Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: scott1968 on November 24, 2014, 09:22:26 pm

Title: Laney VC50 Tube Amp Hum Problem
Post by: scott1968 on November 24, 2014, 09:22:26 pm

I have a Laney vc50 tube amp that does nothing but hum (quite loudly) when you turn the standby switch on. What is going on with this thing????

Title: Re: Laney VC50 Tube Amp Hum Problem
Post by: AZJimC on November 25, 2014, 02:06:39 am

If the Vol control does not effect it, then first place I'd look is output tubes or power supply caps

Title: Re: Laney VC50 Tube Amp Hum Problem
Post by: Jack_Hester on November 25, 2014, 06:35:59 am

If the volume control does affect the hum, you may want to head over to the input jacks.  They appear to be closed circuit types, and ground the input if not in use.  One or both of these being open (not grounded) with no instrument connected can possibly be a problem.  Especially, when you turn the volume up. 

Jack