SuperSeagull Posted February 25 Share Posted February 25 I recently recovered an old Laney Hardcore Max 65watt combo that I had bought s/h some years ago and that was no longer needed by the church I'd bought it for. I was hoping I could leave it at the church I now play at to save lugging gear when I play. But its noisy when the master vol is turned up. Doesn't matter if anything is plugged in or not. Tried different mains leads etc but makes no difference. However if I plug into the fx return there is no noise and it sounds not at all bad although with none of the controls then work. Does that sound fixable or am I best just using the fx return as an input and sticking my sansamp in front of it for eq etc? A quick, uneducated look at the components and PCBs doesn't seem to show anything obviously wrong. Quote Link to comment Share on other sites More sharing options...
Bigguy2017 Posted February 26 Share Posted February 26 What sort of noise? Hum, hiss or crackles? Quote Link to comment Share on other sites More sharing options...
SuperSeagull Posted February 26 Author Share Posted February 26 Sorry, that would have helped! Hum. Quote Link to comment Share on other sites More sharing options...
Bigguy2017 Posted February 29 Share Posted February 29 This suggests the power amp section is AOK and the problem is in the preamp. First stick a jack in/out in all the input and FX send return jack sockets - give them a squirt of contact cleaner. If the opamps are socketed, give them a good push into the sockets. Make certain you have a good working guitar cable... 😉 As usual, look for any bulged or leaky electrolytic caps... Unplug/replug all the internal connectors inc HD3 (preamp / poweramp connections) Also try unplugging the Reverb at HD1 and HD2. If the opamps are socketed, give them a good push into the sockets. Looking at the schematic it appears the preamp supply is Zenered down to +-15 VDC from the +-28 VDC power amp supply. I'd have a good look at the +-15 VDC rails and their smoothing caps C36 C37 C300. Put a 'scope on the +-28 VDC and +-15 VDC rails and look for hum. Obvs, if you have a 'scope (!) you look at the FX send and trace the signal back to the input Take it to a repairman.... 😉 laney_hcm65r_sch.pdf Quote Link to comment Share on other sites More sharing options...
SuperSeagull Posted March 1 Author Share Posted March 1 Helpful, many thanks. That’s not quite the right schematic, I think that is the guitar version inc reverb. Couldn’t see any obvious bulges on first look but will try all else you suggest. I’m content it’s not a cable issue having been caught out on that before 😬. To be honest, if it can’t be sorted it will function perfectly well with a preamp pedal in front of it in that environment. Thanks again, appreciate your expertise. Quote Link to comment Share on other sites More sharing options...
sandy_r Posted March 1 Share Posted March 1 (edited) 47 minutes ago, SuperSeagull said: ... That’s not quite the right schematic... Here are the schematics for the Bass HC Max 65W Sounds like schematics aren't going to help you much ...and a competent Tech will likely have their own service info Edited March 1 by sandy_r 1 Quote Link to comment Share on other sites More sharing options...
MoonBassAlpha Posted March 3 Share Posted March 3 Probably electrolytic capacitors on the preamp power supply not working correctly. If they are largeish, sometimes the vibration can fracture the solder around one of the pins too. 1 1 Quote Link to comment Share on other sites More sharing options...
.gif.9ad672bb8b84505709f76b39c8c256ec.gif)
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.