BTDR-3 Reverb brick discussion

[PRR]

> If the "Depth" pots are connected in parallel with the 11.8K feedback resistors

If that resistance gets below 10K, the repeats *build-up*, reverb feedback swell, and soon become overwhelming.

10K:11.8 is 85% reflection each time. This is in-line with reflection factors in real live rooms (95%-70%). Some change is valuable; but going too far is not wise. (Try it.)

A perhaps better implementation is replace 11.8K with 10.5K plus a series 5K pot. Now "reflection factor" (or repeat level) is 95% - 65% (with 77% at mid-turn). For subtle reverb settings you might go 10.5K+10K pot, to get down to 50% reflection, but all the "dense" settings will be cramped in the last 1/4 turn.

[armdnrdy]

The schematic I posted is for the BTDR-1. The actual resistors in the BTDR-3 (with the adjustable decay) are unknown.

There may be another feedback resistor in series with the Depth pot pins. I was just trying to reason how it might be connected internally.

I have a BTDR-3 module on the way so....I'll report my findings. 

[armdnrdy]

I sent Accutronics/Belton the an email with the following question.


I am planning a build using the BTDR-3 module. I have a technical question regarding the internal connections of Pin 7-10 (1A - 2B, decay adjustment)

I was wondering which part of the BTDR circuit these pins are connected to.

Are these pins connected to feedback paths in the circuit?

I would like to know so that I may possibly experiment with other options such as adding modulation to part of the circuit instead of the whole BTDR output.


I received this reply:

Thank you for your e-mail.

The anwser is as below ;

The depth-adjustment resistors do connect to part of the feedback circuit, and audio does go through these resistors. It is not possible with this module to change the modulation.

I hope it helped for you.

Have a wonderful day.

Best regards/Hyun Park


I think that part of my email was misinterpreted. The BTDR modules already have modulation. I believe that Mr. Park thought that I wanted to try to access the internal modulation from the decay pins.

Since the decay pins are connected to feedback paths...it should be possible to modulate the feedback with a vactrol controlled by a LFO. This should give a different effect than modulating the whole module output.

[snap]

you might as well ask this guy: http://www.diystompboxes.com/smfforum/index.php?topic=72376.0 directly.

[armdnrdy]

you might as well ask this guy: http://www.diystompboxes.com/smfforum/index.php?topic=72376.0 directly.

Accu-Bel Sound Inc. is a Korean based R&D and manufacturing company.

Brian Neunaber holds the patent to the "brick" technology.

I'm sure that Brian licensed, or sold the rights to the brick to Accu-Bel Sound Inc.

The BTDR-2 is just a smaller version of the original BTDR-1
The BTDR-3 uses the same technology as the two previous bricks, but adds four additional pins tapped from the feedback path for adjustment.

Brian Neunaber has his own website where he sells his "new" software based reverb pedal designs.

I don't think that I would be incorrect in assuming that Brian has absolutely nothing to do with Accu-Bell Sound Inc. or any of their new products.

[mth5044]

Oldish thread, but does anyone have the dimensions on the new brick? Looks like the pins are on 0.1" grid, but the 3 isnt even on their site and no info in datasheet.

[armdnrdy]

The same dimensions as BTDR-2.

The pins are centered with the gap between pins 5 & 6 the center of the brick.

I have an Eagle file that I made if you need it.

[Kipper4]

Yes please Larry pm'ed

[mth5044]

Awesome, thanks for the info armdnrdy! They have the dimensions up for the BTDR-2. Thank you!

[Groovenut]

Just wanted to let everyone know that it looks like Accutronics has changed the encapsulating material and external dimensions on the BTDR-3. The new encapsulating material is softer and has a textured appearance, but the biggest difference is the width (pin side to opposite) has become larger by about 1/8" of an inch. The external dimensions are now 1.51"X1.27"(not including pins)X.435"

[armdnrdy]

Just wanted to let everyone know that it looks like Accutronics has changed the encapsulating material and external dimensions on the BTDR-3. The new encapsulating material is softer and has a textured appearance, but the biggest difference is the width (pin side to opposite) has become larger by about 1/8" of an inch. The external dimensions are now 1.51"X1.27"(not including pins)X.435"

Is this something you noted when receiving the actual component or read somewhere?

If read...can you provide a link? I know that Accutronics doesn't seem to be on top of things such as releasing proper data sheets. 

[Groovenut]

Just wanted to let everyone know that it looks like Accutronics has changed the encapsulating material and external dimensions on the BTDR-3. The new encapsulating material is softer and has a textured appearance, but the biggest difference is the width (pin side to opposite) has become larger by about 1/8" of an inch. The external dimensions are now 1.51"X1.27"(not including pins)X.435"

Is this something you noted when receiving the actual component or read somewhere?

If read...can you provide a link? I know that Accutronics doesn't seem to be on top of things such as releasing proper data sheets. 

I measured actual parts I recieved and then spoke with Hyun Park at Accu-Bell Sound about the change. It's an ongoing conversation currently. I've designed this 1590A Reverb pedal that was glove snug with the old module but the new ones wont fit, so I'm trying to work out a fix. It would be nice to convince the manufacturer to shave .100" off the side, but that seems unlikely

Here's my latest




It's largely the application circuit with tonal tweaks in the driver and recovery stages plus tails switching/buffered bypass.

I'll try to get a video demo up soon too.

Finally knocked together a demo clip for this

I think I may need to adjust a few things. I would like a bit more reverb level at max pot settings. I do like the variable depth though.

[armdnrdy]

Thanks for the info.

Yes...it's never a good thing when a manufacturer increases the dimension of a component.

I honestly don't see a problem with using a larger brick in your design....
You have tons of room in that enclosure! 

[italianguy63]

Thanks for the info.

Yes...it's never a good thing when a manufacturer increases the dimension of a component.

I honestly don't see a problem with using a larger brick in your design....
You have tons of room in that enclosure! 

Yeah--  I saw him and Russ (Cozy Builder) down at Starbucks talking the other day....  MC

[Groovenut]

Here's what the new brick looks like modified and installed
http://www.diystompboxes.com/smfforum/index.php?topic=64752.msg1025135#msg1025135