Best preamp for and EAR890 / ESL57 rig


Hello folks, I own a EAR890 amplifier, which drives a pair of Piquet restored Quad ESL57 (that in turn sit on a pair of dipole Gradient woofers, driven by an Acurus250 amplifier). I am currently using a pretty good Klyne SK-6 preamp, but I was thinking to move to a tube preamplifier. What do you recommend? My instinct would be to try either the Shindo Aurieges (around $3K) or the new EAR 868 ($5K). Any recommendation? thanks. Giovanni
ggavetti
Ggavetti, take a look at my recent Gon review of the Audio Valve Eklipse preamp, which is in your budget range. In a past review, on the ASL's Flora preamp I discuss my auditioning of a Shindo Labs linestage that was ok, but nothing special in my system. The Eklipse is a world class preformer, beautifully built with German craftsmanship, and competes with virtually anything out their regardless of price. You might want to the Eklipse on your audition list.
Hi
Do you use an active crossover before the main amps and the bass amps? Or are the amp inputs in paralell ?
If the Aragon amps are in paralell with your EAR tube amp, assuming 10K typical input impedance for a SS amp and 100K for a tube amp, your preamp must be able to drive a 9.000 ohms effective impedance, which is not an easy task for regular tube preamps. Bass extension, dynamics and maybe high-frequency extension will suffer.

You will probably have to narrow it down to robust tube preamps with very low output impedance and huge output coupling caps, for example ARC Ref. 3 and VTL 7.5. Look for a wide frequency response spec into a 10K load.
BTW your Klyne preamp has low output impedance.

Also, you probably need a preamp with two main outputs, to avoid those Y adapters.
I hope this helps
C.A.
Casouza, I use the crossover that comes standard with the Gradient woofers. It cuts at around 120Hz. GG
If CD is your only source consider eliminating a pre all together.

THe Raysonic 168 has balanced tube variable output stage. It is so good I sold a $3K preamp
Tweak 1, I tried what you suggested with poor results -- for some reasons the bass is less precise and too loud, even when I set it at the minimum level using the volume dial that comes with the crossover. Also, the EAR 890 offers poor volume controls. Thanks. GG
Ggavetti, you have one of the best tube amps in the world!!!. You would be crazy not to use a EAR 868 to match it's performance!.
i agree. it's an amazing amp...the reason i asked what other audiogoners thought is that i've heard great things about shindos too. by the way, the klyne I own does a pretty good job. there was a recent klyne on sale the other day but i wasn't quick enough to get it. GG
Giovanni,

If indeed the load is 9000 ohms as stated above, then like Teajay a Shindo is not suited for your current system. Most tube preamps will not work. If you remove the subs and crossover, which I highly recommend, then many tube preamps will work well including Shindo and EAR.

regards,
Jonathan
Jonathan, Why would you recommend removing crossover and subs? The main drawback of the Quads is that they can't go below 55Hz. The Gradient woofers were designed specifically for the Quads (well, I could not find the ones designed for the 57. So, I am using those designed for the ESL 63) and allow you to enjoy the best of the Quads (midrange) and a pretty tight bass from 120Hz to 22Hz. Giovanni
Giovanni, I see that your subwoofer's crossover goes between your preamp and the power amps. It has a low pass output below 110 Hz and a high pass output for the main speakers (from the Gradient page).
So, I was wrong about paralelled amps loading down the preamp down to 9K...and Y adapters.
Anyway, I suggest that you ask Gradient or the distributor what is the crossover's input impedance.
If it is lower than 20 K ohms, most tube preamps will not drive it properly. In that case you need to look for a tube preamp with very low output impedance, lower than 500 ohms.
Any decent tube preamp will work wonderfully with a 50K load, but very few match well with a 10K load, typical of solid state devices.
Preamps with "super tubes" do have low output impedance: BAT, ARC come to mind.
The EAR 868 may work, if it is transformer coupled design as the EAR 912. Ask EAR about output impedance.
You will have decent bass if the crossover input impedance divided by the preamp output impedance equals 10 or more.
I suggest a factor of 20 because most tube preamps are limited in the bass by the size of their output coupling caps. The manufacturer may quote (for example) 500 ohms output impedance at 1 Khz, but it is much higher in the bass range, because the output cap's reactance increases at low frequencies.
Good luck
Thanks casouza. The power amp i use for the woofers actually has a 20K input impedance. I will ask Gradient about input impedance. Thanks. Giovanni
Giovanni. I took delivery of an 868 line only about a month ago. I took a chance and bought it on Bob Levi's high recommendation. I love it. It's dead quiet and more musical than my previous ARC Ref. 3.

Output impedance is 600 ohm. It's a balanced design, transformer coupled in and out with de Paravincini's famous transformers. Same circuit as the 912 but without the extras. I wouldn't be supprised if it sounds better than the 912 since less in the circuit. Only 2 tubes to worry about and the 7dj8's are cheaper than the 6dj8/6922 tubes. If you already have some nice NOS 6dj8's, you can use them also. I'm using a pair of 1957 Philips Holland pinched waist 7dj8's. When I have some time, I'll experiment with other tubes but for now I'm not inclinded to. Looks great with the chrome faceplate and knobs.

Caveats: Cheap plastic remote for volume only and no volume readout. But hey, for the money I'm not complaining.

I'm running a playback Designs MPS-5 into the 868 and then into Lamm 1.2 REF. mono's.
Frank
Giovanni,

My preference with Quad 57's is without any subwoofer or crossover. This makes things technically more extended but in my opinion ruins the magic of the original Quad. Balance is the key to a great system and the Quad by itself has balance. The subwoofer ruins this balance. Just my opinion and from years of listening to 57's. Don't focus on the frequency response specs, just listen to the music. The Quad will be much more connective without all the extra gear. I have Entec subs that I tried with my Quads. And Decca ribbon tweeters. All a waste of time and energy in the long haul. I no longer use Quads but did so for many years.
The impedance specs for the preamp are misleading. Things are not so cut and dry as 10X or 20X. Try and see.

Jonathan
I did some research and I discovered that a few Quad folks recommend strongly the Audible Illusions M3A, even against way more expensive pieces of equipment like the EAR 868 and the Shindo Monbrison. I was surprised at first but then I read a few reviews and it looks like the AI is really a sleeper -- you can get one for between $900 and $1,500 and the performance looks really competitive with much bigger and more expensive brothers. Any thoughts? Giovanni
SInce only one person I'm aware of combines a Monbrison with Quads, why not ask him. He actually has heard a Monbrison. look for him here- http://forum.audiogon.com/cgi-bin/fr.pl?vdone&1070840258
And try to listen for yourself. Others opinions are quite meaningless.
Vunyljh, actually i just closed a deal on a monbrison. the guy who sold me the EAR 890 basically said that he tried 7 or 8 preamps (he also had quads, but a more recent model) and thought that shindo was the best (he had a massetto, which is more expensive than the monbrison, but the basic principles should be similar). thanks for your message. giovanni