Be pleased that you have the 2x15vac version which will rectify to +-21vdc. My unit has the Amveco 70064K which outputs 2x18vac which inputs +-25vdc to the regulators. The 7815, for example, only needs about 18vdc. Higher voltage creates excessive heat in the unit.
The 3.3ohms in your unit make little difference because the big caps and the regulators manage the ripple.
The 3.3ohms in your unit make little difference because the big caps and the regulators manage the ripple.
All the Whammys are not the same because certain parts became unavailable and substitutions needed to be made. Resistors values can vary because of tolerances. No adjustments need to be made because the design tolerates some variation. There is nothing to adjust but you can change the bias resistors if you have unusual headphones. Contact the seller if you are not satisfied or have questions.
Kits like the Whammy are not very DIY-like because you are just soldering the given components. But it is good to start with a kit. Next goto sound-au.com which is Elliot Sound Products -- ESP. Select an interesting project and order the PCB. You get to decide which components will stuff the PCB and you learn from the detailed instructions. It is possible to DIY from the schematic but I find that a PCB assembly is more pleasing than one of my hacks with wires and solder blobs.
Kits like the Whammy are not very DIY-like because you are just soldering the given components. But it is good to start with a kit. Next goto sound-au.com which is Elliot Sound Products -- ESP. Select an interesting project and order the PCB. You get to decide which components will stuff the PCB and you learn from the detailed instructions. It is possible to DIY from the schematic but I find that a PCB assembly is more pleasing than one of my hacks with wires and solder blobs.
Hi everyone.
I'm in trouble.
Something happened while trying to lower the volts on my Whammy.
Now it is totally silent.
The optocouplers seem fine.
The Volts are 16.7V.
I think there was a short between ground and signal from the potentiometer to the pcb..
What could have happened?
Maybe too many volts for an lme49720?
I'm in trouble.
Something happened while trying to lower the volts on my Whammy.
Now it is totally silent.
The optocouplers seem fine.
The Volts are 16.7V.
I think there was a short between ground and signal from the potentiometer to the pcb..
What could have happened?
Maybe too many volts for an lme49720?
If the power supplies are correct (which they are) and there is no DC offset then it sounds essentially OK.
You should see around 0.5v across each of the 10 ohm source resistors (give or take). If that is OK then it would appear functional electrically which really leaves input and output wiring.
Opamps just limit output current rather than switch into some protection mode. If all the DC conditions are correct then it should work.
You should see around 0.5v across each of the 10 ohm source resistors (give or take). If that is OK then it would appear functional electrically which really leaves input and output wiring.
Opamps just limit output current rather than switch into some protection mode. If all the DC conditions are correct then it should work.
That sounds OK given the DC offset is at zero but the voltage on those resistors should really be measured across them rather than from ground
It all sounds good.
99.9999% no for that. If they had failed then the DC conditions would be wrong.
You need to check the input wiring first.
Measure on ohms with the amp OFF and make sure there is no short between ground and each input (on your RCA input sockets or whatever terminations you are using). You should actually read the approx total value of the volume pot doing this, that is whatever value pot you have fitted. Check and make sure you read this value when measuring across each input. It will also have R39/40 added to the total reading.
If that is OK it should work.
If not then check the output wiring and that the centre join between the two 10 ohm resistors go to the headphone output and that the ground continuity is also OK. Check there is no short across the output at the headphone socket.
I reconnected the potentiometer and checked the connections several times.
I replaced the op amp.
Everything sounded great then I changed the wires to the potentiometer.
Only one channel was playing because there was a small short circuit at the input.
Once the short circuit was solved, nothing would sound anymore.
I thought maybe the volts were high and tried to bring it to 15V.
For a moment I had more than 21V.
Now the configuration is 15V.
There aren't many things that can go wrong, maybe op-amp/Mosfet/ optocoupler, but I can't find the solution.
Not the slightest sound comes out, not even a rustle, absolute silence.
Sorry for my bad english
https://www.google.com/search?clien...=2ahUKEwjn37Ptze6FAxWNh_0HHfjhAoYQ1QJ6BAgNEAE
I replaced the op amp.
Everything sounded great then I changed the wires to the potentiometer.
Only one channel was playing because there was a small short circuit at the input.
Once the short circuit was solved, nothing would sound anymore.
I thought maybe the volts were high and tried to bring it to 15V.
For a moment I had more than 21V.
Now the configuration is 15V.
There aren't many things that can go wrong, maybe op-amp/Mosfet/ optocoupler, but I can't find the solution.
Not the slightest sound comes out, not even a rustle, absolute silence.
https://www.google.com/search?clien...=2ahUKEwjn37Ptze6FAxWNh_0HHfjhAoYQ1QJ6BAgNEAE
Highly unlikely.
Look at the circuit diagram. This is a working simulation of the Whammy:
And this shows typical DC voltage conditions:
Can you just check that the voltage at the opamp output (measure on either end of the 47 ohm resistor on the opamp output) is at approx 0.5 volts and not either very high or very low which might indicate a short at the output somewhere.
Here I am.
On the 47ohm resistors (op-amp output) I measure 0.2 Volt.
On R30 (from octocoupler) 0.5Volt.
It seems ok.
I go from the RCA direct to potentiometer input 1/2 and relative ground on the opposite site
I then exit from "wiper" and connect to central pin on the pcb.
The groung from the potentiometer to ground pins of the PCB.
Boh...
On the 47ohm resistors (op-amp output) I measure 0.2 Volt.
On R30 (from octocoupler) 0.5Volt.
It seems ok.
I go from the RCA direct to potentiometer input 1/2 and relative ground on the opposite site
I then exit from "wiper" and connect to central pin on the pcb.
The groung from the potentiometer to ground pins of the PCB.
Boh...
The pot looks correct, certainly the way you have marked it.
Just looking at the first picture. Have you used the correct set of pins on the headphone socket? Some sockets have switched contacts with continuity from side to side when nothing is plugged in and then one side goes open circuit when you plug in.
Just looking at the first picture. Have you used the correct set of pins on the headphone socket? Some sockets have switched contacts with continuity from side to side when nothing is plugged in and then one side goes open circuit when you plug in.