Amazoman Posted December 25, 2011 Share Posted December 25, 2011 I have just bought an Orange AD200, used. When it was demoed it sounded great and I know that I am going to be really pleased with it. After putting it in place I got set up for a session. It was great to start with but after about half an hour it started to make a sound like a raging thunderstorm. One of the valves was flashing like lightning and after about 20 seconds a safety fuse and a HT fuse blew. So two questions: Is it possible to simply remove the offending tube until I can get a replacement or will that render the amp unusable. I am only talking about bedroom practice at low volumes. Does anyone know where I can get the amp serviced around the Nottingham, Derby, Chesterfield Mansfield areas. I know that Champ Electronics is highly recommended on the net but his website says that he is not taking any calls or emails at the moment and I can't find anywhere else. Before anyone says 'Take it back' which is exactly what the wife said I know for definite that the person I bought it from would have no idea about this and he will have sold it in good faith. I am putting it down to a bit of bad luck!. Quote Link to comment Share on other sites More sharing options...
Blademan_98 Posted December 25, 2011 Share Posted December 25, 2011 (edited) If you can't get a replacement in the short term, then Watford valves are a good to deal with (IMHO). [url="http://www.watfordvalves.com/product_detail.asp?id=2236"]http://www.watfordva...ail.asp?id=2236[/url] The link is for the full kit to suit the AD200. I do think you should replace the lot (I would). Edited December 25, 2011 by Blademan_98 Quote Link to comment Share on other sites More sharing options...
Mr. Foxen Posted December 25, 2011 Share Posted December 25, 2011 Really should have to replace the lot, but should be done by a tech that can sort the bias. Plenty of valves are duff form new these days. If you have just bought it, get it fixed under warranty. Or return it and get a Matamp and you'll have less chance of this sort of trouble. Fair chance the dead tube will have taken out some other things with it, so that will need sorting before you are good to go again. Quote Link to comment Share on other sites More sharing options...
icastle Posted December 25, 2011 Share Posted December 25, 2011 (edited) In answer to the first part of your question, no. The valves in the power amp stage are designed to work together - it'd be a bit like taking a wheel off your car and expecting to be able to use it still. To echo previous posts, if you have had a valve go then it makes good sense to replace all of them as the chances are that if one valve has blown then the others will not be far behind it... Edited December 25, 2011 by icastle Quote Link to comment Share on other sites More sharing options...
Mr. Foxen Posted December 25, 2011 Share Posted December 25, 2011 If its new, the valve will have died from a manufacturing flaw, rather than general wear, so not unlikely the others are fine. Not sure how the bias is set up in that amp, if you can bias them individually, won't even need a matched set. Components associated with the valve are the more likely thing to have damage. Quote Link to comment Share on other sites More sharing options...
pete.young Posted December 25, 2011 Share Posted December 25, 2011 Check out the 'Recommended Amp Techs' thread from the Repairs forum for recommended techs in your area. Personally I'd take it to Dave Lunt in Stockport, but I don't know the area . http://basschat.co.uk/topic/198-recommended-amp-techs/ Quote Link to comment Share on other sites More sharing options...
Amazoman Posted December 25, 2011 Author Share Posted December 25, 2011 Thanks for the comments so far. The amp was not new as stated in the OP so swapping it is not an option. As you will probably have already gathered my experience and knowledge of valves is nil. If I were to go for the Watford electronics set(thanks for the link Blademan) which are advertised as a matched set. Is it simply a case of swapping all the valves over or do they still need biasing by someone who knows how to do this? The duff valve doesn't appear to have blown. It still glows and flashes blue. It is only the fuses that blew. I have taken it out ,cleaned the contacts and put it back but this didn't achieve anything. Thanks for the Stockport contact I may venture up there if I can't find anyone around the Nottingham area. Quote Link to comment Share on other sites More sharing options...
clarkpegasus4001 Posted December 25, 2011 Share Posted December 25, 2011 I would get in touch with Champ amps if I were you regardless of what it say's on his site as the site does not get updated like it should. I can highly recommend John (Chambers) he has done some great work for me in the past, he lives locally to me. Quote Link to comment Share on other sites More sharing options...
Blademan_98 Posted December 25, 2011 Share Posted December 25, 2011 (edited) [attachment=95791:Valve Warning.png] According to the Orange web site, when revalving there may be a need to re-bias. Also advises it should be done by a qualified technician. If you are unsure, chat to chaps at Watford Valves. My advice would be to get the valves fitted by a tech. Edited December 25, 2011 by Blademan_98 Quote Link to comment Share on other sites More sharing options...
Mr. Foxen Posted December 25, 2011 Share Posted December 25, 2011 [quote name='Amazoman' timestamp='1324843222' post='1478083'] The duff valve doesn't appear to have blown. It still glows and flashes blue. It is only the fuses that blew. I have taken it out ,cleaned the contacts and put it back but this didn't achieve anything. [/quote] This is classic signs of a dead valve. It can be pretty harmful to the rest of the amp to keep trying to use it, the fuse is there to cut power before damage occurs, but they aren't always fast enough. Quote Link to comment Share on other sites More sharing options...
Big_Stu Posted December 25, 2011 Share Posted December 25, 2011 [quote name='Mr. Foxen' timestamp='1324845664' post='1478099'] This is classic signs of a dead valve. It can be pretty harmful to the rest of the amp to keep trying to use it, the fuse is there to cut power before damage occurs, but they aren't always fast enough. [/quote] Heartily agree with this; it's asking for serious trouble. Any S/H valve amp should always be thoroughly checked out by a qualified tech, unless you know the seller well - and heard the amp going for quite a while - & even then it's no guarantee. As already said - check out the "Recommended amp techs" thread. Quote Link to comment Share on other sites More sharing options...
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