2N5458 in Orange Squeezer ?

[Phend]

When I bought parts for the Micro V I bought extra, hence I have some 4558, then looking for my next project I can across the Orange Squeezer.
Lo and behold,  it uses the same 4558. What luck, usually if I don't have bad luck I don't have any luck at all.

[GGBB]

all pins must be used on a dual opamp, unless you want to invoke strange things happening. it's just that you can't tie (most) opamp inputs to ground without upsetting them, invoking the strange things, undocumented behaviour. so, tie the input instead to some voltage, like V/2. this is allowed.

In this context, that's true because we have a singly supply circuit. But dual supply opamps should ground the non-inverting input and connect output to inverting input, according to TI: https://www.ti.com/lit/an/sboa204a/sboa204a.pdf. (Of course, ground in a dual-supply circuit is like V/2 in a single supply circuit.)

Better still - use the other opamp channel for something helpful - to provide the Orange Squeezer with a stable bias supply:

[PRR]

why not use a single opamp like TL071 or LF351? or a 741, ... the extra pins problem goes away, then.

I thought I touched that point? "...some years the 4558 was cheaper than contemporary single opamps..."

Snow over the roof of my car, and my mailbox, is a problem. I don't see extra pins as a "problem".

The general advice to tie unused pins to half supply is good/valid. In the specific case of 4558, V- (Ground) is also valid, no harm results. With the fall of ALL opamp prices and the rise of chip-rolling, maybe this is now a bad practice. There were a few opamps who would go berserk if inputs were tied to V-, and even suck excess current.

[Phend]

Digging deeper into a box of misc parts I found an old Radio Shack LM741 that I used for a flasher circuit 30 years ago.  As duck_arse suggested, is this workable in an Orange Squeezer, of course the best way to find out is to try it, DIY style.

[percyhornickel]

I would like to take the opportunity as a electronics self-learning guy to ask somebody to explain how this circuit "physicaly" in terms of kindergarden level for an almost retarded people like me.

Once the signal shows up, part of the signal goes to non-inv opamp and the other part to the Jfets section, this is where things turns impossible to understand to me. I know well how Jfets works but I don´t see the way how they work together..  ..worse, I don´t see the funtion of the Jfet with the 2.4K resistor between gate and source.

Another thing, why the used diode must be a germanium one (Vf 0.3V) and not a regular one Vf 0.7V..   1N4148 1N4001/7..  ..ETC.

I would like to clear those things...    ...I am petroleum engineer from Venezuela, my English is not perfect.

Thank you

[GGBB]

Search here for "the technology of the orange squeezer" - I think RG wrote a post some time ago.

Edit: Doesn't seem to show up in forum searches, but it is here: https://www.diystompboxes.com/smfforum/index.php?topic=54308.msg414842#msg414842

LOTS of other posts on the subject as well, but try web search instead of here e.g. https://duckduckgo.com/?q=orange+squeezer+site%3Adiystompboxes.com&t=ffcm&ia=web

[percyhornickel]

Thanks GGBB I will check the sites and try to understand better this circuito. I have read some post but none of them were what I wanted so far.

Percy

[Phend]

I found that if you Search for "Orange" in Building you own stompbox you will get some great history of the OS.  Lots of information that will keep you going this way and that !
Search Box: Upper right of the screen

[percyhornickel]

Thank you Phend...  ..I will search in here too, that is the first thing I always do with many other circuits but for some reason I've have never done before with Orange Squeezer...     

[Phend]

Bread boarding the GGG circuit:
Added electro cap from + to -.
Added protection diode.
Using 1n34.
Trying out J112's.
Connected 1 and 2 of IC1.
Divided voltage for pin 3 per m4268588 using 100k's.
Added a 2.2uf cap from pin 3 to gnd (an OS +++ component).
Did trim adjustment up for just start of gain with next to no noise.
Found resistance of 10K trim and replaced with resistor -500 and a 1K trim.
It is a subtle, I do have an Arion (inexpensive 80's compressor) and use it turned on.
Yes it is subtle but you do know it is there.
I can report that my dyslexia sets in connecting those Jfets, I hear that they are symmetrical, maybe electrically but not physically. Who the heck put pin 3 in the middle on paper and on the end of the actual darn thing.
Still experimenting, might decide to box it up after I add a bypass switch to the BB for a good deciding test.
Voltages of Q1 and Q2 are wacked, battery = 8.2, Trim adjusted for Q2 d=2.5: (J112's)
Q1 d= 8.2  s= 5.3  g= 2.6
Q2 d= 2.5  s= 2.6  g= 0.001 = 0
But it does pass a clean signal....

[m4268588]

Adjusting the Trimmer was a bit tricky. So I used Runoffgroove's Fetzer tester or such a way to checked off-mode Vgs beforehand. (Q2 in GGG schem)

Install the FET and adjust it to the same voltage. You can change from a slightly if you follow the sound.
I try to get back there when I'm not sure about everything.

[Phend]

Thanks, I am now using  1K , 30 turn? Trim. In series with a 1K8 . Adjusting is much easier.

[iainpunk]

i repaired a friends boost pedal with a 30 turn pot once, since i didn't have any other pots of that value in my collection at the time. hes still happy about it, as he says it gives him better control over the amount of gain

cheers

[percyhornickel]

I remember trying a few Jfets before selecting the ones with the "right" drain voltages (2.6V / 4.0V) after adjusting the trim. Some of them were to far for those values.

With the 2N5457 I had on hand I could never get the drain voltages according to GGG and the sound were no that good / difined.

That´s why I tried with the 2N5458 and worked the best for me. I could get 2.6V / 4.0V easily, I think maybe I am lucky on it.

I tried 4558/TL072/5532...   ..and the best one i could get was LF353P, cero distortion..  ..very subtle and nice sound.


Percy

[Phend]

Without ordering other Jfets , of the two I have , 2n5458 and J112 , J112 wins , swapping them , the Q2 drain remains at 2.60 without adjusting the trim , J112 has much more gain and certainly sounds better. So I shall box it.

[percyhornickel]

I just wanted to show my Orange Squeezer puzzle-box (and some others)..  ...I just finished to fit the circuit last night..   ...love it

IC: LF353p
Jfets 2N5458 / Vd 2.6V - 4.0V


















And some other ones: (complete hand made from etching pcb to the enclosures)




REBOTE 2.5 MOD - PULSAR MOD - PHASER - DIST PLUS MOD - RAT - PURPLE PLEXI 800 - TS 808/9 MOD


DISTORTION PLUS MOD - PP 800 - FUZZ FACE BC109 - TS - RANGEMASTER


PUZZLE BOX - PURPLE PLEXI 800


RAT - TUBE SCREAMER 808/9 MOD


MINI RAT - PHASER


Saludos desde Venezuela

Percy

[Phend]

Percy,
Q2 d = 2.6v correct?, what does 4.0v represent?
I am new to this.
Thanks

[percyhornickel]

Both values are the voltage of the jfets source pins.. Q1=4.0V / Q2=2.6V     

Phend my mistake pointing out like drain voltages!!! (maybe I was thinking something like plexi drive which bias is over the drain pins)!!!


Percy

[Phend]

Thanks Percy
Look up sequence of guitar effects.
That is another topic.

[percyhornickel]

Phend that secuence was just for testing purposes..   ...maybe just for the pictures and yes, that´s another topic.

Saludos desde Venezuela


Percy