice, I'll report back once it's been used a bit. R. [attachment=52612:PICT0002.JPG] [attachment=52613:PICT0004.JPG] Quote Link to comment Share on other sites More sharing options...
umph Posted June 19, 2010 Share Posted June 19, 2010 great to see it up and running again! Quote Link to comment Share on other sites More sharing options...
tino Posted June 19, 2010 Share Posted June 19, 2010 [quote name='Rumple' post='648618' date='Nov 8 2009, 12:00 PM']I have an old 60's Selmer valve head that was given to me many years ago and I have never turned it on, I'm curious to see if it works but I seem to remember that it's not a good idea to turn valve amps on without having a speaker attached, is this correct? I only have my EBS cab and don't fancy plugging it into that. Any advise would be appreciated. R. [attachment=35961:PICT0018.JPG] [attachment=46620:PICT0023.JPG] [attachment=46619:PICT0021.JPG][/quote] It aint gonna screw your speaker....but if AFFRAID sell it to me Quote Link to comment Share on other sites More sharing options...
geoffbyrne Posted June 19, 2010 Share Posted June 19, 2010 Dear God, Man - what's happened to that bass???!!! G. Quote Link to comment Share on other sites More sharing options...
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