Where i can find a schematic with all the Orange Squeezer mods?

Started by gigimarga, May 27, 2008, 05:35:08 PM

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gigimarga

Hello,

I've searched the forum and i found a lot of mods for Orange Squeezer, but no schematic including all (or most of them...).
It is a schematic which contains more of them?

I want only the simple mods, involving the replacement of some resitors with trimpots or something like that...not for the mods which uses the unused half of the opamp.

I made the mods suggested by Frank Clarke on his wonderful site (http://www.guitar-pedals-effects.com/SustainControl.html) and i was happy with most of them...but on some certain of the pots i get a very annyoning and strong oscillations...

Thx a lot!




Dragonfly

Mark Hammers site has a heavily modded OS, IIRC....might be more than what you're looking for though. Still, it might spur a few ideas....

Mark Hammer

That would be this little beastie: http://hammer.ampage.org/files/Tangerine_Peeler.gif

Never actually built it, I have to admit, but that's more a case of not having enough time to get to it, rather than lack of confidence in it. The accompanying notes in the diagram explain a lot, but the gist was to:
a) separate the gain required for the envelope-follower sidechain from the gain of the actual audio path
b) add variable release to achieve greater and lesser amounts of apparent sustain
c) give variable adjustment of the treble component
d) provide a means to achieve more of a limiting effect with feed-forward control, as opposed to only feed-back control (as found in the stock uinit)
e) have a "friendlier" high-impedance input stage to buffer the signal.

In general, it can do everythng the stock Orange Squeezer does, but also extends the range of usability a wee bit.  So, a little more and less compression if you want it.  A little more treble bite if you want it.  A little more and less sustain if you want it.

What is the difference between feed-forward and feed-back, you ask?  With feed-back, the envelope you are detecting is that of the modified gain-reduced signal, since the envelope follower comes after the point in the path where the gain/level has been altered.  With feed-forward, the envelope follower is rectifying the signal as seen at the input, without any additional changes to its dynamics.  As a result, feed-forward exerts the most reduction of dynamics at the very beginning when you pick.  Almost everything after that is insufficient to either make it through the 1N34 diode or have any audible effect on the FET.  So, feed-forward is more suitable to peak-limiting, and feed-back is more suitable to compression or constant level.

You can provide for greater and lesser compression in the OS by varying the gain of the single op-amp, but the problem is that as you turn up the compression amunt you also have to turn down the volume.  Tis unit keeps them separate.

If I'm not mistaken, Johan Blomdahl is probably the one who extended the basic Orange Squeezer architecture to include full-wave rectification instead of the half-wave approach the stock unit uses.  Since I included a means to extend the release time, I didn't feel it necessary to "improve" the smoothing of the envelope signal by means of FWR.

It's not God's gift to compressors, but it does more than the average one for only a little more effort and cost.

Dragonfly

Quote from: Mark Hammer on May 29, 2008, 02:52:34 PM
That would be this little beastie: http://hammer.ampage.org/files/Tangerine_Peeler.gif

Never actually built it, I have to admit, but that's more a case of not having enough time to get to it, rather than lack of confidence in it. The accompanying notes in the diagram explain a lot, but the gist was to:
a) separate the gain required for the envelope-follower sidechain from the gain of the actual audio path
b) add variable release to achieve greater and lesser amounts of apparent sustain
c) give variable adjustment of the treble component
d) provide a means to achieve more of a limiting effect with feed-forward control, as opposed to only feed-back control (as found in the stock uinit)
e) have a "friendlier" high-impedance input stage to buffer the signal.

In general, it can do everythng the stock Orange Squeezer does, but also extends the range of usability a wee bit.  So, a little more and less compression if you want it.  A little more treble bite if you want it.  A little more and less sustain if you want it.

What is the difference between feed-forward and feed-back, you ask?  With feed-back, the envelope you are detecting is that of the modified gain-reduced signal, since the envelope follower comes after the point in the path where the gain/level has been altered.  With feed-forward, the envelope follower is rectifying the signal as seen at the input, without any additional changes to its dynamics.  As a result, feed-forward exerts the most reduction of dynamics at the very beginning when you pick.  Almost everything after that is insufficient to either make it through the 1N34 diode or have any audible effect on the FET.  So, feed-forward is more suitable to peak-limiting, and feed-back is more suitable to compression or constant level.

You can provide for greater and lesser compression in the OS by varying the gain of the single op-amp, but the problem is that as you turn up the compression amunt you also have to turn down the volume.  Tis unit keeps them separate.

If I'm not mistaken, Johan Blomdahl is probably the one who extended the basic Orange Squeezer architecture to include full-wave rectification instead of the half-wave approach the stock unit uses.  Since I included a means to extend the release time, I didn't feel it necessary to "improve" the smoothing of the envelope signal by means of FWR.

It's not God's gift to compressors, but it does more than the average one for only a little more effort and cost.

Those are all valid improvements Mark.

as for "Gods Gift" ...it's all in the eyes of the beholder. The stock OS is pretty much a GREAT compressor in the hands of the right player.

gigimarga


Mark Hammer

Thank me when you build it and find that it doesn't sound too bad.  Until then, it's just a picture!! :icon_wink:

frequencycentral

Mark - what FETs were you thinking of specifically for the Tangerine Peeler? And any quad opamp?

Thanks
http://www.frequencycentral.co.uk/

Questo è il fiore del partigiano morto per la libertà!

SPAZ

         I found any mod to the OS right here. The search is a great thing !  I need to thank Mark Hammer for my two knob OS. All I wanted was variable compressoin, and I found exactly out how to do it  by reading and reading over again. I highly recommend the OS circuit ! Oh yea thank you Mark and all you regular contributors to this sight.

Mark Hammer

Given that it IS, after all, just an OS all tarted up, 2N5457 FETs are what is called for, or whatever would work in an OS.

Given that it is a compressor, a quiet input stage is probably called for.  So, a TL074 would probably do just fine.  A pair of NE5532 chips would probably do fine as well.  Feel free to use sockets and monkey around.

rhys

Could one add the tone circuit from Mark's peeler with unused half of the dual IC on an orange squeezer? 

Would it work to feed pin 1 into pin 5,  and insert the tone circuit between pins 6 and 7, or is there something else to it? 

Mark Hammer

The short answer is Yes on the addition of the stage, but No on the direct connection between pin 1 and 5.  If you look at the original OS schematic - http://www.generalguitargadgets.com/pdf/ggg_osq_sc_original.pdf?phpMyAdmin=4a28f86a515b7883e7bc35a68d4e7b6d - you will see that the first stage has a 4.7uf cap on its output.  That cap is needed to block any DC accompanying the  audio output signal.  An analogous cap (1uf) is situated between the tone/gain-recovery stage and the preceding stage in the Peeler.  What I think you would probably want to do to add a stage of variable treble boosting is the following:

1) To the original OS schematic, insert another 4.7uf cap after the point where C6 and R11 meet.
2) That cap now goes to the noninverting input of the next stage/op-amp.  A 220k resistor goes from that pin to Vref to re-bias that next stage.
3) There is a full-bandwidth gain of 11x in that stage in the Peeler, largely because the preceding stage where the attenuation takes place is unity gain.  In the OS that stage has a gain of 23x.  You need to keep that gain in the OS, because you will need it for extracting the envelope (the TP has a separate op-amp dedicated to generating enough gain for the envelope follower).  But you sure as shooting don't need a stage with gain = 23, followed by another with gain = 11 (combined = 243).  So drop that 100k feedback resistor in the "tone" stage down to 22k.  That will keep the overall gain reasonable.

Now, is adding this stage a wise thing to do?  Not sure.  One of the things the TP does is add a high input impedance buffer stage at the front, in order to provide better noise immunity and allow for feed-forward rectification without loading the input down.  Is it smart to stick treble boost (which is what the tone stage does) after a normal OS?  Let your ears decide.

sevenisthenumber

I built the GGG version and want to have a sustain knob. Is the internal 10k trim sustain or some sort of bias?
I wired up a 10k pot in its place but only the last 40% of the rotation does anything.

How can I wire in a sustain knob "ala dynacomp" that has full range on the pot?

sevenisthenumber

is the 1k5 resistor i can replace with a 10k pot different from the trimmer pot?

Mark Hammer

There are two ways you can increase "sustain".  One is to increase the gain of the op-amp so that there is more envelope voltage for the circuit to work with.  The other is to increase how long that envelope voltage remains effective and does its' work.  The stock OS has a fixed gain of x23 and uses a 100k resistor to drain off the 4u7 cap to ground just after the diode.  If the 220k resistor is increased to 270k you will have more gain and so more envelope signal coming through the diode for a slightly longer period of time.  That rectified signal gets stored in the 4u7 capacitor, where it is applied to the gate of the FET for as long as it it can.  The 100k resistor drains the cap fast enough that the envelope only affects the FET for a short period of time.  If you want any gain reduction to take a longer period of time to go away (= greater perceived sustain), then you make that 100k resistance larger, like 470k.  In the Tangerine Peeler, I simply replaced the stock 100k with a 68k fixed resistor in series with a 500k variable resistance to cover the fast-to-slow range.  This mod works analogous to the recovery-time mod that has become so popular in Dynacomp/Ross clones.

As I keep repeating, though, you will NOT notice any effect unless you play in a certain way.  This recovery-time change will only seem more obvious when you play a lot of notes close together.

JohnBlakeArnold

 :icon_mrgreen:
Just want to say how helpful these archives of different mods are!
Everyday, I find something new that increases my knowledge on this board.
Thanks!