Reversed Tape effect (schematic inside)

[pilo]

Hi!

One of my friend ask me if it's possible to built "reversed tape" fx stomp box.
He told about the boss SG-1, the schematic is here :
http://filters.muziq.be/files/schematics/boss_sg-1_servicenotes_001.gif

After looking at it I've got trouble to understand it...

the hard stuff seems to be the fet control voltage, everything after IC1.

Does anyone as ever built a such unit? or can explain in a few words how it works?

thank you!

Pilo

 

[gyraf]

It looks more or less like a noise gate with a very adjustable attack time...

Jakob E.

 

[dukasound]

[quote author="pilo"]Hi!

One of my friend ask me if it's possible to built "reversed tape" fx stomp box.
He told about the boss SG-1, the schematic is here :
http://filters.muziq.be/files/schematics/boss_sg-1_servicenotes_001.gif

After looking at it I've got trouble to understand it...

the hard stuff seems to be the fet control voltage, everything after IC1.

Does anyone as ever built a such unit? or can explain in a few words how it works?

thank you!

Pilo[/quote]

Hi Pilo
Boss SG-1 is Slow Gear pedal. This make effect to sound come slow, not reversed tone.
Duka

 

[Rob Flinn]

A friend of mine has a guitar fx box that does this. I don`t know the manufacturer off hand but could probably find out. Its old & has a metal plectrum that is hooked up to the box. When you pick a string it triggers the gate in th e box. The box is a gate with a long attack & short release, both are adjustable

 

[pilo]

thanks for you answers!!!

I have a diy ssm2166 compressor (I made for my bass along time ago), let's see if I can try something with the noise gate in it

Thank you!

 

[Scenaria]

not the same as reversing tape...

you cant put time before time without reversing tape or recording a phrase into a box then playing it back reverse... :green:

 

[jrmintz]

The Line Six DL4 Delay Modeler has a backwards mode. Very cool sounding.

 

[clintrubber]

Some units mimic the reverse-thing by fiddling with the envelope, like the SG-1. The EH -box (rare) seems better & more complete.

There's also thoise boxes that take snippets & reverse them. I guess the Line-6 as mentioned does it like this. The old 9.5" BOSS RPS-10 does it like this. A strange FX, quite cool.

Peter

 

[SSLtech]

Eventide H949 did this... and the algorythm was emulated in later boxes such as the SP2016. There was a second variation where random lengths of passing signal were looped in reverse and forwards, alternating at random, with no particular pattern. The loop length and direction was randomly triggered and selected.

We used this on the intro to a Black Sabbath track, "Nightwing"... I mention this only because this is the only time that I can specifically recall using the effect... it was one of those "that's pretty cool... I don't know if I'll ever use it but it's pretty cool!" things. -Anyhow, the track fades up from silence with tracked acoustics playing a repeating picking pattern... the "random reverse" effect is prominent as the track begins, then as it fades up, the "chaos" effect fades out and the track becomes more clear as the Bass enters and the vocal starts the tune.

The AMS RMX16 had a 'reverse' setting, but again this is a reverse envelope reverb... it cannot reverse time, and Scenaria is right in saying that nothing can... If they ever build a box that can predict the future, all value is lost and chaos reigns... Douglas Adams wrote about a cathedral that was built and torn down for land development... time travel was then invented, and people decided to go back in time, and save themselves the expense of ever building the cathedral in the first place. After that, postcards of the cathedral from the timeline when it had been built suddenly assumed immense value...

Keith

 

[Aharon]

Hey Pilo,you are in luck, lookee here:

http://www.generalguitargadgets.com/index.php?option=content&task=view&id=113&Itemid=159

Aharon

 

[pilo]

yeah!

thanks for your answers again

Of course I know it's impossible to do the same as reversing a tape (Do I seems so stupid? )
But I was looking for something that sound like a reversed tape.

thank you very much! now I have stuff to study, I don't want to build something I don't really understand.

 

[StephenGiles]

Might I suggest recording what you want to reverse on audio cassette using an endless tape, then take the tape out and turn it upside down. It may then play backwards, but I couldn't be sure. I know this would work on an open reel machine.
Stephen

 

[adamasd]

There is a company called Snarling Dogs or something like that, they make a pedal that does a similation of the tape deck being thrown in reverse. You can probably pick them up cheap on ebay these days. Otherwise find an old cheap tape deck with seperate record and playback heads and work with that to get the sound. The pedal for this is most likely DSP or such, I myself can not see how it could be done analog wise, other then an actual tape deck that is.

adam

 

[BYacey]

It appears that this stompbox inverts the envelope. It has a slow attack that slopes up to maximum gain and then sustains for a bit and then cuts off the signal when it drops to a threshold level. This kind of gives a guitar the soft attack similar to what you would hear from a bowed instrument. Useful for a few special effects, but you wouldn't want to over-use it.