studio pre sound fades away

[ezekiel]

Howdy Y'All,

I've got a studio pre that is acting strange.

I was adjusting the eq but it had no effect. The amp sounded tinny in this state.

I turned up the volume and master pots to the maximum in an attempt to saturate the signal. Something then gave way and the eq started working.

I turned the pots back down and after a while the eq quit working again.

I've read that the eq is a solid state sub-system so it couldn't be a tube gone bad.

Would anyone know what's causing this?

 

[Chewy]

I've recently gotten a Studio pre too - I'd suggest putting "known/working" tubes in it first. The Graphic EQ itself is solid state, but I think is driven by V2 - the second tube from the left, as you're looking from the top. Your Studio is at least 17 years old, so you should probably start by eliminating the easy fixes first.
Good luck.

 

[ezekiel]

Sounds like a good plan. I had forgotten how long I've had this unit.

Is there a good source out there for studio pre tubes out there?

 

[tonefreak25]

Sounds like a good plan. I had forgotten how long I've had this unit.

Is there a good source out there for studio pre tubes out there?

There are actually a multitude of sources as your pre is running 12AX7's and one 12AT7 as the reverb driver. You can find these tubes, from a lot of different places some of which will put together "tube kits" specifically for the pre. I have had great luck with www.eurotubes.com, but dougs tubes is also a great resource and I am sure other folks here can offer some advice as well. Good luck and enjoy the tones!!
'

 

[Chewy]

I've used EuroTubes and been quite pleased. I've more recently bought a Tung Sol gold-pin reissue, and a Mullard (long-plate?) reissue, and have been very happy with the results. I actually plan on getting 2 or 3 more of each to fill out my Studio

 

[Mongo1]

I am just getting through the process of swapping tubes in my Studio-Pre. Trying different tubes absolutely changed the dynamics and I love it even more now.

Here's the thread on my road through discovery.
http://forum.grailtone.com/viewtopic.php?f=16&t=43517