AudioResearch i50 Integrated with ESL-X?

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beekay

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Greetings friends,
Stuck in a quandary and need help. I live in a country with a dearth of audio equipment. Which basically means I have to fly to the nearest neighboring country to buy any equipment. I was looking to purchase AudioResearch i50 integrated tube amps to pair with the ML ESL-X.

Does anyone have experience with this particular brand? I am concerned about their ability to drive my electrostatics.

Here are the specs:
Power Output: 50 watts continuous from 20Hz to 20kHz. 1kHz total harmonic distortion typically 1% per channel, below 0.1% at 1 watt (Note that actual power output is dependent upon both line voltage and “condition” i.e.: if power line has high distortion, maximum power will be affected adversely, although from a listening standpoint this is not critical)

Power Bandwidth: (-3dB points) 10Hz to 22kHz
Frequency Response: (-3dB points at 1 watt) 7Hz to 30kHz
Input Sensitivity: 1.25V RMS for rated output.
Input Impedance: 100K ohms Balanced, 48K ohms Single Ended
Output Polarity: Non-inverting. Balanced input pin 2+ (IEC-268)
Output Taps: 8 ohms, 4 ohms
Power Requirements: 105-130VAC 60Hz (210-250VAC 50Hz) 252 watts at rated output.
Tubes Required: 2 matched pair 6550WE; 3-6922 (1 input, 2 driver).


Any and all help is deeply appreciated!
 

Robert D

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I think with stats, one of the most important figures is the power output of the amp going from 8 ohm to 4 ohm. It should double. So the 50 watts I'm guessing is at 8 Ohms? If it gets close to 100 watts at 4 Ohms then that's great.
 

beekay

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ARC's reply:
"Summary: On the test bench using a simulated loudspeaker load, the i/50 will produce 50 watts from both the 4, and 8-ohm taps.

In practice, it will depend on the characteristics of the speaker, cables, and AC supply."
I think with stats, one of the most important figures is the power output of the amp going from 8 ohm to 4 ohm. It should double. So the 50 watts I'm guessing is at 8 Ohms? If it gets close to 100 watts at 4 Ohms then that's great.
 

Robert D

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ARC's reply:
"Summary: On the test bench using a simulated loudspeaker load, the i/50 will produce 50 watts from both the 4, and 8-ohm taps.

In practice, it will depend on the characteristics of the speaker, cables, and AC supply."
We have some big tube fans on here, hopefully one will find their way on this thread and advise. If you were able to ask them that question, have you asked them what they think about that amp on your electrostats? The panels you have arent huge, so that makes them easier to drive.
 

beekay

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Looks like a nice amp!
It does but it might turn into a $5000 paperweight if I can't drive them adequately. And knowing my preferences, I will only keep transitioning to larger electrostatics in the future.

Hoping someone can weigh in
 

PVMIKE

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I like you have been interested in tube amps driving electrostats. I have a pair of ESL 11A's.
the first problem is that stats like current more than what hence the doubling of power into 4 ohms. Tubs do work with stats but they require more than 50 watts. For me to drive my stats properly I would need at least 250 watts. With this being said I'm thinking you would need close to the same amount of power, especially seeing as your stats are completely passive meaning you are going to need power for the panels and the woofer. Good luck
 

Robert D

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It does but it might turn into a $5000 paperweight if I can't drive them adequately. And knowing my preferences, I will only keep transitioning to larger electrostatics in the future.

Hoping someone can weigh in
Yeah, I can't say that they will suffice. All i know os for the typical class AB amp, the wattgw output should double when you go from 8 down to 4 Ohms. The speakers they say dip down to 2 Ohms.
 

Robert D

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I power my Prodigy speakers, which have large panels, with an Aragon 2 channel monoblock rated at 200 watts 8ohms, and 400 at 4 Ohms. It's a class AB amp though. Big Dog on here has a nice tube amp, not sure how many watts it has. He is powering the CLX speakers though, and they are much harder to drive than what you use. It's possible 50 watts are enough if the current is strong I think.
 

Brad225

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It does but it might turn into a $5000 paperweight if I can't drive them adequately. And knowing my preferences, I will only keep transitioning to larger electrostatics in the future.

Hoping someone can weigh in
My opinion is, if you are going larger in the ML speaker family then 50 watts will not be enough.
 

Big Dog RJ

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Yes, that's correct. Going through the op- beekay's posts, I came across that larger ML's will be purchased down the line... in which case that little ARC amp is not going to do it, in terns of full potential.

The ARC i50 will certainly drive smaller ML's and in a small to average room that would be fine! However, bigger ML's will require more tube power to control and drive the stat panels efficiently.

Although high powered tube amps may seem overkill when driving ML's hybrid line, due to built-in power amps for bass, those additional watts in power is never really used. For example, let's say you get a pair of ARC's Ref160M's or the Ref320M or even the big 700 series monoblocks, that kind of power will never be used during playback. The human ear cannot continuously engage in playback levels exceeding 100 watts, you'll go deaf! Even on the loudest passages in domestic hifi is only around 45-50w the most. So this is not rock concert levels where 100s of watts are being used... actually 1000s of watts!

Rather, what the much larger tube power amps provide is not just more power but also with larger power supplies, there's more current and higher voltages, plus much more stable voltages. So when you compare a low powered tube amp vs a high powered tube amp, they will both work but with the larger one, you'll get more of everything.

Due to this beefed up power supply design, the amps offer much higher current capacity and highly stable voltages, this is what fully grips the stats and drives them effortlessly. You'll hear the differences straight away going from a 50w tube amp to a 100w tube amp or over.

Yes, I currently use Conrad johnson 125w tube monoblocks but they've also been modded to deliver 60w in Class A. They've been modded to switch into Class AB if that power draw goes beyond 80w leading upto 150w if needed. However, since most of my listening sessions are way past midnight and the room is not a huge room, rather average to large, for this particular set up these monoblocks are perfect driving the CLX's with a full grip.

I've tried the ARC Ref160M's and they superb! However, when it comes to ARC just keep in mind when changing tubes the full set needs to be changed or in matched pairs. ARC is heavily focused on matched pairs and they get the best tubes for this purpose solely matching on gain and plate voltages. So if you're new to ARC, there's an awful lot to learn!

ARC is at the forefront of tube design amplification at its finest and they continue to push the boundaries of this technology through research... it's what they stand for "Audio Research!" If you do happen to get involved with an ARC product, it will be for the long term because their gear is SOTA but will come at a price.

With CJ, VTL, Manley Labs, Jadis, and so on... matched pairs is not too critical, although many owners do replace their tubes in matched pairs or sets of matched quads, depending on the output tube configuration... and this is where things can get quite expensive. So unless you're willing to absorb the extra spend in tube maintenance... I would not recommend high powered tube amplifiers.

Hope that helps!
Cheers, RJ
 
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Big Dog RJ

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BTW, Brad225 uses ARC's 700 series monoblocks to drive his CLX's. This is serious power from one of ARC's SOTA in amplification. They are superb in every element of high powered tube design.

I would pm Brad to learn more about ARC gear because only an ARC owner can share with you the intricate details of this fine gear.

I can go on and on about conrad johnson but it may not be to your liking... I've used CJ gear since I discovered what tubes were, and that's going quite a while back to around 3.5 decades. It's less cost to maintain and improvements can be made along the way, provided you have access to a highly skilled tech. Whereas with ARC you have to stick with their design, there's no mucking around..
ARC's service is also top notch! So basically you're getting your monies worth.

Hope it goes well and let us know what you decide on at the end.
Cheers, RJ
 

audioxcel

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I have had Sequels since bought them in 1987 (3 panel changes since then and one woofer change). I used a Tandberg 200 watt solid state amp after trying Carver, Bryson, and Bolder amps until I bought an ARC Classic 60 in 1995.

I have used ARC amps with my Sequels for many years. My first was a Classic 60 (hybrid). It could drive my Sequels in a 16x24' room to volumes that were "too" loud for any reasonable listening except to show off loud rock music. The CL-60 sounded great especially with KT-88s which improved the bass depth and control. It kept up with an ML No. 23 that I had for while except in the sub 25 Hz range where the Levinson had better control.

However, the Levinson sounded cold and sterile by comparison with long term listening so I sold it. Not something that jumps out at you because it is a wonderful amp but something that gradually creeps up with long listening sessions. And, once you notice you will always notice. It may be too clean for its own good.

I currently use an all tube ARC D-70 MkII which is older than the CL-60 but I like it better. It just feels and sounds more natural.
A word of caution though, the D-70 is a biasing nightmare. I have to take it to a tech every time I change tubes.
The good news is that the D-70 only uses four power tubes unlike the CL-60's eight,

I also have an ARC VT-100 that is my back-up amp. It sounds similar to the D-70 MKII (maybe a bit better deep bass) but this doesn't matter much to me because I also use a Mirage BPS400 subwoofer. The VT-100 is a behemoth that overhangs my rack. It is an even bigger nightmare to bias too.

I haven't listened to ARCs newer amps but suspect that they would also be up to the task.
 
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twich54

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My opinion is, if you are going larger in the ML speaker family then 50 watts will not be enough.

I'm in agreement with Brad and with that being said for tube amps to satisfactorily drive stats you need ones with superb bandwidth. For the one area that lesser designed and built tubes will disappoint is high freq roll-off.

For sure Brad can attest to the ability to drive stats with his superb ARC amps, as can I when I drove my Spires with a pair of Rogue M-180 mono blocks. I am a true 'fan boy' of Rogue gear and their ability to punch well above their respective price point.
 

Robert D

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I'm in agreement with Brad and with that being said for tube amps to satisfactorily drive stats you need ones with superb bandwidth. For the one area that lesser designed and built tubes will disappoint is high freq roll-off.

For sure Brad can attest to the ability to drive stats with his superb ARC amps, as can I when I drove my Spires with a pair of Rogue M-180 mono blocks. I am a true 'fan boy' of Rogue gear and their ability to punch well above their respective price point.
I've also heard great things about Rogue. An audiophile store I shop at here sells them.
 
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