Convert instrument level to line level?

Is there a device out there that will step an instrument level input down to a line level input?

I think you're confused, instrument level is the lowest level with line level being the highest (except for speaker level). In order of lowest to highest:

instrument (ie guitar, bass)
microphone
line level
speaker

there's a bit of wiggle room here.

Give it a try and ride the gain... do not blow out the sound... you will not melt anything.

Originally effects loops were used on things like guitar amps to place the effects behind the first tube gain stage... the effects were usually foot pedals putting out something hotter than a instrument level but not a line level.

Frankly, if you're not using full pro gear... the line level is whimpy on most sumer gear... so set it up and work your gain structure until your happy.

You could get all heady and worry about impedance... but then you'd know to much and be in a perpetual bad mood. :-)

best,
mike


edit: change "do blow out the sound" to "do not blow out the sound"

line level to instrument level,

Go backwards thru a direct box. I do exactly that for reamping and it works like a charm.

ORIGINAL: Shadow of The Wind
the input impedance is extremely high, e.g. 1 MOhm instead of 10 kOhm. The reason is that electric guitars have high source impedances. Thus, if you would connect the guitar to a standard line input, the level will be very low, since the low input impedance would almost short circuit the source. It will also change the frequency response quite a bit. (The high, comlex source impedance of an electric guitar also explains why different guitar cables sound differently.)

Hey shadow (or anyone who knows about this stuff), I recently found out that my guitar inputs have an impedance of only 107kOhm. Especially after reading what you wrote, that seems very low. Also, when my particular interface was reviewed in Sound on Sound, the guy wrote:

I suspect some guitarists would prefer a significantly higher input impedance than Mona's 107k(omega) to avoid loading some pickups.

So now I'm worried. What's all this "loading pickups" about? Does it pose a threat to my gear (guitar or interface), or does it also affect the sound quality in any way?

ORIGINAL: mike_mccue

the general thought is that too low an input impedance causes unexpected frequency response characteristics and a generally lower signal level because the voltage isn't "building" up.

best regards,
mike

Interesting, well I guess I've gotta add a DI to my shopping list...

ORIGINAL: Shadow of The Wind
how did you measure that value? On the website it says that the input impedance of the FP10 (formerly Firepod) was 1MOhm. If it was really just 100kOhm, you would, as Mike said, have a low input level, a different sound, and maybe an unusual behavior of the pots. But I would not see a reason for Presonus to ignore the standards.

Oops, I should have mentioned my interface isn't a Firepod, it's an Echo Mona. They published the impedance specs on their website, and I just happened to notice it the other day. I've never had any noticeable problems, but maybe I've never heard my "true" guitar sound yet. In any case, it sounds like a DI would solve my problem (as well as DerGeist's). Thanks for the info guys.

Hey Shadow, great info! I'm slowly getting a handle on all this. It's very tempting to open 'er up and tinker around in there beacause, in addition to this, I'd like to lower the mic preamp input impedance (it's currently set to 1.5kOhm which, I'm told, may cause sibilance problems). But I'd be treading dangerously into the realm of sheer ignorance which usually ends up in a bad way Also I suspect Echo must've had a reason for setting the impedances the way they did (though I can't imagine why), so maybe I should leave it alone.

Levels are not really a problem, so a passive DI might do the trick. But just out of curiosity, does anyone make an active DI with line level outputs like you've described?

ORIGINAL: mike_mccue
Rupert Neve's ... he says the higher the better.

"So shall it be written, so shall it be done."

Thanks for the tip, mike. Wow, I just checked the specs on the Portico mic preamp. Input impedance = 10kOhms. Further reading from a review in Sound on Sound: "...unusually high input impedance — 10k(omega), in fact — which minimises the microphone loading and is claimed to improve 'transparency.' "

That makes sense to me... so what's the deal with the other school of thought--those who say a lower mic input impedance is better? (Actually I think I read it here in the cakewalk forums).

Spaceduck,

You have several options, and you may or may not explore them all.

- Maybe your guitar works well with the relatively low input impedance. Then, leave it as it is.

- If you have issues with noise or unusual sound, try a DI box. A passive one with a good transformer is one option. The other option is an active one. Many of those support phantom power, and some have adjustable gain and a second output. You can try what works better: high gain of the box, low gain of the interface or vice versa. It depends on which of the two amplifiers has the best noise ratio at what gain. I found some cute things like the Behringer GDI21 and the Ultrasound Ultra PDI. Unfortunately, the balanced output has mic level, and the line level output (TRS) is unbalanced... If the unbalanced calbe is short, it might be okay.
If you perform live or if you want to listen to your favorite guitar amp while recording, I would get a DI box anyways.

- There are some 'guitar preamps' that would offer everything. They have balanced line level outputs and sometimes build-in filters or amp simulations. Some a really pricy.

Wilko