• Welcome to the General Discussion forum for UAD users!

    Please note that this forum is user-run, although we're thrilled to have so much contribution from Drew, Will, and other UA folks!

    Feel free to discuss both UAD and non-UAD related subjects!

    1) Please do not post technical issues here. Please use our UAD Support Forums instead.

    2) Please do not post complaints here. Use the Unrest Forum instead. They have no place in the the General Discussion forum.

    Threads posted in the wrong forum will be moved, so if you don't see your thread here anymore, please look in the correct forum.

    Lastly, please be respectful.

2108 pre sounds like a phaser

Hi! The first pre in my trusty old UA 2108 preamp suddenly sounds
like a there's phaser or combfiltering on it. Tried different mikes; still the same. The second pre sound just fine.

Any suggestions is greatly appreciated



Established Member
I knew I should have checked to see if it was solid state. :oops:
Akis said:
saemskin said:
maybe a tube is out.
It doesn't have any.
Right on, dude! No tubes. Thought maybe some of the techheads here would have any clue why it would be producing combfilterlike sounds...
I usually like servicing my own gear, but this time I have no idea...

Anyone please?



Active Member
Weird... I'd say crack it open and do the obvious first -- look for a cold solder joint or a bad wiring connection. Bad transformers can cause a \"ringing\" comb-filterish effect, but I'd think it's unlikely that's the problem. If it will help, PM me and I can point you toward a schematic for the original 1108 preamp, on which the 2108 is based. Might be able to scratch up a 2108 schematic, but if so ya gotta keep it folded up in your back pocket and out of the public eye :)

Edit: While I'm grasping at straws -- does that thing use discreet socketed opamps? If so it should be easy to test 'em by switching channels... If the problem switches channels, there ya go... If it stays, maybe try poking around the components in the feedback networks, make sure their values measure correctly... My money is on bad connection somewhere though....
UAD Bundle Month