What are they asking for here??? To me it looks like a mono input with +9v on both the tip & shield. Doesn't seem right to me but I know I'm missing something. I've seen this on several schematics and searched the interweb to understand it to no avail.
Help a monkey out, please...
(https://i.postimg.cc/wBfdFCvv/input-jack-schematic.png)
Please be kind to post some of the official schematics from well known sources where you saw this Jack with the +9V connected to it in the manner shown.
Thanks !!!
That's a switched DC jack. (I think)
Looks drawn incorrectly.
Edit: I'm tired. Sorry. :icon_redface:
tip has a switch, which is closed normally. it is shown connecting tip to sleeve, which is connected to +9V, suggesting a positive ground circuit. insert a plug into the jack, and the plug tip will shift the tip dinger away from the switching contact. the swict is now open, tip goes off to somewhere useful, sleeve remains connecting to "+9V".
like so:
(http://img.auctiva.com/imgdata/9/8/6/0/1/1/webimg/628003216_o.jpg)
some germanium transistor PNP circuit??
i can't think of any other reason for this.
cheers, Iain
If it is "positive ground" then it makes sense: The input is grounded when not in use to avoid noise when nothing is plugged in. Useful in a mixer for example. Hard to think why a PNP fuzz box would need this....
Quote from: idy on November 07, 2020, 11:42:01 AM
If it is "positive ground" then it makes sense: The input is grounded when not in use to avoid noise when nothing is plugged in. Useful in a mixer for example. Hard to think why a PNP fuzz box would need this....
to not have it make a bunch of unnecessary noise when you accidentally pull the plug out of the fuzz pedal in a gig... it happened to me with a fuzz that goes bezerk when there is nothing plugged in the front.
cheers, Iain
That's correct !!!
The tip normally goes into the input of the circuit.
The switch grounds the input when there is no jack plugged in, so that no noise/RF in amplified
It's connected to +9 since its a positive ground circuit.
Quote from: iainpunk on November 07, 2020, 11:15:35 AM
some germanium transistor PNP circuit??
i can't think of any other reason for this.
+1 agree. Looks like a positive ground circuit to me, so the input is connected to the "ground" when nothing is connected to prevent noise.
Quote from: Vivek on November 07, 2020, 07:45:30 AM
Please be kind to post some of the official schematics from well known sources where you saw this Jack with the +9V connected to it in the manner shown.
Thanks !!!
(https://i.postimg.cc/hPfw1nQ2/rangemaster-schematic.png)
What is confusing me is that it appears that both the sleeve and tip are getting +9v. Am I crazy?
In this circuit it is better to think of +9 as ground. So when nothing is plugged in, both tip and sleeve are grounded. When there plug is inserted, the tip is "lifted off the little upward arrow head, opening the switch so only the sleeve is grounded and the tip is a path for signal. You call this a NC or Normally closed switching jack.
If you are tripping out on positive ground, you can look that up. It is a weird idea mostly found in ancient fuzzes and *Range Masters*.
https://www.electrosmash.com/dallas-rangemaster
First thing, the schematic does not show positive ground!
Second, on most physical hardware, the sleeve is physically connected to ground. Unless insulated jacks are used, this schematic will lead to the jack shorting out the battery.
Maybe there is an error in the schematic ?
PS the electrosmash article talks about grounding issues of the range master.
(https://i.postimg.cc/vc0CDSNF/2020-11-08-09-42-22.jpg) (https://postimg.cc/vc0CDSNF)
There is no error in the schem. No shorts also. The article stated that the rangemaster is a *battery powered* circuit.
OP, check section 5 of the website, "Dallas Rangemaster Treble Booster Mods". I recommend you go the NPN route as the cheapest way without enclosure/grounding problems (if implemented well, of course)
Quote from: 11-90-an on November 08, 2020, 01:07:17 AM
There is no error in the schem. No shorts also. The article stated that the rangemaster is a *battery powered* circuit.
Agree that its a Battery powered circuit
and agree that the schem, if used standalone on a breadboard, is just fine, though a bit quirky
But let us see what happens if we physically try to put the schem into an enclosure
A) Do you agree that the point marked Ground will be connected to the enclosure ?
Thats the negative of the battery
B) Do you agree that most hardware jacks are such that the sleeve is electrically connected to the enclosure ?
The schem asks for the positive of the battery to be connected to the sleeve and that automatically means connected to the enclosure.
If answer to both questions is Yes
Then both positive and negative of battery are connected to the enclosure in a real physical implementation.
Ie battery is shorted
QED
These schematics show shorting jacks, but I'm skeptical. Original Dallas Rangemasters had a hard-wired output cable to a plug, so that's at least one end that wouldn't default to shorting out.
Regardless of the power supply, it doesn't make any sense to short it out when you don't have something plugged into the input, either, I would have used an open-circuit jack there. Are we all going into the weeds because someone just used whatever symbols were available in their circuit-drawing software? :icon_wink:
Nothing wrong with the schematic, no short circuits, though it is drawn unconventionally, which seems to be throwing some people.
Enclosure is connected to +9V, it's a positive ground circuit. No need for isolated jacks.
The tip shorting is recommended to reduce noise if input is unplugged. If the input is left floating it will pick up whatever noise is floating through the air, and will often squeal. Better to have a quiet rather than noisy circuit if you accidentally tug your cord out of the pedal during a gig, right?
Here are two alternative ways to draw the circuit. Left is how I prefer to draw it (positive nodes at top, negative at bottom of schematic - this is the modern convention), and on the right is the way it is most commonly drawn (inverted from modern conventions).
(https://i.postimg.cc/26mFLNkt/Rangemaster2.png) (https://postimg.cc/nsRQN5QK)
EDIT: apologies to anyone who caught the first image I posted. In my haste I made some large errors when transcribing it. This speaks to the value of sticking to conventions when drawing schematics, as it greatly facilitates understanding.
Note, the circuit can also be built with conventional negative ground, to avoid daisy-chain/non-isolated PSU compatibility issues WITHOUT the need for a charge pump voltage inverter. RG has reported potential stability issues if doing so, but to my knowledge he is the only person to report such, and even he notes that it is an uncommon possibility. I personally have never experienced any problems in any new builds or conversions.
(https://i.postimg.cc/Fs1qH3nL/Negative-ground.png) (https://postimg.cc/GHwzM8RL)
Quote from: Phoenix on November 08, 2020, 04:08:47 AMNothing wrong with the schematic, no short circuits, though it is drawn unconventionally, ...
So how do I turn it off? I do not see a power switch or a jack finger.
Quote from: Vivek on November 08, 2020, 12:34:49 AM
First thing, the schematic does not show positive ground!
What do you mean by this comment, Vivek? I don't understand you, sorry.
The circuit looks to me like what is typically called a "positive ground" circuit, since points that would usually be connected to ground (e.g. negative side of the battery) are instead connected to the positive side of the battery. It's a Rangemaster. It's a famous example of this type of thing.
(https://i.postimg.cc/9rBwY2HS/2020-11-08-09-42-22-01.jpg) (https://postimg.cc/9rBwY2HS)
Does positive ground mean positive of battery is connected to ground ? I don't know the convention.
Quote from: Vivek on November 08, 2020, 03:43:37 PM
(https://i.postimg.cc/9rBwY2HS/2020-11-08-09-42-22-01.jpg) (https://postimg.cc/9rBwY2HS)
Does positive ground mean positive of battery is connected to ground ? I don't know the convention.
I'd say a better way to describe it is that the "ground" and "+V" symbols are reversed. The "ground" symbol still appears in the circuit diagram, and like on the power supply cap you posted, that obviously has to be the right way around.
But whereas the sleeve of a jack and similar places would ordinarily be considered as "ground", instead these points are connected to +V, hence "positive ground".
Phoenix's diagrams showing alternative ways of representing the same situation are nice. Both of those diagrams represent it with 0V and -9V, but the Electrosmash diagram shows 0V and +9V, so that's a third way of drawing the same thing. Nightmare.
But I completely agree, it really is only a convention, and it's pretty confusing and causes no end of trouble. In fact, here we are again!
In my opinion, the Electrosmash schematic is drawn incorrectly and does short the battery. They have a ground symbol where most people would put "-9V." Then they have "+9V" connected to the jack sleeves. Even if you isolate the jacks from the enclosure, the sleeves are going to connect to ground at some point. It looks like 'Smash started to draw it as an "upside down" PNP circuit to be negative ground, but labeled the jacks for positive ground. Hense, shorted battery.
Quote from: PRR on November 08, 2020, 01:46:08 PM
Quote from: Phoenix on November 08, 2020, 04:08:47 AMNothing wrong with the schematic, no short circuits, though it is drawn unconventionally, ...
So how do I turn it off? I do not see a power switch or a jack finger.
A fair criticism. I omitted power switching just like the original rendering of the schematic under discussion. It's fairly common for this information to be "implied" and left to the builder to intuit, which is hard to argue isn't just bad practice and laziness.
My comment was levelled at the concerns about the battery being shorted out. I think we can agree that it is *functional* as drawn (though unintuitive, leading to this discussion), but lacks the practical aspect of being able to turn off without disconnecting the battery.
EDITED: to add schematic with input jack power switching. Also removed output jack NC connection from Electrosmash rendering as it serves no purpose
(https://i.postimg.cc/PrNHsqpr/Rangemaster-sw-itching.png) (https://postimg.cc/9r3KyCYv)
Phoenix,
Your drawings and descriptions are great !!!
I still do feel that there are "errors" in the schematics. That is not "Confusion created by convention" but real errors.
Error 1 :
In positive ground systems, the positive of the battery connects to ground. But the schematic shows the negative going to ground in the power section (Cap parallel to battery)
(https://i.postimg.cc/9rBwY2HS/2020-11-08-09-42-22-01.jpg) (https://postimg.cc/9rBwY2HS)
Error 2 :
There is a ground symbol shown on the top of the schematic but the +9 is written at the bottom. This means that the top is not at +9V. which means that the ground is not at +9 Volts.
Implied error 3 : There is a ground symbol shown on top. It has to be the negative terminal of the battery since the +9 is written at the bottom.
It is implied that ground is connected to enclosure. There is a +9 connected to the sleeve. Most jacks are not isolated, it means that the sleeve will touch the enclosure. That means that the battery will be sorted.
(https://i.postimg.cc/sgzz6kPX/2020-11-08-09-42-22.jpg) (https://postlmg.cc/vc0CDSNF)
There is nothing wrong with the concept of positive ground since, for AC signals, both the terminals of a battery should be equivalent.
There is nothing wrong in convention 1 or convention 2 as long as they are consistent.
The schematic is the one that has errors.
I made an attempt to rectify the Rangemaster schematic using my feeble brain. I hope I did not introduce even more errors
(https://i.postimg.cc/gkC5bqFr/corrected-dallas-rangemaster-schematic-parts.png) (https://postimg.cc/F7xGjSKQ)
For fewer headaches, just change "+9V" to "-9V" (because that's exactly what it is). Don't get hung up with the markings on a PP3.
Quote from: ElectricDruid on November 08, 2020, 05:19:53 PM
Quote from: Vivek on November 08, 2020, 03:43:37 PM
(https://i.postimg.cc/9rBwY2HS/2020-11-08-09-42-22-01.jpg) (https://postimg.cc/9rBwY2HS)
Does positive ground mean positive of battery is connected to ground ? I don't know the convention.
Phoenix's diagrams showing alternative ways of representing the same situation are nice. Both of those diagrams represent it with 0V and -9V, but the Electrosmash diagram shows 0V and +9V, so that's a third way of drawing the same thing. Nightmare.
I still do believe
Phoenix' drawings are correct
Electrosmash has an error. This is not "confusion due to convention", it is plain error
In a positive ground system, the positive of the battery and the ground are the same thing. Phoenix shows it that way.
In the power supply section, Electrosmash shows that +9v and ground are two different things.
In the main circuit, if ground = +9V in positive ground section and the top rail is ground, it means top rail and bottom rail are at the same voltage. This is error. This is not "Confusion due to convention"
================
I stand corrected !
Please read https://www.diystompboxes.com/smfforum/index.php?topic=125770.msg1199569#msg1199569
Quote from: Vivek on November 09, 2020, 02:55:29 AMError 1: In positive ground systems, the positive of the battery connects to ground. But the schematic shows the negative going to ground in the power section (Cap parallel to battery)
Where you are tripping up is how you are interpreting the ground symbol used in the schematic. There are at least three most commonly used "ground" symbols
(http://1oomzzme3s617r8yzr8qutjk-wpengine.netdna-ssl.com/wp-content/uploads/2016/10/figure-1groundingsymbols.png)
Signal/circuit ground is an arbitrary reference. It only denotes where all voltage measurements are taken from, but critically, it *does not* imply a chassis or protective earth connection. It is common to see circuit/chassis/earth ground connected, which is why this is throwing you for a loop, but it's important to know there are very important differences.
"Earth ground", as used in the Electrosmash schematic, is the tricky one. In a schematic with multiple different ground symbols, it denotes a connection to protective earth - almost always a safety critical connection. But, it is also often used in schematics in place of the circuit ground symbol, where it does not imply anything about a chassis or protective earth connection. As the "earth ground" symbol is used in isolation in the Electrosmash schematic, it's implied that it's only indicating circuit ground in this case.
Chassis ground is *only* used to denote chassis connections. The Electrosmash schematic does not specify this connection, but it is implied by the jack connections and other circuit details that if it were present, it would connect to +9V.
Examples of where you might see circuit ground and chassis ground *not* connected include audio products with ground-loop isolation through the use of bypassed diodes, floating power supplies, etc.
Quote from: Vivek on November 09, 2020, 02:55:29 AMError 2: There is a ground symbol shown on the top of the schematic but the +9 is written at the bottom. This means that the top is not at +9V. which means that the ground is not at +9 Volts.
Further confusion is caused by the schematic being inconsistent with top-to-bottom polarity. The schematic is drawn almost entirely with negative potentials at the top and postive at the bottom, with the glaring exception of reservoir capacitor C4. Modern convention has postive potentials at the top of schematics, but remember it is only a convention to aid in understanding. If the clarity of a schematic is aided by inverting top-to-bottom polarity, even if just for a section of an otherwise conventionally drawn schematic (like if a large number of crossing wires would be required to maintain absolute consistency), then that is preferred. These conventions only exist to aid in clarity, if they work against this aim then they can and *should* be ignored.
I do agree that the Electrosmash schematic is a particularly poor example, but it does *not* contain any short-circuit errors.
Quote from: Vivek on November 09, 2020, 02:55:29 AMIt is implied that ground is connected to enclosure.
This is the root of your misunderstanding.
Here's a reference from National Instruments (https://www.ni.com/en-au/support/documentation/supplemental/18/chassis--earth-and-signal-grounding--terminology-and-symbols.html) noting the differences between "ground" symbols.
Pay particular attention to the following section:
"Note that none of these grounds are necessarily equivalent. Ground is a point of reference from which a potential (voltage) may be measured. Different grounds will have voltages between them that we must take into account when connecting equipment together and making measurements."
Thanks Phoenix !!!
^^^ You may be right, but I kinda doubt Electrosmash was thinking in the same way, I think they screwed up an attempt at negative-ground PNP. They may be a good source for circuit function explanations, but MOST of the schematics I've seen from them contain errors. If I'm wrong, they should stick with more conventional labeling of circuit portions, to avoid sewing confusion among the newbs they exist to assist. In my overly-simplified understanding of guitar electronics, ground is ground, and it connects to cable shield, guitar bridge, amp chassis, etc. We don't stick a ground symbol on Vref in a Tube Screamer, and specify all voltages relative to that point, put "-4.5V" on the jack sleeve, etc. That would just cause unnecessary confusion, for no benefit.
(Vivek posted as I was typing, but I'm replying to Phoenix' post up a couple)
What is the convention here if one makes a post,
and then gets wiser and corrected after reading other posts ?
Do you edit the earlier post ? or just let it be ?
Quote from: willienillie on November 09, 2020, 04:44:15 AM
^^^ You may be right, but I kinda doubt Electrosmash was thinking in the same way, I think they screwed up an attempt at negative-ground PNP. They may be a good source for circuit function explanations, but MOST of the schematics I've seen from them contain errors. If I'm wrong, they should stick with more conventional labeling of circuit portions, to avoid sewing confusion among the newbs they exist to assist. In my overly-simplified understanding of guitar electronics, ground is ground, and it connects to cable shield, guitar bridge, amp chassis, etc. We don't stick a ground symbol on Vref in a Tube Screamer, and specify all voltages relative to that point, put "-4.5V" on the jack sleeve, etc. That would just cause unnecessary confusion, for no benefit.
(Vivek posted as I was typing, but I'm replying to Phoenix' post up a couple)
yeah, i'd dis-recommend electrosmash for beginners in general, they tend to over simplify and i guess they have no proofreader either because its riddled with mistakes. i'd never use one of their schematics to build anything. i wonder who's behind that website. i guess its a hobbyist without formal training.
nice new profile pic.
cheers, Iain
edit:
Quote from: Vivek on November 09, 2020, 04:51:58 AM
What is the convention here if one makes a post,
and then gets wiser and corrected after reading other posts ?
Do you edit the earlier post ? or just let it be ?
i always like to edit underneath my ''cheers, Iain" signoff, like this "edit: bla bla bla", i think its at least polite to let people know you learned something with an edit.
Quote from: Vivek on November 09, 2020, 04:51:58 AM
What is the convention here if one makes a post,
and then gets wiser and corrected after reading other posts ?
Do you edit the earlier post ? or just let it be ?
one common method, that doesn't make the thread loose it's -erm- thread, is to go back to your troublesome post and use the (https://www.diystompboxes.com/smfforum/Themes/Prince_of_Darkness_201/images/bbc/strike.gif) strikeout formatting. [that's how it looks in the Prince ... theme.] you only get 24 hours from when you posted for correctings, tho.
There is no "ground". Play in a rubber-tire car. Play the Space Station.
There are "COMMONS". Not topologically essential but super-practical. Signal common. Power common. And shielding.
Quote from: PRR on November 09, 2020, 05:38:35 PM
Signal common. Power common. And shielding.
In the vast majority of guitar gear, all of these are connected, and referred to collectively (
if only by me) as "ground." Maybe slightly more correct to say "all points at the same potential as earth ground." And in my own setup, surely most others, it does all run outside to actual dirt via the third prong on the amp's power cord. Not so with a battery-powered amp, of course.
> referred to collectively ...as "ground."
An oversimplification that sometimes leads us astray.
> it does all run outside to actual dirt via the third prong on the amp's power cord
It does; but this is frequently irrelevant. It gives "dirt" an exalted image it can't fill.
Working around utility AC, it "IS" useful to reference audio common to power common. Even with battery amps, which are never quite hum-free inside a room. Play in an airplane: you want to reference the plane power (not some ground 8 miles low). Play in an airship without electric power, "grounding" is not needed.
I grew up with Ge PNP and + "ground". These concepts do not disturb me unless a draftsperson mangles the drawing. (Yes, even in 1958 that happened often enough.)