Guitar to PC Line In: What's the delay?

[geo]

I've got my guitar plugged into a headphone amp, and I'd love to send it into the PC after that so I can pass it through some filters and listen to the sound live, but even when I've got the stereo mix turned on and it's not going through any additional programs or anything there's a 0.25-0.5 second delay between playing a note and hearing it through the PC speakers. What's the fix?

Headphone amp works fine on its own, PC runs Windows 7 on whatever integrated soundcard they have on the Lenovo Y500.

[roadtonever]

First off, unless you have active pickups or a Hi-Z instruments input in your sound card there will be an impedance misstach and your tone will likely suffer.
The solution is connecting a dedicated DI or a buffered pedal in bypass mode between the guitar and sound card. Check the specs and look for an input impedance of 1MΩ and output impedance of 1.25kΩ or less.

As for the delay thats perfectly normal. For realtime monitoring and recording you use a low latency ASIO driver and DAW. If your soundcard doesn't have the former try this: www.asio4all.com/ For the later try this www.mutools.com/index.html or this www.acoustica.com/mixcraft/

[ashcatlt]

Half a second is not really normal on a modern machine, but I think a lot of people overestimate these things. You should really try to find yourself a decent interface with an instrument/DI input.

[ux4484]

I have that same laptop, and the conjoined mic/headphone jack does generate some significant latency processing through the built in sound card. There are any number of 1/4 to USB adapters that can do what you want at Amazon on the cheap, often packaged with software that don't require an ASIO compatible DI and software package to make work. I saw one of those first act ones in clearance at Target for $5 and while it doesn't sound as good as my line 6 ux1, it's much easier and faster to hook up and use (seen by the computer as USB line in (mic) audio as well as by ASIO software packages), this means you can use audacity with it (audacity requires hacking to use most ASIO DI devices).
You may have to go into your windows audio settings and enable the USB audio device (usually seen as a USB microphone) once connected to get it to work.

[geo]

Would the ASIO driver fix the issue on my sound card without the need for a USB adapter, or will I need that adapter either way?

I wouldn't worry about impedance mismatch; I'm going from the guitar to a headphone guitar amp to the computer's sound card, I didn't just plug it directly in.

[ux4484]

It's possible, but you'll likely still have some noticeable delay from the sound card processing the audio, and even then, it will only be in audacity. I am not aware of a way to stock replace the windows audio driver with ASIO.
Most ASIO drivers prefer a USB connection so they can recognize the device utilized to bypass the slower windows sound driver. The technology is licensed as such by steinburger who seem to take issue with generic drivers for free/donateware like audacity. You can compile a version of audacity to do what you want (google: audacity ASIO) and mess with your windows settings to get it to work, but honestly... a $9 Amazon 1/4" to USB adapter will do exactly what you want so much easier, can be used with or without the headphone amp, and work in ANY software you might want to use.

I've used my $5 cable to record spoken performances line out from a mixer and live monitored on the computer with hardly any discernible delay. It's simple, and a treat by comparison to 1/4" to 3.5mm adapters and futzing around.

[sumgai]

geo,

As you poke around looking for solutions, I want to give you a heads-up on terminology.

In audio-speak, a delay is intentionally inserting some time in the loop between the inputting of a signal and the arrival of that signal at the output - commonly, this is called "Echo", but it is a delay function.

Comparatively, when the output does not arrive at the output when expected, that's called latency. Yes, in normal English that would also be a delay, but think... we're speaking of a specific technical field here, that of audio, and even more specifically of musical instruments and effects. When you see the word 'latency', you are looking at the problem you first described, that of a half-second's worth of time between the input and output. Devices and/or software designed to reduce or eliminate latency are what you want/need, not devices/software that reduce a delay - those would be nothing more than shortening the time of an echo.

I know, I know, it's nit-picking, but.... I'm hoping to reduce your frustration factor when you search for help on The Great White Innerwebs. Techno-weenies can be such dorks when it comes to stating precisely what you really mean, and not what you think you mean.

Personally, I'd go with ux's proposed solution. Even if money werent' equal to time, simply reducing the hassle factor has to count for something.

HTH




sumgai

[lunaalta]

I get about 30 m/sec latency on my music computer, using a Tapco Link firewire interface, into Sonar 8 Pro.
The computer is using XP/Pentium 4,CPU 3 Ghz, 3 GB RAM. Certainly not the latest, but good enough for recording/doing what I want to do.
Not good enough to listen to live sound running through effects, in the way you describe.......

In the past, I used ASIO4ALL with Audacity and other programs, including Krystal. Worked fine, but still latency.

If that helps......

[geo]

Thanks for the help! I'll explore ASIO drivers, then look into that cable, see if one/both fixes things. Also, thanks for the terminology correction; communication is key!