ER Audio Electrostatics - QUAD ESL beaters.

[Toppsy]

I have been asked by a new member to this forum to pen this new thread, so before I start, welcome to our little world MICHAELPAGE26.

As older members of this forum will know I have built the ESLIII kit and Acorn Kit and have a pair of One Thing Audio refurbished Quad57ÃÂ*s. Now the ER Audio Acorn ESL versus the older kit ESLIII, (that is still available), is it a better sounding speaker than the older kit, the ESLIII. In a nutshell I have to say YES I think it is and to my ears both better the 57ÃÂ*s.

Before I progress to sound differences I think a little on the design of each speaker might be of interest.

For those not familiar with these electrostatic speakers they come in kit form from ER Audio in Perth Australia. Rob Mackinlay (a UK expat) has been designing ESL speakers for around 10-years now and has produced several designs in kit form for the DIY builder.

The Acorn consists of a stacked pair of panels with discreet bass, midrange and treble sections to each panel. Each Acorn panel measures 925mm high x 450mm wide. One panel is stacked vertically above the other, thus making then 1850mm high! Low frequencies are bled from the mid and treble sections by discreet inline resistors from the audio transformer. Similarly high frequencies are bled from the bass panels. The Acorn is the front pairing speakers to a full 5.1 surround sound ESL system. The rear effect speakers consist of a single panel version of the mains. There is also a curved front ESL in the pipeline.

The ESLIII consists of 2 x 225mm wide full range panels with a 75mm wide treble panel between. The panels measure 1200mm high. Each panel is fed the full frequency range through the audio transformer. The 2 bass/full range panels are angled to give larger dispersion of soundstage.

Now to sound comparison:

To my ears of the three pairs of electrostatic speakers I own, the Acorns are by far the best sounding of the three. One does not loose ambience of soundstage whether sitting or standing. They throw a big convincing soundstage with fantastic transient attack and produce good deep, accurate and low bass. I think those attending the last EggFest would agree these speakers can deliver bass? These are the best sounding ESLs I have heard to date and well worth the extra cost over that of the ESLIII kit. As a comparison the ESLIIIs are a little lacking of convincing bass, but match the Acorns in the midrange and nearly match them in the high frequencies. They benefit from a subwoofer. They do not throw quite as large a soundstage as the Acorns and one looses ambience if standing. But they are still better sounding than the Quad 57s to my ears and both the ER Audio kits do not suffer the single directionality of the Quads. Move a little from the sweet spot of the Quads and you loose one speaker, not so ERs. In fairness to the ESLIII these were designed around high power solid state class ëAÃÂ* amps and seem to be more amp dependant than the Acorns. I have heard mine driven by a Sugden A21a amp and this gave amazing bass in comparison to my WAD 6550 amp but lost out to the better midrange from the 6550.

So Michael:

NO the Acorns do not need a subwoofer for normal hifi use.

YES I think they do justify the price difference over the ESLIII, especially if you consider the cost of adding a decent sub woofer this speaker will take you to the cost and above that of the Acorn kit that doesnÃÂ*t need one. Especially if you go the active sub route I experimented with. And then there are the issues of getting the sub(s) to react as fast as the panels which IÃÂ*ve not yet convincingly achieved.

These IÃÂ*m sure are QUAD beaters and represent value for money. I doubt they would be outperformed by the new Quad 2805 and 2905 speakers that retail in UK for £4500 and £6000 respectively. The Acorn speaker kit will cost from around £1550 in the UK which is less than a third the cost of the new 2905ÃÂ*s! And remember QUAD GMBH in Germany are making new 57ÃÂ*s for the princely sum of £6,300 or if you want a pair of new 63ÃÂ*s these will set you back £7,500!! What more can I say.

Presently IÃÂ*m enjoying listening to the Acorns through the Yarland 845SE amp featured elsewhere on this forum. I have done the same upgrade mods as posted by GLOBAL. With this amp they sound simply stunning and only delivers around 16W per channel.

By-the-way, thanks GLOBAL for all your help in modding the Yarland.

Regards

Colin (aka TOPPSY)

[Global]

Very welcome Colin!

Glad the Yarland is pushing the electrostatics in a satsifactory manner.

Mark

[Toppsy]

Out of interest does any member living within travel distance from Rossendale, Lancs. have a pair of Quad 988 or 989 or Martin Logan's that they would be interested in me bringing over my Acorns for a comparison listen? Could be interesting as I've never heard either of these quads and would love to know how the OZ DIY kit compares.

[michaelpage26]

I would like to thank Toppsy for opening this thread for me, as it was a little bit difficult to be with you in Eggfest3 (I don't live in UK) to make up my own opinion regarding the Er-audio Acorns.
Also the idea of a comparison between his Acorns and commercial designs like Martin Logan Vantages,Aeons,Ascents etc, and Quads 989,988,2805 and 2905 , would really help future owners including me. Also comparision between Acorn and conventional designs would help much, too.
I would like to thank everybody in this forum for his interest to my request, and I hope that this thread will gather as much as possible information and many opinions about the Acorns.
Any opinions about advantages but especially shortcomings of Acorns are really appreciated.

Best Regards
Michael

[Toppsy]

HI Micheal,

glad you got your postings issue sorted and welcome.

I have one of the forum members coming around to my house tonight for a listen to the acorns. Surprisingly he only lives down the road from me.

He has listened to Quad 989's before, through the WAD 6650 amp at the Bristol Show, I think, and is eager for a comparison listen, though he will be comparing from memory. I have a WAD KaT6550 as well as my 845SE amp.

I will ask him to post his opinions so you have an independant assessment.

I'm sure some of the guys who attended the last eggfest may wish to post their own opinions?

Regards
Colin

[Stratmangler]

Hi Colin (Toppsy)

Very many thanks for the listening session around at your place last night - I enjoyed myself immensely !

I would first like to say that I applaud the standards of construction and finish you have attained with your Acorns - I have seen commercially made products that do not come near to your efforts for presentation.

As for the sonics of the Acorns, I can honestly say that it is a pleasure to listen to such a wide bandwidth design.

A lot of folks reckon that electrostats need to be bolstered up with subwoofers and things - that relates only to inferior transducers, and although revolutionary in their time I am of course thinking of the Quads.
And that also relates to the current Quad product (although I haven't heard the stuff they've just released the same probably still applies)!

I've rarely heard a "stat" equal the lower register power of a box design - the Acorns do just that.
And then you've just got a beautiful seamless journey up to the limits of the audible frequency range.
And the Acorns image well - you're not as tied to the "hot spot" anything like as much as the Quads.

Of your two amps the Yarland gets better results with these speakers - the WAD design seems to be a little bit uptight and proper in comparison.

The Yarland/Acorn combo cuts the mustard, and that's a fact !

The only downside, as far as I can make out, is that one becomes accutely aware of things such as poor vocal mic techniques used in the studio - it takes a little mental readjustment to filter poor engineering techniques out and concentrate on the overall recording and performance(s).

Once again, thanks for a great evening.

Chris

[Toppsy]

Hi Chris,

glad you enjoyed the evening, it was good to have someone elses opinion of how these speakers sound in a real home environment. Your views just confirm my own opinion of these speakers. It is difficult to get varied opinion when mine are the only pair in the UK!

As you rightly comment the only downside of listening to very revealing speakers like the Acorns is they show up how bad some recordings are. But the other side of the coin with good recordings like the Annie Lennox album "BARE" sound simply stunning.

I have now reduced the cabinet height by 90mm. This has made them a little less intimidating. I can reduce this further by 100mm or so by having the audio transformer and EHT supply mounted externally. However to do this requires major surgery to the cabinets. May be worth while making some new cabinets as this would reduce the overall height to a little over 1800mm. Much more acceptable to your average wife/live in lover.

Colin

hi, i also had the pleasure of listening to colins ER Audio electrostatics last night.

Now bear in mind these are the only electrostatics ive heard and i must admit for the first few minuits (sp) its quite odd how different they sound. Im so used to the presentation of box speakers it was almost unsettling for the first 10 mins
We started with the ESLIII and i was impressed, we spun a track or two of led zeppelin and it sounded very nice indeed, they even coped well with some reasonably pacy drum and bass (i appologise if that track isnt to you usual tastes )
However when we listened to pink floyds granchester meadows something seemed different. What did you think colin? Im very used to this track but it seemed a little thin and it was the only track that didnt sound better through these than it does with my wd25as. I wouldnt say it sounded worse though!

Onto the acorns, they just blew me away!!!!!!!!! What can i say, ive not heard anything like it, they made me smile almost constantly. Very Very good.
So open, just a nice big open sound that just hangs in the air, superb bass, well, superb everything really. What really did surprise me was the detail of the bass notes rather than 'just bass'
Going back to granchester meadows, it sounded superb. The acorns have more body, sound fuller and smother without beign warm, just full and detailed. I really cant fault them.
I know im reasonably inexperienced, but i just dont really see how it can get much better than what i heard last night. I think i need to get saving. There amazing value in my eyes (ears)
Thank you for the opertunity, i think im going to be hooked on good esl's

We also tried them out with my kel84 and it seemed to cope with the task very well. Maybe not quite as good as the yarland which gave a little more bass and was generally just a little smoother. A swap for some mullard ecf80's helped though.

Once again, thank you for giving up your time for me, much appreciated.

[Toppsy]

Graeme,
pleased to hear to enjoyed the evenings listen and you were very welcome.

This is what the forum is all about being able to share the pleasures of ones efforts. I'm sorry if I've sent you on a tangent to hifi nivana, but you can perhaps understand why I am reluctant to go back to box speakers. The only box speakers that I've heard with conventional cones that come close to the ESL transparency is James's OB Quazars. Now I could live very happily with these if I didn't have my electrostatics.

Now to that Pink Floyd track. I know from where you are comming and agree with your observations. Since my recent recovering of the panels of the ESLIII's with a new thinner mylar film and clear conductive coating I have noticed a slight increase in brightness over the original sound. This I think is the reason for it sounding a little thinner and something I have noticed on a few of my records.

I think I am going to replace the pp signal caps in my WAD6550 power amp to copper PIOs and replace the tung sols with svetlana C's. This I'm hoping will mellow out the brightness. If this does not fully redress the balance then I may recover again but using the original slightly thicker mylar.

I have the original standrd 845 valves to try out in the Yarland. These are less dynamic than the ones you litened to last night and may hepl with better synergy to the ESLIIIs. I will try this out tonight.

I have decided to try and get a half size Acorn speaker (ie single panel version) ready for EggFest4 in November. So I'll have to get there early so I can bag a place in the small room. I doubt these will perform well in the main hall.

[Toppsy]

Having pondered a little and discussed with a colleague on the slight over brightness of the rebuilt ESLIII panels it may be I am now getting too much treble now which is masking some of the midrange. I may need to bleed off some of the EHT voltage to the central treble panles.

The treble panels do not require the same amount of step up voltage as the bass/midrange panels. This is how the EHT charge to the panels is set-up in the Acorns. At present all three panels are fed from a single EHT take off point. I will therefore experiment with tapping off the treble EHT at an earlier point on the step up circuit and report back my findings. I can also experiment by bleeding off some of the upper frequency audio signal to the bass/midrange panels also as per the Acorns. All this and a pair of half size Acorns before EggFest4!