Comments on: Re-tension Your Tube Sockets http://billmaudio.com/wp Small amps, big sound. Wed, 08 Sep 2010 00:19:31 -0400 hourly 1 http://wordpress.org/?v=3.0.1 By: John http://billmaudio.com/wp/?page_id=171&cpage=1#comment-9766 John Mon, 26 Jul 2010 21:16:22 +0000 http://billmaudio.com/wp/?page_id=171#comment-9766 +100 Tip: if you remove the chassis completely, take the tubes out first! As the last bottom chassis screw comes out, the speaker magnet grabs the chassis and slams the tubes against the speaker, if you're lucky, as I was, just bending the pins and loosening the tube sockets. All OK now! Another thing to look for with snap crackle and pop (and hum) is those pesky springs that hold on the aluminum heat sink/retainer for the power tubes. When I first bought the amp it hummed like crazy. There was a nice purple glow between one of the springs and the wall of the tube it was touching (couldn't really tell if the glow was inside or outside the tube). Replaced the output tubes and 'dressed' the spring, and now all is well, even with fat-bottle EH tubes. +100

Tip: if you remove the chassis completely, take the tubes out first! As the last bottom chassis screw comes out, the speaker magnet grabs the chassis and slams the tubes against the speaker, if you’re lucky, as I was, just bending the pins and loosening the tube sockets. All OK now!

Another thing to look for with snap crackle and pop (and hum) is those pesky springs that hold on the aluminum heat sink/retainer for the power tubes. When I first bought the amp it hummed like crazy. There was a nice purple glow between one of the springs and the wall of the tube it was touching (couldn’t really tell if the glow was inside or outside the tube). Replaced the output tubes and ‘dressed’ the spring, and now all is well, even with fat-bottle EH tubes.

]]> By: bill http://billmaudio.com/wp/?page_id=171&cpage=1#comment-9336 bill Sat, 17 Jul 2010 23:18:31 +0000 http://billmaudio.com/wp/?page_id=171#comment-9336 I really don't know if the socket springs in the ceramic sockets are any better than the standard sockets. And some of the ceramic sockets don't allow you to reach in with a screwdriver to retension the springs. I really don’t know if the socket springs in the ceramic sockets are any better than the standard sockets. And some of the ceramic sockets don’t allow you to reach in with a screwdriver to retension the springs.

]]> By: Rob Weathers http://billmaudio.com/wp/?page_id=171&cpage=1#comment-9274 Rob Weathers Fri, 16 Jul 2010 23:23:58 +0000 http://billmaudio.com/wp/?page_id=171#comment-9274 Hey Bill, I ordered the basic kit and T020 last week. I can't wait for them to arrive. I put in a nice set of NOS Sylvania JAN power tubes dated 1970 (green ink/ gray plate), for the 6BQ5 outputs and NOS Sylvania 12AX7 pre-amp tubes dated 1961,(green ink/ gray plate), the other night in anticipation of the mods and transformer. I turned on the amp and ...nothing. One of the 12AX7s felt really loose. Did a little reading on this website, re-tensioned all 5 sockets and voila, I'm back in business. Thank you so much for the tips! You taught me something and saved me some money. Thank you! I noticed that I can get pc board-mountable 9 pin sockets in ceramic on the web. Is there any value to this if one of the sockets eventually fails? The plastic base subjected to all of that heat has to be problematic over time. Also, they have octals in pc board-mountable ceramic as well. Can these be soldered into the tube board if you clearance the chassis metal instead of your new wires to board approach? Reason being that I think I would like to try 6V6s at some point. Thanks in advance. Best regards, Rob Weathers Hey Bill,

I ordered the basic kit and T020 last week. I can’t wait for them to arrive. I put in a nice set of NOS Sylvania JAN power tubes dated 1970 (green ink/ gray plate), for the 6BQ5 outputs and NOS Sylvania 12AX7 pre-amp tubes dated 1961,(green ink/ gray plate), the other night in anticipation of the mods and transformer. I turned on the amp and …nothing. One of the 12AX7s felt really loose. Did a little reading on this website, re-tensioned all 5 sockets and voila, I’m back in business. Thank you so much for the tips! You taught me something and saved me some money. Thank you!

I noticed that I can get pc board-mountable 9 pin sockets in ceramic on the web. Is there any value to this if one of the sockets eventually fails? The plastic base subjected to all of that heat has to be problematic over time. Also, they have octals in pc board-mountable ceramic as well. Can these be soldered into the tube board if you clearance the chassis metal instead of your new wires to board approach? Reason being that I think I would like to try 6V6s at some point. Thanks in advance.

Best regards,
Rob Weathers

]]> By: bill http://billmaudio.com/wp/?page_id=171&cpage=1#comment-3790 bill Sun, 07 Feb 2010 21:13:32 +0000 http://billmaudio.com/wp/?page_id=171#comment-3790 Right, Pin 6 is unused. So are pins 8 and 1. Right,

Pin 6 is unused. So are pins 8 and 1.

]]> By: Glenn http://billmaudio.com/wp/?page_id=171&cpage=1#comment-3761 Glenn Sat, 06 Feb 2010 23:15:42 +0000 http://billmaudio.com/wp/?page_id=171#comment-3761 Hi Bill. Just finishing up my mods, retentioning my tube sockets and inspecting solder joints. Sure enough V5 had a number of loose connections so I resoldered them. BUT... I noticed the pad of pin 6 raised from the board when the solder melted and figured I'd have to fix this one. Upon inspection it seems that pin 6 does not have a trace connected to it? I've been looking at Schematics on line but have not found a lay-out to check for use of this pin. V4 looks the same. Am I correct that it is not in use and I'm good to go? Thanks for all your help. Hi Bill. Just finishing up my mods, retentioning my tube sockets and inspecting solder joints. Sure enough V5 had a number of loose connections so I resoldered them. BUT… I noticed the pad of pin 6 raised from the board when the solder melted and figured I’d have to fix this one. Upon inspection it seems that pin 6 does not have a trace connected to it? I’ve been looking at Schematics on line but have not found a lay-out to check for use of this pin. V4 looks the same. Am I correct that it is not in use and I’m good to go? Thanks for all your help.

]]> By: bill http://billmaudio.com/wp/?page_id=171&cpage=1#comment-2151 bill Fri, 20 Nov 2009 15:09:15 +0000 http://billmaudio.com/wp/?page_id=171#comment-2151 Your problem may be bad solder joints on the sockets, not loose springs in the socket. To discharge the amp, just turn it off after you've been playing it. Leave the standby in "play" position and the amp will discharge itself. Unplug it. After that, you can work on it warm or cold. Your problem may be bad solder joints on the sockets, not loose springs in the socket.

To discharge the amp, just turn it off after you’ve been playing it. Leave the standby in “play” position and the amp will discharge itself. Unplug it. After that, you can work on it warm or cold.

]]> By: Jeff http://billmaudio.com/wp/?page_id=171&cpage=1#comment-2148 Jeff Fri, 20 Nov 2009 03:00:49 +0000 http://billmaudio.com/wp/?page_id=171#comment-2148 I am having the problem mentioned above. I have a Marshall jcm 900 running Groovetubes and the socket is loose. It runs about 10 minutes and goes quiet. If I press down the sound goes up again so I know its a loose socket. My question is should I re-tension the socket while it is "warm". I see you should do this after the amp discharges, so I'm wondering if thats what you mean. Basically work on it while its warm? Thanks and great forum. Jeff I am having the problem mentioned above. I have a Marshall jcm 900 running Groovetubes and the socket is loose. It runs about 10 minutes and goes quiet. If I press down the sound goes up again so I know its a loose socket. My question is should I re-tension the socket while it is “warm”. I see you should do this after the amp discharges, so I’m wondering if thats what you mean. Basically work on it while its warm?
Thanks and great forum.

Jeff

]]> By: bill http://billmaudio.com/wp/?page_id=171&cpage=1#comment-1147 bill Thu, 02 Jul 2009 00:13:08 +0000 http://billmaudio.com/wp/?page_id=171#comment-1147 That's filament rattle or a loose grid. Your speaker is vibrating the tube; it's a common failure for tubes in combo amps. You might be able to overcome it for a while with some silicone O-rings to damp the tube, but ultimately, you'll have to replace it. That’s filament rattle or a loose grid. Your speaker is vibrating the tube; it’s a common failure for tubes in combo amps. You might be able to overcome it for a while with some silicone O-rings to damp the tube, but ultimately, you’ll have to replace it.

]]> By: S. Riley http://billmaudio.com/wp/?page_id=171&cpage=1#comment-1146 S. Riley Wed, 01 Jul 2009 18:10:12 +0000 http://billmaudio.com/wp/?page_id=171#comment-1146 Bill, I hear a rattle coming from the 12AX7 tubes when the tone is thick with low-mids and bass. It is more of a physical rattle rather than an electrical hum/hiss. It's very annoying when recording. If I touch the tubes, the rattle subsides. Could this still be a socket issue in that the tube isn't held firmly and is vibrating? Or could it be the tube guts vibrating? Bill, I hear a rattle coming from the 12AX7 tubes when the tone is thick with low-mids and bass. It is more of a physical rattle rather than an electrical hum/hiss. It’s very annoying when recording. If I touch the tubes, the rattle subsides. Could this still be a socket issue in that the tube isn’t held firmly and is vibrating? Or could it be the tube guts vibrating?

]]> By: Paul http://billmaudio.com/wp/?page_id=171&cpage=1#comment-476 Paul Mon, 16 Mar 2009 15:02:39 +0000 http://billmaudio.com/wp/?page_id=171#comment-476 Bill, I'm about to purchase a BJ with your mods already done. It does have the black sockets which I understand can be problematic. Antique Electronics Supply has some ceramic sockets that will probably work. If you were swapping out sockets, which would you recommend? Bill,
I’m about to purchase a BJ with your mods already done. It does have the black sockets which I understand can be problematic. Antique Electronics Supply has some ceramic sockets that will probably work. If you were swapping out sockets, which would you recommend?

]]>