Comparing power output of amplifiers

[FennerMachine]

Partly out of curiosity I've been checking specifications of suggested amplifiers from various members.

I've been trying to compare power outputs of some amplifiers.

Example: Yamaha A-S2100 and Marantz PM-14S1.

The Yamaha looks more powerful at 105W vs Marantz at 90W, until you read the distortion figures.

Yamaha 4 ohm 160W 0.7% THD.

High Dynamic Power rating: 8/6/4/2 105/135/190/220, so this rating is 190W instead of 160W at 4 ohms so must be around 1% THD?

This means that Yamaha 105W into 8 ohms must be around 1% THD, and Marantz 90W, without any other measurements to go by, must be at its rated 0.02% THD, and 140W 4 ohms at 0.02% THD.

So what do you think the Marantz would be capable of using the same measuring criteria of 1% THD?

Or are these 2 amplifiers too similar to even worry about differences?

 

[Deleted member 116933]

To be honest spec sheets arn't really worth the scratch there writen on and should only be taken with a pinch of salt.

There's not really a set standard for messuring within the industry and there not enforced or regulated either. Hence cooked numbers

The numbers quoted are never normally anywhere near what they say. The big main stream brands being some of the worst offenders.

Real world manufactures (as i like to call them) from the likes of NAD and Rotel are normally bang on the money.

i say just sit back and enjoy and not let figures get in the way

 

[RobinKidderminster]

Interesting to know what is real world about NAD and Rotel but non-real world about Yamaha and Marantz??? The figures quoted however, I can add no useful insight other than it is unlikely to run any amp at its limit and if you did then THD figures would be the least of my worries.

 

[FennerMachine]

So in a small room, around 11x13 feet, and not at rock concert levels, a 40W amplifier would do the job?

 

[Andrewjvt]

Real world manufactures (as i like to call them) from the likes of NAD and Rotel are normally bang on the money.

i say just sit back and enjoy and not let figures get in the way

I say: spot on 50 w on a nad will sound more powerful than some japanese competition

also 50w on naim will sound more also

 

[iceman16]

So in a small room, around 11x13 feet, and not at rock concert levels, a 40W amplifier would do the job?

IME..Yes but also depends on what speakers you're using

 

[margetti]

So in a small room, around 11x13 feet, and not at rock concert levels, a 40W amplifier would do the job?

IME..Yes but also depends on what speakers you're using

My 33W (into 8 ohms) amp with 88.5db sensitivity speakers certainly does the job for me in a 25x11 ft room

 

[iceman16]

So in a small room, around 11x13 feet, and not at rock concert levels, a 40W amplifier would do the job?

IME..Yes but also depends on what speakers you're using

My 33W (into 8 ohms) amp with 88.5db sensitivity speakers certainly does the job for me in a 25x11 ft room

My amp is rated at only 35wpc and I much prefer it (soundwise) to some Plinius amps( Hiato and Hautonga) which I have home demo.

 

[margetti]

So in a small room, around 11x13 feet, and not at rock concert levels, a 40W amplifier would do the job?

IME..Yes but also depends on what speakers you're using

My 33W (into 8 ohms) amp with 88.5db sensitivity speakers certainly does the job for me in a 25x11 ft room

My amp is rated at only 35wpc and I much prefer it (soundwise) to some Plinius amps( Hiato and Hautonga) which I have home demo.

My (recently acquired) amp is a Sonneteer Orton, which replaces a Sonneteer Alabaster (or will, still have both in the rack) and I much prefer the Orton over the 55wpc rated Alabaster. Which is as it should be really considering the Orton is twice the price of the Alabaster. I've never taken too much notice of spec sheets, but the Orton has certainly shown just how immaterial specifications really can be.

 

[iceman16]

So in a small room, around 11x13 feet, and not at rock concert levels, a 40W amplifier would do the job?

IME..Yes but also depends on what speakers you're using

My 33W (into 8 ohms) amp with 88.5db sensitivity speakers certainly does the job for me in a 25x11 ft room

My amp is rated at only 35wpc and I much prefer it (soundwise) to some Plinius amps( Hiato and Hautonga) which I have home demo.

My (recently acquired) amp is a Sonneteer Orton, which replaces a Sonneteer Alabaster (or will, still have both in the rack) and I much prefer the Orton over the 55wpc rated Alabaster. Which is as it should be really considering the Orton is twice the price of the Alabaster. I've never taken too much notice of spec sheets, but the Orton has certainly shown just how immaterial specifications really can be.

Im not talking about boom and tizz here but with full dynamics, instrument separation, resolution and detail, but with fluidity and warmth

 

[CnoEvil]

Im not talking about boom and tizz here but with full dynamics, instrument separation, resolution and detail, but with fluidity and warmth

You tell 'em, Iceman! *wink*

 

[iceman16]

Im not talking about boom and tizz here but with full dynamics, instrument separation, resolution and detail, but with fluidity and warmth

You tell 'em, Iceman! *wink*

Nope.. I'll ask them to listen and see

 

[iceman16]

IME. there's a lot to enjoy.. Naim (prat) foot tappin' etc.. but nothing compares when you have goosebumps while listening..

 

[iceman16]

Sorry FennerM for the "out topic" posts.

 

[margetti]

Im not talking about boom and tizz here but with full dynamics, instrument separation, resolution and detail, but with fluidity and warmth

Ditto here tbh, but not to the same degree as your system I'd wager. The Orton retails at £2.5k (although I bought mine second hand) - if I'm getting the enjoyment I am getting, then I would be happily amazed to hear the 35i Notthat I could ever afford one! Kudos.

 

[Deleted member 116933]

Interesting to know what is real world about NAD and Rotel but non-real world about Yamaha and Marantz??? The figures quoted however, I can add no useful insight other than it is unlikely to run any amp at its limit and if you did then THD figures would be the least of my worries.

just quoting that others have said and mesaured (and personal experiance) that those pertictular brands tend to be more real world with the figures. I never said they where absolutly acurate just pretty close. I also said that spec sheets arn't worth the scratch there written on.

 

[busb]

Quoted output power figures are pretty useless & as the OP points out, depends on the chosen allowed THD. Other factors often missed out are output impedance & max current delivery - either will effect the power available into more complex loads. One tel-tel spec is quoted power into different load impedances where halving the impedance does not come close to doubling the power which indicates a higher than optimal output impedance (or low damping factor which is just different way of characterising output impedance). Another measurement often missing is power bandwidth which indicates frequency v power flatness into the load at so-called real world listening levels. Knowing the drop in rail voltage v output power v frequency is also enlightening when considering instantaneous output power. A power amp's output stage is only as good as its power supply!

Measuring steady state output power into an 8 Ohm resistive load is just laughable. The Hi Fi industry lacks the will to standardise measurements which rather renders them useless. Things get even worse when wanting to match a power & preamps from differing manufactures where gain plays a part in perceived loudness & the ratio of gain between the two parts effects the match amongst other factors.