Orange Squeezer Diode

[krister]

Hello All,

I have been doing some research on the Orange Squeezer. I am fairly new to this hobby. I've built two NPN Boosters, a Little Gem with the Ruby's buffer, a Smash Drive (simple version), and modded the heck out of my Dunlop Original Crybaby. I would like to build an Orange Squeezer next. I have been studying what the diode does in the circuit. I usually source my parts at Radio Shack and they don't have Germanium diodes. Only silicon it seems. From the posts I read it sounds like I could leave the diode out rather than use a Si diode and the compression would work just fine in the Orange Squeezer. Am I correct here? Thanks!

Kris

[Peter Snowberg]

Welcome to the forum.

The diode is a vital part of the envelope detector so you can't get rid of it. Think of the envelope detector as a bucket with a small hole in the bottom. There's a pipe with a one way, pressure activated value that dumps water into that bucket and the amount of water in the bucket will determine the output value of the detector. The valve is the diode.

The idea is that during the positive half of the input signal cycles, the pressure (signal) will push the valve open and drop water in the bucket. If more water goes in than drains out, the output value rises. The size of the drain is the release time setting and on the schematic it's the resistor in parallel with the cap that is charged by the diode. If you're not filling the bucket, it will become empty as soon as the water drains.

If you didn't have the one way valve, the other half of the input signal cycles would suck the water right back out of the filling pipe and nothing would collect in the bucket.

The amount of pressure required to open that valve is analogous to the "forward voltage" of the diode.

A Ge diode is specified because the forward voltage is lower than a silicon diode. You can also use a Schottky diode which has a much lower forward voltage than a regular silicon diode. I'm sure you could just use a silicon diode with reduced performance until you found a Ge unit to replace it. A good salvage source for Ge diodes are telephones from the 80s... especially multi-line units made for small offices. Transistor radios will usually have a couple as well. Sadly, RS is not much of a source any more.

Best of luck with your build!

[cmat]

Small Bear has germanium diodes and his prices are great and shipping is fast.  If you are going to build pedals you gotta get to know Steve   www.smallbearelec.com

[krister]

Thanks guys, for the good info on the Orange Squeezer diode. It looks like I will have to buy some Ge diodes to get the effect I want. This site has been a really great resource for info and techniques. Hats off to Aron.

Kris

[Mark Hammer]

You can also consider increasing the gain of the op-amp to compensate for what the silicon diode takes away, relative to a Ge unit.

That can involve either increasing the 220k feedback resistor, decreasing the 10k resistance to ground...or both.  I suspect sticking a resistor in parallel with the 10k part is probably faster and cheaper to do than getting hold of a Ge diode.

Just keep in mind that increasing the gain to yield "more envelope signal" will require some adjustment of the trimpot, and also the volume control for unity output.  But it will work.

[krister]

Thanks, Mark.

Sounds like excellent advice. I'll have to buy a few parts and try it outjavascript:void(0);

Kris

[krister]

I'm having trouble finding a 2200pF cap. Is this a difficult cap to find? Thanks.

Kris

[Mark Hammer]

It shouldn't be.  Heck, I think it's even available at Radio Shack.

The 470k/2200pf network between the drain and gate of the 2N5457 is probably there for the same reason it is seen on a number of FET-based phasers - to improve signal handling capability in the FET and provide more distortion-free headroom.  As such, my sense is that the 2200pf cap has no impact on the tone, but may have some impact on the tracking or response time of the FET.  I may be dead wrong about this, but I'm guessing that a slightly larger (e.g., as high as 3300pf) or slightly smaller (e.g., 1200-1500pf) cap may make minimal difference.  Use one of those if you have one, until such time as the 2200pf ship comes sailing into the harbour.

[krister]

I couldn't find one at the Shack. I bought one of the assortment packs of ceramic caps and hoped one would be in there. Unfortunately there isn't. I have four 560pF caps that add up to about the right value or how about a .01uF film cap. Thanks, Mark.

Kris

[spudulike]

Check out your local skips (dumpsters) for old vcr's etc - you can remove small value mylar caps from them
Most of my spares are from stuff like that ...

[krister]

I've already cannibalized an old cd player, but it didn't have a 2200pF cap. I'll have to see what else I have laying around. I think there an old dvd player hanging out in the garage. Thanks!

Kris

[krister]

I just opened up an old answering machine from 1980 to see what was inside. I was looking for the 2200pF cap and I found a bunch of Ge diodes, 1n48, 1n41, 1n148 the writing is hard to read on these things. Would any of these diodes work for the Orange squeezer? The closest cap I could see was a 4700pF film cap. It also has a bunch of chips in it LM567CM, JRC 6047, LM324N, TDA11548652, plus a bunch of caps, resistors and Si diodes too. Last time I checked this thing still worked but I haven't used it in years and I think I might just take it apart for parts. Sound interesting?

Kris

[krister]

Would a 1N4148 diode work with Orange Squeezer? I just plulled a bunch of them out of that old answering machine along with a couple 2200pF caps Thanks!

[KMS]

If it is a GE diode it will work.

I just finished experimenting with my OS and I had some old GE diodes laying around from old crystal radio kits when I was a kid.  I tested all of them...........I even tried putting them in parallel together...just to see what would happen.  I could tell no difference from any GE I used or any configuration of parallel that I tried.  I don't know what any of my GE(s) are and I have one that I bought that is supposed to be a 1N34 but it has no markings on it either.  I even used a cracked GE and it made no difference.    I did try it with no diode and you can get some effect out of the OS with no diode......but not hardly anything....basically it is clean without the diode and I am considering putting a switch to defeat the circuit at that point instead of using true bypass.

I just took all my OS parts off my experiment board and will be soldering the GGG layout to a PCB in about 20 min.  It took me several days to get it to sound like I wanted, but the result is fantastic. I do not really know what I'm doing but used some of the advise over on GGG.....scroll down on the main OS page and read about some of what others have done.

I used some of Mark Hammer's advice and some of R.G. Keen's, and some form the forum here.  Do a search using the key words Orange Squeezer and also OS, also try a search on 2N5457.  You will find a lot of stuff about the OS.  Also look at tonepad.com build reports for the OS and some tips on the main OS page.

I used 2N5485 and they work just fine.   The 4558 sound best for the op amp.

I will be posting all my mods later.

The circuit will give you mild compression with no mods.....primarily dampens the beginning loud peak of each note with not hardly any extended apparent sustain.....unless you crank the bias pot...which then makes noise....but it sounds good with no mods, just like the tone samples over on GGG.

I notice a lot of noise with it in front of distortion FX when the bias pot is set for max compression which for my unit is that 10K pot off of Q2 set at about 3.68K but at that setting I hear no significant noise without using distortion FX. I put an MXR clone noise gate between the OS and the distortion FX and the problem is solved.

I guess I could go ahead and post all my mods now since there is at least one other who is working on this at the same time....maybe it will save you some time if your looking for long "apparent sustain" .


Look for my mods as a reply to this post http://www.elixant.com/~stompbox/smfforum/index.php?topic=40743.0

[krister]

Thanks, KMS for the reply. I looked the diode up and unfortunately the 1N4148 is a silicon diode in a glass tube with 500mAdc surge going forward and 150 mAdc average rectified current. I guess I could try it and see how it goes. Thanks for the mods also

[PenPen]

I couldn't find one at the Shack. I bought one of the assortment packs of ceramic caps and hoped one would be in there. Unfortunately there isn't. I have four 560pF caps that add up to about the right value or how about a .01uF film cap. Thanks, Mark.

Kris

This is just a 2.2nF cap. Look for a cap that has the marking "222". That is a 2200pF cap. I KNOW the Shack has these.

[krister]

Thanks, PenPen. I found two film caps that had 222 on them that I pulled out of the old answering machine. When I was at the shack they had no caps with 222 on them. The Ge diode is the pain in the keester. I've been looking around the house for some old electronics that may have some Ge diodes inside. So far no luck. I thought there were some in the answering machine but they turned out to be Si

[PenPen]

AH, sorry I didn't see that post where you said you found some. Thats odd that your Shack didn't have that value, the one here does. And I got a few from their 'assortment' pack that you got.

Can't help with the Ge diodes. I don't really mess with Ge anything, too much hassle. Personally, I'd go with Mark's suggestions, using a Si diode with more gain from the opamp.

[krister]

Thanks. I should just listen to Mark and get on with it and an Si diode

[krister]

Hi everyone, I finally got around to building my Orange Squeezer that I had collected parts for but never got around to building. I guess I was afraid it would sound like crap. As it turns out it sounded like a monster distortion pedal with tons of sustain and compression when I first plugged it in. Then came the problem of adjusting the 10k bias trim pot which I'm still fiddling with. If I turn it way down it squashes the sound and takes a lot of the highs away. As I open up the pot a bit more the highs come back with a bit of a volume swell after the inital attack. I am wondering if I should remove the trim pot and use a regular linear 10k pot instead, so I can vary the bias to achieve a wider range of tones from the OS. What have some of you done? I find the trim pot very hard to set.

I have not built this OS to spec but it sounds like the sounds samples I have found on the net (Tangerine Squeezer). Some of the differences are:
1N4001 Si diode [used Mark Hammer's gain mod suggestions (270k + 8K2 resistors) to up the gain of the op-amp to compensate for silicon diode], TL072 op-amp, MPF102 FET, and a few slightly different resistor values (like 2k2 instead of 2k4 and 330k instead of 390k). All cap values are to spec. Thank you to all of you for your help and comments.