Okei. I don't have the print. So i did't have to take that into consideration.
Hi guys,
Im building the Whammy currently. I might not want to use the P1 as I'm controlling the volume with a preamp or DAC. The headphone has 37 Ohm impedance. So I guess the best is to just populate R39/40 with 2.2k and put two very high 100k or 1M resistors to GND. Right?
Any recommendations?
Im building the Whammy currently. I might not want to use the P1 as I'm controlling the volume with a preamp or DAC. The headphone has 37 Ohm impedance. So I guess the best is to just populate R39/40 with 2.2k and put two very high 100k or 1M resistors to GND. Right?
Any recommendations?
Build it with the potentiometer and turn the knob all the way clockwise. That will bypass the resistive track in the potentiometer and let the signal straight through.
In the future if you ever find that attenuating at the whammy’s input is useful, and you will
, the potentiometer will already be there. 
In the future if you ever find that attenuating at the whammy’s input is useful, and you will
, the potentiometer will already be there. Hi. Can I use these 2.2uF caps for C1& C5?
https://au.element14.com/ampohm-wou...f-630v-5-pp-panel/dp/1438472?ost=fp-ca-2.2-au
https://au.element14.com/ampohm-wou...f-630v-5-pp-panel/dp/1438472?ost=fp-ca-2.2-au
Guys you must try this mod, and i need to know what its done to mine. I took 690ohm resistor from the output of the whammy to to the output of its nested opamp in order to bias it into class a via bootstrapping and the sound has improved dramatically. Wayyy less distortion. However the bass seems weaker- less attack. Did the bootstrapping affect the impedance of the circuit?
My understanding is you are unloading the output of the opamp asymmetricaly, so it will behave more like a single ended circuit like Aleph 0.
It would be helpful to provide a basic schematic of exactly what you did rather than for us to make too many assumptions of what you actually have done.
It would be helpful to provide a basic schematic of exactly what you did rather than for us to make too many assumptions of what you actually have done.
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I think member donovas should be congratulated for bravery. Devising a modification himself (not copied out of a forum post or a hobby magazine or a website) and giving it a listening test, took chutzpah. Congratulations mate and well done!
After the change, the sound improved! Perhaps that's somewhat expected, just because of "proud parent" bias if nothing else. But nevertheless, if he likes it better after the modification, that's the only important consideration. What other people believe "should happen", is insignificant.
Maybe member donovas will listen to his modified WHAMMY for several weeks or months, and get accustomed & acclimated to the new improved sound. Then perhaps he'll remove the circuit change, and listen to the stock WHAMMY again, to see whether the "before modification" circuit is still inferior to the "after modification". Or maybe he won't. It's his life, it's his WHAMMY, he can do as he pleases and disregard the commands of others.
After the change, the sound improved! Perhaps that's somewhat expected, just because of "proud parent" bias if nothing else. But nevertheless, if he likes it better after the modification, that's the only important consideration. What other people believe "should happen", is insignificant.
Maybe member donovas will listen to his modified WHAMMY for several weeks or months, and get accustomed & acclimated to the new improved sound. Then perhaps he'll remove the circuit change, and listen to the stock WHAMMY again, to see whether the "before modification" circuit is still inferior to the "after modification". Or maybe he won't. It's his life, it's his WHAMMY, he can do as he pleases and disregard the commands of others.
You didn't say which opamp your using, try a higher current output opamp - the 690 Ohm resistor may be causing it to run out of steam.
Thanks guys for encouraging feedback. Yes im just a hobbist but i so wish i was in this line of work if only for the joys of discovery. Once again all i did was add an extra resistor from the output of the opamp to the output of the whammy in otherwise an untouched circuit. I took the clue from linuxguru's lf02 module, and hifisonix's ovation preamp where they both employ the same trick to bias the opamp. All i can say is it works, is stable, and im enjoying the sound! (Smile)
I am using 5534 btw
I am using 5534 btw
something's wrong with your explanation, or with my understanding
please enclose edited schmtc, showing what you exactly did
connecting output of opamp with output of OS via resistor is hardly doing anything, simply because there is practically no voltage potential between these two points , in AC domain
in DC domain there is some difference (difference of Ugs between N channel and P channel mosfet) , but that's hardly relevant , considering value of 690R
please enclose edited schmtc, showing what you exactly did
connecting output of opamp with output of OS via resistor is hardly doing anything, simply because there is practically no voltage potential between these two points , in AC domain
in DC domain there is some difference (difference of Ugs between N channel and P channel mosfet) , but that's hardly relevant , considering value of 690R
Isnt it the injected current at the opamps output that shuts off half the circuit and turns it single ended? Since the output of whammy is running in class A id think theres a plenty of constant current.
Sorry guys i do all my affairs on my smart phone and its rlly quite a hassle to post an image let alone draw a circuit. I literally took a 690ohm resistor from the output of whammy (between r16 and 22 in the first schematic) to the output of the opamp (pin 7)
Sorry guys i do all my affairs on my smart phone and its rlly quite a hassle to post an image let alone draw a circuit. I literally took a 690ohm resistor from the output of whammy (between r16 and 22 in the first schematic) to the output of the opamp (pin 7)
whatever you heard, it's placebo
with resistor connected as that, there is no predictable and possible difference, simply because if any current change in OP, there can be max 1/2mA and that's nothing
what regular praxis for pushing OP OS more in class A is connecting output pin to negative rail , via adequate valued resistor
with resistor connected as that, there is no predictable and possible difference, simply because if any current change in OP, there can be max 1/2mA and that's nothing
what regular praxis for pushing OP OS more in class A is connecting output pin to negative rail , via adequate valued resistor