Price is not much of an issue for me personally.
Why optical encoder? They output CMOS or TTL level squarewaves so no debounce circuitry is needed. The few I have looked at from Bourns does anyway.
However, there will be a debounce circuit on the PCB in case someone wants to use a cheaper mechanical rotary encoder, those require debouncing.
Why optical encoder? They output CMOS or TTL level squarewaves so no debounce circuitry is needed. The few I have looked at from Bourns does anyway.
However, there will be a debounce circuit on the PCB in case someone wants to use a cheaper mechanical rotary encoder, those require debouncing.
I agree that mechanical encoders require debouncing. Probably some of the worst looking signals I have encountered. What has worked for me is a 10K pullup, a 22nF cap to ground, and another 10K in series with that to the input of a processor or sensing logic.
I've used both. There is no need for debouncing and they are really nice 🙂
In these projects:
GitHub - FutureSharks/preamp-two: An digitally controlled hi fi preamplifier 🔈🎵
GitHub - FutureSharks/preamp-passive: This is the Arduino code, PCB layouts and 3D drawings for a HiFi passive preamplifier
There is obviously no visual indicator for what level you are on though. I solved this with RGB LEDs but you could also use an LCD panel or similar.
Did you use versions with detent or without?
I am considering using a detent version for a better "feel" when rotating the volume knob.
I didn't try a version with detents. Also this is only an option on the EM14 range. The EM14 has a very nice feel though, there's nice resistance. The EN costs more, has more PPR but rotates more freely which doesn't feel as good.
Thanks for the info. 😎
The "feel" when turning a volume knob is rather important to many, including myself.
Which is another reason why I am considering a detented version, beside the "feel" aspect. 🙂
Hi Neutrality
I put together the attenuator but I am having pops at -16 and -32. I am using just 6 relays, I got rid of the 1/2 LSB trick to simplify things (smallest step is non jumping so far) and using a 112.5Hz clock (8.8ms) to drive the flip-flops. Relays are panasonic TQ2 (3ms activating time according to specs). What should I look closer to fix it? I am not using you boards, I just made a few from scratches.
Thanks!
g
I put together the attenuator but I am having pops at -16 and -32. I am using just 6 relays, I got rid of the 1/2 LSB trick to simplify things (smallest step is non jumping so far) and using a 112.5Hz clock (8.8ms) to drive the flip-flops. Relays are panasonic TQ2 (3ms activating time according to specs). What should I look closer to fix it? I am not using you boards, I just made a few from scratches.
Thanks!
g
Since you are not using my boards, but have built your own, I need to see the exact schematic of your design.
I inverted the relays!
When OFF they have no attenuation, when ON they attenuate. It should be the other way round
... basically when I am switching all relays OFF it pops as there is no attenuation at all. I also had to reverse the connections at the POT to increase vol clockwise. I will redo the board.
When OFF they have no attenuation, when ON they attenuate. It should be the other way round
... basically when I am switching all relays OFF it pops as there is no attenuation at all. I also had to reverse the connections at the POT to increase vol clockwise. I will redo the board.hi Neutrality (or another forum member if they reply first!!)
I'm keen to build the attenuator to replace the ALPS RK27 50K pot used in the WHAMMY HPA
https://www.diyaudio.com/community/threads/whammy-pass-diy-headphone-amp-guide.317803/
I can replicate the resistor figures using this calculator: Logarithmic Attenuator Calculator
by setting the values as:
Can i confirm that the change to suit my situation is as simple as changing the constant r to be 50k in the calculator?
Also, there is mention that a 10k termination resistor is needed. I assume this is the same one shown in the calculator schematic, but it doesn't seem to be shown in the attentuator V3's schematic.
Does it get added from CON1-1 to GND 2, for both channels?
thanks for your help
Cheers
Craig
I'm keen to build the attenuator to replace the ALPS RK27 50K pot used in the WHAMMY HPA
https://www.diyaudio.com/community/threads/whammy-pass-diy-headphone-amp-guide.317803/
I can replicate the resistor figures using this calculator: Logarithmic Attenuator Calculator
by setting the values as:
- stage constant r = 10k
- stage attenuation = 0.6db
- resistor values = E96
- number of stages = 7
Can i confirm that the change to suit my situation is as simple as changing the constant r to be 50k in the calculator?
Also, there is mention that a 10k termination resistor is needed. I assume this is the same one shown in the calculator schematic, but it doesn't seem to be shown in the attentuator V3's schematic.
Does it get added from CON1-1 to GND 2, for both channels?
thanks for your help
Cheers
Craig
Is it possible to make my own using your schematic but only THT equivalent ? SMD is not my stuff ... 😉
Damien
Damien
Theoretically yes... but you would have to replace all the AMT parts with THT parts and some parts are currently only available as SMT packages e.g. 74AHC1G4210 & TPS7B950
Your biggest problem may be finding the THT package variant of the ADC0804 which is showing as 0 stock at Digikey and Mouser
Your biggest problem may be finding the THT package variant of the ADC0804 which is showing as 0 stock at Digikey and Mouser