Ampeg SVT-2 Pro problem

[jmpa]

Ok this is my first post on this forum and excuse me because my english is not good.
The problem is that when I turn the amp on it goes to protection. I have checked the speaker connections and I have the impedance matched with the amp. I have done one test removing two power tubes from the amp (one from each side) and biased the amp without these tubes and the amp turn on and plays well but at lower volume.
The problem could be the power tubes or something else?
thanks.

 

[JimmyM]

power tube would be my first thought. you should have them tested. btw, don't get hoodwinked into replacing them all. it's often only one tube that goes out, and they work in groups of 3, so at most you'd only need to replace 3 if one is bad.

 

[paulhamus]

I wasa wondering if anyone has had a volume problem with the svt 2 pro head, mine has to be turned up to 7-8 on the master to get it as loud as my svt classic that is set on 2 the classic has more balls on the low end but the 2 pro has better tone. just a problem with the volume . oh one more thing my 2 pro does make that strange noise when you bring it out of stand by that is the voltage and magnetic pull on the lid from the transformers, kind of scary it's because the lid is only 1/8 of an inch from the transformers and is in the magnetic feild when turned on. best thing to do is don't leave in stand by for more than 5 minutes. I need help on this volume problem

 

[eastcoasteddie]

My 2-pro is Stupid loud, even with a single 4x10.

When I take mine out of standby, it maked that loud bang/buzz noise...but not always. It will actually make stuff that I have sitting on top of my rack jump up about 1/4 inch when it does that. I figured it's normal...

 

[jmpa]

my amp was doing the same noise when taking it from standby until the problem started

 

[paulhamus]

I got my amp back today it was the cathode resisters next to v2- v4- v6 on the preamp and that was messing up the volume through the impedence selecter switch, the vibrating and buzzing noise is still there . I don't know what to do my tech is the best in the world dave sarge. he said to take the top off and leave it in a rack ampeg messed up and put a metal top to close to the top of the transformers and power tubes, when you take it out of stand by the magnetic field from the tube getting full power generates to the top metal cover and will vibrate for a few seconds until the feild is stable. but when the top is removed there is no noise. I put mine in a home bulidt rack with 6 inches clearance above the tubes and is working better and no noise coming out os stand by.