stewblack Posted November 22, 2019 Share Posted November 22, 2019 Got a technical question. Quote Link to comment Share on other sites More sharing options...
stewblack Posted November 23, 2019 Author Share Posted November 23, 2019 @Ashdown Engineering tried contacting you but it wouldn't let me kept saying serial number must be less than 0. I'm not very good with numbers but my serial appears to have 4 of them (might be 3 can't quite be sure if the first digit is a 0 or a 6) and so these always add up to more than 0! Quote Link to comment Share on other sites More sharing options...
Ashdown Engineering Posted November 23, 2019 Share Posted November 23, 2019 If you just email [email protected] you should be able to get in touch... cheers 1 Quote Link to comment Share on other sites More sharing options...
stewblack Posted November 23, 2019 Author Share Posted November 23, 2019 3 hours ago, Ashdown Engineering said: If you just email [email protected] you should be able to get in touch... cheers Thank you kindly Quote Link to comment Share on other sites More sharing options...
stewblack Posted November 23, 2019 Author Share Posted November 23, 2019 😔 Quote Link to comment Share on other sites More sharing options...
Ashdown Engineering Posted November 23, 2019 Share Posted November 23, 2019 Weird... will get that looked into. In the meantime try [email protected] 1 Quote Link to comment Share on other sites More sharing options...
Quilly Posted December 7, 2019 Share Posted December 7, 2019 Yep...what’s the question? Quote Link to comment Share on other sites More sharing options...
stewblack Posted December 7, 2019 Author Share Posted December 7, 2019 52 minutes ago, Quilly said: Yep...what’s the question? Well, I was experiencing a nasty crackly noise and could not bias one of the valves. I wanted to know if I was doing any thing wrong with the biasing mainly. Good sense has since prevailed and our man @basstone has the amp on his repair shop. I didn't really want to dabble in there! He can explain what was wrong better than I can. 1 Quote Link to comment Share on other sites More sharing options...
Quilly Posted December 7, 2019 Share Posted December 7, 2019 54 minutes ago, stewblack said: Well, I was experiencing a nasty crackly noise and could not bias one of the valves. I wanted to know if I was doing any thing wrong with the biasing mainly. Good sense has since prevailed and our man @basstone has the amp on his repair shop. I didn't really want to dabble in there! He can explain what was wrong better than I can. I was going to suggest a new set of power valves but yes you probably made the best decision to get it looked at professionally. 1 Quote Link to comment Share on other sites More sharing options...
Woodinblack Posted December 7, 2019 Share Posted December 7, 2019 On 23/11/2019 at 10:26, stewblack said: @Ashdown Engineering tried contacting you but it wouldn't let me kept saying serial number must be less than 0. I'm not very good with numbers but my serial appears to have 4 of them (might be 3 can't quite be sure if the first digit is a 0 or a 6) and so these always add up to more than 0! Your lucky, my serial number only has 1 digit 1 Quote Link to comment Share on other sites More sharing options...
basstone Posted December 10, 2019 Share Posted December 10, 2019 On 23/11/2019 at 10:26, stewblack said: @Ashdown Engineering tried contacting you but it wouldn't let me kept saying serial number must be less than 0. I'm not very good with numbers but my serial appears to have 4 of them (might be 3 can't quite be sure if the first digit is a 0 or a 6) and so these always add up to more than 0! Yes, I had exactly the same problem. I even tried negative numbers and 0. nothing worked, so I phoned instead and spoke to a very helpful Dave Green. I think that the 4 digit CTM serial numbers relate to manufacturing sequence- first 2 digits, year of manufacture - third and fourth digit. Quote Link to comment Share on other sites More sharing options...
basstone Posted December 10, 2019 Share Posted December 10, 2019 On 07/12/2019 at 15:49, stewblack said: Well, I was experiencing a nasty crackly noise and could not bias one of the valves. I wanted to know if I was doing any thing wrong with the biasing mainly. Good sense has since prevailed and our man @basstone has the amp on his repair shop. I didn't really want to dabble in there! He can explain what was wrong better than I can. Yes it was faulty power valves. One eventually shorted completely and totally destroyed the protection fuse and its holder in the cathode circuit of the valve. There is a lot of stored energy in the HT power supply so thankfully the fuse did it's job and no other components were damaged. A new set of power valves, a new fuse holder and fuse and all up and running with the bias nice and steady on both valves. It's a nice touch on the CTM to use the VU meter to set the bias which can be done separately for each valve. 2 Quote Link to comment Share on other sites More sharing options...
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