So this is where I am with my Pandora...

I love the Honey Bee as a low gain overdrive, but if you expect it to sound like a rat at low gain, you might be disappointed. The Honey Bee has soft clipping LEDs, a different corner frequency for bass roll off, a different tone control configuration, the extra feedback loops... basically everything that gives the honey bee its characteristic sound (frequency response, clipping character, dynamics) is different than the rat. That said, I think both have their place as great effects.
 
Oh I agree! I've built and played the HB a lot and appreciate that there is a lot of difference between them! There are things I like and don't like about both. One thing I like about my modded Rat is that the low strings are quite clear at low gain, and that's something I really like. So if I can extend the low gain range a bit more - ie lose some of the really high gain area - that would be worthwhile for me. As it is I doubt I would ever use it with gain above 10.00!
 
Well, after getting my Expandora to sound amazing (better than I'd hoped) I have now also built myself a Rat which I really like. This is what I love about forums like this - one thing leads to another and you never know where you'll end up.

So today I built a Rat with the bass pot mod, used a 5n6 cap instead of the 3n3 on the tone pot, a 47nF input cap and an A10K gain pot. I also used a 3u3 cap from the 47R resistor on pin 2 to ground - not because I felt it tonally superior but because I ran out of 2u2 caps. :oops:

And it sounds great! With my Gibsons it's a simple, great sounding OD with a very tight but full low-end. I would like to increase the lower mids a little but it's a very usable overdrive as it is.

And all of this because of an Expandora.
 
So a small confession - the Expandora I built for this thread was on a board from Fuzz Dog. I have now built another with a Pedal PCB board and an exterior bass pot with what I have learnt from Chuck and it's a better pedal - again, thanks to Chuck. It seems that the Pedal PCB board is better designed because I have no issues with weird tremolo effects - in this case that is a good thing!

Pand02.png
 
So the changes from stock were the bass pot mod - which I can show a vero layout for - and I added a 330nF cap to C13 to make it a virtual 430nF cap. It does make a difference - it helps my Strat sound fatter and squawkier. If I was to build it again I would just use a 470nF cap for C13. This was from an idea from Fuzz Dog.

Here is where I added the cap - the board looks terrible in this pic. I think it's reflections because it doesn't look this bad in real life. o_O

pand01.jpg
 
And here is everything bolted down. You can see the bass pot mod very floating around there - don't worry, I'll be putting something around it to keep it safe.

Pand03.jpg

And here is the incredibly simple bass pot mod as described to me by Chuck. I grounded it at the output jack alongside the board ground. The connection to the board is underneath at the + connection of C9. I'm surprised at how much I like this pedal. It's actually a great sounding overdrive/distortion/fuzz pedal. It's a lot of fun and I am so grateful to Chuck to helping me get the most out of it. For me it is so much more useful than stock now. Not only can I get great Strat bridge pickup sounds from it but the neck pickup on the Strat is fantastic through this - really good!

Expandora bass pot.png
 
I don't see how making C13 bigger has any audible effect. C13 (stock value=100nF) and R19 (1M) have a 100ms time constant. That equates to a bass rollof freq of 1.6Hz. Adding 330nF in parallel with C13 extends the freq response at that point in the circuit down to 0.4Hz. Either you hearing is extraordinary or... ;)

Nice build though.
 
Yeah I don't know either! But it definitely made a difference, or else I'm crazy. Could be either. I am used to making changes to things which shouldn't work according to people far wiser than myself and finding I prefer it. I have been told that Sozo caps in amps don't sound any different from Orange Drops but I can hear it. I can't hear the difference with caps in guitars though when the tone knob is on full - and I have told that I should. I don't know enough to know when I should hear things or not but in general I trust my ears because they're the one thing I have no choice with. :)

I have tried to understand more about electronics but I get to a point where my head hurts and no more knowledge can fit. I don't believe in half the crap that mojo-guys try to tell me but sometimes I try something and it just sounds good to me. Maybe I nudged something else when trying out my pedal after installing the cap - entirely possible. All I know for sure is that I like this pedal a lot now and you're the one I need to thank for most of that - so thanks! It's great to have someone such as yourself help out and make my tinkering more worthwhile.
 
Listening is a subjective experience, which makes it next to impossible to be objective about it. Suppose we built two identical amplifiers, that 10 of us agreed sounded the same. Then you left for an hour and when you got back I told you I changed the caps in one of them from Orange Drop to SoZo. What do you think would happen when you listened to them after that?

The other mod I like for the Expandora, one that Bixonic did themselves on later models, it to replace the switches with a pot.
 
Here's what I did with mine...
I connected a C5K CONTOUR pot + 47uF cap + 22R resistor in series and then put them in parallel with C9. With the pot fully CCW, it's the normal Expandora bass rolloff. As the pot is rotated clockwise, more and more bass comes in until at full CW the response is basically flat from 50Hz on up.

View attachment 2114

I also added a CLIP switch, similar to what reubenreub did here.

BTW, all of those cap changes you made affected the frequency response below 4Hz. C14 might help a little if you're driving a real low impedance pedal. The bass response is really all about C8, C9, R6 & R7.
Just came accross your post, thanks for sharing! I imagine it sounds about the same as the Ruetz mod (adding a 1k pot between R7 and C9), am I right?
 
Both mods flatten the freq response as you turn the BASS knob up. The Ruetz mod lowers gain for the mids and treble frequencies. My mod raises the gain for the bass frequencies. If you use lower DISTORTION settings, then the Ruetz mod will work for you. If you prefer high DISTORTION settings, then my mod is the way to go.
 
Both mods flatten the freq response as you turn the BASS knob up. The Ruetz mod lowers gain for the mids and treble frequencies. My mod raises the gain for the bass frequencies. If you use lower DISTORTION settings, then the Ruetz mod will work for you. If you prefer high DISTORTION settings, then my mod is the way to go.

thanks a lot, I’ll keep using the Ruetz mod then as I really like the lower drive tones it offers. Thanks again !
 
Just saw this and figured I would try it out on my Pandora's Box. Currently, it seems like nothing happens until the knob is basically all the way up. At that point, I do hear some increased bass response. The rest of the sweep has no effect on the bass.

I went over everything multiple times and couldn't find anything obvious. Any ideas on what might be going on?

I'm using a C5k pot and grounded it to the output jack.
 
You should hear the bass sweep across the entire control range. You're connected to pins 2 and 3 of the C5K pot, right?

The effect is much more pronounced with the Rat because the Rat has more gain in the 2nd stage. Try it in Forbidden Mode.
 
I think the GATE control is totally optional. It's useful if you want sputter, but is otherwise not needed. Having two gain controls definitely adds flavor.
 
After hearing how Linjor's build sounds I went and tried my Pandora's box with the mod - and I think I hear what he is saying. There is a gradual rise in bassiness but most of it is at the end of most bassiness. And that's with a C-taper pot. I don't mind - I get what I want.

So I had a listen to a Rat I had built with a bass pot done in a similar way and which now sports a metal-can LM308n (!) and it behaves in a similar way. Again, it doesn't bother me. I get what I want.

So then, because I always have to know, I swapped out the 47µF cap for a 100µF. Ha! Now it's fun! Crazy FUN! Extra doom. And lots of varieties of doom along the way. Actually I can see it turning into a godawful mess with powerful HB pickups but with a Tele it's hilarious. Recommended.
 
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