scotteggshell
Member
- Joined
- Jan 28, 2009
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Hi :
I have been having some very irritating issues with my LSS, it's a beautiful sounding amp but worthless if unreliable. I've documented what I did in case anyone else experiences a similar iassue, I'm pretty sure I'v got it licked, but you never know
The issue was the amp would cut in and out and become severly distorted by times. Power cycling the amp would fix the issue for a bit - Last week at rehearsals it finally got much worse and stayed in its "bad " mode and I was able to do some analysis . Obviously all cables were swapped for known good as well as speaker. Also all tubes swapped for new, kown good, when intermittent first began.
1) Issue is present on both channels
2) It occurs when the Loop bypass is engaged and when not. (eliminates V3 and loop jacks)
3) It occurs on all power levels (eliminates Rectifier tube)
4) The Reverb still works when it is having issue (banging the cab makes the reverb "Bong" (eliminates power section)
So I pulled the amp from the chassis, recorded all voltages and then fed it with a looper into a load at nearly full volume for nearly 2 hours - no breakdown. I froze every component - no breakdown.... Tapped all components and wires with a pencil - no breakdown. Got more aggressive and started flexing the board - all good. Got aggressive with tapping relays - POW, got it. The relay just to the right of V2 causes the issue when tapped hard enough . Power cycle, relays reset, and all good tap, tap, tap - Out again (repeated numerous times). So I'm pretty sure it's the relay.
I've ordered the relay from Mouser, my question to any techs out there is: Whats the easiest way to get access to the solder side of the board in order to replace the relay ? Looks like pulling the controls and folding it back may be the easiest, but maybe someone has a better idea ...
Thanks
Scott
I have been having some very irritating issues with my LSS, it's a beautiful sounding amp but worthless if unreliable. I've documented what I did in case anyone else experiences a similar iassue, I'm pretty sure I'v got it licked, but you never know
The issue was the amp would cut in and out and become severly distorted by times. Power cycling the amp would fix the issue for a bit - Last week at rehearsals it finally got much worse and stayed in its "bad " mode and I was able to do some analysis . Obviously all cables were swapped for known good as well as speaker. Also all tubes swapped for new, kown good, when intermittent first began.
1) Issue is present on both channels
2) It occurs when the Loop bypass is engaged and when not. (eliminates V3 and loop jacks)
3) It occurs on all power levels (eliminates Rectifier tube)
4) The Reverb still works when it is having issue (banging the cab makes the reverb "Bong" (eliminates power section)
So I pulled the amp from the chassis, recorded all voltages and then fed it with a looper into a load at nearly full volume for nearly 2 hours - no breakdown. I froze every component - no breakdown.... Tapped all components and wires with a pencil - no breakdown. Got more aggressive and started flexing the board - all good. Got aggressive with tapping relays - POW, got it. The relay just to the right of V2 causes the issue when tapped hard enough . Power cycle, relays reset, and all good tap, tap, tap - Out again (repeated numerous times). So I'm pretty sure it's the relay.
I've ordered the relay from Mouser, my question to any techs out there is: Whats the easiest way to get access to the solder side of the board in order to replace the relay ? Looks like pulling the controls and folding it back may be the easiest, but maybe someone has a better idea ...
Thanks
Scott
