yet another diy plate reverb

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kooma

Well-known member
Joined
Jan 26, 2006
Messages
473
Location
Espoo-Finland
I thought I would share my experiences on building a "smallish" plate reverb;

This all started after reading some old topics here and  while buying some stuff for my home renovation,  I saw this 1mX20cm steel plate and thought,could you make a smaller plate reverb out of that?
I was also missing some bits of my mouser order to get to free shipping limit,
so I added some PUI exiters and few piezos to try out..

Since this isnt based on anything sizewise/technically
I'm not expecting this to sound like EMT or some proper plate,
hopefully I get something weird but usable out of this:)

after buying 20mm square tube I was ready to weld my frame
 

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I havent used mig/tig in 15 years so  those welding seams look awful:) but they seem to hold..

Next I drilled holes for plate hooks (and in plate).
this plate was 0.75mm thick so I  used flap disk grinder to sand it bit thinner.

Had a quick test and yes it works.
will post soundfiles later.
 

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hazel said:
great!

Any clue on drivers/pickup?
I tested it with something like this:
http://www.mouser.fi/ProductDetail/PUI-Audio/ASX03308-SM-R/?qs=sGAEpiMZZMuTkJYgZlQcSbbsRNIPfhoPBYlxBh7QXOmF1L8ItpkkJw%3d%3d
(cant remember exact model)
and a piezo pickup
 
proper DIYI
Nice work.
One day i'm going to make one.
It's the frame that's the tricky bit for me. No welding gear.
 
Thank you for comments!
I was suprised (first) that I got it working
and then that it sounds kind of ok.

I must still look into how grinding that plate even thinner, tensioning it more,
positioning driver&mic or differend driver/mic would work.

I'm bit annoyed by that loud ringing on some frequencies,
but I dont know is it caused by plate tension/mass/size or drivers properties..

mrclunk said:
One day i'm going to make one.
I actually thought like that for a long time,
but always thought it would be bulky big,expensive and really hard to get right..
then I just thought f*ck it;  I'll try something cheaply, if its pos then I just bin it, if its something usable..then its all good:)

I think you could bolt those square tubes with no need to weld ;)
 
One day...
One of my brothers works in metal roofing so i can get sheet material cut to size quite easily.

If you want a way to adjust the tension, try turnbuckles?
e.g
https://www.screwfix.com/p/hardware-solutions-turnbuckle-hook-5-16-zinc-plated/22755#_=p

You might need some sort of triangular metal sandwich in the corners of your sheet so it doesn't rip through?
The plates in the emt's i've worked on are under alot of tension!
 
I like your work. 

Some observations:

I think you may find it easier to tune if you have 2 bolts per corner at right angles to each other like on an EMT/echoplate/stocktronics.

Normally the length of the long side of the plate seems to be a multiple of the short side.  For example the EMT is 1m x 2m.  WHen you tune it you flick the middle of one edge & try to make the opposite edge the same pitch.  The short edges are tuned to twice the pitch  or octave of the long edges, which makes sense when the plate is 1m x 2m.    So edge edge is tuned in relation to the others.    There was a tool you could buy for tuning, but when I used it I found it easier to do it by ear. 

If it's out of tune the decay sort of pulses rather than being a smooth taper.  This may not be very obvious on your plate because the decay is relatively short compared to a big plate.
 
ok, thanks for tips!
especially that tuning info was interesting..
I thought about using turnbuckles, but it would have made the whole thing bigger(or plate smaller)
so I used these hook bolts.
if I make revision#2 I wouldnt use these, or I would find something with finer pitch thread
and  now tightening these bolts seems to twist my plate :'( so maybe small/short turnbuckles would be ideal..
Holes for the bolts are drilled bit slanted so pull would be affecting  both long and short sides,

I thought about using just 3points to  fasten plate&frame, now I see why the "real plates" used 2 per corner.
but this might be impossible to tune properly anyways
(since my plate proportions would require 5 octaves(?) difference if I understood that right )

My plate corners have full 0.75mm thickness, and plate has been otherwise sanded much thinner what I thought would be enough to keep corners ok.
-but still those additional corner pieces might be good idea!

 

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now welded more support to corners and tightened plate allmost tight as I dare:)
it could get bit tighter, but I kind liked the ealier sound more..

https://soundcloud.com/anodivirta/levykaiku2

fisrt dry, next 3 have stereo plate driven first low, then medium and last high gain(there is distortion from driver&amp clipping)
 
Nice build.

I wanted to build a plate reverb for ages, I actually did a lot research at some point and have quite a lot on documentation on it.

Send me a pm if you want me to send you the docs I have
 
kooma said:
ok, thanks for tips!
especially that tuning info was interesting..
I thought about using turnbuckles, but it would have made the whole thing bigger(or plate smaller)
so I used these hook bolts.
if I make revision#2 I wouldnt use these, or I would find something with finer pitch thread
and  now tightening these bolts seems to twist my plate :'( so maybe small/short turnbuckles would be ideal..
Holes for the bolts are drilled bit slanted so pull would be affecting  both long and short sides,

I thought about using just 3points to  fasten plate&frame, now I see why the "real plates" used 2 per corner.
but this might be impossible to tune properly anyways
(since my plate proportions would require 5 octaves(?) difference if I understood that right )

My plate corners have full 0.75mm thickness, and plate has been otherwise sanded much thinner what I thought would be enough to keep corners ok.
-but still those additional corner pieces might be good idea!

The hook bolts are alright.  Just hold it wth some pliers to stop it twistng when you adjust it.  Also the emt has little clips that go through the plate hole & round the hook bolt. as a sort of intermediate part.  I think it is good because you have a very small area of contact on the plate which makes it resonate better.  See here http://www.ebay.co.uk/itm/EMT-140-plate-clips-newly-manufactured-slightly-stronger-than-stock-Tuning/231320598496?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649
The plate  wth the 2 holes hooks over the clip so it doesn't open up when you tighten the bolts.    But if you crank it up too much they snap & fly off like bullets.    Safety glasses are a must.
 
Just got back from travelling and painted the frame. so no modifications to frame.
but thinking should I buy another plate for testing, i think welding my washers to support plate holes made my plate too heavy..
then again now I can tension it really tight.

also going to test bass/guitar pickups on  this.

whoops: sent you a pm! :)
 
just to share with you guys, this is the best DIY Plate reverb unit I ever saw,
it was made by a Kid.

Really well done:

https://www.youtube.com/watch?v=XJ5OFpvX5Vs
 
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