Peter, as I stated above I allways strive to have as low impedances as possible. I would use even 1 k if it was possible but 10 k is a very good choice, also for the noise. 100 k is not hifi according to me. You will get also better bandwidth with low values.jazzpeter65 said:Is this sound of a voltage divider something that can be described in a technical term?
50K pot: I had the same feeling when I bought the 50K - It should have been smaller. At that point I just didn't knew the load impendance. 50K was a compromise...
Not the sound of voltage divider, but terminated cable (please review audio buffer page).
It is a point we have been investigating for a long time - minimalization of different signal cables influence. Do not want to get into details, it makes no sense this way. It is really very easy to try it when you have your circuit built.
It is a point we have been investigating for a long time - minimalization of different signal cables influence. Do not want to get into details, it makes no sense this way. It is really very easy to try it when you have your circuit built.
More gain?
Per,
I think I did overlook something. R10 and R12 is a voltage divider, right? Omitting R12 will give me more gain at a factor of. 0.5? If this is right I will have plenty of gain.
PS: I'm comparing my new built preamp with my old NAD preamp. In this a and B test I can hear that the commercial preamp has more gain. I just want to reach the same level.
Per,
I think I did overlook something. R10 and R12 is a voltage divider, right? Omitting R12 will give me more gain at a factor of. 0.5? If this is right I will have plenty of gain.
PS: I'm comparing my new built preamp with my old NAD preamp. In this a and B test I can hear that the commercial preamp has more gain. I just want to reach the same level.
Yes, the first two but not the last. It's a little bit more complicated but you can approximate if the last link has at least 10 times higher impedance than the first. If you want a second order filter it's better you use an active filter, maybe from Walter Jung's excellent books!jazzpeter65 said:
Pavel,
You wrote:
"Per is right, and I can tell the best solution: CD - buffer - switched resistor attenuator at very low impedance - buffer/preamp..."
This is not my signal chain. I go from: CD -> DAC -> 50K pot -> Buffer/preamp -> poweramp.
Maybe it's really the same. My DAC is what you call "buffer " after the CD, right?
You wrote:
"Per is right, and I can tell the best solution: CD - buffer - switched resistor attenuator at very low impedance - buffer/preamp..."
This is not my signal chain. I go from: CD -> DAC -> 50K pot -> Buffer/preamp -> poweramp.
Maybe it's really the same. My DAC is what you call "buffer " after the CD, right?
Pavel,
You asked about the difference of my old NAD 1155 and the new one.
To be honest the difference is not that big. Which means that my good old bipolar NAD isn't that bad after all...
I'm retiring it because mostly because it's slowly falling apart and making noises.
The sound stage of the new one is wider though. The noise is lower, but it is a little sterile. That's what I have exsperiences before when I built my DAC with OPA627AP as I/V and buffer. It's almost "too good".
The most musical opamp I had in my hands on was the OPA2604. The specs. is not that good but it has a certain "warm" sound that I liked.
You asked about the difference of my old NAD 1155 and the new one.
To be honest the difference is not that big. Which means that my good old bipolar NAD isn't that bad after all...
I'm retiring it because mostly because it's slowly falling apart and making noises.
The sound stage of the new one is wider though. The noise is lower, but it is a little sterile. That's what I have exsperiences before when I built my DAC with OPA627AP as I/V and buffer. It's almost "too good".
The most musical opamp I had in my hands on was the OPA2604. The specs. is not that good but it has a certain "warm" sound that I liked.
Pavel,
This is funny.....
I really like the sound that you "don't like"!!.........it makes me laugh....
I just cut the 51 ohm at output going to ground and put some music on to check.
Sound is much better. It's tighter and more present. Bass is incredible, rock solid. Also the midtones seem in balance.
Maybe it's the added gain that puzzles me, I don't know, but I'm happy.
BTW: After this mod I got all the gain I will ever need. IT'S VEEEERY LOUD NOW!! I better turn it down before I have my neighbours at the phone...
Thanx for the tip!
This is funny.....
I really like the sound that you "don't like"!!.........it makes me laugh....
I just cut the 51 ohm at output going to ground and put some music on to check.
Sound is much better. It's tighter and more present. Bass is incredible, rock solid. Also the midtones seem in balance.
Maybe it's the added gain that puzzles me, I don't know, but I'm happy.
BTW: After this mod I got all the gain I will ever need. IT'S VEEEERY LOUD NOW!! I better turn it down before I have my neighbours at the phone...
Thanx for the tip!
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