Messages

Well that was a stupid question, you are totally right. I biased it wrong. Now that I've done it correctly (and know how to read a JFET schematic symbol) the FAT knob issue is gone and there is ample headroom on tap. Thanks!

[really]

Just finished a successful Fatpants build - I absolutely love how it sounds with my tele! The one issue that I'm having, however, is that I mostly play a pedal steel guitar with really high output pickups which is causing the pedal to distort quite noticeably. For example, I had to tweak the internal trims on my Keeley Compressor to keep it from clipping. I plan to use the fatpants as a tone shaper quite often instead of a volume boost, so keeping a pristine clean signal at unity gain is preferred.

My question - what's the best way to do this? I'm a bit of a noob - the way I know to do it would be to add a little trim pot between the 3pdt and the circuit board to cut down the input level. Is there a more elegant solution? If not, what's the best pot resistance value to use? The fatpants is always after a buffer (Cornish buffer clone) built into my pedal board.

Thanks in advance!

P.S. one little question, is the volume supposed to drop out when I max out the Fat control? The very last few degrees of travel in the knob completely cause the output to reduce to zero (no volume loss effect is seen elsewhere in the travel of the knob).

Thanks for the reply guys! I had another fatpants board for another build (this time integrated with another pedal) so I went ahead and built that for comparison. It is perfectly noise free, so now I have a reference when comparing voltages and such. I think I can take it from here but will report back if I can't figure it out.

I had some time tonight so I poked around with an audio probe. The noise is introduced right at Q2. I replaced it with another J201 and it reduced the noise to a usable level. The swirly sound is still there, just not very noticeable at unity gain (it is definitely noticeable at higher boost levels though). Any tips on reducing it further? Other than that I am incredibly happy with how it sounds!

Also, the body switch seems to add a lot of volume, is this normal?

Thanks for your time!

Hi All,

I just completed my first build, Fatpants 2012 edition (no mods or swapped parts). I think that it sounds great, but I am getting some swirly noise whenever the pedal is engaged. I have uploaded a youtube video demonstrating the problem:

I didn't quite know what I was doing with grounding so maybe that's the issue? I tried another 3PDT switching diagram but that didn't help. Or could it be a bad component somewhere? I adjusted the trimpot so that I get exactly 9V over Q2 so I don't think that's it. Any advice would be much appreciated. Also as you can hear from the video I'm getting a lot of "pop" when you engage the switch.

Thanks!

I guess I'm thinking about something similar to the Durham Buff Master Pre - i thought the fatpants would be a good base as many people seem to be using it as an "always on" effect.

http://www.durhamelectronics.com/products.html

9Lives, thanks for the info - I will check the amz site out.

jkokura - it is definitely possible that I am misunderstanding things. Here are my observations - my amp has 2 patches, one before and one after the EQ section of the preamp. I have found that my steel sounds better/more alive running straight into the amp and then with all of my pedals in the pre eq section of the amp than it does going guitar => pedals => amp. The first pedal in my chain is a boss TU-2 that is always on in the bypass mode, so my signal is hitting a buffer already. I just figured that the difference that I hear may be due to a cheap and/or bad buffer in the TU-2. Am I mistaken? FYI the amp is a Peavey Nashville 112 (it's a pedal steel amp).

Thanks!

Thanks for the response, especially the pickup info. I guess the buffer questions come from this in the PDF:

The 2012 version adds a JFET input buffer, a new Body switch for high-gain/full spectrum boost and a re-tooled output section.

I'm wondering if it's possible to somehow enable a mode where it just uses the input and output buffers but skips the boost circuitry?

Hey everybody, please forgive my ignorance as I'm new to a lot of this. I'm thinking about building a fatpants as an always on kind of pedal at the start of my board - basically a buffer with some coloration, and i might twist the volume knob a bit when I'm about to take a solo. A few questions:

• Does it have a pretty good (high) input impedance and low output impedance?
• Can it handle really hot pickups? I mostly play pedal steel guitar and my output is hot - for example I had to really play with the internal trims on my 2 knob keeley compressor to get it not to clip
• Finally, how easy would it be to wire in a switch that would bypass the boost circuitry and turn it into just a simple buffer? What section of the circuit would I bypass?

Thanks so much!
Kevin