How much power ?

[Ronin]

How much power do you really need? In my case it doesn't seem a lot

At the moment I can barely turn the volume up on my NVA AP20 ( 20 watts, I think) driving the Goodmans Magnum K.
I can appreciate I'm using a CD-player , which seems to have a higher gain (output) into the amp but, the sound just gushes out !with the slightest turn of the knob, which easily fills my room ( 12 x 24 ft ).

Can anyone explain this phenomenon

Of course I'm not to concerned because I've still got enough volume control but,why do we need hundreds of watts (20 in my case) if you can't use them..I don't really understand why I have so much volume control that is redundant.

I've tried searching the web for this information but to no avail.

I'm hoping in the not so distant future to try my BIL's Single Ended 8 watter.So I'll report back with my findings.

[jammy395]

Speaker sensitivity will have a bit to do with it Ronin........But theres probably a whole lot more to it than that.
An 8 watt amp played through a 104db sensitive speaker will probably make yer ear's bleed at vol 11.....!!!!

[Dr Bunsen Honeydew]

There are really efficient horn speaker that will fill your room with music from 1/2w. But what you don't realise that like all specs watts are meaningless unless seen it context, they are just gifts to the marketing men so they have something to talk about. They mean something to me because I make things, but to be really patronising you shouldn't worry your pretty little head with them

The only reason my amps get more watts as you go up the range is for less efficient speaker 85 to 88db but mostly for the bigger (more VA) power supplies, that is where the *musical* difference comes from.

[Lindsayt]

There are 4 main variables in the equation to determine if you have enough power or not:

Max power of the amplifier before clipping / objectionable amounts of distortion. This is only a very rough guideline as it varies with impedance and with signal duration - ie continuous vs transients. It can also vary with frequency.

Speaker sensitivity. Some manufacturers lie about this specification. Also it's measured in dbs for an input of 2.83v at 1 metre. IE this specification is more flattering to low impedance speakers.

Listener's distance from speakers.

How loud the listener wants it.


Also the position of the volume knob does not tell you how close you are to clipping. Some sources deliver a higher voltage to the amp than others. I have some source / amp combinations that have a hair trigger volume knob. All this usually means is that I'm hitting clipping power levels at the 10 O'clock position due to too much gain in my system, not that I've got loads of power in reserve.

[Dr Bunsen Honeydew]

(refering to my post not Lindsays)

PS - there is a lot more to do with it apart from that, like signal level and input sensitivity, but to cover it all I would have to teach you amplifier design - a long job and not my job. BTW if you live in N. London or outside the N. M25 you can learn amplifier design as I am looking for a new Padawan.

[Shevans]

Some powerful amps sound poor in comparrison to lesser output models, they tend to loose that enjoyabilty factor. Must be something to do with stuffing up the enormous power supply.

[jammy395]

But theres probably a whole lot more to it than that. (Jammy)

Told you so Ronin........

Some powerful amps sound poor in comparrison to lesser output models, they tend to loose that enjoyabilty factor. Must be something to do with stuffing up the enormous power supply.

I agree with you there Shev - I geuss it aint the amps watt's its what the amp does with them...........
Have heard 200w amps sound shit & 20w amps sound bloody good........Design thing i suspect.

[Ronin]

Thank you Guys for for making the effort to try and enlighten me .I can't say that I'm much the wiser though but i guess i'll never fully appreciate what's going on unless i understood amplifier design (as doc mentioned) maybe .

The only tool that I have at the moment is my ears, which, are being subjected to high volumes of sound with the slightest turn of the volume control. Am i missing something by not being able to tun the volume up.

Just makes me think, do I need 20 watts Is it be possible to build a higher quality solid state amplifier but with much lower power or should I look at a flea powered valve amplifier in the future.

Some powerful amps sound poor in comparrison to lesser output models, they tend to loose that enjoyabilty factor. Must be something to do with stuffing up the enormous power supply.

I can relate to this Shevans .My BIL has got a low powered Single ended (what ever that is?) valve amplifier (8 watts) and the sound to me was much more appealing than some High powered amplifiers.

BTW if you live in N. London or outside the N. M25 you can learn amplifier design as I am looking for a new Padawan.

I would love to be your "Padawan" but I'm about 170 miles off target

[Dr Bunsen Honeydew]

OK I will confuse you even more. I think your AP20 comes from the '90s when we used a "blagged" Linear Cermet Pot as VC. That meant the logic curve of the volume progression was more linear than logarithmic in nature. The human ear is not linear in its perception of loudness it has a log curve, meaning it is far more sensitive to volume changes at low SPL. The current pot we use is straight logarithmic to a logB curve so if you want to solve the problem send the amp back for the new pot to be fitted.

[Ronin]

OK I will confuse you even more. I think your AP20 comes from the '90s when we used a "blagged" Linear Cermet Pot as VC. That meant the logic curve of the volume progression was more linear than logarithmic in nature. The human ear is not linear in its perception of loudness it has a log curve, meaning it is far more sensitive to volume changes at low SPL. The current pot we use is straight logarithmic to a logB curve so if you want to solve the problem send the amp back for the new pot to be fitted.

Yes,I can full appreciate the difference ,that must have been the reason I sent it back to you last year to have the "straight logarithmic" one fitted .

Actually,the real reason was.the volume pot give-up the ghost, and your right it's from the 90s.