I have an audio, two channel, potentiometer that I removed from a tube amplifier kit I built a while ago. Adding it to the ACA Mini would there be a decrease in volume? Does adding this potentiometer introduce anything negative?
if you connect it properly ( in front of ACA Mini), it'll do intended job, regulating volume from silence to full
What value is the pot you have?
One from a valve amp could be quite high in value which can introduce slight HF roll off in some applications... all depending on what it is working into.
One from a valve amp could be quite high in value which can introduce slight HF roll off in some applications... all depending on what it is working into.
That's quite high when talking of solid state equipment.
If the preamp or source components you are connecting to the ACA all have a low output impedance (such as modern solid state gear) then you could usefully go to something a lot lower like a 10k or a 22k but your 100k will work just fine.
If the preamp or source components you are connecting to the ACA all have a low output impedance (such as modern solid state gear) then you could usefully go to something a lot lower like a 10k or a 22k but your 100k will work just fine.
Well, I used the 100K potentiometer I had in my junk drawer....Works perfectly. Quick question, on the circuit board I left the RCA jacks and just soldered the pot leads onto the lands. If I connect the output of the preamplifier directly to the circuit board mounted RCAs, will the pot, not being used, still have some influence on the sound?
If I'm visualising what you have done correctly then yes, the pot will have an effect when the pot is turned down. I'm assuming you have fed the wiper of the pot onto what would be centre pin of the RCA socket. If that's not what you mean then its best to draw it out 🙂
At minimum volume it will shunt the ACA input (the centre pin of the RCA socket) to ground. A solid state preamp would work normally until the pot got down to around a few 10's or hundred or so ohms. So in practice nothing is noticed until the volume control is on almost minimum. Anything higher than that and no effect.
Thank You! Here is a quick sketch of what I did......I didn't want to remove the RCA jacks on the PCB.....So the question is, if I wanted to use the PCB RCA jacks, which are still connected, would the POT influence the sound although it is not being used.....
@Rbertalotto
I have a suggestion. How about one thread called "My ACA Mini Build and Questions" or something to that effect. Post all of your content to that thread rather than starting a new thread for every question.
I have a suggestion. How about one thread called "My ACA Mini Build and Questions" or something to that effect. Post all of your content to that thread rather than starting a new thread for every question.
That means that the maximum source impedance seen by the input of the amp is about 20K,
which is a little high, but doable with slight loss of high end that your dog probably won't hear.
🙂
Thanks. So it sounds like you are all sorted 🙂 Your diagram is how I imagined it, as you turn the pot down the board input RCA sees a lower and lower resistance shunted across it. That low resistance appears as a load to the preamp.