Hi there. I've been building a DIY MOD Wave Spring Reverb kit for a few weeks. I got right to the finish line (almost) but I'm having problems with feedback when turning the reverb level up past 1 or 2. Something is definitely wrong and it appears that DIY MOD have stopped offering tech support on their kit builds due to it being too time consuming. I was thinking maybe someone here might have some suggestions? Perhaps someone else has built this kit and may have gone through similar troubleshooting? I've built a few pedal kits but this is my first full power build. I'm pretty new at this and have been very careful to solder the components into the right places. But, I'm pretty sure I did something wrong.
One thing also that has been perplexing is that the input to the reverb tank shows continuity between the sleeve and center. I asked the MOD DIY folks about it and they said it may read 1.8 ohms on my meter. I'm reading about 1.0 ohms. So not sure if this is the issue?
Any thoughts? Hopefully this is the correct forum to ask this question. Thanks so much!
One thing also that has been perplexing is that the input to the reverb tank shows continuity between the sleeve and center. I asked the MOD DIY folks about it and they said it may read 1.8 ohms on my meter. I'm reading about 1.0 ohms. So not sure if this is the issue?
Any thoughts? Hopefully this is the correct forum to ask this question. Thanks so much!
NO CLUE about
so please upload all data you have (guess assembly manual including schematic and layout at least) plus a couple pictures showing what you actually built.
Thanks! Here's a link to all of the documentation and schematics:
Effects Kit - MOD(R) Kits, The Wave, Spring Reverb | Amplified Parts
I'm going to upload a video of the feedback symptoms soon.
Effects Kit - MOD(R) Kits, The Wave, Spring Reverb | Amplified Parts
I'm going to upload a video of the feedback symptoms soon.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Here's a video of the feedback problem. Also, there's a grounding issue that is picking up tons of radio interference. But the Feedback is the main issue right now. Thanks!
https://youtu.be/jpwzRyrgaj0
https://youtu.be/jpwzRyrgaj0
Ouch!!!
Lots of issues with that expensive kit.
Anything new has teething troubles by deffinition, but they are usually ironed out along time, here it looks they made the original one, it worked (sort of) and never ever was corrected, even *easy* corrections.
Starting by the least annoying (to you, at least you don´t complain about them 😉 )
1) Project is 3 U high but they supply a 2 U rackmount panel? REALLY?????
2) NO LABELS WHATSOEVER? That turns a semi-pro and expensive project into a cheesy made-on-the-kitchen-table kludge, at least visually, by forcing you to use CHEESY sharpie -on-paper-tape or silver/gold/white sharpie handwriting on front and back panels.
They could at least have supplied an adhesive paper sheet with basic graphics and labels.
Although silkscreening is cheap and easy to add if more than a few units are made (and copyright is from 2014).
3) now to your problems:
NOWHERE they even MENTION that reverb tank must FLOAT.
Unless otherwise indicated you will tightly bolt reverb tank to chassis which isn WRONG (not your fault).
Reverb tanks use rubber grommets through tank case through which you pass screws (say, 1/8" x 1") which are NOT TIGHTENED UP so not only they are not compressed in the lightest but also you can move tank/grommet up/down 3 or 4 mm to ensure they are not receiving any pressure.
Your howl/feedback is mechanical, bet you are not too far from amp speaker.
Increase distance.
4) the input jack MUST be a shorting type , copy a typical Fender input jack circuit, so pulling guitar cable shorts input. Not sure why they didn´t do that.
That 470k in series with 220pF "Phono in" makes no sense at all and is a Hum factory.
5) the straight output joining of the buffered input (V4 cathode) and Reverb recovery (V3 plate signal) does not make much sense here, you need mixing resistors (say, 47k each) or tghe asked for output mox pot (100k to 250k linear).
It´s incredible they never cared to solve those BASIC errors.
Demos sound good, project has potential, probably works in a controlled environment , but also has inexplicable flaws.
Oh well.
Lots of issues with that expensive kit.
Anything new has teething troubles by deffinition, but they are usually ironed out along time, here it looks they made the original one, it worked (sort of) and never ever was corrected, even *easy* corrections.
Starting by the least annoying (to you, at least you don´t complain about them 😉 )
1) Project is 3 U high but they supply a 2 U rackmount panel? REALLY?????
2) NO LABELS WHATSOEVER? That turns a semi-pro and expensive project into a cheesy made-on-the-kitchen-table kludge, at least visually, by forcing you to use CHEESY sharpie -on-paper-tape or silver/gold/white sharpie handwriting on front and back panels.
They could at least have supplied an adhesive paper sheet with basic graphics and labels.
Although silkscreening is cheap and easy to add if more than a few units are made (and copyright is from 2014).
3) now to your problems:
NOWHERE they even MENTION that reverb tank must FLOAT.
Unless otherwise indicated you will tightly bolt reverb tank to chassis which isn WRONG (not your fault).
Reverb tanks use rubber grommets through tank case through which you pass screws (say, 1/8" x 1") which are NOT TIGHTENED UP so not only they are not compressed in the lightest but also you can move tank/grommet up/down 3 or 4 mm to ensure they are not receiving any pressure.
Your howl/feedback is mechanical, bet you are not too far from amp speaker.
Increase distance.
4) the input jack MUST be a shorting type , copy a typical Fender input jack circuit, so pulling guitar cable shorts input. Not sure why they didn´t do that.
That 470k in series with 220pF "Phono in" makes no sense at all and is a Hum factory.
5) the straight output joining of the buffered input (V4 cathode) and Reverb recovery (V3 plate signal) does not make much sense here, you need mixing resistors (say, 47k each) or tghe asked for output mox pot (100k to 250k linear).
It´s incredible they never cared to solve those BASIC errors.
Demos sound good, project has potential, probably works in a controlled environment , but also has inexplicable flaws.
Oh well.
Thanks for the detailed response. Some of these things sound like good suggestions. I'm hoping to start from a point where the unit is functioning as described in the build instructions. I'm looking to get things working as they are in the company demos. After that, I'm very interested in improving the design and eliminate some noise issues associated with the original design.
Per item 3)
I'm assuming that the units are intended to be firmly attached together as no flexible grommets were included or mentioned in the instructions. Perhaps a good future upgrade though.
The reverb unit was across the room from the amp, so there's no physical connection with the speaker. Also, for the end result this will be used as an extra reverb for a studio. It won't be paired with any loud amps/speakers. Just sitting in a gear rack.
Item 4) Good idea on the input jack. Thanks.
Regarding "That 470k in series with 220pF "Phono in" makes no sense at all and is a Hum factory." Did you have a suggestion of how to better wire this element to avoid noise?
Item 5) I'll have to look into this. I'm new to electronics so I'll have to do a bit of research.
All in all, the project goal was to have fun building something and hopefully learn a bit in the process about electronics. I've had fun building pedals in the past. This one it turns out has been a bit more challenging. If the end result sounds like the demos I saw online, I'll be happy.
Thanks and I look forward to any more suggestions you may have.
Per item 3)
I'm assuming that the units are intended to be firmly attached together as no flexible grommets were included or mentioned in the instructions. Perhaps a good future upgrade though.
The reverb unit was across the room from the amp, so there's no physical connection with the speaker. Also, for the end result this will be used as an extra reverb for a studio. It won't be paired with any loud amps/speakers. Just sitting in a gear rack.
Item 4) Good idea on the input jack. Thanks.
Regarding "That 470k in series with 220pF "Phono in" makes no sense at all and is a Hum factory." Did you have a suggestion of how to better wire this element to avoid noise?
Item 5) I'll have to look into this. I'm new to electronics so I'll have to do a bit of research.
All in all, the project goal was to have fun building something and hopefully learn a bit in the process about electronics. I've had fun building pedals in the past. This one it turns out has been a bit more challenging. If the end result sounds like the demos I saw online, I'll be happy.
Thanks and I look forward to any more suggestions you may have.
I was just wondering if/or how it is possible using a pre amp like the Behringer MIC100 as a driver for the reverb tank.
Looking at the photo of the inside of your build, I see that the chassis is being used to connect several parts to ground/eachother. I also see that the chassis is lacquered. Did you use tooth lock washers between the chassis and those connectors/soldering supports? Because they 'chew' themselves in when tightening, they secure a good contact to the chassis.