- Joined
- Oct 15, 2014
- Messages
- 3,419
- Tagline
- ---not quite right
It’s worked great other than issues I caused or am still chasing as I’m a relative n00b to this stuff... overall I would say the 700/1 is very worthy of repair. Keep in mind mine is not a full WOPL conversion so the original backplanes are still in play. The new driver board solved idle noise and DC offset issues of the original amp, I’m having an intermittent bias issue with the right channel which I believe is going to turn out to be a bad output transistor socket, I’m currently removing the right channel back plane to clean/inspect/swap sockets from my WOPL’d 400.
If you can solder and have a multimeter, with all the help and guidance available here I have no doubt you can fix yours yourself. It’s been a great learning experience for me and it’s relaxing way to kill a rainy day. Don’t feel bad if you make mistakes, I blew Tim up twice a couple days ago on the work bench, second time there was fire! Also I believe the parts are available to fully WOPL the 700/1 now also if you choose to go that way you can buy the boards assembled then it’s nearly plug and play with some fairly easy testing during bring up.
so this morning I’m disassembling Tim. Going to completely remove the right side back plane, inspect the sockets and test all the semi conductors. I had an intermittent issue of bias running high during bring up most often when installed the second row of outputs. That rows tranny sockets look to have been over tightened at some point so hopefully there’s an issue there. I smoked the bias resistors the other day too, whatever the issue is it caused over 12vdc bias and in short order lit them 1/4 watt resistors on fire... I think I’m going to install Linda’s Phoenix connectors on Tim’s board and order more, I was too optimistic that I probably wouldn’t have to remove the driver board, desoldering wasn’t a big deal but then connectors would sure make things easier.
If you can solder and have a multimeter, with all the help and guidance available here I have no doubt you can fix yours yourself. It’s been a great learning experience for me and it’s relaxing way to kill a rainy day. Don’t feel bad if you make mistakes, I blew Tim up twice a couple days ago on the work bench, second time there was fire! Also I believe the parts are available to fully WOPL the 700/1 now also if you choose to go that way you can buy the boards assembled then it’s nearly plug and play with some fairly easy testing during bring up.
so this morning I’m disassembling Tim. Going to completely remove the right side back plane, inspect the sockets and test all the semi conductors. I had an intermittent issue of bias running high during bring up most often when installed the second row of outputs. That rows tranny sockets look to have been over tightened at some point so hopefully there’s an issue there. I smoked the bias resistors the other day too, whatever the issue is it caused over 12vdc bias and in short order lit them 1/4 watt resistors on fire... I think I’m going to install Linda’s Phoenix connectors on Tim’s board and order more, I was too optimistic that I probably wouldn’t have to remove the driver board, desoldering wasn’t a big deal but then connectors would sure make things easier.
