craig.g Posted February 13 Posted February 13 Hi, how do i find out if my amplifier is high or low gain, and does it make a difference. My speakers are sensitive, 95db 8ohms. Thanks.
muon* Posted February 13 Posted February 13 (edited) It will be in the amps specs as a 'db' figure. Edit: after looking at some amp specs, sadly they don't seem to include that spec. https://calculatorshub.net/tools/amplifier-gain-calculator/ Edited February 13 by muon*
VanArn Posted February 13 Posted February 13 An indication of the make and model of the amplifier would be helpful in determining the performance figures that matter. Basically, sensitivity of the amplifier for a given output in watts into a specified load resistance would be a starting point. An amplifier that supplies 50 watts into an 8 ohm load for a 1 volt input( 1kHz), would be of a higher sensitivity (higher gain) than another amplifier that required a 2 volt input for a 50 watt output. An important added consideration when using speakers of a higher sensitivity than average is the signal to noise ratio, although the noise from a phono pre-amplifier is more likely to be of concern. 1
craig.g Posted February 13 Author Posted February 13 Hi, thanks for the replies and help, unfortunately my amps manual does not have the figures needed for this. I mainly wondered if the difference between high gain and low gain made a difference to an amps particular sound characteristic. My amps are Esoteric I-05. and Luxman 507uxii. Thanks.
andyr Posted February 13 Posted February 13 3 hours ago, craig.g said: Hi, thanks for the replies and help, unfortunately my amps manual does not have the figures needed for this. Then you need to measure it, using a signal generator and an oscilloscope. For instance ... 1v ptp input signal and 20v ptp output signal (at the spkr terminals) means a gain of 20x ... which is 26dB gain. 3 hours ago, craig.g said: I mainly wondered if the difference between high gain and low gain made a difference to an amp's particular sound characteristic. No, I don't think it does.
RoHo Posted February 14 Posted February 14 22 hours ago, craig.g said: Hi, thanks for the replies and help, unfortunately my amps manual does not have the figures needed for this. I mainly wondered if the difference between high gain and low gain made a difference to an amps particular sound characteristic. My amps are Esoteric I-05. and Luxman 507uxii. Thanks. In very broad terms if overall gain is too low than your system won't go loud enough with the volume turned right up. And if you have very high gain from one component you may get audible noise/hiss. Within these extremes, which is 99% of cases, you'll be OK.
aussievintage Posted February 14 Posted February 14 On 13/02/2025 at 3:21 PM, craig.g said: Hi, how do i find out if my amplifier is high or low gain, and does it make a difference. My speakers are sensitive, 95db 8ohms. I am wondering what relevence the second bit of information has to the first question? It is making me think that more explanation is required. The question normally asked is about amplifier power and speaker efficiency, and whether it will be loud enough. If the answer to that is yes, THEN you might ask, has the amplifier enough gain to allow it to produce that rated power, given the available input signal. Happily the last problem is the easiest to solve as adding gain via a preamp or something is easier and cheaper than changing power amps and speakers.
georgehifi Posted February 15 Posted February 15 (edited) On 14/02/2025 at 7:47 PM, aussievintage said: I am wondering what relevence the second bit of information has to the first question? It is making me think that more explanation is required. Don't worry about "Gain" if you can utilize all output the source has to give, and your volume control is around half way up or higher and the speaker level is as loud as your ever going to listen to. Then you have a good system gain structure with the least amount of of noise and distortion, from unwanted extra gain that's never going to be used. If your volume control is around 9am for the loudest you are going to listen to using all the source volume, then it time to throw out some active gain stages. Cheers George Edited February 15 by georgehifi 1
craig.g Posted February 16 Author Posted February 16 Thanks George, thats very helpful. I find that about 10am on the volume control is about as loud as i will ever listen. 1 of my amps has a feature where you can trim input gain, is this something i should look into. Or reduce volume output from the source, ie the dac. Thanks.
georgehifi Posted February 18 Posted February 18 (edited) On 16/02/2025 at 1:45 PM, craig.g said: 1 of my amps has a feature where you can trim input gain I looked at both your Esoteric and Luxman they only have active preamp volume controls. Only the Esoteric has power amp inputs but no passive level trim controls for the poweramp section. What I would try with your source/s that have digital domain volume control, is to feed the L&R output of them into the Luxman's "poweramp inputs" (attached circled in red) and use the sources volume control, just make sure the sources volume is at 0 when you turn it all on. NB: The golden rule going direct is switch source on first and Esoteric on last. And opposite when turning off. Cheers George Edited February 18 by georgehifi
craig.g Posted February 18 Author Posted February 18 Thanks George, sounds like you have done a lot of work for me on this, i will try this when i get time. Thanks for your help. Craig.
georgehifi Posted February 18 Posted February 18 (edited) If you find that sounds the best (which it should), I think you can do this to keep multiple sources switching also as it by-passes the active preamp and volume control. (someone can correct this if I'm wrong as I'm not an integrated user with all the tape in/out/monitoring switching) Take the tape outputs to the poweramp inputs with a pair of short rca's, then you can use all your Lux switchable source inputs if they have volume controls on them. Cheers George Edited February 18 by georgehifi
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