How much power do you REALLY need?

gonefishin · « **Reply #60 on:** 15 Mar 2005, 09:11 pm »

If I may...

Quote from: pem

Dear rmihai,

...Both Dave and Hugh recommended me to take the 55N+ instead of the 100N+....

kind regards,
Pierre-Etienne

...so this all comes back to an issue of How much power do you REALLY need?

dan

rmihai0 · « **Reply #61 on:** 15 Mar 2005, 09:34 pm »

And here it goes again. Which AKSA amplifier should I get for my needs? The 55 or the 100?

The speakers:
Sensitivity 84db
Impedance: 8 ohms nominal ;dips to a low of 6.2ohms in the bass region.
Sound Pressure: 90db

Music: classical 2/3; anything else (from rock to jazz, world and folk) 1/3. Only Lp's. NO DIGITAL.

My room: 18 x 20 feet (5.4m x 6.1m)

rmihai0 · « **Reply #62 on:** 15 Mar 2005, 09:36 pm »

I forgot to mention that someone told me that a MF rated at 125W per chanel was not up to the task to drive the Ellis 1801b and he was looking to upgrade it to something in the 170W region. So, where is the truth? Some are saying 30-35W should be enough others are saying that 125W are NOT enough?

AKSA · « **Reply #63 on:** 15 Mar 2005, 09:50 pm »

Hi Rmihai0,

You rightly raise the issue of power. It's confusing. The reasons are complex, so they are unrealistically simplified for easy description.

All amps are not the same. Powerful amps can have real problems driving some loads (speakers) and quite little amps can punch well above their weight. A single ended triode of only a few watts can sound astonishingly powerful; recently I designed and built a 1.5 watt SET using the 6EM7. Last Saturday night we played it through a set of Spendor three way speakers, and it was incredibly loud for its size, and just wonderful on female vocal. These little tube amps are very load tolerant, as is the AKSA 55W.

David Ellis, creator of the 1801b, says that the AKSA is fine with his speaker, and makes glowing comment about the system performance. Since he has no axe to grind, perhaps his judgement in the matter is sufficient; of course, a little depends on how loud you like it, but if you like vinyl (despite your time in a rock band

) you probably have a moderate attitude to sound pressure levels......

The essential difference between the 100W and the 55W is the dynamics, and a slightly greater 'size' to the sound from the larger amplifier. In all other respects the 'sound' is the same. Into 4R the 55W AKSA will produce 90W, the 100W AKSA around 175W.

Cheers,

Hugh

WEEZ · « **Reply #64 on:** 15 Mar 2005, 10:21 pm »

Seems like if the designer of the speaker likes the 55N- that says it all.

WEEZ

(sorry Hugh & Dave- didn't mean to intrude, but rmihai0 has asked about this on other threads and forums- over and over)

DVV · « **Reply #65 on:** 15 Mar 2005, 10:32 pm »

In general, it's always good to have power reserves. Too much power won't hurt you (unless you misuse it), but lack of it will mean compressed and modified sound.

So, if in doubt, always go for more powerful. Power does have its virtues, within reason, of course.

Regarding the question of additional investment into power transforers, capacitors, etc, I can attest to the very simple fact that this is money extremely well spent. It's precisely here that the industry at large tends to "save" money, ALWAYS at the cost of the sound. To get to the sound, you need the juice for it; you can't ask a man with a weak heart to run a marathon.

Which brings us to what would always be my prime motive for going DIY with class - it would allow me to invest the money where it counts, not in sexy displays, learning remotes, expensive adevrtisements, etc. This is exactly what differentiates kits such as AKSA from run-off-the-mill products, this is how they in good part manage to sound so good.

Just my 2 cents' worth.

Cheers,
DVV

stvnharr · « **Reply #66 on:** 15 Mar 2005, 11:11 pm »

rmihai0,
The power issue is genuine, especially with a speaker such as the 1801. Dave is very comfortable with my amp (55N+) in his room. The issue for you is how much sound do you need to put out in your room. The definitions of large room and small room are not fixed, but for a small to medium sized room, the 55 is likely enough. Although with the 100 you get a lot more dynamic headroom which is helpful on the orchestral climaxes. It can be a tough call.

As for the price issues, if anything the Aksa amps are underpriced, given their performance. Bargaining will only get you frustrated!
For your anticipated costs, just check out audiogon to see what the same money might get you in the used market. In the kit market, check out www.audiokits.com for the Borbeley kit amps (which do come complete, although you do have to put them together).
While your anticipated costs may seem high to you, remember that you are getting the best value for your money. You are paying mostly for directly incured costs with the minimal amount of markup.

Tbadder1 · « **Reply #67 on:** 17 Mar 2005, 02:55 am »

Okay, I'll chime in here without having read the whole thread--so my apologies if I'm repeating. I'm not a big believer in tons of power. It's the quality of the power that counts. My Clayton S40 has only 40wpc, but can also handle dips as low as 1 ohm, consequently it can manage a lot of speakers. It's pure Class A, so those 80 watts are pretty wholistic, a nice balance of slam (7 on a 10 scale) and tonality (9 on a 10 scale). My 300B amp is really special and of course manages only 8wpc, but it's hooked up to the 6h30 supertube that ARC and BAT use and tube rectified, so the ancillary aspects of the watts really enhance those 8 little beauties--that's super important. Okay, I'll go back and read the rest of the thread. Take care all.

ginger · « **Reply #68 on:** 22 Mar 2005, 06:47 am »

First - my speakers VAF Research DCXs - 95dB/W/m sensitivity. Nominal Impedance 6 Ohms (no dips below 5 Ohms)

Next my Amps in decreasing power
AKSA 55N+
55W into 8 Ohm 90W into 4 Ohm - Drives the VAFs beyond any level required.

EL34 (4 output tubes per channel) Triode Mode Parallel Push Pull.
40W into 4 Ohms - drives the VAFs to any level required

845 SET 20W into 4 Ohms
Drives the VAFs adequately to any level at which I can stay in the room

EL84 Ultralinear (43%) Push Pull - 10W
and
ECL86 Ultralinear (20%) balanced shunt feedback Push Pull - 10W (output transformers half the size of the EL84 amp)
These 2 amps exhibit a bit too much distortion at Very High listening levels BUT are gorgeous at reasonable listening levels. Some evidence of clipping on loud bass transients on the ECL86 amp (or it might be output transformer saturation I can hear).

So which sounds best? They ALL sound gorgeous - I change amps according to my mood and my listening preferences on the day.

By the way VAF recommend the speakers for amps between 10W and 200W.

Cheers,
Ginger

doug s. · « **Reply #69 on:** 22 Mar 2005, 03:44 pm »

Quote from: rmihai0

And here it goes again. Which AKSA amplifier should I get for my needs? The 55 or the 100?

The speakers:
Sensitivity 84db
Impedance: 8 ohms nominal ;dips to a low of 6.2ohms in the bass region.
Sound Pressure: 90db

Music: classical 2/3; anything else (from rock to jazz, world and folk) 1/3. Only Lp's. NO DIGITAL.

My room: 18 x 20 feet (5.4m x 6.1m)

speakers rated at 84db? no brainer, imo - go w/the 100. whatever anyone sez about how well the 55 works w/this particular , if the 100 has the same sonic signature (as hugh sez), then the 100 is easily the right choice. it will only work better, in all circumstances. sure, if the room is small, & yure playing chamber music, the differences won't be as great, but why limit yourself?

doug s.

JLM · « **Reply #70 on:** 22 Mar 2005, 05:26 pm »

I'm sure the Ellis 1801 are very fine speakers, but they're only 2-way standmounts, so don't expect thunderous spls in an 18 x 20 room with any sized amp.

As Doug mentioned, you're only talking about another 3 dB (half again as loud).

I believe that the 84 dB/w/m rating is very conservative compared to most others.

A better solution given the 1801s, your room size, and your power concerns would be to add a powered sub to take much of the heavy lifting off the 1801s and use a smaller amp for them.

doug s. · « **Reply #71 on:** 22 Mar 2005, 05:37 pm »

Quote from: JLM

I'm sure the Ellis 1801 are very fine speakers, but they're only 2-way standmounts, so don't expect thunderous spls in an 18 x 20 room with any sized amp.

As Doug mentioned, you're only talking about another 3 dB (half again as loud).

A better solution given the 1801s, your room size, and your power concerns would be to add a powered sub to take much of the heavy lifting off the 1801s and use a smaller amp for them.

this is good, but i'd go one step further: i would recommend using a pair of passive subs - actively cross over the the ellis's at 60hz or so. this will definitely lighten the load of the amp driving them. prolly improve their sound in the upper bass/lower midrange as well!

if you yust go w/a powered sub & still run the ellis' full-range, their load will *not* be lightened at all. but i'd still stick w/the aksa 100 over the 55.

ymmv,

doug s.

RussKon · « **Reply #72 on:** 22 Mar 2005, 06:02 pm »

i'm surprised that in 8 pages of this thread no one posted the following link

http://www.myhometheater.homestead.com/splcalculator.html

a great little SPL calculator that can show what the peak SPL will be in your room based on speaker efficiency, amplifier power, speaker placement and distance from the speakers

rmihai0 · « **Reply #73 on:** 23 Mar 2005, 07:34 pm »

Thank you very much!

I used the calculator, and according with the speakers positioning
- 56W RMS it will do it (I was surprised to see a figure that close with the AKSA 55!)

As long as I am ussually listening to 60-70db, I think the 90db that I was trying to get will cover ALL the peaks! I've read that peaks measure around 10db.

Am I right?

Thank you again

There is a nice feeling knowing that you have took a decision being scientifically informed.

doug s. · « **Reply #74 on:** 23 Mar 2005, 07:59 pm »

Quote from: rmihai0

Thank you very much!

I used the calculator, and according with the speakers positioning
- 56W RMS it will do it (I was surprised to see a figure that close with the AKSA 55!)

As long as I am ussually listening to 60-70db, I think the 90db that I was trying to get will cover ALL the peaks! I've read that peaks measure around 10db.

Am I right?

Thank you again

There is a nice feeling knowing that you have took a decision being scientifically informed.

realize that the 100 gives you only 3db more headroom. what if you move into a larger room, or change to slightly less-efficient speakers? if there's any way your budget can afford it, i would still get the 100's. it would be different if hugh said the 55's sound better if yer speaker/room combo doesn't need the add'l power. but that isn't what he said...

ymmv,

doug s.

JLM · « **Reply #75 on:** 24 Mar 2005, 02:13 am »

rmihai0,

Use a sound pressure level meter (even a $40 Radio Shack) so that you know what your talking about.

Most audiophiles I run with average about 80 dB for serious listening of jazz, folk, and other small ensemble genres that have 10 dB peaks. Rock concerts average 110 dB, classical peaks (very rarely) at 105 dB with typical levels around 70 dB.

rmihai0 · « **Reply #76 on:** 24 Mar 2005, 02:26 am »

Thank you JML. I will follow your advise.

There is something that I need to mention about the "audiophiles" who are doing tests on jazz, vocals and alike: I've seen this fashion also here in Toronto. Jazz, vocals and alike are NOT for equipment testing! If you want to test audio equipment feed it with the hardest! Heavy metal, hard rock, large symphonic orchestras. That will give a proper perception.

Listening to some vocals (so called jazz) that is a good test for midranges at best, but nothing else.

I've tested so called audiophile equipment with difficult passages from rock and classical. Do you know what happened? The obvious - the tested equipment couldn't manage it - doesn't had the nerve and the dynamics! I am kind of sick about "audiophile' electronics. The guy who manufactured that piece tried to explain me that it will have to cost several thousands dollars a piece of "audiophile" electronic to be able to reproduce the way I like: EVERYTHING. Sorry, but I don't agree with him. I played bass guitar since I was 12 - and do you know what? We never had "audiophile" equipment - because, obvious, we couldn't afford. But I will tell you what: most of the equipment that we were using was better then today "audiophile" equipment.

Cheers

JoshK · « **Reply #77 on:** 24 Mar 2005, 02:30 am »

I disagree with doug and think you should skip the 100 and get the 55. All the more reason to build a 100 at a later date to biamp with if you run out of juice because of a move into a bigger abode. The 55 is suppose to be ever so much sweeter than the 100. I heard the 100 and it is on my top 3 list, and I've heard a lot.

JoshK · « **Reply #78 on:** 24 Mar 2005, 02:33 am »

Quote from: rmihai0

Thank you JML. I will follow your advise.

There is something that I need to mention about the "audiophiles" who are doing tests on jazz, vocals and alike: I've seen this fashion also here in Toronto. Jazz, vocals and alike are NOT for equipment testing! If you want to test audio equipment feed it with the hardest! Heavy metal, hard rock, large symphonic orchestras. That will give a proper perception.

Listening to some vocals (so called jazz) that is a good test for midranges at best, but nothing else ...

Absolutely positively agree!!!

Most audiophile listen to 'little girl with a guitar music' because that is all they can do with their systems. No thank you.

beat · « **Reply #79 on:** 24 Mar 2005, 05:04 am »

Quote from: JoshK

Absolutely positively agree!!!

I concur. I havent been to many serious listening sessions but at the RMAF everyone was playing the same or same type of stuff. I do enjoy listening to some good vocals over a glass of wine but it is not much of a workout for any of my systems that is for sure. It was funny when it became my turn to listen to a disc up at RMAF, within 30 seconds the room cleared almost everytime.

Along the same lines, I still don't see what the big deal is with horns and little full range drivers. I understand the principle and the "cool" part of it, but IMO, I just think the sound can really lack unless you are sitting in the one and only sweet spot that hardly allows you to move but a few inches..This is coming from my limited experience though.