Substitute guitar signal best practices

[wjmwpg]

I'm looking for recommendations on how best to provide a guitar signal to my prototypes while experimenting with different component values/configurations, etc.

I started with "dry" guitar recordings played into my circuit through a reamp box to correct the impedance (to something "guitar-like"), but quickly found that my fuzz circuits react very differently when I play an actual guitar into them vs this kind of reamping playback setup.

So as I've been making some final tweaks over the past few days I've been doing it with a guitar hanging around my neck, which is really awkward when standing at a work bench trying to swap one cap value for another, or turning a trimmer with a tiny screwdriver, all through a spaghetti-sea of wires, and have woken today with a major kink in my neck as a result.

So any insights from those of you who have found a better way will be hugely appreciated!

[Mark Hammer]

Get a cheap looper and record the sorts of phrases you'd likely want the effect pedal for.

[wjmwpg]

Thanks Mark. I've never used a looper pedal. Do you find "old" fuzz circuits respond to the signal from a looper similarly to how they would respond to the same signal coming directly from the guitar?

[Mark Hammer]

Haven't tried it, but there is no reason why they shouldn't.

[wjmwpg]

Copy that. I'll buy a DITTO and report back.

[DIY Bass]

If the looper by itself doesn't work then Jack Orman's pickup simulator after it will probably help

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

[wjmwpg]

Yeah, I've ordered the transformer already! The one thing I wasn't sure about is adding the tone pot and cap as it will create a peak and roll-off on the signal when really that has already happened in the guitar itself when recording the loop. So I've been thinking I'll put that part of the circuit on a switch so I can try it with only the "inductor", or with the entire emulation circuit.

[PRR]

> fuzz circuits react very differently when I play an actual guitar into them vs this kind of reamping playback setup.

Levels must be MATCHED, live versus tape. When played clean, your neighbor (who can't see you) should have no way to tell if it is fresh or canned.

[wjmwpg]

I have perfectly matched the level of my guitar into my circuit with the recording of my guitar (through reamp transformer) into my circuit. The circuit reacts to each very differently.

[anotherjim]

I don't think there is any substitute for a guitar. My reasoning is that the sound you get causes an experienced player to modify the picking technique to suit, and does it subconsciously. To put it another way, a recording won't play how you would play with the current sound.

A loop recording would just give me listening fatigue and that will cloud my judgement. On top of that, you have the already mentioned fact that the electric source characteristic of a guitar isn't present in a recording device.

I find that with the bench and seat at the right heights, I can sit with a guitar on my lap and still be able to reach over and see the breadboard. Somebody took it further and had their test guitar on a swing arm mount.

It will sound different again anyway when used at stage/rehearsal volumes. It's an iterative process. Some have made breadboards in a stompbox or other screened enclosure to take away for final judgement.

[wjmwpg]

Yeah, this is quickly the reality I'm accepting, but I thought maybe someone out there had discovered a golden solution. Nevertheless I'm going to try a looper pedal and Jack Orman's pickup simulator circuit (separately and together) to see how close I can get a "playback" signal to behave like a played signal. The closer I can get the less drastic the change in circuit response will be when I have to plug the guitar in.

I may have to change my work area from a standup to a sit-down design. With the standup bench I can't sit with guitar in my lap, so all the weight is on my shoulder, and when I lean forward to futz with the circuit the guitar wants to swing forward and smack into the bench - it's awkward. And my penchant for heavy guitars is coming back to haunt me now.

[edvard]

I'll second the looper and pickup simulator idea, but if you have the spares, maybe try this:

At Trading Musician in Seattle, they had a pedal test bench behind the counter which was a guitar neck, pickups, knobs, and a hardtail bridge bolted to the side of the bench and strung up (never in tune, but it didn't matter), and two cables snaking from the back of the bench; one from the pickups, and one to a small amp.  Plug-plug-click-strum=pedal good/bad.  If you have a spare neck or even just a couple of anchor points for some old strings and a spare pickup to screw under them, you have quick out-of-the-way method to generate string noises.  Tune it to your favorite open chord and grab a slide and one of your parents have a brother named Robert.  Even cooler if you have an Ebow...

[wjmwpg]

Huh . . . This never crossed my mind. I like it!

[ElectricDruid]

I have perfectly matched the level of my guitar into my circuit with the recording of my guitar (through reamp transformer) into my circuit. The circuit reacts to each very differently.

This indicates to me that the circuit under test is badly designed. It's clearly very sensitive to the impedance/capacitance/something of whatever feeds it. That means it won't respond well to many guitars. It'll be one of those effects some people love because it happens to sound decent with their gear and other people don't understand what those first people are on about because it sounds terrible with *their* gear.
There are plenty of very basic old fuzz circuits like that, but we're much better than that these days and we design stuff that everyone can make work.

A Ditto looper and a guitar at the same level are the same thing for any decent effect circuit. It's an identical audio input, and that's all it is. If the circuit uses characteristics of the input beyond that, it's going to cause problems.

[wjmwpg]

I totally get where you're coming from, but this was my goal from the start. There are a multitude of pedals makers out there more adept than I at making the "stable stuff", and I respectfully leave that to them, and buy those from them.

In "stock" FY2 mode my pedal is solid (well, solid as any FY2), but with successive toggle switch flips (changing component values and routings) it becomes more and more "unstable", finally to the point of oscillation, which you can "play" or tune with your guitar pots. I love dialling in those settings on the verge of collapse where notes ring through the chaos, only for the chaos to re-emerge as the notes die. It's a gnarly beast. And it does react very differently to my different guitars and pickups, which I'm thrilled about - I'd be bummed if it didn't.

[ElectricDruid]

It's a gnarly beast. And it does react very differently to my different guitars and pickups, which I'm thrilled about - I'd be bummed if it didn't.

Fair enough. If that's the design goal, then it sounds like you've nailed it! A gnarly beast, as you say!

[wjmwpg]

I really should've been clear about that from the get go, as it is the primary reason I need some kind of signal provider that most closely replicates guitar pick ups and controls... Also probably why there's no real solution outside of a guitar. That said I'm loving the idea of building a guitar into the side of my bench.

[BJM]

Haven't tried it, but there is no reason why they shouldn't.

I read somewhere that some pedals don't work well with buffers before them? I suppose a looper will also act as a buffer?