The gain of the preamp is, I would expect, specified at maximum. So it will be less as you turn the volume down.
The gain of the power amp is typical of power amps I have used, as is the sensitivity of your speakers. I would think this would be fine.
Typically, home audio components have more gain than necessary in most situations. But if the units are quiet enough (most are) that is not a problem in the practical sense. |
That’s a lot of gain, works out to around 2500W into 8Ω at full volume. A rule of thumb is that every 6dB of gain doubles the voltage, if you know Ohm’s law you can work out the rest.
If you ran a unity gain (0dB) preamp into that power amp it’d need to be capable of 150W into 8Ω, or with a preamp with 6dB gain around 600W.
Main thing to make sure of is your preamp output doesn’t exceed the power amp input sensitivity figure.
Edit... not sure if the OP changed or I just read it wrong. If your power amp has an input sensitivity of 575mA then you need 12dB of attenuation between the DAC and the power amp. If you use a preamp with 18dB of gain then your volume control will be at -30dB when the power amp is at max rated output. |
pragmasiThat’s
a lot of gain, works out to around 2500W into 8Ω at full volume. A rule
of thumb is that every 6dB of gain doubles the voltage, if you know
Ohm’s law you can work out the rest.
If you ran a unity gain (0dB)
preamp into that power amp it’d need to be capable of 150W into 8Ω, or
with a preamp with 6dB gain around 600W You've confused gain (and input sensitivity) with power output. They are two completely different things. There's no way to calculate power output in watts from the information the OP has provided.
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You’ve confused gain (and input sensitivity) with power output. They are two completely different things. There’s no way to calculate power output in watts from the information the OP has provided. Input sensitivity, gain and power output are all related mathematically and you can work out one from the others if you assume a certain loudspeaker impedance. I didn’t say the system would be capable, just that an 8Ω speaker driven by the maximum output voltage would need 2500W from the amplifier and need to be able to tolerate it. |
Short answer: what this means in practical terms is that you'll very likely only be using your preamp's volume control at the lower end of its range. |
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pragmasiInput
sensitivity, gain and power output are all related mathematically and
you can work out one from the others if you assume a certain loudspeaker
impedance. There's no way to calculate power output in watts from the information the OP has provided. You simply don't know what you're talking about. |
If your concerns have anything to do with the previous thread on Gain wars there is no need to worry. 2V output from the source is just about industry standard. Actually those specs you listed look common and should mix and match easily. Some high end designs can have some pretty unusual specs and can be more difficult to mate, but really isn't an issue for the vast majority of gear.
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@cleeds There's no way to calculate power output in watts from the information the OP has provided. You simply don't know what you're talking about. I'm going to dip out after this. If you know the gain and the input voltage, you know the output voltage. If you know the output voltage you can work out the power required to drive a loudspeaker of given impedance, whether or not the system has the ability to drive that loudspeaker is another matter. I try (and don't always succeed) to explain things in simple ways as people here have commented that they don't like the detail. And when I do someone always turns up to tell me I'm wrong because I didn't show my working. That is you in this case and you've resorted to insults straight away. Anyone can look up Ohm's law and work it out for themselves, yourself included. |
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I may be confused but if your pre-amp can put out 575mv, the amp will be at full rated power. I don't think it matters what the gain stages are. |
I had a gain matching problem between amp and preamp in my system (Pass Lab XA60.8 and AR Ref 6). Added to this my speakers are 106 sensitivity. Could not take the preamp volume past 7 (out of 100), it was too loud. Loads of background noise. Tried a set of Rothwell attenuators between preamp and amp. Problem solved. I don’t know if you will have a problem. Many in this forum more expert than myself. What I can assure you is that you can fix that problem for all of $25 (as I recall). |
Just plug it in, turn the preamp up to max, wait 5 minutes, and see if you have any hearing or speakers left. Geesh! (The things some folks stress about!) |
Just as long as something in the chain goes to 11. |
russ69"I may be confused but if your pre-amp can put out 575mv, the amp will be at full rated power. I don't think it matters what the gain stages are."
This is correct and accurate and it is all that is really relevant in this case there is a lot of misinformation in this thread how can you calculate power amplifier output without knowing any details about the power amplifier capabilities, performance, or specifications theer is technical "word salad" in this thread if you can't show you're math work then you can't make the argument, sorry fella! |
"...there is a lot of misinformation in this thread how can you calculate power amplifier output..."
Amplifier power measurement has to include the frequency, the load, and the distortion level to have any meaning. It's a moving target, you just can't pick one number and say you have determined the power output of an amp. |
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@cleeds is correct in that you can’t determine/calculate the amplifier output power (Watts) based on the information provided by the OP.
Cha |
