Spider Valve MKII Head Direct out problem

[JoePoma]

Hello,

            The last couple gigs towards the end of the night. I get this loud Bassy feedback thru the PA when the amp goes into tuner mode while I'm using the direct out. Different venues and it does start till after I've held the button and the amp actually switches to tuner. anybody else have this problem. Wondering if it's overheating, but not having any other issues.

 

[jpicc2880]

I'm not having that problem... yet... but I do have a question as to how you're using the direct out; are you plugged into a 4X12 cabinet and using the direct out? Or are you going direct out to the PA without plugging into a cab?

[JoePoma]

Using a 4x12 and going direct out to P.A.

[jpicc2880]

Thanks

[ferrazzo]

hi

 

i m in belgium and i have exactly the same problem

 

did you find the solution ? 

 

thank you caus i m ready to sell the amp  :angry:

 

maybe you can respond on my mail ; laredo1@skynet.be

[psarkissian]

1- Good. Never run a valve amp without a matched load on the speaker output. Matched load being,

that if you plug into the 8-Ohm output, that there is an 8-Ohm speaker load on it.

 

2- When was the last time the valves were changed? 

Once every 12-18 months for a working musician, 20-24 months for weekend warriors and bedroom

rock stars,... unless something happens sooner than that.

 

3- Are they the specified 5881WXT (matched set) power tubes, and properly biased?

These amps are not forgiving of mods, even valve mods. It's already a hot rod.

 

4- Is the person working the mixer console/board making use of input trim and filters? 

 

 

Resonance that turns into feedback can occur for a number of reasons.