I've always used 1 MOhm input impedance inputs for the Stick whether it be preamps or effects. Not deliberately, but that just seems to be the typical value for these things. I've never closely A/Bed the difference between preamps with 1 and 2.2 MOhm input impedances and would suspect the difference is on the subtle side, given that the 2.2 M impedance would be a bit more appropriate for a full range passive pickup.

When Greg stopped by a couple times and I tried out the StepABout with the PASV-4 pickups, it sounded great. Afterwards I went back and was able to improve the sound of my effects by starting with a dry tone and playing with input level knobs and switches to get closer to what I was hearing with the Stepabout.

Agreed Rob...you have to start using phrases like 'singing highs', 'lively mids' and 'warm lows'

I have A/B tested 1 MOhm vs. 3 MOhm and for me the difference is not subtle. I much prefer 3 and I suspect that 2.2 would be very close to 3 in sound. The difference is not just in the highs, the lows are improved, too. For me the StepABout seems like the ideal Stick starting point. However, I'm still saving for my 12-string and the StepABout will be a ways after that. For now I'm making due with DIY preamps and buffers made from circuits I find on the web.

Hi Eric, I''m curious which specific devices you tried here, since I'd like to learn as much about this as I can.

One issue of concern is using a standalone preamp with guitar effects that only accept high impedance inputs... I've had noise issues in that regard (low impedance preamp output going to high impedance guitar effects input)... it seems better to use effects boxes that accept line level signals in that case. My Boss GX-700s have been progressively crapping out on me so I'm trying to decide what effects direction I want to go before deciding whether a high-quality preamp is necessary (the VG-99s have 2.2 MOhm input impedances, which might make a StepAbout redundant).

The dynamic quality of the circuit is also very important. The StepAbout has a fast response time so it preserves your dynamics better than most transistor preamps would.

Hi Greg;

I assume when you mentioned "fast response" you're talking about Slew rate which is the amout of delay a given circuit or device will add to your signal. "Dynamics" have more to do with the headroom of the device (component) and the power supply that's running it. Generally speaking, pre-amps that use op-amps have a much poorer slew rate performance than pre-amps that use a discrete transistor design. The fewer components used in the signal path, the better. Op-amps contain VERY MANY transistors.

I actually prefer tubes (valves) in pre-amp designs and I'm currently working on a tube stereo instrument pre-amp that I plan on marketing in the future.

Regarding input impedance, in a blindfold test, I doubt anyone could tell the difference in sound between a 1 megohm and a 2 or 3 megohm input impedance. Input impedance is a trade-off, as Rob mentioned, as your input impedance rises, noise starts to become an issue, so while you may be squeezing that tiny bit of very high frequency response out of your input circuit, you are at the same time adding introducing noise.

Just some food for thought.

Good luck with your preamp. I'll be curious to check it out when you're done. The more two-channel processors out there the better.

Perhaps a separate thread about the unit is in order, I'm feeling like a bit of a hijacker....