Low-Z to High-Z impedance conversion,reamping

S

schnoops

New member
Hi,

I'd like to re-amp dry guitar tracks through an amp, and I need to raise the impedance of my sound card's output to a guitar-like impedance (8-10k Ohms).
My sound card is an Omnistudio, and I can't figure out the output impedance of the line outs.

Do any of you have an idea about how to achieve this impedance matching, while retaining a good sound quality?

can I use a standard direct box and plug it the inverse way? I mean the blanced out of my delta into the mic output, and the input of the DI into the input of my amp?
 
I found those audio technica CP8201 XLR-1/4" transformers, with an input impedance of 250 ohms and an output imepdance of 50,000 ohms.

They're meant to be used with capacitor mics, but do you think this can do the trick converting line out to guitar like? or will I have to by an expensive reamp box?
 
Very often a low-impedance output will drive a high-impedance input with no problem. If I were you, I'd just plug it in and see what happens. Let your ears be the judge. (Maybe you've already done this, in which case never mind.)

If you find that you aren't satisfied with the sound, you can try a passive direct box in reverse, but an active direct box won't work in reverse.
 
I tried it the direct way, but the signal out of the delta is way too hot compared to what comes out of a guitar, I had to lower the volume from the delta mixer, which gave me a lame signal to noise ratio.

A transformer will reduce the voltage but give more current, at the risk of damaging the amp (or over saturating the preamp) I need some sort of dissipating device to get rid of the extra power, but I still want to output at high volume from the delta to get the best signal to noise ratio.

A voltage divider maybe? and is it best to lift the ground between the delta's out and the amp?
 
Just out of curiosity, what setting are you using for the Delta's output level? (+4/Consumer/-10)

If you just need to pad the output level, you really don't need anything fancy — a resistor in the path would be adequate.
 
Hi again,

even at -10dbv it still somehow overloads the stomps and amp.

I tried to reamp a take through my big muff through my blues deluxe combo, the fuzz was over-over-distorted (I couldn't get the creamy fuzz tone I have with my guitar on the same setting), and as I lowered the volume from within the computer, background noise started to be very noticeable.

I guess the guts of the "Reamp" box are of some utility after all... Lower the volume while retaining a good SNR and spectum width.
 
that's exactly what I was talking about, and that's a little expesove for me at the moment... one day hopefully...
 
Why not.....

.... just run through a DI box backwards??

My Berhinger DI pro was like 20 bucks and you can run the line out of your sound card into the OUTPUT of the DI and the hook the INPUT of the DI to the amp input.

This is what I have done in the past and mic'd the re-amped sound.
It works pretty good.

-mike
 
consider building your own device: just go to the jensen website and see how easy it is!

and if you can find some used transformers (or pull them out of some piece of dead gear) you can make a really high class DI box for well under $100. heck, you could do it for $20.

all depends on the transformer cost.

damn expensive little (heavy) fellows.
 
Hi Schnoops,
I have an Omni-studio and I'm planning to try reamping some tracks out of it without buying a Reamp, too. I haven't done it yet but I've read you can maybe feed an amp/pedal with the headphone outputs. Since you can turn the levels down and slowly bring them up to be safe, I'm gonna give it a try, you might want to as well. If you do, let us know!
-Michael
 
How cool is that, I'm so dumb I never thought of doing it this way!

I'm gonna try this week end and keep you informed. Stay tuned. Cool.
 
Re: Why not.....

formerlyfzfile said:
.... just run through a DI box backwards??

My Berhinger DI pro was like 20 bucks and you can run the line out of your sound card into the OUTPUT of the DI and the hook the INPUT of the DI to the amp input.

This is what I have done in the past and mic'd the re-amped sound.
It works pretty good.

-mike
Click to expand...

The problem is not the levels because any soundcards output can be adjusted---its the impedance--when mismatched it cause a hum that shows the need for a transformer

Id be intersted to know if that Behringer introduced this hum--cause usually you cannot reverse a DB like you were doing--at 20 bucks that would be great though
 
yes that's right, impedance matters as much as level, I could experience this with the big muff, it gets really muddy even at low levels when reamping from the delta's line out, with volume set low. It also changes the treble response of the amp.
 
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