Frequency Central Stasis Leak build thread

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DJMaytag
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Frequency Central Stasis Leak build thread

Post by DJMaytag » Mon Feb 17, 2020 11:18 pm

Working on a Frequency Central Stasis Leak module at the moment, and am scratching my head at what appears to be a mistake on trace routing.

There’s a 33R resistor on the jack board which is in between the 9V voltage regulator and what’s supposed to be pin 1 on the ABE FX chip, but as far as I can tell... it’s being routed to pin 13, based on all the markings on the PCB, both a label and the fact that there’s an square pad at what’s labelled as pin 1. There’s also a picture of the ABE chip installed the way it seems to be correctly installed in the build guide.

I was at first having problems getting ANY effect sound, as voltage at pin 1 was VERY low (3.8V, should be within 5.5-9.5V) and pin 13 was up around 5V. I swapped in a 15R in place of the 33R, and that seemed to put the voltage within range of proper operation for ABE’s pin 1, getting it up to 7.2V. I managed to get the reverb working, albeit poorly, and no controls were working. However, I realized that was checking for and getting 7.2V at PIN 13, not pin 1!!!

So I went back and checked pin 1, and it was up slightly to 4.2V, which maybe was just enough to get the FX chip to work. I then looked into checking the voltage at pin 8 (GPIO 1) to determine if the 3-position switch was working. NO CHANGE when flipping the switch. For shit and giggles, I counted backwards and found that the switch voltage was going to, and working within the proper ranges, at pin 6!!!

I’ve taken a good bit of time the past couple days to reverse engineer the PCB’s, using a continuity meter to trace where things are going on the PCB’s as well as where they’re going on the other PCB once they hit the board bridge. Can anyone else verify what I’m getting?
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Re: Frequency Central Stasis Leak build thread

Post by DJMaytag » Mon Feb 17, 2020 11:34 pm

ABE FX chip spec sheet, with schematic that matches 100% to what’s in the Stasis Leak build, or is supposed to match it 100%:

https://frequencycentral.co.uk/wp-conte ... on_ABE.pdf
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Re: Frequency Central Stasis Leak build thread

Post by Just another rookie » Wed Feb 19, 2020 1:23 pm

Did you email Rick?
He’s a cool guy.

Add some of your build pics to save your self some time.

I’m current engaged in conversation with him but I’m too distracted in the real world to concentrate on learning what I did wrong or perhaps how to identify a fault?

Sometimes it takes a day or two, but he has never let me down with a reply.

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Re: Frequency Central Stasis Leak build thread

Post by Just another rookie » Wed Feb 19, 2020 1:52 pm

Could the 9v regulator be involved somehow?
That should be the feed to pin1? Vdd

Looking at the schematic.....
9v > 33r > pin 1 of Belton abe.

The output pin of the 9v reg is nearest the 47uf caps.
The 10uf cap between the reg and the 47s is the smoothing cap? For the 9v line. (9v Smoothing Includes the 100nf polytop)

Pin 13 takes a 4.5v ref from the 9v reg which is set by the multi turn pin 2.

He was kind enough to supply me a schematic but it is not my property.

Are you getting 9v at the output of the regulator?

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Re: Frequency Central Stasis Leak build thread

Post by DJMaytag » Wed Feb 19, 2020 6:54 pm

Just another rookie wrote:
Wed Feb 19, 2020 1:52 pm
Could the 9v regulator be involved somehow?
That should be the feed to pin1? Vdd

Looking at the schematic.....
9v > 33r > pin 1 of Belton abe.

The output pin of the 9v reg is nearest the 47uf caps.
The 10uf cap between the reg and the 47s is the smoothing cap? For the 9v line. (9v Smoothing Includes the 100nf polytop)

Pin 13 takes a 4.5v ref from the 9v reg which is set by the multi turn pin 2.

He was kind enough to supply me a schematic but it is not my property.

Are you getting 9v at the output of the regulator?
I discovered the short, which was at the ground pad of the Time CV jack. I was using a PJ301 jack, and removed it, and the shirt went away. I resoldered a new jack back in place, and... the short came back. I couldn’t figure out why, as inspection under a magnifying glass showed no visual short. It. Ugh the that some solder was creeping onto the ground pad from the square pad. The distance between those two pads is pretty small.

The solution? I used a PJ138 and soldered a resistor leg to the PJ301 jack next to it, such that I’m not using the ground pad on the Time CV jack at all.

I’m still getting 4.5V at pin 1 and 7.2V at pin 13, but that seems to make sense, just... opposite, for whatever reason. Yes, the regulator is definitely putting out 9V, but even with a 15R in place of the 33R, it’s only giving 7.2V to the ABE chip. I guess that’s within range, so I’m not going to lower it any further.
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Re: Frequency Central Stasis Leak build thread

Post by DJMaytag » Wed Feb 19, 2020 7:03 pm

Just another rookie wrote:
Wed Feb 19, 2020 1:52 pm
He was kind enough to supply me a schematic but it is not my property.
Schematics are definitely helpful, but taking the time to sketch out the traces is something that I think can be helpful understanding a circuit better than being handed a schematic. Learning how to troubleshoot something sans schematic is a good learning experience, and is helpful to figuring things out faster IMHO.

That said, this design is based largely on the schematic on the ABE FX chip suggested design, so having that was a pretty huge help. That’s also why I was confused as to why pin 1 and 13 seem to be reversed.
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Re: Frequency Central Stasis Leak build thread

Post by DJMaytag » Wed Feb 19, 2020 7:31 pm

C397D2F8-6B35-4094-BC7F-8B949431E711.jpeg
E060DFEA-2523-48D2-B2F4-A9835E46C9BE.jpeg
Maybe it’s just an optical illusion with that white line between the pads on the component side, but it LOOKS like the pads are dangerously close compared to the bottom side. Doesn’t it?

This is a second Stasis Leak PCB set, which I’m pretty sure I will always order whenever I build something for the first time. I’m glad I had this handy to refer to when I needed to figure out signal paths via continuity tracing, which wouldn’t work on a built board with a short somewhere.
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Re: Frequency Central Stasis Leak build thread

Post by Just another rookie » Mon Feb 24, 2020 12:39 pm

I wish I had the technical knowledge to deal with any problems I had or may have!
I agree with the idea of “there’s nothin like hands on for learning!”
But the constraints of time/life hold me back somewhat.

I’m pretty sure the case around the jack would impede the flow of solder. Along with the solder mask. That does a good job of keeping gear on the pad.... even if you whack loads on it still forms a great ball on the pad. I think you would need to feed a shoelace amount of solder to overflow that. But it can happen!
And you’re soldering from below, without the silkscreen....
You would notice from the direction you're soldering from, which in my experience takes on more solder than the backside way before you bridged that.
Hopefully I have that right!
Just my thoughts anyway, really some pros could chime in with some educational pointers!

I haven’t got to the root of my issue yet but I’ve been real busy! So far I’ve had some help but i still need to dig a bit deeper! It’s only the second time I’ve had to debug so you probably know more than I do!
Either way,
It’ll probably involve some new tools! Yay!!!!!!

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Re: Frequency Central Stasis Leak build thread

Post by DJMaytag » Tue Feb 25, 2020 11:48 am

Just another rookie wrote:
Mon Feb 24, 2020 12:39 pm
I’m pretty sure the case around the jack would impede the flow of solder. Along with the solder mask. That does a good job of keeping gear on the pad.... even if you whack loads on it still forms a great ball on the pad. I think you would need to feed a shoelace amount of solder to overflow that. But it can happen!
And you’re soldering from below, without the silkscreen....
You would notice from the direction you're soldering from, which in my experience takes on more solder than the backside way before you bridged that.
If you’re doing a good job of soldering, it should flow through the pad and look nice on BOTH sides. In reality, I often have to touch up the other side. FWIW, I usually solder as much as I can from the top side, such that the legs are hanging down through the PCB, as SynthDIY guy (Quincas) on YouTube does.

Obviously I’m not doing that with the jacks, but with the jacks being secured and foremost to the panel and THEN soldering in place, the bottom of the jack doesn’t always fit snug up against the PCB. It’s still possible for the solder to curl up and touch the ground pad, especially if there’s any sort of pad debris/shards between the two pads. I’d have to get a microscope to see if that indeed is happening on these, but it kinda looks like maybe something is in between the two pads, with the naked eye.
Just another rookie wrote:
Mon Feb 24, 2020 12:39 pm
I haven’t got to the root of my issue yet but I’ve been real busy! So far I’ve had some help but i still need to dig a bit deeper! It’s only the second time I’ve had to debug so you probably know more than I do!
What’s your issue? Maybe I or another observer might be able to help?
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Re: Frequency Central Stasis Leak build thread

Post by Just another rookie » Tue Feb 25, 2020 12:58 pm

Here’s my effort.
3A87643F-3E4A-4F00-9C56-A8599FDF8D41.jpeg
5E4CCBDF-6632-42CC-A2D4-94B27F877F27.jpeg
C5400495-9F2E-4A1E-8DBC-C70C518FB5E5.jpeg
15C09E47-A94B-4FEC-A973-9B6C962051C2.jpeg
Still needs the tap tempo switch but it will work fine without that.

I’ll dig out the notes I have maybe.
That could well be useful!
It will be some form of education for me anyway but I’m not ready to ask the world just yet. Figuring it out with some assistance from the creator and a random mad bloke who builds way too many synth modules gives me greater depth of learning I guess.....work that grey matter v being told ah....xyz.

Hopefully it’s just a wonky cap my end, it’ll be something trivial I’m sure (I hope!).

I actually enjoy building frequency central kits.
They seem Well set out so far, but I’ve only touched the basic stuff!
wave runner, x adsr, mult.
Think this is my fourth built, from him, but there are a couple of panel sets sat about too.
Dual vca and another mult because I like it!
It’s about the 10th kit built overall....
So, just another rookie applies!

The only other kit to cause me issues was the early release of the divkid mutes, but that was clerical error, umm incorrect bom spec. once found it was easily fixed! All involved did a grand job putting it right. But this build/circuit is more complex for sure! Beyond my brains capabilities at this time.

It would be quicker to dab/glide/drag a hot iron on/across anything suspect, maybe a touch of braid too but..... from my limited dabbling with vero, this was a good method without braid.
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Re: Frequency Central Stasis Leak build thread

Post by soon_come » Mon Jun 22, 2020 9:19 am

Has anyone noticed that the tap tempo / sync input doesn't seem to sync up very nicely using a standard pulse wave? It appears to receive the pulses on time, but the delay is audibly a bit long for every timing setting.

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Re: Frequency Central Stasis Leak build thread

Post by oozitron » Tue Jun 23, 2020 8:40 pm

What about 1~4ms triggers instead of pulses?

(I don’t have a Stasis Leak but it’s on my to-build list!)

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Re: Frequency Central Stasis Leak build thread

Post by soon_come » Tue Jun 23, 2020 9:33 pm

I’ve tried everything from very short pulses to longer (50%) duty cycles. It still seems not to sync perfectly.

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Re: Frequency Central Stasis Leak build thread

Post by jmsiener » Tue Aug 25, 2020 12:19 pm

Has anyone noticed an unreasonable amount of noise in their build? I’ve got a udervish and a clouds going into the returns of my hexpander and they’re dead silent unless sending a signal through. The stasis leak always has a fair amount of hiss on the output even after getting everything trimmed up to spec on the trimmer.

I didn’t use nice 47uF caps but since they were for bypassing I went kind of yolo otherwise everything is a pretty decent component. Soldering looks good, no shorts after measuring so I’m thinking that if the Belton module is getting crappy power on the 9V maybe that would cleanup some hiss? Thinking outloud, cool module otherwise.

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Re: Frequency Central Stasis Leak build thread

Post by DJMaytag » Sun Sep 13, 2020 3:13 pm

I can’t say I’ve noticed any unreasonable noise.
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