What if you could have one of each guitar--free?

[Tonegeek]

Gregor's post with the multiple amp/guitar videos gave me a crazy idea: What if we had a way to share our guitar clips - so instead of hearing clips of others amps we could hear our own amps with other's guitars? This would be the ultimate way to compare one amp against another because the input would be exactly the same for each. This would be the raw sound of the guitar recorded directly from the guitar output jack onto an MP3 or some other emailable/postable format. It would be so cool to be able to output say 'Dogears' Baker B-1 or one of Gregor's guitars into our amps for a reality check on what someone else's guitar might sound like. Great for tweaking purposes. In my case, I would love to hear some humbucking types through my amp since I am now humbuckerless (sold my Reverend). The trick is to get the voltage and frequency range coming out of the sampled guitar to be the same thing going into the amp on the other end.

I know there are some technical challenges to doing something like this correctly, but it should be possible.

Here's one way this might go:

1) You would need an impedance matching/loading device between the guitar and the computer. Ideally this would load the guitar down similar to a tube amp input (not much). Maybe some FET thingy would do.
2) On the other end you would need an impedance matching device to go between the computer and the amp.
3) You would need a computer and some software for recording mp3's. The biggest challenge is to get the level going into the recipient's amp to match the level coming off the guitar's jack. One low-tech, inefficient way to do this is to get a voltage reference and record a few test tones. For example: Dogears would play an 'A' on the open fifth string and measure the voltage with a voltmeter (The guitar would have to be plugged into the impedance matcher while it is being measured to put the proper load on the output). To make it more accurate (compensate for pick attack), Dogears would do 3 takes of a few seconds each and then average the readings. He would then record 3 takes the same way. Then he would record the phrases he wanted to use as his guitar sample sound. This mp3 and the voltage measurement would then be emailed to the recipient or posted on Ampgarage.com.

The recipient would play Dogears test tones and measure the output after the inpedance matcher (while plugged into the amp for proper loading) and adjust the output to be the same voltage that Dogears sent for his test tone average.

Once the signal is calibrated, the mp3 can be played.

Some limitations are:
1) requires some special equipment (most of which I bet most of us already have except maybe the impedance devices.)
2) Freq. response of each user's equipment. Since we are dealing in guitar frequencies, this should not be too much of an issue.
3) If impedances are not similar from one user's computer to the next, this could be an issue. I expect most sound cards would have line ins/outs meeting some standards for the industry.
3) since the guitar is missing on the recipient end, you get no feedback which would have an affect on the sound.
4) requires a group effort as recordings would have to be made. (hey at least you don't have to worry about mic placement, or waking the neighbors LOL!) And, for each guitar (and pickup combination), you only have to record the test tones and voltages once. Those can be re-used from then on until you change pickup adjustments, etc.

I may try fooling with this on my own but If anyone is interested in pursuing this as a project, let me know. Might need some EE types to weigh in on this pipe dream...

[benoit]

re-amping is done all the time in the recording world. You might try searching tapeop's message board for info, or post if you don't find anything.

[LeeMo]

You might get some ideas here:
http://www.amptone.com/reamp.htm

LeeMo

[stelligan]

http://www.radialeng.com/re-prormp.htm

[stelligan]

http://www.radialeng.com/re-prormp.htm

[odourboy]

I've done exactly as you've described to help a friend dial in his D-clone. It worked surprisingly well and was easier that I thought it would be. We took a pretty low-tech approach. I used a Voodoo labs amp selector pedal (which provides buffering and outputs for up to four amps simultaneously) and used one output to drive my amp, and a second which I fed into my mixing board and into a PC for recording. I set everthing for unity gain. Ripped the tracks to MP3 and emailed them to my buddy. He used a Zoom handheld player/recorder (H4?) to play them into his amp. Worked like a charm. I could also play them back through my amp selector and it recreated the guitar input - great for tweeking becuase there's no playing variation between trials.

Ideally, you'd want to include a test tone so you can get the levels set exactly right.

I'd love to have some raw Dogear's clips to mess with! My own playing is pretty lame in comparison.

[Tonegeek]

I've done exactly as you've described to help a friend dial in his D-clone. It worked surprisingly well and was easier that I thought it would be. We took a pretty low-tech approach. I used a Voodoo labs amp selector pedal (which provides buffering and outputs for up to four amps simultaneously) and used one output to drive my amp, and a second which I fed into my mixing board and into a PC for recording.

Good idea, the amp as the monitor probably helps you play with better dynamics

I set everthing for unity gain. Ripped the tracks to MP3 and emailed them to my buddy. He used a Zoom handheld player/recorder (H4?) to play them into his amp. Worked like a charm. I could also play them back through my amp selector and it recreated the guitar input - great for tweeking becuase there's no playing variation between trials.

So does the amp selector take a line level input too (I assume line level is coming from your PC soundcard for playback)?
If not then this looks like the ticket for playback:

http://www.radialeng.com/re-prormp.htm

Ideally, you'd want to include a test tone so you can get the levels set exactly right.

Yep, to be near perfect you would want to match the voltage of the guitar output to the end user's voltage at the amp input using the test tone although you could maybe skip this step if you are mostly just doing tone tweaks and not gain tweaks.

[mdroberts1243]

I use a Zoom H4 all the time this way. It is possible to rig it up to take the 1/4" input from the guitar and record that, take an SM57 mic'ing the cabinet into the XLR input and record that on a second channel. You arrange the monitor output levels so that only the 'dry' guitar signal appears on the headphone jack and adjust the headphone volume control on the side of the H4 to set the equivalent original guitar signal level, then pipe it into the input jack on your amp. The player gets all the dynamics of the amp and you get a reference recording with a dry guitar recording that you can use in subsequent testing.

I found this indispensable when I was trying to get to the root cause of the 'double-stop IM' problem on my Bluesmaster build... see "BM Double-stop OD Problem" https://tubeamparchive.com/viewtopic.php?t=4430

The IM problem only became nasty with a particular player/guitar/pickup combination and the dry clip I recorded was able to duplicate the issue perfectly (and you could tell the problem wasn't in the 'dry' version to boot!). (BTW I provided a dry clip in that post that you could use to see how your amplifier responds).

I have used this as well to a/b/c/d... test different tweaks and listen to them back to back. I notice that Eminence used dry-clips and the same cabinet/amplifier to make a very good serious of comparisons between the various speaker drivers on their web-site too.

I would love to have some really good playing captured this way so that we could all share comparative recordings of amplifier/speaker/cabinet/mic'ing!

I've done exactly as you've described to help a friend dial in his D-clone. It worked surprisingly well and was easier that I thought it would be. We took a pretty low-tech approach. I used a Voodoo labs amp selector pedal (which provides buffering and outputs for up to four amps simultaneously) and used one output to drive my amp, and a second which I fed into my mixing board and into a PC for recording.

Good idea, the amp as the monitor probably helps you play with better dynamics

I set everthing for unity gain. Ripped the tracks to MP3 and emailed them to my buddy. He used a Zoom handheld player/recorder (H4?) to play them into his amp. Worked like a charm. I could also play them back through my amp selector and it recreated the guitar input - great for tweeking becuase there's no playing variation between trials.

So does the amp selector take a line level input too (I assume line level is coming from your PC soundcard for playback)?
If not then this looks like the ticket for playback:

http://www.radialeng.com/re-prormp.htm

Ideally, you'd want to include a test tone so you can get the levels set exactly right.

Yep, to be near perfect you would want to match the voltage of the guitar output to the end user's voltage at the amp input using the test tone although you could maybe skip this step if you are mostly just doing tone tweaks and not gain tweaks.