Hi folks,
One of my amps has the following written in its description - “Single Gain Stage Transconductance Amplifier.”
Now, it’s been in my system for a couple of years, and just now started to read its literature (thanks to Covid). I’m not exactly technically savvy, so just wanted to know in layman’s terms if it really means something usable, or just another bulls@it audio-expression.
I know Pass’ First Watt stuff also called transconductance amps, but not sure if the principle is the same comparing to my amp.
The device in the question is Audio Analogue Donizetti Anniversary.
Appreciate your input.
One of my amps has the following written in its description - “Single Gain Stage Transconductance Amplifier.”
Now, it’s been in my system for a couple of years, and just now started to read its literature (thanks to Covid). I’m not exactly technically savvy, so just wanted to know in layman’s terms if it really means something usable, or just another bulls@it audio-expression.
I know Pass’ First Watt stuff also called transconductance amps, but not sure if the principle is the same comparing to my amp.
The device in the question is Audio Analogue Donizetti Anniversary.
Appreciate your input.
Any amplifier in which its output voltage is controled by a voltage at its input(s) is called a voltage amplifier.
Any amplifier whose output current is controled by a voltage at its input(s) is called a transconductance amplifier.
Any amplifier whose output current is controled by a voltage at its input(s) is called a transconductance amplifier.
According to OldDIY's first link, it has an output resistance of 0.15 ohm, so the whole circuit is actually a voltage amplifier rather than a transconductance amplifier.
"Uses our SeGeSTA (Single Gain Stage Transconductance Amplifier) configuration followed by a group of four transistors (...)" Apparently the four transistors change it into a voltage rather than current output.
"Uses our SeGeSTA (Single Gain Stage Transconductance Amplifier) configuration followed by a group of four transistors (...)" Apparently the four transistors change it into a voltage rather than current output.
Thanks for the explanation, guys. More or less got the idea, and the first link is really insightful.
I don’t remember if any modern manufacturer ever mentioned “transconductance amplifier”in their manuals, which made me curious, hence the question.
Still can’t understand what exactly the audible benefits are.
I don’t remember if any modern manufacturer ever mentioned “transconductance amplifier”in their manuals, which made me curious, hence the question.
Still can’t understand what exactly the audible benefits are.
Sure, the TransNova power amp by Jim Strickland (here's one link among many) was a commercially sold, transconductance amplifier.
So was the FirstWatt F5, a (small production run) commercial amplifier.
And the Mark Levinson JC-2, designed by John Curl in 1973, was also a transconductance preamplifier.
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So was the FirstWatt F5, a (small production run) commercial amplifier.
And the Mark Levinson JC-2, designed by John Curl in 1973, was also a transconductance preamplifier.
_
Thanks again folks.
One more question - do you think pairing transconductance (TC) amp with TC pre is preferable?
One more question - do you think pairing transconductance (TC) amp with TC pre is preferable?
Your amplifier is not a transconductance amplifier. It consists of a transconductance amplifier and some other circuit and the combination acts as a voltage amplifier.
Besides, it has a voltage input so the preamplifier has to have a voltage output (which all normal preamplifiers have).
"Uses our SeGeSTA (Single Gain Stage Transconductance Amplifier) configuration followed by a group of four transistors to provide all the necessary current without affecting the gain stage"..."power stage with 12 bipolar transistors per channel"
The main feature of the amplifier noted by the manufacturer is the absence of GNFB. Undeclared THD. Relatively high output impedance. Large weight.
The main feature of the amplifier noted by the manufacturer is the absence of GNFB. Undeclared THD. Relatively high output impedance. Large weight.
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There is something strange with the data-sheet/description of the amplifier.
The output resistance is that of a voltage amplifier, but the absence of indications on the THD suggests an assembly perhaps with feedback voltage taken before the final current amplification stage.
It is an idea which was in vogue a few years ago.
This does not detract from the general quality of the product.
In any case, it is a great lot of vocabulary to occupy the advertising notices.
The output resistance is that of a voltage amplifier, but the absence of indications on the THD suggests an assembly perhaps with feedback voltage taken before the final current amplification stage.
It is an idea which was in vogue a few years ago.
This does not detract from the general quality of the product.
In any case, it is a great lot of vocabulary to occupy the advertising notices.
