Help Design a community pedal (Shimmer - Reverb.)

[chromesphere]

Hey guys,
I built the deadastronaut reverb, you may have seen my demo video of it? http://www.youtube.com/watch?v=GhRVwDS6ios

Its a fantastic sounding reverb.  Top notch. 

Reading through this thread i had an idea.  Now, you will have to excuse my non-EE approach here, I was just thinking 'modular' i guess.  Couldnt you just make a wet only output (additional output) and send it to, something like the madbean lowrider (clean octave up / down) and then back to the reverb again?  I was thinking of something like a send / return on the reverb.  THe low riders got HEAPS of options as well, you would really be able to tweak the shimmer effect.  You coould also make a volume control to control the overall level of the shimmer. 

Probably some fundametnal problem with this idea, like i said, im no EE, just thought if it worked, could be a relatively simple implementation.  You'd just have to mod the deadastronaut reverb to have send/return!  Thats where you guys come into

Paul

[Ark Angel HFB]

Hey guys,
I built the deadastronaut reverb, you may have seen my demo video of it? http://www.youtube.com/watch?v=GhRVwDS6ios

Its a fantastic sounding reverb.  Top notch. 

Reading through this thread i had an idea.  Now, you will have to excuse my non-EE approach here, I was just thinking 'modular' i guess.  Couldnt you just make a wet only output (additional output) and send it to, something like the madbean lowrider (clean octave up / down) and then back to the reverb again?  I was thinking of something like a send / return on the reverb.  THe low riders got HEAPS of options as well, you would really be able to tweak the shimmer effect.  You coould also make a volume control to control the overall level of the shimmer. 

Probably some fundametnal problem with this idea, like i said, im no EE, just thought if it worked, could be a relatively simple implementation.  You'd just have to mod the deadastronaut reverb to have send/return!  Thats where you guys come into

Paul

The only thing I can see as a problem would be that the octave up on the Lowrider is clean at all... it sounds like the signal is being clipped. which is what I'm trying to avoid with the phase inverter and recombining negative wave and positive.

Not to get side tracked but... On the topic of the "Dead Astronaut" sounds really really nice... Why not build it in a bigger box... and sub out the toggle switch controlling the oscillation for a momentary footswitch... that was as you are playing you can step on the footswitch and hold it down for as long as you want the effect.

[chromesphere]

The low rider sounded pretty clean to me, but i may be mistaken.  Only so much you can tell from an audio clip on youtube.  Interested to so what you come with Ark!

When i put the reverb in the BB i was actually using a bigger then recommended enclousure Most people are building them in B size, im glad i didnt though as with the mods it probably wouldnt have fit.

Paul

[WaveshapeIllusions]

Well, the issue with standard full wave rectification is the crossover distortion. The threshold voltage for the diodes leaves gaps between the negative and positive peaks. It shows up as a kink in the zero-crossing region and sounds rather unpleasant. The lack of a negative side could be solved by a series capacitor, which will remove any DC offset and center it around 0V. It will still be assymetric however. The crossover distortion issue can be solved by using a precision rectifier as Keppy mentioned. There will still probably be intermodulation, but there will always be intermodulation. In this case it shouldn't be as bad.

Another idea is the doubler circuits offered by RG. He drew up a JFET doubler and a MOSFET doubler. I think Tim Escobedo made a similar one with BJTs. They basically cancel the input and use the 2nd harmonic distortion of the devices to create the octave up effect. The downside with this is that intermodulation will probably be very bad.

Someone earlier suggested using part of Mark Hammer's Woody circuit. I think that could add a nice sound to it. Perhaps we could still add the octave up, in between the high pass sections. High pass before the octave up, somewhere around 160 Hz to lower the fundamental a bit, just a gentle rolloff. After the octave, a heavier highpass (4-pole, more?) at the same point to cut out low frequency content and any difference frequencies. Possibly a bit of clipping, or another gentle highpass at 240 Hz. Then reverb.

[Keppy]

Is the LM13600N at the being used as a buffer? If so then I'd stile need to split the signal and get a Phase inverter to give me a negative wave form to be mixed back in with the Positive.
No but honestly what is a good way to invert the phase after it has been rectified?

The 13600/13700-based schems I posted are not rectifiers, they are multipliers. I posted a link with several opamp-based rectifiers to choose from.

[Ark Angel HFB]

The 13600/13700-based schems I posted are not rectifiers, they are multipliers. I posted a link with several opamp-based rectifiers to choose from.

Thanks for the help... Sorry for the confusion.

So they will multiply will bring the pitch up 1 octave. Will the multiplier still leave the signal clean?

[deadastronaut]

buy a cheapo behringer pitch shiftter and graft it onto the reverb. ...


all the diy octaves ive heard have bee naff imo..

the low rider isn't too bad though...best diy one ive heard so far....

interested to see what you guys come up with...

[Ark Angel HFB]

http://i73.photobucket.com/albums/i215/Ark-Angel-H-F-B/OctaveIdea_zps00afabbc.png

Here is a Vero for the multiplier if anyone wants to give it a shot.

[mth5044]

Don't forget to connect the IC's to 9v+ and GND. Also I believe there are a few mistakes - pin 1 of the 13600 connects to a 10k resistor that is also on the same strip as pin 4 of the TL072, which needs to be grounded. The other end of that resistors needs to go to pin 1 or the opamp chip. You need a 10k resistor from Vb to pin 5 of the 13600. I think you may have tried to do this around pin 1 of TL072 but it's a bit hard to decipher. Unless I'm totally missing something, but it's easier to look at layouts when you have the components a little transparent so we can see were cuts and jumpers are under components.

[Ark Angel HFB]

Don't forget to connect the IC's to 9v+ and GND. Also I believe there are a few mistakes - pin 1 of the 13600 connects to a 10k resistor that is also on the same strip as pin 4 of the TL072, which needs to be grounded. The other end of that resistors needs to go to pin 1 or the opamp chip. You need a 10k resistor from Vb to pin 5 of the 13600. I think you may have tried to do this around pin 1 of TL072 but it's a bit hard to decipher. Unless I'm totally missing something, but it's easier to look at layouts when you have the components a little transparent so we can see were cuts and jumpers are under components.

Sorry I'm a bit of a noob so I followed the schematic exactly... I did make a one mistake with the pin 5 to 7 jumper. Everything should be fixed now.

Pin 4 of the TL072 is now grounded. Pin 6 of the LM13600 is now grounded. Actually saved a column doing this.

[mth5044]

I didn't check over the entire layout yet, but the TL072 is still not connected to +9v ( pin 8 )



Edit: pin 8 not pin  haha

[Ice-9]

How about this one I made earlier, theres more to this than the shimmerverb and I can easily fit it into a 1590b enclosure.

Sound clip is of one setting of the shimmer. You will need to click the url as on this forum I can't seem to post a video in the normal way.
http://s90.photobucket.com/user/lenny1dog/media/shimmerverb_zps2bbc4a96.mp4.html

Its a project I am working on to release on the forums when It's finished but will happily post it as it is now if anyone wants to look at it.

[armdnrdy]

Mick,

Not a whole lot excites me....That sounds fXXXXXG great!!!!!

Please release that!

What technology is inside that little beast?

It sounds like you stuffed a violinist........ (a pretty female one) inside that box!

[Ice-9]

Mick,

Not a whole lot excites me....That sounds fXXXXXG great!!!!!

Please release that!

What technology is inside that little beast?

It sounds like you stuffed a violinist........ (a pretty female one) inside that box!

It can do anything really, the audio path is only   '-input buffer - FV1 chip - output buffer- ' the whole circuit is through hole components except for 2 chips which are SMD and very easy to solder up.

1590b version in this picture , single sided pcb.

[armdnrdy]

Did you accomplish that with the "stock" IC or did you have to program it?

[Ark Angel HFB]

Did you accomplish that with the "stock" IC or did you have to program it?

^

No but really... that sounds awesome... I guess it is time to look more seriously at the FV-1.

[Ice-9]

Did you accomplish that with the "stock" IC or did you have to program it?

^ ^ ^

No that program is loaded on an Eeprom, which I got from the Spin FV-1 website/ forum (there are lots of people on there developing free to use programs also). The pedal I made can have the Eeprom programmed with 8 different effects, direct to the pedal from the PC.

[Ark Angel HFB]

Did you accomplish that with the "stock" IC or did you have to program it?

^ ^ ^

No that program is loaded on an Eeprom, which I got from the Spin FV-1 website/ forum (there are lots of people on there developing free to use programs also). The pedal I made can have the Eeprom programmed with 8 different effects, direct to the pedal from the PC.

How much is an Eeprom... and is there a way to program stuff yourself?

And can this FV-1 handle tap tempo...

Lastly, does it make coffee? I could use a cup.

[armdnrdy]

Where do I sign up for the free coffee maker?.....uuh I mean please post details/links.

[Ice-9]

Did you accomplish that with the "stock" IC or did you have to program it?

^ ^ ^

No that program is loaded on an Eeprom, which I got from the Spin FV-1 website/ forum (there are lots of people on there developing free to use programs also). The pedal I made can have the Eeprom programmed with 8 different effects, direct to the pedal from the PC.

How much is an Eeprom... and is there a way to program stuff yourself?

And can this FV-1 handle tap tempo...

Lastly, does it make coffee? I could use a cup.

1.The Eeproms are about 40p and are available as 8pin SMD or through hole (24lc32a)

2.That effect in the video if you look closely at the left pot has markings that are notes, and they are settings for the tap tempo delay, set up as 1/4 notes triplets and dotted note tempo's (Ian , better known as Slacker wrote the tap tempo code)

3. I'm working on the coffee bit. I could probs get it to sound like it was making coffee though.