Connecting guitars to your computer

[Justin]

In general, electric guitars need a high impedance input, but most computer soundcard's microphone inputs are low impedance. You can get away with connecting them directly, but it's not ideal and at best you will get some occasional quality problems. Converting the impedance is actually pretty simple, and relatively cheap. Here are a couple of cheap (< $30) boxes that I've tried that work pretty well:

Rolls DB25: http://froogle.google.com/froogle?q=rolls+db25&btnG=Search+Froogle

radioshack 274-017: http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=274-017

The outputs of these are XLR, so you'll need a cable that goes from XLR to 1/4" or 1/8" input for your soundcard. Personally I favor some of the cheap USB soundcards for input too.

Alternatively to all of this, you can buy a $99 GuitarPort from Line6. It only works on Windows, but has pretty decent ASIO drivers, has the correct impedance, and seems to do 24 bit pretty well.

Line6 GuitarPort: http://froogle.google.com/froogle?q=guitarport&btnG=Search+Froogle

[alex_n]

Any tips on recording with Linux?

My setup right now is:
gitar->effects(comp->eq)->Delta66->jack->ardour(->Delta66->headphones)->jamin

I'm not home at the moment (should get back to work, really), so I can't test it out with Jesusonic. Where in the chain would it fit? How's latency?

(I wish I knew about the high-impedance thingama-deal before I blew 120$ on the delta...although it is quite nice. I hope nobody plugs their guitar into the mic-in, that's what line-in is for.)

[Justin]

Any tips on recording with Linux?

My setup right now is:
gitar->effects(comp->eq)->Delta66->jack->ardour(->Delta66->headphones)->jamin

I'm not home at the moment (should get back to work, really), so I can't test it out with Jesusonic. Where in the chain would it fit? How's latency?

(I wish I knew about the high-impedance thingama-deal before I blew 120$ on the delta...although it is quite nice. I hope nobody plugs their guitar into the mic-in, that's what line-in is for.)

Actually guitars do need preamps, so mic-in, not line-in is what should be used (unless you are using your external preamp).

At this point in time Jesusonic on linux only uses ALSA or OSS, so using it with other tools may prove to be difficult. We will have it running as a JACK plug-in soon.

[alex_n]

D'oh, you're right about the preamp. When I had a soundblaster, I used to run my amp's line-out into sb's line-in (adapter and all). Delta acts as the preamp, now. I was under the impression that mic-in is a low quality input, quite noisy. I guess that's what you mean about those adapter/transformer boxen, I should read before I post....

Well, no sweat about JACK, hope it comes out soon.

[sardonic]

So connecting a guitar requires some work, from what i read. Is there a easier way to do this? resistors inline on a cable or something? To connect a line-out to a amo would it be just a cable right to the amp?

[alex_n]

It's actually pretty simple, if you have a cable adapter for your instrument cable, like so: guitar->amp->adapter->computer
I don't know cable denominations (1/4" to 1/8"?), so I just brought a sample to a local radioshack. They sell them pretty cheap.

One thing to watch out for, if you use unbalanced cables (tip/sleeve?), and a stereo adapter (tip/ring/sleeve), you're going to get one channel. Probably a good idea to get a mono adapter/converter. Or something, I had a bunch of them lying about, had to mix and match a bit.

[fosh]

so...just to clarify...no external amp is required...just a direct wire from guitar to computer, preferably with some impedance balancing shiz in it?

[Justin]

so...just to clarify...no external amp is required...just a direct wire from guitar to computer, preferably with some impedance balancing shiz in it?

That is correct. Without the impedance balancing, it should still work, though the quality will be less than ideal (i.e. the pickups won't be loaded properly and your volume knob may cause the preamp in the soundcard to get real noisy at times). If you want to get something working fast, just do direct, then add the impedance balancing later.

-Justin

[Goner]

forgive me for being dense, but...

So from the 1/4" mono cable on my guitar, I need an adapter to make it 1/8" stereo, male and plug it into the mic jack on my sound card? What's the deal with the impedence? Is there some sort of in-line conditioner I can stick on there with parts from radio shack? I'm not afraid of a little soldering... Is there a little electronics thingamabob (transistor, capacitor, whatever) I can stick in there to take care of conditioning the signal? I gather that the 1/4" Jack-to-A3M XLR Plug Adapter/Transformer item from radio shack does it (for $15) but I assume that doesn't take care of the size conversion and the mono/stereo conversion at the same time... I'd like to manufactur a nice cable without static-prone connections to deal with for the purpose of plugging my electric to the computer..

As an aside, thanks for putting this package out, Justin! I have been dreaming about this for YEARS (specifically, the loop recorder) ever since I picked up an electric guitar and looked across the room at my old 486 way back when... I Always have wanted something I could riff out a bit of a rhythm with and then put some lead over it in relatively real-time.. seems like a rather simple concept, but without your tool, it's at least a $100 (up to $1000 or more!) proposition to purchase some sort of rack effects and pedals, etc.. Now I can actually try it out with a couple of little do-hickey's and your program.

This program is the kind of thing that keeps me up at night wondering just how much this shifts the greater paradigm of things beyond the obvious (sort of how winamp and gnutella have changed the way people listen to and acquire music!)

Again, hats off to you, sir!

Goner

[Justin]

forgive me for being dense, but...

So from the 1/4" mono cable on my guitar, I need an adapter to make it 1/8" stereo, male and plug it into the mic jack on my sound card? What's the deal with the impedence? Is there some sort of in-line conditioner I can stick on there with parts from radio shack? I'm not afraid of a little soldering... Is there a little electronics thingamabob (transistor, capacitor, whatever) I can stick in there to take care of conditioning the signal? I gather that the 1/4" Jack-to-A3M XLR Plug Adapter/Transformer item from radio shack does it (for $15) but I assume that doesn't take care of the size conversion and the mono/stereo conversion at the same time... I'd like to manufactur a nice cable without static-prone connections to deal with for the purpose of plugging my electric to the computer..

As an aside, thanks for putting this package out, Justin! I have been dreaming about this for YEARS (specifically, the loop recorder) ever since I picked up an electric guitar and looked across the room at my old 486 way back when... I Always have wanted something I could riff out a bit of a rhythm with and then put some lead over it in relatively real-time.. seems like a rather simple concept, but without your tool, it's at least a $100 (up to $1000 or more!) proposition to purchase some sort of rack effects and pedals, etc.. Now I can actually try it out with a couple of little do-hickey's and your program.

This program is the kind of thing that keeps me up at night wondering just how much this shifts the greater paradigm of things beyond the obvious (sort of how winamp and gnutella have changed the way people listen to and acquire music!)

Again, hats off to you, sir!

Goner


Converting from 1/4" mono to 1/8" stereo is pretty easy, you can just use any adapter (you can plug in a 1/8" mono jack into your soundcard's mic in and it will work fine).

As far as the impedance matching, all that is required is a transformer of the correct type, which is what that radioshack part does. Though yes, it has XLR output which involves more cabling...

-Justin

[fosh]

Created appropriate cable today, and my electric sounds fine thru an sblive. My accoustic doesnt create any sound tho. I know the pickup in it works, it plays fine thru conventional amps.
Could this possibly have to do with the lack of impedance balancing thingy?

[smudge8]

I just downloaded Jesusonic and think it's fantastic.

Just to clarify things in this thread a bit, from what I understand, the 'impedance matching thingy' is basically a D.I. box. A DI box converts a low-impedance signal into a signal suitable for plugging into a sound desk's mic input, and also converts the signal from unbalanced to balanced.
Since the sound card's input (unless you spent big bucks) is generally unbalanced and not an XLR connector, you need to make an adapter from your DI box to your computer which makes the signal unbalanced.

As far as I know:
For connecting to a mono input, eg. mic in:
Pin 2 (hot) ==> Tip (hot)
Pin 3 (cold) ==> Sleeve
Pin 1 (shield) ==> Sleeve (combine them)

For stereo, it's the same, just connect pin 2 to both the tip and the ring. But do some research first, because I'm not 100% sure and can't be held responsible for your $eleventybillion sound card blowing up.

But yeah - you basically never want to do the above, because a) your sound card's mic input, particuarly its pre-amp, is designed for adequate speech quality and is therefore crap, and b) your guitar can't be connected directly to the line-level input unless you have a pre-amp somewhere in there.

The ideal way to connect your guitar to your computer, from my experience, is through a cheap mini sound desk. You can buy something like a Behringer UB502 (http://www.behringer.com/UB502/index.cfm?lang=ENG) for about US$40. You connect your guitar to the TRS jack on channel one, then hook the Tape Out of the desk into your line in via a stereo RCA => stereo mini-TRS lead (like the one you'd use to hook your computer to your stereo). Plus you can add a couple of other sources if you want, and it adds in an extra EQ. Of course, when I do it, I go through a cheap Alto tube pre-amp first, then into the desk, but that's just me.

You guys have got me wanting to make a Jesusbox now. Kinda like an Ark of the Covenant for your guitar.

Edit: By the way: D.I. = "Direct Injection"

[smudge8]

My accoustic doesnt create any sound tho. I know the pickup in it works, it plays fine thru conventional amps.
Could this possibly have to do with the lack of impedance balancing thingy?

I have seen similar problems with my guitar and with an accoustic bass a friend of mine owns - let me guess, the end of the lead that goes into the guitar has got a tip, ring and sleeve? (ie, it's a stereo plug?) For some reason some accoustic pickups just don't turn on when you plug a stereo/balanced lead into their jack - it's like it screws with the 'lead is present' sensing or something.

Try a mono (tip & shield, or unbalanced) plug and see if that works.

If you're wondering about balancing, here's a quick lesson:
In conventional guitar leads, there are two paths - the 'live' lead down the center of the lead (the tip of the plug) and the 'cold' lead around the outside of the lead. The cold bit is also the signal shield - shield and return share the same path. This is called 'unbalanced'. Because there is no seperate shield, over long cable runs, unbalanced leads are very likely to pick up interference and suffer signal quality loss.

Balanced leads, on the other hand, have seperate 'hot', 'cold' and 'shield' leads - the 'hot' and 'cold' leads in a mic cable run down the inside of the cable with the shield surrounding them. But the shield never actually connects to the actual sound sources - only to their metal bodies sometimes. Because they're shielded, balanced leads are much better for running longer distances.

[Zevensoft]

Theoretically a balanced lead should run an infinite distance without noise because of the way that balancing works. One of the signal leads is given the inverse signal of the other, meaning that any noise gets added to both leads, which doesn't affect the difference between the leads (which is used to recreate the signal)

[blaze25]

how would i go about connecting my computer to my amp... i already have my guitar connected to my computer and i use some effects on my computer but no i want the sound to come out of my amp how would i do that?

[Newbie Brad]

My opinion only, much respect to others.

There is no impedence mismatch if the sound card is adjusted properly with the PC system audio mixer. And sound quality of guitar to guitar cord to 1/4-to-1/8-adapter to a stock HP soundcard microphone input with the PC system audio mixer adjusted properly is not objectionable at all. The PC system audio mixer has a monitor page and a recording page. In the recording page, the microphone channel has a advanced tab with a microphone boost switch. You can experiment with raising and lowering the volume on the microphone channel to eliminate clipping and also experiment with turning the boost off (it's an additional preamp) if you find the sound too hot or too noisy. You can set the microphone channel gain quite low to eliminate as much clipping and unnecessary noise as you want and use the gain and other adjustments in your amp sim software to get the simulated gain and amp tone you want. Another tip is to turn off the microphone channel on the system audio mixer monitor page and leave it turned on on the record page, then you'll only hear the guitar as processed by your recording, host and/or amp sim software, which is probably what you want to hear. Expensive sound cards sound great, but the stock one is acceptable to me without the additional equipment recommended in this thread. It is also good to have the shortest cord you can comfortably use, and you have to have an ASIO audio driver software for best results.