I was thinking about making DBS. People seem to just add a pot between the battery and power pad in the circuit, although such a resistance can add itself to collector resistors and work as volume increase, which is what i don't want. Can this be sorted by a cap across the pot, so the signal will bypass this additional collector resistance?
a LARGE cap will be necessary, as R is small (my almost dead 9V batteries seem to have 200 ohms internal reszistance). Try 100uF. That'll give voltage drop without increasing gain.
here we go - an external DBS 8)
(http://www.hoho.cz/osobni/SDB.jpg)
I'm not sure if i'm on the right track here,
with a fully charged battery it can supply x amount of current at the given voltage but as the battery is dying and the circuit trys to draw that x amount of current then the voltage falls.
If this is correct then the voltage divider part of a circuit can possibly be desinged to simulate the dying battery, eg if your VDivider is made up of 10k resitors to provide a good current for Vref , try using 1M resistors, this would limit the current that it can supply thus starving the circuit of current.
values are just examples and you would need to do some calculations to work out how much current your circuit requires and how much to starve it by.
just my 2p worth. Maybe someone with a bit more knowledge could could confirm / deny this idea.
If you're going to simulate a dying battery, do it right.
A battery is a voltage source which varies from 9.5 or so when it's fresh to 7V or so when it's all tapped out, in series with a resistance, which varies from a fraction of an ohm or so when it's fresh up to a few K when it's all tapped out. Both conditions need to be diddled to get a realistic simulation. Using just a resistor simulates... just a resistor. The voltage varies with load in the pedal, and the resistor needed to drop the voltage may not be reasonable for the impedance of the battery when the voltage is right. And the resistor for the same voltage will be different from pedal to pedal depending on how much current the pedal draws.
There's been a dying battery simulator circuit at GEO forever. Well, OK, since 1998 at least. It's here: http://geofex.com/Article_Folders/pedalbdpwr/pedalbd.htm (http://geofex.com/Article_Folders/pedalbdpwr/pedalbd.htm) . Granted, it takes more than one resistor and a cap, but it actually does the job correctly.
As a humorous aside, that circuit is patented, and not by me. The patent application was six months AFTER the file was put up on geofex. :icon_lol:
6 years later but anyway - is there a way of simulating a dying 9V battery without necessity to use 12V power source?
Musique.co has this article : http://www.muzique.com/lab/patent2.htm
There is a simple simulation circuit at the bottom of the page that uses diodes in series to the 9V power source (7809) and it comes with the following text:
"The diodes will have an internal voltage drop that increases with the current draw from the effect circuit, i.e. the sag effect."
What makes diodes in this position different from a resistor?
I understand the voltage drop on diodes is not linear (depending on the current draw), i just wonder how that makes it closer to the dying battery simulation.
Quote from: yeeshkul on April 12, 2015, 03:40:14 PM
I understand the voltage drop on diodes is not linear (depending on the current draw), i just wonder how that makes it closer to the dying battery simulation.
I don't think it makes it closer to the DBS, particularly. The change in forward voltage isn't terribly close to what a battery does, nor a great simulation of the drop in voltage.
A battery is an electrochemical cell. Actually, two half-cells. Each terminal reacts with the electrolyte to pump electrons out of the negative side, sucking them in through the positive side. As a battery discharges, the electrolyte and terminals are chemically changed into "leftovers", stuff which cannot further supply energy in the battery. A perfect battery would provide a constant voltage from completely fresh right up to completely exhausted, then the voltage would drop to zero. However, in real batteries, the "leftovers" interact with the still-working half-cells to (1) increase the resistance between the battery terminals and (2) lower the total voltage of the two half-cells. There is both a voltage drop and an increase in internal resistance.
A carbon-zinc, old-school 9V battery is about 9.2V when perfectly fresh, and this voltage tapers down as current is drawn out of the battery; the internal resistance increases too. A fresh CZ battery might push 1A into a short, but one that has discharged down to 8V would not be able to supply that much current because its internal resistance is bigger. The makers of batteries decided that a 9V CZ is discharged when its open circuit voltage reaches 7V. At that point the internal resistance is bigger, but they don't specify that very well.
Dropping a voltage or so off a 9V regulated supply gets the voltage down in the "dying battery range", OK, but doesn't do much about the internal resistance. As a gross generalization, a nominal silicon diode has a forward resistance in the range of 10-15 ohms. Batteries typically have an internal resistance that's different from that, but exactly what the value is depends on the battery chemistry and state of discharge. So both lowering the "open circuit voltage" of the DBS and adding a resistance is a much more accurate simulation.
Then there's the issue of whether the circuit cares if its battery is dying. Circuits vary in how much current they pull. The less current a circuit pulls, the more a "dropped voltage only" DBS is accurate for it. The more current it pulls, the more difference the internal resistance of the DBS makes.
Not many people use portable radios operated with a 9v battery anymore, so they tend not to have the more informative experiences that a continuous audio signal can provide. I had my great learning about carbon-zinc batteries when I was laid up in bed with mononucleosis in 1966, and had to rely on the near-dead batteries in my radio to be able to hear my favourite tunes on the top 40 playlist. I'd leave my radio off for 90 minutes or so, to be certain I had enough juice regained in them to hear the tunes I knew would be played at relatively predictable times (and at the time, I was enamored of the guitar intro to The Hollies' "Look Through Any Window:)
Carbon-zinc will spontaneously "recharge" if you leave them for a bit. That is, the chemical reaction will reverse with disuse, and they will regain a little bit of life. And I emphasize the word "little". If I kept the volume down, I could hear a whole tune, but if I cranked it up, i'd get a very audible compression, until finally the batteries crapped out. This "Hold on, give me a sec to catch my breath" phenomenon would only occur when the batteries had dropped in voltage a bit.
The "dying battery effect" is NOT, as some would have it, merely a lower, but stable, voltage. You won't get it from an alkaline, or lithium-ion, or from a wallwart with a bunch of diodes in series, or anything similar, because they are providing a power source that can meet the current demands of the pedal. What is fundamental to the impact a dying battery has on a fuzz (and nobody seeks dying battery sounds for delays, tremolos, EQ, wahs, etc.), is that a brief respite allows the battery to catch its breath but a peak transient saps the battery of current. That is, the impact of a dying battery on a fuzz is a dynamic phenomenon, that corresponds to picking strength, and input signal amplitude. That's what imparts a certain sponginess or compression, in addition to a bit of gateyness here and there.
I'm confident something can simulate that, but I'm equally confident that much of what gets suggested as a dying battery simulator probably won't, simply because they do not incorporate any means for the power source to "choke", cough, wheeze, or whatever you want to call it. That is, they provide a steady and stable current delivery capability.
Guys thank you very much for taking time to explain that. It is all clear now.
Mark Hammer: Now you got me into enthusiastic design mode for a new product!
Like I say, I'm confident somebody will be able to simulate it. The first step is for people to have a clearer notion of what it is they are attempting to simulate. My own very biased view is that we have been trying to simulate only one part (and the simplest part, too) of what takes place with a well-used 9V carbon-zinc battery when it is asked to power a high-gain circuit amplifying a guitar signal that has lots of peak transients.
Best of luck in your experimentation! If you are successful, I'm certain you will make many happy. :icon_smile:
Not exactly what you're discussing but year's back The Tone God did a power supply sag thing, sagged in response to playing dynamics. It's probably still around here somewhere in the FX-X competition archives.
At the moment I am thinking of something similiar to a compressor but instead of being controlled by audio level it's controlled by current and which reduces "gain" of a setting of a constant current source. Attack and release(especially) will be much, much slower though.
That sounds pretty cool. I was thinking maybe just a current limited power supply might do interesting things, would only work with circuits where current draw varies in response to playing though.
Here's The Tone God's thing http://tech.thetonegod.com/punisher/punisher.html (http://tech.thetonegod.com/punisher/punisher.html)
Quote from: slacker on April 13, 2015, 03:37:27 PM... would only work with circuits where current draw varies in response to playing though.
[/url]
Is one of these Si Fuzz Face? Hmmm, it probably is ...
Quote from: slacker on April 13, 2015, 03:37:27 PM
That sounds pretty cool. I was thinking maybe just a current limited power supply might do interesting things, would only work with circuits where current draw varies in response to playing though.
Here's The Tone God's thing http://tech.thetonegod.com/punisher/punisher.html (http://tech.thetonegod.com/punisher/punisher.html)
The concept of the design looks about right, but something deep inside me says the time constants (attack/recovery time) may be too long. It's an empirical question, though, I suppose.
For a simple approximation though:
(http://i.imgur.com/2e1MSYj.png)
Although the cap(s) have to be fairly large, and the resistor needs to be tuned accordingly. Possibly add another about 4 times the pot resistance between ground and the pot as well, provided large enough, the pot regulates voltage and "regen" time.
Holger do i get it right that in your scheme you are simulating the dying battery by the large cap and you are limiting the current that charges the cap?
Exactly. also the pot regulates the max voltage, the cap will be charged to. Porbably needs lots of tweaking and large caps though.
Just got a pair of 6.8mF caps. What i am gonna do is to feed my Fuzz Face by an old 9V battery - 7V that is. I am gonna hook it up to my scope, play chords and observe the DC changes. When i have a rough perception of what should be going on, i am gonna try your design, again hook it up to the scope and tune it up to what i want to see. If possible.
Cool, I hope you will post results here too, eager to see them :)
For the first time i've had a reason to use the battery clips in my Boss DD-3, aka the battery killer. :D
Interesting, nothing is really happening to my depleted battery when i play guitar to a Fuzz Face circuit.
I used a 9V Green Cell carbon zinc 1604G 6F22 battery (it really gives 10V open circuit).
I depleted the power down to 6.5V open circuit, and connected it to my silicon Fuzz Face circuit. The voltage went down to 6.2V.
I connected the battery to my oscilloscope, and played guitar (humbuckers) into the FF. Nothing happened. Then i used the Transient recorder
and did the same thing. Again, nothing happened, it drew a straight line 6.2V.
Last night I played with my mates KORG monotron delay, the batteries were dying, got some REALLY interesting sounds out of it, the delay chip couldn't quite get the power to work properly and the LFO LED kept pulling all the current messing with other parts. When I get the time, I will hook an ammeter and an oscilloscope to it and collect data. I guess analog meter would be better too for this task.
I keep draining the battery. Let's see when it breaks and starts listening :)
Battery down to 6V open circuit. It gives 5.6V connected to the FF. No change in the voltage when i play guitar into the FF.
I either:
1. do something wrong
2. this carbon zinc battery is not what i am supposed to test this way
3. the battery dynamic response is a highly exaggerated phenomena
interesting... How's the sound behaving? And what does the voltage do when you switch it on and off?
When on 5.6V, the sound was quieter and more farty, but not ugly. Nothing magical soudwise though.
Oh mine, i've just realized there is a 220u cap (DC-Ground) inside to filter the power source riddles. If anything, this was it.
Now i have to do it again without the cap, just a pure FF circuit.
Trying to revive this old thread instead of opening a new one (I never know what is better/gets more attention). However, I have been asked if I could reproduce the sound of this pedal:
https://www.youtube.com/watch?v=yoQVR-hN0PU
To my ears it sounds quite similar to the Peach Fuzz but with the added starving battery bonus. So I'd like to try it. As I found out, there is a simple but according to RG overly simple dying battery simulator (DBS) that Beavis had up on his side (one potentiometer one resistor finito). RG has a better circuit on his site (here (http://geofex.com/Article_Folders/pedalbdpwr/pedalbd.htm)) that has the drawback of utilising 12 V AC as power source.
Now finally my question:
Would something like this with a LT1054 as charge pump in front of tthe circuit be suited to replace the transformer/rectifier part?
(http://i1244.photobucket.com/albums/gg578/lars-musik/DBS.jpg)
Thanks all in advance!
Lars
The internal resistance of a dying battery changes very little as the chemicals in it are depleted. Certainly the resistance increase is much much less than most dead-battery simulators use.
The change in tone is due to the lowered voltage.
I measured some depleted batteries here: http://www.muzique.com/lab/batteryz.htm
Best regards, Jack
Thanks very much Jack. So, if I want to adjust the sag it looks like I could do this with your setup by switches to add diodes for higher forward voltages
(http://www.muzique.com/lab/images/sag1.gif).
Beavis audio presented to different approaches: First with raising series resistance (which you say shouldn't be the focus)
(http://i1244.photobucket.com/albums/gg578/lars-musik/Schematic_Series.gif)
Or with a voltage divider (which seems logical to me).
(http://i1244.photobucket.com/albums/gg578/lars-musik/Schematic_Simple.gif)
Could you shortly explain pros and cons of beavis's voltage divider and your voltage drop method?
Thanks a lot!
:icon_cool:
Quote from: amz-fx on November 21, 2016, 09:33:16 AM
The internal resistance of a dying battery changes very little as the chemicals in it are depleted. Certainly the resistance increase is much much less than most dead-battery simulators use.
The change in tone is due to the lowered voltage.
I measured some depleted batteries here: http://www.muzique.com/lab/batteryz.htm
Best regards, Jack
I agree with this, partly.
What most "dying battery" simulators really attempt to do is provide a
stable reduced supply voltage and/or current. In my own experience, what most dying carbon-zinc batteries do is provide a dynamically-shifting current (and possibly voltage), that changes in response to transient peaks. The battery is able to effectively catch its breath a little between notes, or groups of notes, and is only able to provide suitable current for the first transient, after which it limps along, because it hasn't enough juice to carry it the rest of the way.
That dynamic, moment-to-moment variation in current/voltage is what's so hard to mimic via a simple circuit. As always, whatever provides interesting sounds remains musically valid, whether it is an accurate simulation of something or not. But for folks who want to mimic
exactly what a dying carbon-zinc 9V battery does, it's gonna take more than a few resistors.
And once again, I encourage folks to explore the use of current limiters, as exemplified by the late Charles R. Fischer's EM Fuzz that was published post-humously in
Electronic Musician. You can find all the relevant files in this directory: http://www.generalguitargadgets.com/wp-content/uploads/ Scroll down to files beginning with EM.
What about a small, poorly designed home-made 220v to 9v transformer that begins to sag at 1ma?
mac
QuoteI measured some depleted batteries here: http://www.muzique.com/lab/batteryz.htm
Nice collection of results Jack!
For the hell of it my DMM battery came-up with low battery the other day I took some measurements from it:
Energizer 9V
Size: 522, 6LR61 -6AM6-9V
Made in USA
Date 2010 (manufacture date)
Code: 0105J
Test Date: Nov 2016
Measurement take not long after removing from DMM with low battery:
Voc: 7.511V
RL: 980 ohm
VL: 7.355V
I= 7.51 mA
R0 = 20.79 ohm
A short time later again: parenthesized values use original Voc
Voc: 7.602V (7.511V)
RL: 275 ohm
VL: 7.1V, after 1min and decreasing
I= 25.82mA
R0 = 19.44 ohm (15.9ohm)
1 day rest time.
Voc: 7.744V
Retest:
Voc: 7.744V
RL: 980 ohm
VL: 7.531V (after 30sec, still decreasing but slowly)
I= 7.685 mA
R0 = 27.72 ohm
Voc: 7.744V
RL: 275 ohm
VL: 7.2V (after 30sec, still decreasing)
I= 26.18mA
R0 = 20.77 ohm
It's pretty normal for battery voltages rise and fall with long time constants after applying and removing loads.
One Energizer 522 datasheet (there are many kicking around) shows impedance vs discharge and terminal voltage vs time. Based on 7V end-point voltage I estimated my battery is at 70% depth of discharge (as manufactures rate 100% discharge at 5.4V end-point). The impedance graph for 70% depth of discharge shows 5ohms. However manufactures show AC impedance at 1kHz and the DC impedance tends to be about double this value so RoDC would be more like 10ohm.
Doesn't match up with my results but my test conditions of an old battery aren't the same as their one-session discharge. Also my DMM current is lower than the 620ohm energizer test which makes my discharge deeper.
At full discharge the datasheet shows approx RoAC=13ohm so RoDC = 26ohm which is in the ballpark of my results.
Anyway just another data point.
Quote from: Mark Hammer on November 21, 2016, 12:26:14 PM
In my own experience, what most dying carbon-zinc batteries do is provide a dynamically-shifting current (and possibly voltage), that changes in response to transient peaks. The battery is able to effectively catch its breath a little between notes, or groups of notes, and is only able to provide suitable current for the first transient, after which it limps along, because it hasn't enough juice to carry it the rest of the way.
I used to believe this too, and it is does happen with some power amplifiers, but there are several reasons that it is not having an impact on effects circuits.
Most effects that depend on the dying battery phenomenon are class A circuits, and the current draw is consistent throughout the wave cycle. There is no dynamic shifting from idling to passing an audio signal. Also, the current draw in effects circuits is so small, that even non-class-A opamp circuits have little difference between idling and working. If you look back at the article that I posted, I measured several effects circuits and there was no difference in the current draw with or without a signal present. Even if there were a small difference in the current draw, the small size of the current and the low value of the battery resistance means that there would be very little voltage-change-dynamics. Also, if there is a filter capacitor on the power rail in the effect pedal, it would tend to smooth out the impact of any small shift from the battery draw - basic Fuzzface circuits that have no filtering would be the most likey impacted, especially since they are usually asymmetrically biased. However, most other effects have a sound change that is only due to the lowered voltage.
Even so, if a modest value resistor inserted in series with the power rail creates a sound that a player likes, then it is valid and there is no reason not to use and enjoy it! :icon_biggrin:
Best regards, Jack
Quote from: amz-fx on November 22, 2016, 08:17:57 AM
Quote from: Mark Hammer on November 21, 2016, 12:26:14 PM
In my own experience, what most dying carbon-zinc batteries do is provide a dynamically-shifting current (and possibly voltage), that changes in response to transient peaks. The battery is able to effectively catch its breath a little between notes, or groups of notes, and is only able to provide suitable current for the first transient, after which it limps along, because it hasn't enough juice to carry it the rest of the way.
I used to believe this too, and it is does happen with some power amplifiers, but there are several reasons that it is not having an impact on effects circuits.
Most effects that depend on the dying battery phenomenon are class A circuits, and the current draw is consistent throughout the wave cycle. There is no dynamic shifting from idling to passing an audio signal. Also, the current draw in effects circuits is so small, that even non-class-A opamp circuits have little difference between idling and working. If you look back at the article that I posted, I measured several effects circuits and there was no difference in the current draw with or without a signal present. Even if there were a small difference in the current draw, the small size of the current and the low value of the battery resistance means that there would be very little voltage-change-dynamics. Also, if there is a filter capacitor on the power rail in the effect pedal, it would tend to smooth out the impact of any small shift from the battery draw - basic Fuzzface circuits that have no filtering would be the most likey impacted, especially since they are usually asymmetrically biased. However, most other effects have a sound change that is only due to the lowered voltage.
Even so, if a modest value resistor inserted in series with the power rail creates a sound that a player likes, then it is valid and there is no reason not to use and enjoy it! :icon_biggrin:
Best regards, Jack
Bingo. And it was nearly exclusively Fuzz Face type circuits that prompted the entire notion of "sag" with respect to effects pedals. Especially when guys like Eric Johnson, et al., started talking about Fuzz Faces and carbon-zinc Eveready batteries. Eventually, the notion of sag got divorced from its original context, and of course the emergence of robust stable pedalboard supplies pretty much wiped battery concerns off the map, particularly for those with a very recent history in the world of FX. But I concur with you that, even if one is not talking about the prototypic dying red battery in a round-chassis fuzz, the exploration of "other" supply voltages is not unjustified.
Someone asked here recently "Why 9V?", and I think the question is legit. The corollary is "Why not something
other than 9V?". If it sounds good, it sounds good.
I'd offer my warmest regards, Jack, but we have a few inches of snow here, so I'll leave it at "best regards".
Cheers, Mark
Isn't it interesting that as we "modernize" some circuits by fixing the bias and adding power supply filtering, that we have engineered much of the character out of it. Many times the "mistakes" make the magic. :icon_biggrin:
Best regards, Jack
ps: If you need some exercise, we are still mowing the lawns down South since the night temperatures are only about 40F. Come on down! :icon_mrgreen:
> class A circuits, and the current draw is consistent throughout the wave cycle. There is no dynamic shifting from idling to passing an audio signal.
When a "class A" amplifier is driven to OVER-DRIVE, class thinking may go out the window.
The ideal chalk-board "class A" never quite touches cut-off. Some observation of Over-Driven circuits can show full cut-off over large parts of the wave. Many of the simple classic pedals show what we useta call "grid blocking", a cap charges-up/down until the device is biased-off most of the time.
A side-note: the rise of LEDs may mask all this. FuzzFace may be 1mA, and say 0.1mA when beat into blocking; an older LED may be 10mA steady. 11mA to 10.1mA is no real difference to an external battery faker.
200 Ohms is not insignificant. In the FuzzFace we often take a Loud signal off a 680 Ohm tap. With no B+ cap, almost 1/3rd of that appears on B+, sneaks back to the input stage, which is high-gain. (20 Ohms of the fancy cell seems insignificant.)
I agree that Voltage may be the real issue. It is a shame there is no simple way to controllably drop Voltage....... or is there? (Hm.)
It is noteworthy that the FuzzFace's bias is stable many ways, but the drop across Rc2 is nearly fixed (Rc*Vce/Re) so supply voltages have a large effect on Vc2 and on clipping (a)symmetry.
QuoteIt is noteworthy that the FuzzFace's bias is stable many ways, but the drop across Rc2 is nearly fixed (Rc*Vce/Re) so supply voltages have a large effect on Vc2 and on clipping (a)symmetry.
In the old germanium days there was a lot of unit to unit variation due to leakage. The root cause was usually a mis-biased Q2 voltage. You had a lot of pro players gathering up "good ones".
I think a lot of the flat battery stuff come about because it fixed the biasing of some of the poorly biased units. That being said there's people who like the misbiased sound ... IIRC there was an Eric Johnson Fuzz-Face produced and it doesn't bias Q2 to 4.5V.
Has anyone tried using a battery? In Series using One 1.5V AA or Two.
With less than 1mA, I think the battery will not be able to survive. ::)
Output voltage range around 7.5V for one battery, or around 6V if two.
How does it actually work that a signal that goes through FF loads the dying battery so the DC level swings?
As replacement for RBat, the circuit I try (Fuzz Face) still work.
(https://i.postimg.cc/1V87wYKN/Dying-Battery-Ex.png) (https://postimg.cc/1V87wYKN)
Dying battery becomes softer DC source. I am not sure you can simulate it by a fresh battery of lower voltage.
My battery is no longer fresh, I measure about 2.763 volt
I short circuit the battery
Battery Output
2.526 6.59
2.14 6.83
1.87 7.04
1.16 7.92 One Battery
It's weird if the fresh battery tastes sour like tom yum
The lower the Output voltage (6.59) sound like a coughing bear
the high is softer, less spicy but like too much pepper I guess. ???
Is this sound of dying battery? hahaha :icon_biggrin:
Quote from: zbt on December 22, 2021, 12:45:26 AM
Has anyone tried using a battery? In Series using One 1.5V AA or Two.
With less than 1mA, I think the battery will not be able to survive. ::)
Output voltage range around 7.5V for one battery, or around 6V if two.
i think different Zener diodes or LED's would be a safer/cheaper/better option.
some home audio tube amps used batteries to provide bias to the cathode, but those needed replacement every so often because they would over-charge and bad things can happen.
Quote from: yeeshkul on December 22, 2021, 03:17:37 AM
How does it actually work that a signal that goes through FF loads the dying battery so the DC level swings?
when the Fuzz Face puts out full volume signal, internal bias shifts, this means the circuit tries to pull more current, and this higher current makes a larger voltage drop over the batteries internal resistance, dropping the voltage a bit.
cheers
Again, let's go back to original source-context: a Fuzz Face and a carbon-zinc 9V battery. What one measures at the output of the battery is certainly reflective of what is happening at the junction of the 6 internal cells, but I think that is unlikely to be mimicked by individual AA cells, whose "junction" is nice shiny metal. Keep in mind that alkaline 9V batteries are not reputed to yield the legendary "dying battery" effect, and they consist of 6 sub AAA cells internally, spotwelded to each other in a manner more like a clip of multiple 1.5V batteries.
Yes, Sir.
I also try to understand the purists, or at least my friend.
I use this 9Volt battery, and my current circuit is silicon fuzz face, without diode protection and filter capacitor.
(https://i.postimg.cc/87cnBvv7/batt.png) (https://postimg.cc/87cnBvv7)
My first introduction to voltage sag came from beavis board.
I tried it while trying the treble booster circuit, with a 10K resistor, and it didn't sound good to me.
Then I read about using batteries, interested in the difference between zinc and alkaline, for me batteries are wasteful and expensive,
so I also tried with a 12V motor battery, and lowered the voltage to 9V, used a regulator and it worked fine, enough for a year.
The only think I like about using battery is less noise.
My curiosity reappeared after reading this article https://www.analogman.com/fuzzface.htm (https://www.analogman.com/fuzzface.htm) There is you Sir.
No nice fancy led, is this what makes the guitarist legendary? even i'm starting to think they practice with their eyes closed. ahah.
And why a dying battery, isn't a fresh battery better?
Then I read this Amazing Spider Keen http://geofex.com/article_folders/oldspyder/oldspyder.htm (http://geofex.com/article_folders/oldspyder/oldspyder.htm) and that I know that Rbat is for simulating dying battery.
if it's already in the design, there's definitely something useful.
I just don't know how to use it, even in this realm there are myths also :o.
Last time
Using dead 9Volt battery sound bad, and then silence, recharge a little, sound bad then stop.
Set PS to 8Volt, 7Volt, 6Volt the lower sound just like lower gain Using Red Led, same as lower the supply
Find resistor value, 3K9 around 7volt sound like piezo, the fizz gone. below 3K9 sound different from 1.5 AA Battery.
I prefer to use two 1.5 AA batteries, the fizz still there but much softer, while overall sound more low.
May be is not the same as actual dying sound, but now I know the battery can make the fizz softer.
yes, that might work, but using batteries like that is an
> UNSAFE
idea, since they don't really like being over-charged.
maybe put a huge capacitor from the new, lowered vcc to ground when using LED's, resistors or lower power supply voltages, this will soften some of the harsher overtones.
cheers
What would help a LOT is if the experts who swear by dying 9V carbon-zinc batteries would either describe, in words, what the impact is on the behaviour of their fuzz, and also measure the actual voltage of what "dying" is. It certainly isn't dead. Maybe it's just really exhausted, in the sense of able to walk but not ready to run up the stairs.
And as I hasten to remind people, a stable voltage or current-limited supply isn't necessarily a bad thing or a musically useless thing. Even if all the simpler "supply degraders" do not accurately mimic a dying battery, that does not mean they can't do something that pleases us. They just don't do EXACTLY what an exhausted carbon-zinc battery might do for a Fuzz Face
I measure the current is about 600uA the battery voltage at 2.661V so the R = 2.661/0.0006 = 4435, I replace it with 4K7 resistor, still sound different.
I measure the current again with signal, it raise about 50uA and voltage drop at about 1mV, 2.660/0.0065 = 4093, around 340 ohm different.
At this time, I feel RBat is like spring or variable resistor, the more fresh battery like ps, is hard to pull, at dying process it weaker.
Quote from: Mark Hammer on December 23, 2021, 03:22:02 PM
measure the actual voltage of what "dying" is. It certainly isn't dead. Maybe it's just really exhausted, in the sense of able to walk but not ready to run up the stairs.
If the capacitor is tumbler, I just give a fuzz a drink a little, may be a cup, just to make refresh a bit.
R
---[ RBat ]----*----///----
|
=== C
|
V
RBat = 4K7, R = 390, C = 470nF close enough,
adding diode the string is like rubber, and sound like boing! boing! at single note :icon_lol:
same like make RBat bigger but more tight rubber
I like RBat = 6K8, R = 390, C = 470nF, too mantain the fizz.
The bigger the C, good if used a ripple supply.
RBat work, put again using POT 10K, RC just make softer, diode also nice
Quote from: iainpunk on December 23, 2021, 09:30:35 AM
yes, that might work, but using batteries like that is an
> UNSAFE
idea, since they don't really like being over-charged.
maybe put a huge capacitor from the new, lowered vcc to ground when using LED's, resistors or lower power supply voltages, this will soften some of the harsher overtones.
cheers
Everyone try this 1.5V battery, please be careful
Quote from: amz-fx on November 22, 2016, 02:00:10 PM
Isn't it interesting that as we "modernize" some circuits by fixing the bias and adding power supply filtering, that we have engineered much of the character out of it. Many times the "mistakes" make the magic. :icon_biggrin:
Quote from: Mark Hammer on December 23, 2021, 03:22:02 PM
And as I hasten to remind people, a stable voltage or current-limited supply isn't necessarily a bad thing or a musically useless thing. Even if all the simpler "supply degraders" do not accurately mimic a dying battery, that does not mean they can't do something that pleases us. They just don't do EXACTLY what an exhausted carbon-zinc battery might do for a Fuzz Face
:icon_mrgreen:
Quote from: yeeshkul on May 01, 2009, 08:08:36 AMhere we go - an external DBS 8)
(http://www.hoho.cz/osobni/SDB.jpg)
hey, old topic but, did this work? what's the value of the potentiometer? and is that a 100uF capacitor?
thanks!
al b