Hi, are there commercially available buffer amplifiers where the gain is 1 but the input impedance is made very high and the output impedance very low? This is very common needs so there must be some products, isn't it? And also very minimal distortions like 0.000008% Or do all buffer amplifiers introduce distortions that can never be removed? What is the best THD it can reach?
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Buffer amplifier
- Thread starter Eujene
- Start date
Amplification will introduce always distortions and noise. It can’t be removed later without degrading the original signal. Technically a buffer is needed to overcome the signal degradation from impedance mismatch and has to be the smaller worst. Good design is all to find the best compromise. From the view of a product for end users there is normally no need for it because most manufacturer take care of some unwritten standards for input- output impedance. (Not all)
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Universal Buffer
Fully differential buffer which provides a differential (balanced) and a single-ended (unbalanced) output with extremely low distortion. Great building block for a DIY preamp.
Waxx
Major Contributor
Buffers are a part of a preamp, it's almost only in diy enviroments that that is seperated in an own device. But a standard preamplifiers has a gain (a variable voltage gain stage) and a buffer (a fixed gain current amplifier mostly). with the eq or other processing in between them. Today a buffer stage is very easy to make with a good opamp in 0dB gain config, Even the classic NE5534 opamp is good enough for that to get top results without colouration when used right.
There are many boards for that on the web, some gooed and some bad. But ready made devices i don't know about except some ridiculous expensive ones that i won't mention. Best is to buy one of the boards, and build the device yourself (just put it in a case with a good psu board, and i/o connectors) or just buy a good preamp and keep gain at unity (0dBVU).
There are many boards for that on the web, some gooed and some bad. But ready made devices i don't know about except some ridiculous expensive ones that i won't mention. Best is to buy one of the boards, and build the device yourself (just put it in a case with a good psu board, and i/o connectors) or just buy a good preamp and keep gain at unity (0dBVU).
Roland68
Major Contributor
There are many circuit boards, kits and ready-made modules from simple to top end. I am not aware of any finished devices with housings.
If you let us know what you need the buffer for, someone might recommend something.
Killingbeans
Major Contributor
Sounds like what you're looking for is a simple circuit consisting of a dual or two single op-amps configured as a unity gain amp + an ultra low noise dual rail voltage supply.
The performance of the op-amp itself will be the limiting factor. You can get a sense of that by looking in their respective data sheets.
Yes. Everything in an audio chain adds distortion and/or noise, but more often than not the contribution of the individual parts is so tiny, that even when you stack them up, the distortion/noise is way, way below the scope of human hearing.
Even "low tier" audio purpose op-amp have no problem performing more "transparent" than any reasonable person could ever ask for
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