New SVT issue

[sedan_dad]

I really hate posting this .
The SVT CL I just got sounds great when you first turn it on but then after say 1 1/2 hours it starts making these scratchy ,staticy noises through both cabinets.Sort of like a loose speaker connection kind of noise.It's not constant but very frequently.This is with the standyby on and the amp is just sitting there not playing.It's not real loud but seems to be relitive to the amps volume.
I have a Ampeg 410he and a Ampeg 1015he.I have turned both of the horns off and I'm using speakon cables on both cabs. I'm daisy chaining the 1015 off of the 410.
Any ideas?

 

[Plain Old Me]

Sounds like it needs to be taken into a tech. My Mesa 400+ did something similar when I first got it; it played fine for a few minutes then it went staticy. I sounds like you need a cap job, but I would let a tech determine whats wrong.

 

[sedan_dad]

A cap job?
it's a 2004 model.
You really thing so?

 

[BurningSkies]

Make sure all the tubes are firmly seated. It's possible as the amp heats up, some of the contacts aren't quite staying as tight as they should and you're getting an intermittant crackling.

I'm sure that a few others will pop up to give you some other suggestions.

 

[nysbob]

It could just be a marginal preamp tube too...there are a lot of them & it just takes one bad character...

 

[jpark]

Very sad indeed. On an up note, a fellow tb'er is hooking me up with an svt classic

 

[8mmOD]

I am guessing its the tubes. One of my rehersal studios had really shoddy power and I burned through a set of power tubes pretty fast. It was years ago, but I seem to recall similar symptoms as yours.

 

[sedan_dad]

Well the tube susgestion does make me feel better.
I hope thats all it is because I love the tone -headroom-bottom-punch and everything about it-----except this.

 

[DaveMcLain]

I think I would take a look at the tubes first, it's the easiest thing to do and also the most likely source of the problem. I think I would try unplugging and repluging each preamp tube a couple of times as a first step.

 

[sedan_dad]

Very sad indeed. On an up note, a fellow tb'er is hooking me up with an svt classic

Good for you Joe.
I hope you have better luck than me.You will love that boat anchor.It'll be the last amp you ever buy.This pig I have sounds great ,....for a while. I'll get it together.

On a side note,3 of the preamp tubes are accessable from the rear of the head.Where are the other 2 and how do you get to them?

 

[nysbob]

Good for you Joe.
I hope you have better luck than me.You will love that boat anchor.It'll be the last amp you ever buy.This pig I have sounds great ,....for a while. I'll get it together.

On a side note,3 of the preamp tubes are accessable from the rear of the head.Where are the other 2 and how do you get to them?

There are a bunch of them mounted at an angle up high behind the tone controls - you access them by taking the front cover off.

 

[Jerrold Tiers]

I'll go with tubes as the first guess also. It is the simplest possibility, although an hour plus is a bit longer time than I'd necessarily suspect for a tube problem thermal delay......

As far as the other two tubes, they are indeed up in the preamp portion. What you see on the lower chassis is driver tubes.

But this is a CL. Therefore, you have to remove the preamp chassis to get at them.

If you do that yourself, do the usual, unplug and be sure voltages have plenty time to discharge since the last time it was powered up before sticking fingers in. We don't recommend that end users etc, etc............

The good news is that since that is a 2004, if you got the store receipt with it, it is under warranty with no hassles. So if there IS anything other than tubes, it should be a warranty repair.

 

[sedan_dad]

I think I have it.
When I pull the pre amp out to check tubes I found 6 pin(I think) white connector that was not seated all the way.
Don't ya miss ptp wireing?
Keeping my fingers crossed.

 

[i_got_a_mohawk]

not really, and seeing the original SVT was mainly PCB, i dont think it matter too much

 

[sedan_dad]

Well I've had it on all night and no funky sounds.
I'll sleep better tonight.

 

[sedan_dad]

If anyones interested here's the offending connector that caused all my worries.
Right in the center of the picture with the brown wires and yellow wires.
Sucker was not seated all the way.It's been rock solid since.