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DIY Stompboxes => Digital & DSP => Topic started by: chenron7 on March 28, 2018, 12:18:40 PM

Title: BTDR-2H
Post by: chenron7 on March 28, 2018, 12:18:40 PM
Hello :) Im trying to build a reverb pedal and I cant understand how the reverb unit ( in this case BTDR-2H) works. can anybody explain or send a link that explains it? thanks
Title: Re: BTDR-2H
Post by: vigilante397 on March 28, 2018, 02:13:11 PM
Welcome to the forum :)

Have you had a look at the datasheet? diy.smallbearelec.com/Library/Datasheets/Belton_BTDR-2.pdf

It's my understanding that the Belton Reverb Bricks are essentially 3x PT2399 delay chips cascaded together with some lovely filtering, so the overlapping delays give a lovely reverb-esque sound. It's obviously digital (there's no springs in there), but a nice digital in that you don't have to program anything yourself :P
Title: Re: BTDR-2H
Post by: chenron7 on March 28, 2018, 03:32:51 PM
Thanks :) So each one of the PT2399 makes delay in other rate and thats what makes it reverb?
Title: Re: BTDR-2H
Post by: vigilante397 on March 28, 2018, 04:52:39 PM
That's it in a nutshell, yup. The delay times are tuned just right so they kind of wash together like reverb. There are actually a few projects out there (including several on this site) that do the same thing but without the Belton brick, i.e. just using multiple PT2399's to get reverb.
Title: Re: BTDR-2H
Post by: chenron7 on March 29, 2018, 02:35:08 AM
Can you direct me to a post about this? searched but didn't find.
Title: Re: BTDR-2H
Post by: MetalGuy on March 29, 2018, 05:57:06 AM
It would be a better idea to get a Belton BTSE-16FX module which has 16 different effects (several reverbs among them) instead of resorting to pseudo solutions like the BTDR bricks or just go for the FV-1 forum project or similar FV-1 based.
Title: Re: BTDR-2H
Post by: Ice-9 on March 29, 2018, 08:20:04 AM
Quote from: MetalGuy on March 29, 2018, 05:57:06 AM
It would be a better idea to get a Belton BTSE-16FX module which has 16 different effects (several reverbs among them) instead of resorting to pseudo solutions like the BTDR bricks or just go for the FV-1 forum project or similar FV-1 based.

I have just looked up the datasheet for the Belton BTSE-16FX and from the list of 16 effects and descriptions it is exactly the same as the Wavefront AL3201B effects list, very likely that it is using that DSP chip, does anyone know this for sure ?
Title: Re: BTDR-2H
Post by: vigilante397 on March 29, 2018, 09:18:17 AM
Quote from: MetalGuy on March 29, 2018, 05:57:06 AM
It would be a better idea to get a Belton BTSE-16FX module

I feel like there's a HUGE "it depends" attached to that. If you just need reverb there really isn't any point in getting a 16FX module. I'm a big fan of the Belton bricks and what you can do with them.

As for PT2399 reverbs, the first that comes to mind is Merlin (Valvwizard)'s Equinox: http://www.diystompboxes.com/smfforum/index.php?topic=93868.0 which you can also see (with an updated version) on his website: http://valvewizard.co.uk/equinox.html He also released a simpler version called the Solstice using the chips in series rather than parallel: http://www.diystompboxes.com/smfforum/index.php?topic=97310.0 Merlin's explanation was that the Equinox sounds closer to a spring reverb, whereas the Solstice has more of a hall-type sound.

I swear there was another one out there and now I'm having trouble finding it :P
Title: Re: BTDR-2H
Post by: reddesert on March 29, 2018, 03:01:08 PM
Culturejam's "Ersatz Verben" project is a fun lo-fi reverb that uses only a single PT2399. It is easy to build. There is a FSB thread, a vero layout at http://tagboardeffects.blogspot.com/2012/03/ersatz-verben-psuedo-reverb-by.html (http://tagboardeffects.blogspot.com/2012/03/ersatz-verben-psuedo-reverb-by.html), a perfboard layout, etc.
Title: Re: BTDR-2H
Post by: MetalGuy on March 29, 2018, 03:47:23 PM
Quote...it is exactly the same as the Wavefront AL3201B effects list...

Yes, it looks like the FX16 is the AL3201. The FX32 and FX99 however are repacked ACE32 and ACE99 modules from THK Japan.
I wrote about this here:

http://www.diystompboxes.com/smfforum/index.php?topic=105089.0

http://www.thk-japan.com/

Since the FV-1 became available I wouldn't settle for anything less if I need a reverb but I guess like most things it's a matter of taste.