Members Yan M Posted June 18, 2015 Members Share Posted June 18, 2015 ps:I should take the time to draw a schematic but i feel lazy facing the job(still no one available?) Link to comment Share on other sites More sharing options...
Members crsnot Posted June 18, 2015 Members Share Posted June 18, 2015 I have the schematic. I'll attach. Link to comment Share on other sites More sharing options...
Members crsnot Posted June 18, 2015 Members Share Posted June 18, 2015 I have schematic and can attach but I need to write something in the "reply box " and it won't let me type in there...I can only comment. I'll see if I can PM you it. Link to comment Share on other sites More sharing options...
Members Yan M Posted June 19, 2015 Members Share Posted June 19, 2015 Ok great...the best way is perhaps to give you my mail Link to comment Share on other sites More sharing options...
Members Yan M Posted June 20, 2015 Members Share Posted June 20, 2015 sorry :you already sent a post with schematic (old vintage 6L6 6 valves version)the 4 valves reissue schem is not yet available I think,but that will do... BTW your mod cure the remaining small hum(I had yet to reset my "virtual center tap pot "mod)it is now completely silent (apart from a very liht hiss,but as i said above,this can be seen as sort of "certificate of autheticity"! Link to comment Share on other sites More sharing options...
Members crsnot Posted June 21, 2015 Members Share Posted June 21, 2015 Hi Yan - I have emailed the schematic thru - it is the new version one. I got this from Gibson. Maybe you will be able to post it as I don't seem able to. Link to comment Share on other sites More sharing options...
Members Yan M Posted June 22, 2015 Members Share Posted June 22, 2015 thanks again for the schematic.Well indeed,it seems that theres an uploading problem. I'll try anaother way,stay tuned... Link to comment Share on other sites More sharing options...
Members crsnot Posted October 1, 2015 Members Share Posted October 1, 2015 Well I finished the mods by changing the speaker. I put a 1966 Cleveland alnico in. For Harmonica it's amazing. Huge breakup with a hint of natural reverb due to the time stack change. It's not as loud as most 18w amps maybe might be but I think it was probably more like 12w actually. Also running 2 Russian 6n6c tubes in it. Smoother more controllable into breakup for blues harp. You'd swear it was an old Masco amp type. Sounds as cool as it looks. Onto the next project now! Link to comment Share on other sites More sharing options...
Members Jeff Wewers Posted December 19, 2015 Members Share Posted December 19, 2015 Does anyone have of the resistor mod? I am electronicly challenged. I could follow a photo much easier than I could figure out how to " adding on each side of the end of the circuit(last 12AX7) black&white wires a pair of 100R resistor(2Wis a good value) connected to ground". In any case, which 12ax7 is the "end of the circuit"? Is there one black wire and one white wire attached to this tube socket? If more than one of either, which is the correct one to attach the resistor to? Where is a good place to ground the other end of the resistor(s)? Link to comment Share on other sites More sharing options...
Members hoglundtw Posted May 6, 2020 Members Share Posted May 6, 2020 Hi Yan M and crsnot (if you're still out there). Was reading this thread on fixing the hum on a Century Electar Anniversary reissue and wanted to ping you, since I'm tackling the same problem (60 cycle hum with nothing plugged into the amp and volume at 0). On page 2 of the thread you start talking about fixing the center tap issue and connector C32 and refer to a description and picture which is not in the thread. I think you went off into personal emails to get a schematic to each other and maybe some of that discussion happened there and not in the post. So if you can resurrect your thinking from 5 years ago, that would be great. I've rewired the heater wires the correct way on mine all the way from the circuit board to the power tubes to the 12ax7s and that didn't help a bit. Also tried the temporary test of grounding the end of the heater wire runs on the last 12AX7 with some alligator clips and 100 Ohm resistors and that doesn't help. Did chopsticks on all the connections. Although it would probably cause 120 cycle hum instead of 60 cycle, I also measured the capacitors and they're all over performing a bit (although one 47mF 500v is measuring over 100 mF on my Fluke meter). Don't think an over performing capacitor would cause the 60 cycle hum though. So looking for other ideas and wondering what you did on the center tap and C32? Also, did you find the schematic for this reissue? If so please post. Also, do you know whether this is a push-pull amp where the heater wires for the power tubes should be in phase with each other or a parallel amp where I should wire them out of phase? I did them in phase (i.e., white wire to the same pins in both power tubes) as that's the way the amp was originally wired. Link to comment Share on other sites More sharing options...
Members crsnot Posted May 6, 2020 Members Share Posted May 6, 2020 I'll send you a pm with my email so I can send you schematic and the photos of the rewire of ground wire that's most of the issue. I'm not sure about the phasing but definately need to twist their heater wires and run them around the socket and as far away as possible from the signal pin on the valve base to clean the hum. Link to comment Share on other sites More sharing options...
Members 1001gear Posted May 6, 2020 Members Share Posted May 6, 2020 A dIRECT HIT !!1!!1 Link to comment Share on other sites More sharing options...
Members Max plaza Posted June 3, 2020 Members Share Posted June 3, 2020 Who has the schematic that they can send me. Please. Thank you On 6/21/2015 at 7:53 PM, crsnot said: Hi Yan - I have emailed the schematic thru - it is the new version one. I got this from Gibson. Maybe you will be able to post it as I don't seem able to. Link to comment Share on other sites More sharing options...
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