Home » VintageKustom.com » Repairing Kustom Amps » Krossroad 500 - "pop" when shutting off
Krossroad 500 - "pop" when shutting off [message #26007] Tue, 14 March 2017 15:49 Go to next message
rodak
Messages: 511
Registered: October 2001
Location: Georgia
Senior Member
Just a little off-track here - I have a Krossroad 500 bass head, and when I turn the power switch off, there's a pretty loud "pop" or "snap" from the speakers. I used to be able to turn the little horn in the 2x10 cab all the way down which would at least eliminate most of the sound, but I tried that the other day, and even through just the 2x10 and 1x15 speakers it was really pretty loud. Any ideas what component might be going south that would cause that? I do know the amp has a gizmo that keeps the speaker outputs disconnected for a second or so after power on, presumably to avoid any unpleasant "thump" (what a terrible idea!), but I don't think it's intended to turn the outputs off prior to powering the amp off.

I don't have schematics - anyone know if any are available? Last time I checked, they weren't to be had.


www.combo-organ.com
Re: Krossroad 500 - "pop" when shutting off [message #26008 is a reply to message #26007] Tue, 14 March 2017 19:13 Go to previous messageGo to next message
chicagobill
Messages: 2005
Registered: April 2003
Senior Member
Normally the speaker protection relay will turn on slowly to hide the turn on thump and turn off quickly to hide the turn off pop. It could be that the relay timing cap is gone off value.

Or it could be that the power amp is making a bigger turn off pop than it used to. Most times these pops are cause by the top and bottom sides of the power amp turning on or off at different rates. This could be caused by leaky transistors, aging capacitors, off value resistors, etc.

I have personally not seen many Krossroads amps, and I have never seen any schematics.
Re: Krossroad 500 - "pop" when shutting off [message #26009 is a reply to message #26008] Wed, 15 March 2017 20:38 Go to previous message
rodak
Messages: 511
Registered: October 2001
Location: Georgia
Senior Member
Thanks, Bill. I'll have to open this guy up soon and check out that relay and stuff.

www.combo-organ.com
Previous Topic: Changes in capacitor values - from schematic
Next Topic: K-250-4 head
Goto Forum:
  


Current Time: Thu May 23 06:12:02 EDT 2024
.:: Contact :: Home ::.

Powered by: FUDforum 3.1.3.