True. In my case, it's just a differential amplifier taking a balanced signal from an upstream source. Maybe the upstream source injects DC, maybe it doesn't.
If DC is the problem, can the buffer stage be eliminated if I put DC blocking caps on both legs of the balanced input, taking care to impedance-match the two legs?
The INA is just the #451 circuit in a small box, but the THAT Ingenious diff line receiver maintains all required specs.
I dont know what it costs, and you may want to check if a simple buffer works well enough for you, do some listening tests and/or measurements if you can.
Otherwise, the THAT Ingenious is failsafe.
BTW Why do you want to go to se, can't you maintain it bal all the way?
Jan
I dont know what it costs, and you may want to check if a simple buffer works well enough for you, do some listening tests and/or measurements if you can.
Otherwise, the THAT Ingenious is failsafe.
BTW Why do you want to go to se, can't you maintain it bal all the way?
Jan
Yes, I revisited the INA134 datasheet, and its internal circuit is basically the same as the output buffer stage which XRK is using in the BTSB.
Why do I want to go SE? Look, I'm not very smart, electronics-wise, and I just want to accept a balanced input into an active speaker, and then feed the signal to a normal active xo, which will then feed a set of normal Class B amps. What else am I supposed to do? If I didn't have a few friends and diyaudio.com, I wouldn't even attempt what I'm trying to do.
The THAT 1206 seems affordable at least for my low-volume hobby usage. The INA 1651 is one-third the price.
Interestingly, the INA 165x has exactly the same single-opamp based output buffer which the BTSB is using.
Why do I want to go SE? Look, I'm not very smart, electronics-wise, and I just want to accept a balanced input into an active speaker, and then feed the signal to a normal active xo, which will then feed a set of normal Class B amps. What else am I supposed to do? If I didn't have a few friends and diyaudio.com, I wouldn't even attempt what I'm trying to do.
The THAT 1206 seems affordable at least for my low-volume hobby usage. The INA 1651 is one-third the price.
Interestingly, the INA 165x has exactly the same single-opamp based output buffer which the BTSB is using.
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Just curious. Lots of active speakers and other stuff these days have bal inputs.
Sometimes you just need a se signal, and then the best of the best is the superbal, but you often can get good results with simpler circuits also.
If you are aware of the issues and you find the resuklt less than you would want, you know there are better solutions.
But, as Nelson used to say: "it's all entertainment, not dialysis"!
Jan
Sometimes you just need a se signal, and then the best of the best is the superbal, but you often can get good results with simpler circuits also.
If you are aware of the issues and you find the resuklt less than you would want, you know there are better solutions.
But, as Nelson used to say: "it's all entertainment, not dialysis"!
Jan
Oh, I am not insisting that the bufffer be dropped, as I sort-of clarified at the end of #451. I am trying to understand the rationale, because some designs seem to have something like this, and others do not. I want to have some scientific basis for deciding whether to retain or drop it, in my design, that's all.
That's sort of what I'm trying to do. I'm aiming for a "pretty good" level of performance and avoiding total bloopers, but I'm not under any illusion that this is "endgame" (a word I see some people using in the audiophile world). The way I see it is:
- I do some draft design, to the best of my limited abilities, and post here.
- For the remaining questions, I ask here. Maybe some veteran dudes like you will answer, maybe I'll get the royal ignore. I've received both, so it's a matter of luck if I get guidance.
- I build what I've arrived at.
- I try to measure the performance (HD, IMD, noise) of the thingie with my Scarlett 2i2. It's not an AP, but it's more than good enough to tell me whether something is seriously screwed. I can live with 95dB THD+N when others are doing 120+, but I don't want to accept 70.
- I post queries again here, ask for help, be a bit of a pest, and see what I can learn. I then build a v2. And the story goes on.
So I think I'm doing exactly what you suggested.
Is this copyrighted? I'd like to tattoo this on my forehead when I meet my "special" friends, you know --- those who use risers to raise their power cables off their floors.
Yes it could work - but as Jan said, it’s only half the signal and you need a GND reference. Best thing is to stick with circuit as designed - why omit a $3 opamp and lose that extra functionality and introduce sub optimal performance?
Thanks X.
Since I have the luxury of a fresh designs, should I put in two opamps then and make a Superbal block?
Since I have the luxury of a fresh designs, should I put in two opamps then and make a Superbal block?