View Full Version : Fix my amp? Please?:)
http://www.martinloganowners.com/forum/attachment.php?attachmentid=9151&stc=1&d=1228170511
Needs fixing but it is a bit beyond my capabilities. I've tried twice!
Job: double sided PCB. Tube socket PCB track ripped on the way to pin 4 (heater) of an EL84 on the wrong side of the PCB, meaning the whole PCB needs removing. Not too hard, only a few wires to de-solder, but then comes the tricky bit - re-building the track to pin 4 somehow. Trouble is to get really good access to do that you need to de-solder quite a bit more. Fixing the track so it doesn't then later break (been there, done that) is not simple, it would appear.
I'd much rather someone came round here to fix it, rather than send it anywhere. Will pay reasonable cash & travel expenses for anyone who rates themselves with a soldering iron and mending amps in general.
The idea is then to sell said amp.
Any takers? I'll feed you well and deafen you with loud music should you so desire...:D
PM if you are up for it...
I have a reel of silver wire I use to replace PCB tracks. As long as its not too great a distance, bend to shape and solder both ends. If some of the track is still intact, use that to secure the wire to as it goes along. If its lomger, I use the same wire in PTFE sleeving. If you are stuck, I will put a length of it in the post for you.
I repaired one of those a year or so ago. Worth checking the voltages, the el84 are run close to their limits with 240v mains. Or at least was in the one I had to repair.
Hi Nick,
It is a bugger. I tried with some copper wire - the track is about 1 to 1.5 cm away from the pin. It is raised a bit off the PCB but getting a good connection with the track is hard. It simply broke when the amp got hot.
The amp works fine with the dead tube, though obviously is down on power in one channel.
There's no rush as I have had the amp for 20 years.... and it has done nowt for the past few years. If you're still up for some Lampized 211'd Apogee madness and now for some cash too, you're more than welcome to come round sometime:)
nice looking piece of equ....mmmmmmmmmmmmmmmmm
Arkless Electronics
14-10-2013, 00:09
If you do end up needing to send it away I can fix that no problem... pity you're not closer!
Follow the track back to the first place that goes to that is fixed (another component probably) and connect to that instead of the loose end of the PCB.
Follow the track back to the first place that goes to that is fixed (another component probably) and connect to that instead of the loose end of the PCB.
There's a plan - unless the track is hard to follow, I guess.
The reason the track is bust, BTW, is that the valve socket went. I replaced it, not realising it was a double sided PCB, and wacked it out with some force. The socket is soldered on both sides, hence ripping the track on the invisible soldered side. I did a whole load of cap replacements / put new ALPs pots in etc at the same time. Lucky to get away with just this one problem, considering I replaced a few other slightly dodgy valve sockets too. Only the one gave any grief.
Still open to anyone Bristol localish doing it. Will drive the amp up to 50 miles for a fix. I've kind of lost patience with it a bit.
Wakefield Turntables
14-10-2013, 15:03
It must cost a fortune to replace all those valves??
Yep, I had to replace a bunch of the sockets on the one I repaired as well. all good fun :-)
I have a reel of silver wire I use to replace PCB tracks. As long as its not too great a distance, bend to shape and solder both ends. If some of the track is still intact, use that to secure the wire to as it goes along. If its lomger, I use the same wire in PTFE sleeving. If you are stuck, I will put a length of it in the post for you.
I repaired one of those a year or so ago. Worth checking the voltages, the el84 are run close to their limits with 240v mains. Or at least was in the one I had to repair.
I used to do that on computer circuit boards. I would use a PTFE insulated wire from the nearest through-plated hole, pad or component and then route the wire along the path of the existing track and tape or lacquer the wire to the board. I generally didn't try to solder the wire to an exposed broken end of track as it is difficult to get a solid reliable connection. It is not uncommon to have this problem removing a socket or old component - I generally try to break up sockets with pliers or simiar, exposting the pins and desoldering them individually. It helps to check whether the board is single or double-sided!.
Cheers,
Alex
GEC used to use double print boards on their Telly's in days gone bye...
These things aught to be banned!
It must cost a fortune to replace all those valves??
NOS is not an option, though it sounds good with mil spec Russian EL84s and better still with the less reliable JJ EL84s. Both pretty cheap, really.
Nick has given me a lead for some help, BTW. Cheers Nick!:)
Floyddroid
23-10-2013, 21:47
That is a fantastic amp and well worth fixing.
http://www.martinloganowners.com/forum/attachment.php?attachmentid=9151&stc=1&d=1228170511
Needs fixing but it is a bit beyond my capabilities. I've tried twice!
Job: double sided PCB. Tube socket PCB track ripped on the way to pin 4 (heater) of an EL84 on the wrong side of the PCB, meaning the whole PCB needs removing. Not too hard, only a few wires to de-solder, but then comes the tricky bit - re-building the track to pin 4 somehow. Trouble is to get really good access to do that you need to de-solder quite a bit more. Fixing the track so it doesn't then later break (been there, done that) is not simple, it would appear.
I'd much rather someone came round here to fix it, rather than send it anywhere. Will pay reasonable cash & travel expenses for anyone who rates themselves with a soldering iron and mending amps in general.
The idea is then to sell said amp.
Any takers? I'll feed you well and deafen you with loud music should you so desire...:D
PM if you are up for it...
This amp is currently in the hands of a professional. It will probably be available for sale, though I am kind of loath to part with it, the bottom line is I don't own any speakers it can drive, even at a healthy 50 Watts.
If anyone is interested in it, PM me. It will be in extremely nice condition for its age and approximately 50% of its components have been replaced - it should be good for quite a while when it comes back.
Audio Al
06-05-2014, 20:30
J
Your PM inbox is full :)
Not no more Al - fire away!;)
All back from the menders and ready to sell.
FS thread may appear in a couple of weeks. You can PM me offers I suppose. Big ones that is. This Beard is in waaayyyy better condition than any other BB100 I have seen.
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