It is very hard to adjust the 4 trim pots.
-53db of 3rd and 5th, looks like the regulator has a big impact.
-54 in the other channel, same.
I could adjust it better than the PCM-K, BUT it is not as good adjustment as in the 2 trimpot version in the other dac.
I will do a listening test to see if it WOW me like the PCM-K did yesterday.
So if it sounds glorious like the PCM-K or better (which I doubt), then I will switch the i/V opamp to rule out that the OP604 could be that good.
Maybe it is simply the change I did to the filter Cap.
-53db of 3rd and 5th, looks like the regulator has a big impact.
-54 in the other channel, same.
I could adjust it better than the PCM-K, BUT it is not as good adjustment as in the 2 trimpot version in the other dac.
I will do a listening test to see if it WOW me like the PCM-K did yesterday.
So if it sounds glorious like the PCM-K or better (which I doubt), then I will switch the i/V opamp to rule out that the OP604 could be that good.
Maybe it is simply the change I did to the filter Cap.
I did a small listening session, and I was asked to play under the street lamps, it didn't sound good. On the classical music earlier it was very good to my ears.
We listened to the original of 1960s of what under the street lamp did and what is that? It sounds better on a Mac than on my system.
I don't know who else experienced that? On a good neutral system it will not sound as people expect: a mess of euphoria?
No, the mid-rangy noisy simplified part will appear naked, the true horror of the recording is exposed?
We listened to the original of 1960s of what under the street lamp did and what is that? It sounds better on a Mac than on my system.
I don't know who else experienced that? On a good neutral system it will not sound as people expect: a mess of euphoria?
No, the mid-rangy noisy simplified part will appear naked, the true horror of the recording is exposed?
Hello everyone,
I'm looking for help with a Bluetooth preamp that uses the NE5532 op-amp. The preamp works quite well for the price, but I now need higher output voltage – around 3–4V RMS, to properly drive a professional power amplifier with an unbalanced input.
The problem is that I can't identify the resistors responsible for setting the gain, and I'm also not entirely sure how the preamp section is designed. The board uses two NE5532 op-amps for tone control. Volume is controlled by an encoder, and the board includes a Chinese bluetooth chip for audio input.
Has anyone worked with this type of board before? Do you have a schematic or can suggest a modification to increase the output level?
I tried contacting the supplier, but – unsurprisingly – got no response.
Thank you.
I'm looking for help with a Bluetooth preamp that uses the NE5532 op-amp. The preamp works quite well for the price, but I now need higher output voltage – around 3–4V RMS, to properly drive a professional power amplifier with an unbalanced input.
The problem is that I can't identify the resistors responsible for setting the gain, and I'm also not entirely sure how the preamp section is designed. The board uses two NE5532 op-amps for tone control. Volume is controlled by an encoder, and the board includes a Chinese bluetooth chip for audio input.
Has anyone worked with this type of board before? Do you have a schematic or can suggest a modification to increase the output level?
I tried contacting the supplier, but – unsurprisingly – got no response.
Thank you.
You should not mess with such small circuit, purchase a pre-amp which can add gain and functionality!
I can obtain schematic from China because I know someone but....
I can obtain schematic from China because I know someone but....
Sounds like exactly the same premise to me: somebody is trying to figure out a ready-made opamp board they bought. That both are made in China is kind of secondary. (Or so the Germans would have us believe, to quote Norm McDonald.)
So you know the guy in China who designs all these boards? How about the tube amps?
No clue, but there is some good designs made and they are copy of copy of copy, but the guy I know has someone who draw the schematics. These things are made to place in other assembly and resale them, they build this in great quantities.