Guitar into PC?

[ConanB]

I'm getting plenty of ideas from here, but I'm still wondering; is it fine to just have the PC audio's out change into a 1/4" cable that I could run into other FX and an amp?

It's possibly a straightforward "yes", but I'm still curious.

[lvs]

The soundcard line out is normally stereo and just Y-ing these outputs together into a mono cable would not be a good thing.

There can also be a ground loop hum problem (PC and amp(s) having supply ground and no ground lift switch), which I solved by inserting transformers into the signal path. Small, cheap transformers work well enough for this if they are right after a low impedance output to preserve low frequencies. There's no need to build active low output impedance buffers, if those that are already present in the chain are usable... the sound card line out of my PC apparently had low enough output impedance.

I just put two Etal P2781 transformers + zobels after the soundcard, and from there to two separate amps, or two separate inputs of a keyboard amp.

[George Giblet]

Plenty of buffers here:

http://www.muzique.com/lab/buffers.htm

I'm not fond bias method that has two resistors on the opamp + input; like the ggg buffer.

Better is two resistors with a cap to ground, the centre creates a Vr voltage, then a 470k to 1MEG resistor between Vr and the opamp + input.  It's the same bias network most people use in effects.

As far as the PC inputs go.  I'd use line-in.  Connect the output of the buffer to both L and R input.

On the PC output side I wouldn't go connecting the outputs together.  If you aren't connecting to a stereo system there isn't much point using the two outputs - if you are connecting to stereo then obviously the two output go to different places.  Just connect to the Left output.

[Fleetdog]

Last night I fired up my home recording setup for a whopping $3.  I already had a PC.  I already had guitars that include a Washburn electric acoustic.  I dropped in GC and picked up a 1/4" female to 1/8" male converter and just went guitar->instrument cable->adapter->line in.  I downloaded Audacity for free and I'm off and running.  The guitar has a built in preamp so buffering isn't an issue.

Now I realize that this will NEVER sound professional, but my intention was simply to have a kind of musical sketchpad for working out multi instrument parts.  As for latency, I simply turned off the option to hear what I'm recording so that the only thing coming out of the speakers is what I previously recorded.  Since it's an accoustic guitar I can already hear it.  After recording each track, I do have to move the track back a bit in time to match up with the other tracks but I haven't had much trouble doing that yet. 

So how would this work for an electric?  Well, I'm considering building my own little interface box that would take a guitar signal in and split it sending one to the computer's line in (with a volume control) and the other to a 2 channel mixer/blender inside the module.  The other channel of the blender would come from the computer's speaker out.  The output of this mixer would then go to a speaker/headphone jack.  This would give the same effect as letting the currently recording track play with the already recorded tracks except without the latency.  Some form of preamp, eq, and/or cab sim before the splitter could also be added if I want to get fancy.

[501]

I have tried this before without buffers or anything and it seemed to work fine for the most part. I used an adapter to plug it to the mic in and I also used a cord that I have that has a USB plug on one end and a 1/4 plug on the other. Both did good for recording, but as far as just playing out of the speakers, i got a horrible delay between when I strummed and when I heard the sound, which made playing anything really hard. I think the delay problem is just cus my sound card is cheap.

[Ed G.]

As far as the delay:

You need ASIO drivers.
There's a driver you can download for free, it's called ASIO4ALL.
It'll minimize your delay to maybe 3 or 4 milliseconds.

[arawn]

Okay what i am doing is guitar and any stompboxes into my digitech rp80 and using the pair of 1/4 outputs on that adapted to a single 1/8 stereo plug into the stereo line in of my sound card I haven't noticed any latency issues and the sound quality is pretty good for home recording without purpose built hardware

[ConanB]

I might head on down to Jaycar and grab one of those 1/4" to USB converters and get that ASIO4ALL.
Personally not after a home recording setup, more of a PC based gigging setup, running guitar into maybe a laptop that has some FX software running.
Or what I'd like to do is build something using a NanoITX PC complete with switches and pots in a pedal-ish setup. Then again, I could just buy a multi-FX unit...