There's a litle more to "line" and "instrument" signals than just the amplitude (level). Line signals are usually balanced and medium impedance, whereas instrument levels are single-ended and high-impedance. That said, you may not need a high impedance input if your instrument (guitar?) has an active rather than a passive pickup, but you certainly ought to check that your rack effects unit is single-ended and not balanced.

So, come back to us saying whether the pickup on your guitar or other instrument is active (has its own electronics) or passive (direct coil output or piezo), and whether your rack effect units have balanced or unbalanced I/O. Listing the models of the rack units would also help.

Hello Boswell, thank you for your speedy reply,

The guitar has passive pickups and the rack has balanced i/o (peavey valverb specifically)

Use the front panel input and turn the Master down so it doesn't clip the next device.

The I/O on the Peavey Valverb is unbalanced, and its input is designed to take a guitar pickup signal directly. My quick reading of the Peavey literature is that they expect you to put the Valverb inline between a guitar pickup and amplifier or other high-impedance recording input. Maybe I have misunderstood your question, but is this not what you want?

It is indeed what i want, but here is the issue, when i place the valverb between the guitar and amp i get both a humm and a white noise. When i place it as an insert on my desk, no hum, no white noise. I opened it up and it looks like the i/o has three wires, i assumed it is balanced because of this.

There's no indication in the manual that it's balanced.

It seems to have enough gain but I don't like the half meg input impedance with a passive pickup. I'd want something with around 10meg input impedance between the guitar and Valverb.

Does your amp have an effect loop? That's where I'd put it based on the level and impedance specifications, and reverb usually works best later in the chain anyway.

Do you have a keyboard or something else less impedance sensitive to try it with for comparison?

The hum and white noise begin befor i plug any instrument in. Tried my ms-20, didnt make a difference. I put in the line loop of one of my amps, its better, but by no means 'right'

So.... No help with this? Anyone own a valverb and have a similar issue? Heavy white noise and hum through the amp. I've email peavey a week ago but am yet to hear back.

Is it me or the way to use line level effects would be to use an amp with an insert loop ?

Well... Everyone seems to think its not a line level effect. And even on my amp with a line loop i have the same issues.