[bhobba]

Hi Hugh and All

I have had some recent discussion on some forums I frequent about my interest in Hughs amps like the Soraya.  I am thinking of using them with speakers that are 87db efficient (Aether Audio's Timepiece Mini).  Here is some of the responses I have received: 'The speakers are rather unefficient, that requires lots of power to sonorize a medium room (the Soraya is only 105W).  I dont think you are up to a big disappointment, but a not ideal match is very likely.'

I must admit this has left me scratching my head a bit.  My math tells me at that efficiency you can easily reach levels of 90 db with plenty of head room to spare with a Soraya. Listening even at that level for more than 40 hours a week will lead to ear damage.  Now of course no one really listens to their stereo system 40 hours a week but it is sobering to know this.  I have discussed this issue quite a lot on other forums and they seem to think more and better amplifier power is good.  I am of course sure of the better power bit but the more stuff still has me a bit flummoxed.

Interested to hear what others on Hughs forum think.

Thanks
Bill 

[lonewolfny42]

Bill.....

I don't think you will be disappointed in the Soraya and Mini combo....I run my Minis with a 100 watt Nirvana+....sounds good to me.
And the Soraya is a better amp...I've heard Occam's/Paul's many times....and when it first came out at RMAF in Hugh's room...

The larger SP Tech/Aether Audio models....they soak up the power.

[Occam]

Bill.

The Soraya sounds like no 100 wpc I've ever heard or owned. Its a veritable dominatrix of an amp, she can slap you around, but can be ever so gentle....
And with Hugh's new power supply, I can only fantasize. 

FWIW,
Paul

[Tliner]

Hi All,

I agree with Paul regarding the performence of the Soraya.

From a personal experience a few years ago when the VSonics were in development, only about 88 db efficient then, and I had a LifeForce 100. I was asked at short notice to provide music at the local sailing club. They were having a dinner dance and the band was stranded on the other side of Port Phillip Bay when they missed the ferry. The room is about 90' by 45' and had about 300 people packed in. The LifeForce was never turned up beyond the 2/3rd mark as the dinner goers could not hear them selves think if more volume was used. Aspen 100w+ amps have plenty of power! In fact that evening the sax, clarinet player turned up and played along with the CD's. He exclaimed that the amp and speakers did a really fine backing job when they were turned down a bit as they could easily drown him out.

Don't worry about a 100w LifeForce or more particularly a Soraya being a bit weak in the power dept.

Cheers,

Laurie

[LM]

Bill,

I run quite large Vandersteen 3A Sigs (3 or 4 way depending on your definition) variously quoted at 87 or 88 db with my Soraya.  They are nominally 6 ohm dipping to 4 ohm speakers with a first order crossover reputedly hard to make sing and it handles them with ease.  The Soraya runs lukewarm, never hot however hard I use it and can supply 105 watt into 8 ohm and 205 watt into 4 ohm for great punch.  This is not some overly current limited/protected amp or receiver.  Be at ease with your choice or there is is the new 150 Watt amp due in the near future to consider though I doubt for one moment that would be necessary. 

[Rhythm Willie]

I have run 100n+'s and Soraya 1 amps with Vaf Research I93's Mk 1's which are (to some peoples opinion)a difficult load as although around 89db efficiency, dip to 2 ohms at some frequencies and both amps only cruised to establish loud clear music in my largish loungroom for hours on end. I just can't get the heatsinks more than a slight feeling of warmth even in the middle of summer, I have so much headroom I feel I could run a largish professional line array with these amps.

I keep getting convinced (as I have some very powerful "other" amps that quoted power output and massive transformers,capacitance etc can be very misleading way to match amps and speakers in the real world.

[bhobba]

Bill.....

I don't think you will be disappointed in the Soraya and Mini combo....I run my Minis with a 100 watt Nirvana+....sounds good to me.
And the Soraya is a better amp...I've heard Occam's/Paul's many times....and when it first came out at RMAF in Hugh's room... :thumb:

The larger SP Tech/Aether Audio models....they soak up the power.

Thanks very much for that Chris.  I am now however tending more towards Hughs new amp the Maya.  I get one great evil (in a good way ha ha) feeling about that new amp of his.  Oh and its 150W.  Eagerly awaiting Hugh releasing full details.

And of course thanks to all the others that replied.    :thumb: :thumb: :thumb: :thumb: :thumb:

Hey does anyone know why I am not getting the thumb icons displayed?

Thanks
Bill

[Greg Erskine]

I have run 100n+'s and Soraya 1 amps with Vaf Research I93's Mk 1's which are (to some peoples opinion)a difficult load as although around 89db efficiency, dip to 2 ohms at some frequencies and both amps only cruised to establish loud clear music in my largish loungroom for hours on end. I just can't get the heatsinks more than a slight feeling of warmth even in the middle of summer, I have so much headroom I feel I could run a largish professional line array with these amps.

I keep getting convinced (as I have some very powerful "other" amps that quoted power output and massive transformers,capacitance etc can be very misleading way to match amps and speakers in the real world.

Hi Rhythm Willie, I've been tempted by the VAF Research I93's Mk 2's (3 ohm), but I only have AKSA 55N+. Have you tried yours on the smaller AKSA? The AKSA 55N+ works well with my VAF DCX Gen IV's (6 ohm).

Would you buy the VAFs again?

regards

[bhobba]

Would you buy the VAFs again?

At the time I was getting my last upgrade about 13 years ago now the VAF's were all the rage since they had a speaker featured in Electronics Australia at the time.  I did a lot of research into them at the time and while they are good the conclusion I reached was other speakers were better for the money and got Axis LS88's.  Nowadays I hear there is a trend to po po VAF and while I am not in that camp I still believe others may perhaps be a bit better eg Equinox:
http://www.equinoxaudio.com.au/products/speakers/index.php
http://www.equinoxaudio.com.au/about/testimonials/i-93vsjupiter.php

Thanks
Bill

[Greg Erskine]

Thanks bhobba,

If I remember the Equinox/VAF saga correctly, this comparison was spammed on many forums at the time. Even if it has some thruth, I thought at the time that someone had an agenda, plus, I don't think posting such a comparison on a vendor's site is quite ethical. I really would rather purchase locally, you know support the local guy, but I am still hesitant.

At the same time, on a local hifi newsgroup, VAF was attacked by a one particular individual. It was interesting to see how just a couple of people could sway opinion. A good lesson learnt.

regards

[AKSA]

Greg, Bill,

Phillip Vafiadis is a forthright fellow with huge energy who is involved in many community projects in South Australia as well as running VAF Research, which also has a retail business at front of house.  He is fond of the radical approach, and not afraid to pour tens of thousands into development of his products.

Such people are not always well regarded in Oz because of our tall poppy syndrome, and so it follows that many will have Phillip in their sights.  Take it all with a grain of salt.....

BTW, Rythym Willie, aka Dennis, really knows the man and his companies well.  Dennis, do you have chapter and verse on this situation, am I close to the mark?

Folks, thanks for all the nice things said about the AKSA/Lifeforce/Soraya.  This latest, the Maya, will put blood on the walls - it too goes very loud and nearly raised the roof at the Melbourne Audio Club last Wednesday night with 90dB/watt/metre speakers (the VSonics).

Cheers,

Hugh

[Rhythm Willie]

Hugh,

I usually tend to sit back and just get amused at some posts on various forums, but since you asked.

Yes there is very much a "tall poppy syndrome" regarding companies as successful as Phillip,s and I think the rare criticism of Vaf products is that with probably the largest R&D programme in Australia, the one thing they won't compromise on is accuracy - this can always be a two way sword, don't set the speakers up right (positioning/partnering equipment etc) and badly recorded CD's can sound very "badly recorded".  Yes they could roll off the highs and boost the mid bass like some manufacturers do and please a lot of people, buuuutttttt.

Phillip is the most ethical (he never criticises other products) successful business person I know(look at Zen Technologies) and have never caught him out with any misinformation. He has a brilliant mind and as you said is on a number of boards including the SA Museum, Premiers Advisory, Young Entrepeneur of the Year Award etc.

He still has a passion for his speakers and still can't resist talking to and advising people who walk into Vaf's showroom.

I continue to listen to many hi end speakers on a regular basis both in Adelaide and on overseas and interstate trips and none of them has convinced me to change speakers in my setup yet.  They sound wonderful with my valve pre and your amps.

One huge hint with the I93's is to always position them way out from the back wall of your room to let that big bass port at the back breath, it makes a massive difference to their bass delivery putting them into a different league than most speakers.

[ginger]

There is a useful "Rule of Thumb" for required amplifier power.

For a moderate to largish size listening room and being able to listen at highish volume levels when occassion demands then you need to be able to achieve around 102db sound level at 1m.

Speaker Efficiency is quoted in dB/W/m
so when you see a figure of say 89dB quoted it means that a 1 Watt amplifier will produce 89dB sound level at 1m from the speaker.

Now when we talk about dB here we are talking POWER and not voltage so doubling of power means +3dB.

Create a little Table:
For an 89dB/W/m speaker
1 Watt => 89dB at 1m
2 Watts => 89 + 3 = 92dB at 1 m
4 Watts => 95dB
8 Watts => 98dB
16 Watts => 101dB
32 Watts => 104 dB

To reach that "Rule of Thumb" sound level of 102dB from 89dB/W/m sensitivity speaker you need an amp with between 16 and 32 watts - say around 20 Watts.

Now I use the original VAF DCX speakers (not the latest Gen IV version) with a sensitivity of 95dB/W/m

Doing the above again for 95dB/W/m
1 Watt => 95dB
2 Watts => 98db
4 watts => 101dB
8 Watts => 104dB

I occasionally drive then with my AKSA55Nivarna+ but most of the time I run them on a 10 Watt per channel EL84 Ultralinear Valve Amp and the best I have ever heard them was on a 8W per channel 6V6 Ultralinear Valve Amp.

That is why the audio nutters who insist on using a Single Ended triode 300B amp (or similar) which is capable of no more than 8 watts BUT needs to be kept to say 4 watts or less to keep distortion at tolerable levels, use horn loaded speakers with sensitivities of 98dB/W/m or even higher.

Cheers,
Ian

[bhobba]

Hi Ginger.

I 100% agree.  Also spot on about guys who insist on 300B triode amps.  They sound great for sure but I am not sure insisting on them is essential to get great sound - in fact I am pretty sure its not.

But with my money situation slowly abating I may just give one a whirl.  I listen at very low levels anyway do even with the relatively inefficient speakers I am looking at I would probably find it listenable.

Thanks
Bill

[poseidonsvoice]

There is a useful "Rule of Thumb" for required amplifier power.

For a moderate to largish size listening room and being able to listen at highish volume levels when occassion demands then you need to be able to achieve around 102db sound level at 1m.

Speaker Efficiency is quoted in dB/W/m
so when you see a figure of say 89dB quoted it means that a 1 Watt amplifier will produce 89dB sound level at 1m from the speaker.

Now when we talk about dB here we are talking POWER and not voltage so doubling of power means +3dB.

Create a little Table:
For an 89dB/W/m speaker
1 Watt => 89dB at 1m
2 Watts => 89 + 3 = 92dB at 1 m
4 Watts => 95dB
8 Watts => 98dB
16 Watts => 101dB
32 Watts => 104 dB

To reach that "Rule of Thumb" sound level of 102dB from 89dB/W/m sensitivity speaker you need an amp with between 16 and 32 watts - say around 20 Watts.

Now I use the original VAF DCX speakers (not the latest Gen IV version) with a sensitivity of 95dB/W/m

Doing the above again for 95dB/W/m
1 Watt => 95dB
2 Watts => 98db
4 watts => 101dB
8 Watts => 104dB

I occasionally drive then with my AKSA55Nivarna+ but most of the time I run them on a 10 Watt per channel EL84 Ultralinear Valve Amp and the best I have ever heard them was on a 8W per channel 6V6 Ultralinear Valve Amp.

That is why the audio nutters who insist on using a Single Ended triode 300B amp (or similar) which is capable of no more than 8 watts BUT needs to be kept to say 4 watts or less to keep distortion at tolerable levels, use horn loaded speakers with sensitivities of 98dB/W/m or even higher.

Cheers,
Ian

Ian,

I do agree with what you've said but:

1) Efficiency numbers are less accurate than sensitivity numbers (i.e. 2.83V) since it takes into consideration the general impedance of the loudspeaker. Manufacturers who say 95dB efficient with a 4 ohm loudspeaker are hiding something from you!

2) These efficiency and sensitivity numbers are only stated for playing one speaker at a time and most of us I believe listen in stereo not mono.

3) These numbers are at 1 meter or about 3 feet away and most people don't listen at 3feet away unless its near field monitoring. For point source monopoles (i.e. not linesources), those efficiency and sensitivity values DROP by 6dB for every doubling of the distance that the audience is. This generally becomes about 10dB less for about 10 feet away.

4) Rooms in general give back a little in midrange to high end on the order of about 1-2dB unless there is heavy drapery.

5) In smaller rooms (i.e less than a cathedral/amphitheater size), large amounts of gain can be available below 200Hz, i.e. below the Schroeder frequency. Room modal issues DO exist causing peaks and dips on the order of +/- 30dB resulting in an inaccurate bass line unless room treatment, multiple subwoofers and/or equalization is used. So music in general does sound 'louder' in the low end depending on room size but may not necessarily be smooth.

The devil is always in the details 

Anand.