Angry Andy Plus - Bug or feature?

MichaelW

Well-known member
Hey guys,

I just finished building an Angry Andy and not sure if the boost is working correctly.

In non-boost mode, everything works fine.

In Boost mode, it works as its supposed to when the gain knob is 12 o'clock or less.

But if I turn the gain up any higher it starts squealing like a stuck pig. Not "good" feedback mind you, but uncontrollable squealing when there's no note being played. If I play through the squeal it works but as soon as I mute the strings its starts squealing.

If I put my finger on the boost stompswitch the squealing stops. I'm wondering if there's a ground issue?

But then why would it work fine when the gain is dialed back to noon? I searched and found a couple of old threads describing the same issue with no apparent resolution. Does this pedal just really need a noise gate after it at the highest gain settings?

Thanks in advance!

M-



IMG_2747.JPG IMG_2751.JPG
 
Ok, so I built Angry Andy #2 yesterday. Triple checked my component values, triple checked every solder joint for proper flow through.

And......it does the EXACT same thing heh......

I used RG174 shielded cable for the I/O cables, (even though shielding these didn't help the first one.

In the pic below is the setting where the squealing/feedback begins. Gain knobs needs to be above 1 o'clock (top right knob)
and the Boost level needs to be above 2 o'clock (lower right knob).

I think it's unlikely I would have made the exact same mistake twice on two builds spread 3 weeks apart, so I'm going to assume for the moment it's not a bad solder joint or wrong component.

Just thinking back on where I sourced the BS170's. I've gotten 2 batches, one from Tayda and another from GuitarPCB. Unfortunately, I mixed them all up in the same static bag, but I could probably sort them by lot number.

The IC's (NE5532) also came from 2 sources, one batch from Tayda and the other from Mouser, but I'm NOT sure which ones I used for which of these pedals.

The other possibility is that it's my power source. However, my whole rig runs off a Furman power conditioner. Maybe it's proximity to my computer monitors or something, but I'm planning to isolate everything today, plug an amp in on the other side of the house with just guitar, pedal and amp and see if it still does the squealing.

Last thing I did last night was order a real JHS AT Plus....heh....gotta love Amazon Prime! I'm going to see if the real thing does it too, in which case it would confirm that it's my environment and not my build.


signal-2022-04-03-200801_001.jpeg
 
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Adding to the story. Just for S&G's I swapped out the BS170 for a 2N7000, same problem, so I don't think I have a bum batch of BS170's.

I swapped the LM833 for an LM358. Same problem, so I don't think I have a bad batch of LM833's. Also I double checked, I got the LM833's from GuitarPedalParts.com, not Tayda.

I'll try the pedal on a different power circuit in the house later today and see if that makes any difference.
 
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Adding to the story. Just for S&G's I swapped out the BS170 for a 2N7000, same problem, so I don't think I have a bum batch of BS170's.

I swapped the NE5532 for an LM358. Same problem, so I don't think I have a bad batch of NE5532's. Also I double checked, I got the NE5532's from GuitarPedalParts.com, not Tayda.

I'll try the pedal on a different power circuit in the house later today and see if that makes any difference.
Can you put up a GOOD picture of PCB & Resistors for this Build!
 
You may want to read this:
Read the REVIEWS, especially the first one!
Hmmm....yah so maybe it IS operating correctly. Like I said, it's only when the gain is cranked AND the Boost is cranked.

Realistically I can't see anyone ever using this pedal that way, but then I'm not a high gain player, this is for a friend of mine.

I'd think if you wanted more gain you'd get something like a Boss MetalZone, but then wtf do I know, I'm just a blues noodler heh.

Well, I should have the real JHS AT Plus here in a couple of days, I'll see how the real thing works. Maybe dialing the boost is just a setting that needs to be nuanced.

So one thing I did try, since this is a "Boost AFTER overdrive design" I tried using a couple of boost pedals after the AA+. They all work fine, it sounds particularly good at high gain settings then boosting with a Greengage in clean boost mode after it.
 
I find this with most JHS pedals, He nearly gets it right, they always fall short.
I own alot of Original pedals & not one JHS!!!!
That's pretty funny actually. I've sold every JHS pedal I own hahah. I'm not planning to keep the AT Plus, just verify the behavior then return it.

I do have the PCB for the "Van Pelt" drive. I owned the JHS Charlie Brown for a while. It wasn't worth the $200 for me to keep it. But building one to use occasionally is something I'm down for. I don't think it sounds anything like a JTM45, as it's supposed to, but its still a cool sounding "amp-ish" pedal.
 
Maybe a silly question: but how’re you powering it? I’ve experienced this issue with a daisy chained wall wart supply when testing the pedal - both footswitches engaged with drive and boost past 3 o’ clock. As you said, that is way too much drive for my taste as well and a dirty power supply could’ve caused the squealing. I’ve never ran into this since as I’ve isolated supply on my board and that much gain is unusable for me.
 
Maybe a silly question: but how’re you powering it? I’ve experienced this issue with a daisy chained wall wart supply when testing the pedal - both footswitches engaged with drive and boost past 3 o’ clock. As you said, that is way too much drive for my taste as well and a dirty power supply could’ve caused the squealing. I’ve never ran into this since as I’ve isolated supply on my board and that much gain is unusable for me.
Not a silly question at all, I actually tried it with a dedicated Boss 300ma wall wart and took it out of my board (which has an unregulated PS, need to address that).

So here's some interesting new information. I got the actual JHS @ Plus pedal in yesterday and tried it side by side.
The JHS pedal does indeed feedback at high boost and gain settings, but it does not "squeal" like my 2 AA+'s do.

A few interesting observations:

1. The JHS pedal is a warmer sounding pedal, almost sounds a bit "muffled" compared to the AA+ builds.

2. The "Boost" feature of the JHS pedal does virtually nothing. I mean it's a "boost" in name only. It doesn't really boost the gain channel very much. It might be because there is so much gain already in the gain channel. I was incorrect in thinking this was a "boost after gain" arrangement, the boost side actually comes first.

3. I can "eq" match the AA+ builds to the JHS pedal by dialing the presence and eq knobs back about 20% (both my AA+ builds are much brighter than the JHS). When I do that, the squealing problem is much more mitigated but it's still there.

4. I was actuality thinking it might be "dirty power" from my house circuit, although my guitar rig all runs off a Furman power conditioner.

I have a couple more things to try to isolate the problem but I'm beginning to think that it might simply need a few tweaks to the components to tame the high end a little bit. At this point this is an academic exercise for me heh, it's way too much gain for me. At those gain levels it all sounds like "mush" to me with no real definition in my chording. I suppose if I played like Andy Timmons, I could make it sound good hahah.
 
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Not a silly question at all, I actually tried it with a dedicated Boss 300ma wall wart and took it out of my board (which has an unregulated PS, need to address that).

So here's some interesting new information. I got the actual JHS @ Plus pedal in yesterday and tried it side by side.
The JHS pedal does indeed feedback at high boost and gain settings, but it does not "squeal" like my 2 AA+'s do.

A few interesting observations:

1. The JHS pedal is a warmer sounding pedal, almost sounds a bit "muffled" compared to the AA+ builds.

2. The "Boost" feature of the JHS pedal does virtually nothing. I mean it's a "boost" in name only. It doesn't really boost the gain channel very much. It might be because there is so much gain already in the gain channel. I was incorrect in thinking this was a "boost after gain" arrangement, the boost side actually comes first.

3. I can "eq" match the AA+ builds to the JHS pedal by dialing the presence and eq knobs back about 20% (both my AA+ builds are much brighter than the JHS). When I do that, the squealing problem is much more mitigated but it's still there.

4. I was actuality thinking it might be "dirty power" from my house circuit, although my guitar rig all runs off a Furman power conditioner.

I have a couple more things to try to isolate the problem but I'm beginning to think that it might simply need a few tweaks to the components to tame the high end a little bit. At this point this is an academic exercise for me heh, it's way too much gain for me. At those gain levels it all sounds like "mush" to me with no real definition in my chording. I suppose if I played like Andy Timmons, I could make it sound good hahah.
I would try increasing the 100pf's up to 220pf for starters.
Try C6 first. See if it's for the better, then also change C3.
 
Not a silly question at all, I actually tried it with a dedicated Boss 300ma wall wart and took it out of my board (which has an unregulated PS, need to address that).

So here's some interesting new information. I got the actual JHS @ Plus pedal in yesterday and tried it side by side.
The JHS pedal does indeed feedback at high boost and gain settings, but it does not "squeal" like my 2 AA+'s do.

A few interesting observations:

1. The JHS pedal is a warmer sounding pedal, almost sounds a bit "muffled" compared to the AA+ builds.

2. The "Boost" feature of the JHS pedal does virtually nothing. I mean it's a "boost" in name only. It doesn't really boost the gain channel very much. It might be because there is so much gain already in the gain channel. I was incorrect in thinking this was a "boost after gain" arrangement, the boost side actually comes first.

3. I can "eq" match the AA+ builds to the JHS pedal by dialing the presence and eq knobs back about 20% (both my AA+ builds are much brighter than the JHS). When I do that, the squealing problem is much more mitigated but it's still there.

4. I was actuality thinking it might be "dirty power" from my house circuit, although my guitar rig all runs off a Furman power conditioner.

I have a couple more things to try to isolate the problem but I'm beginning to think that it might simply need a few tweaks to the components to tame the high end a little bit. At this point this is an academic exercise for me heh, it's way too much gain for me. At those gain levels it all sounds like "mush" to me with no real definition in my chording. I suppose if I played like Andy Timmons, I could make it sound good hahah.
The boost is indeed quite subtle as it adds gain to the drive circuit. This is due to it being a pre-boost, as you mentioned. You could rewire boost to be post-boost easily.The boost circuit actually reminds me of the AMZ MOSFET booster by jack orman. http://www.muzique.com/schem/mosfet.htm
The drive circuit is exact copy of mi audio crunch box (captain crunch) sans addition of 1k resistor in feedback loop. This probably keeps drive consistent but disables guitar vol knob cleanup, unlike crunchbox.

I like to use the boost side as a standalone push to my amp. It has a really nice mids centered crunch if you set amp just at or slightly past breakup. On a clean amp the boost reminds me of a klon boost with a very polished mid hump.. atleast on my setup I hear it that way YMMV.

I absolutely agree with your “AA+ is brighter” analysis. You could try mods suggested by music6000. What worked for me to take that chime away was a JRC4558. The LM833 is a very hi-fi chip with lots of good definition - but a tad “too defined” for my taste. I prefer the highly colored transistor stacked drives and distortions over hi-fi IC ones. Overall it’s a great sounding build.

One day I’d like to wire it as one or other effect with a single footswitch instead of two extremely close ones. Currently, I hit both to achieve that but that’s not very refined. If anyone has a wiring diagram they can link here that’d be cool.
 
When you say squeal, do you mean going to feedback ? Mine was having a lot of feedback. It was my first build, thought i'd come back to it later... well later was today.

First, i used a big enclosure to have a spot for a battery, and for my first build, it was a total fail due to bad planning :ROFLMAO:. But i used wires to move the pots apart. All was kinda loose. I twisted the wires together, tucked the in and output wires on the sides and guess what, no more feedback. That thing sounds so agressive but no more goes totallyout of control. Like some said, last 25% of boost knob brings some changes in the sound but that feels 100% more like normal.
 
When you say squeal, do you mean going to feedback ? Mine was having a lot of feedback. It was my first build, thought i'd come back to it later... well later was today.

First, i used a big enclosure to have a spot for a battery, and for my first build, it was a total fail due to bad planning :ROFLMAO:. But i used wires to move the pots apart. All was kinda loose. I twisted the wires together, tucked the in and output wires on the sides and guess what, no more feedback. That thing sounds so agressive but no more goes totallyout of control. Like some said, last 25% of boost knob brings some changes in the sound but that feels 100% more like normal.
Hmmmm, interesting. Do you have some pictures? I'd like to see what you did.
Not really feedback, more like a banshee screaming after it stubbed it's toe.....(do banshee's even have toes?)
 
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