I am, and can confirm that our habits are disgusting, and that anything protective that can be built into any electronics that will be used in the same room as one of us, should be.
Example: have the top of the case sloping so we can't rest our beer glass on top of it.
It is non-inverting in post #53, with 236 kohm input resistance.
The voltage across C2 will settle with a 51.7 second time constant.
Here is a link to a review of different op amps and how they sound in a tube screamer: https://www.diystompboxes.com/smfforum/index.php?topic=56542.0
Since your design uses the same "clipping diodes in the feedback path" concept...
The 5532 does not score very well with this reviewer, and neither does the OPA2134.
As I said in a previous post, the lowly 741 sounds great.
Listen and decide for yourself of course!
Since your design uses the same "clipping diodes in the feedback path" concept...
The 5532 does not score very well with this reviewer, and neither does the OPA2134.
As I said in a previous post, the lowly 741 sounds great.
Listen and decide for yourself of course!
bear with me 😆
I'm still learning
you are right, the cap values are not exactly calculated. that's the next part I'm working on...
regarding C2: I thought this cap has to be large to act like a voltage reservoir ?
I'm still learning
you are right, the cap values are not exactly calculated. that's the next part I'm working on...
regarding C2: I thought this cap has to be large to act like a voltage reservoir ?
Might I suggest a TL074? You'll get 3 sections to make proper dirty & clean guitar front end, plus 1 section for a proper hifi front end. I don't know why you want guitar and hifi to plug into the same opamp, you do realize they do not share even the same standard connectors, let alone different signal properties?
Big capacitance gives high time constant tau=R*C yielding low crossover frequency fc=1/(2*pi*R*C). With tau=1sec you get fc=0.16Hz.
Generally it is a good idea to cut extra low frequencies as these to not contribute to sound and subsonic noise may eat up your output power.
For guitar applications I recommend fc about 80Hz corresponding to R*C=2msec.
Generally it is a good idea to cut extra low frequencies as these to not contribute to sound and subsonic noise may eat up your output power.
For guitar applications I recommend fc about 80Hz corresponding to R*C=2msec.
Seems to buffer the tone network.
Trying to be both a "instrument" and a "hi-fi line" input at the same time may not be simple. However unless we are doing careful A/B comparisons, a '5532 for guitar does not suck (I've seen far worse on professional musician's rigs).
The top of an amplifier IS for your beer. The trick is to make the top over-hang on all sides like a thatch roof to throw the beer away from the electrics.
As promised here is a comparison between the NE5532 and OPA2134.
On the clean signal (from a signal generator) I could not see any differences on the scope. Frequency response and distortion was practically identical.
With a guitar signal the same picture. Very similar harmonics.
I don't know but to me there are no meaningful differences.
Maybe you can suggest an appropriate measure approach ?
OPA2134 / g string clipping
NE5532 / g string clipping
On the clean signal (from a signal generator) I could not see any differences on the scope. Frequency response and distortion was practically identical.
With a guitar signal the same picture. Very similar harmonics.
I don't know but to me there are no meaningful differences.
Maybe you can suggest an appropriate measure approach ?
OPA2134 / g string clipping
NE5532 / g string clipping
There should be a difference between the noise levels when operating with a realistic source impedance (electric guitar, not a signal generator). No idea whether the difference is big enough to worry about.
Accidentally I noticed that the 5532 is more sensitive to the low pass filter. In the graph there is more noise with the filter open.
All in all the 2134 seems to be more "indulgent" to filter changes.
NE5532
OPA2134
All in all the 2134 seems to be more "indulgent" to filter changes.
NE5532
OPA2134
The noise isn't the real problem, the frequency rolloff of the guitar signal is the elephant in the room.
OP, if you need the ******* similator to show you the ******* difference why don't you model the ******* guitar pickup in your ******* simulator.
What simulator? I only see measurements.
Why do you expect a noticable difference in roll-off of the guitar signal between two types of op-amp?
Why do you expect a noticable difference in roll-off of the guitar signal between two types of op-amp?
My apologies, I thought that was a simulator output. My point remains, though. A passive guitar pickup is high impedance.
https://ironstone-guitar-pickups.co.uk/guitar-impedance-matching-lcr/
https://ironstone-guitar-pickups.co.uk/guitar-impedance-matching-lcr/
Attachments
That's exactly why I expect worse noise with an NE5532 than with an OPA2134, considering the higher equivalent input noise current of the NE5532. No idea if it is enough to worry about, though.
I still don't understand how you could get a noticable difference in high-frequency roll-off between the op-amps. The input impedance of the buffer stage at the input of the guitar amplifier is dominated by the input resistor and bias resistor, not by the op-amp type (the 300 kohm spec for the NE5532 only applies open loop).
I still don't understand how you could get a noticable difference in high-frequency roll-off between the op-amps. The input impedance of the buffer stage at the input of the guitar amplifier is dominated by the input resistor and bias resistor, not by the op-amp type (the 300 kohm spec for the NE5532 only applies open loop).