Ypsilon Aelius II


Anyone with a great audio system knows that a key part of achieving that is the synergy between all the pieces. And this is true for families and businesses as well. This page you are reading now includes a rare opportunity for someone to reap the benefits of High End Zone's system adjustments in relation to the crossover of family and business. We had a major health crisis in the family last year and our son just started college. So, we are downsizing our stereo for the time being by selling this pair of Ypsilon Aelius II amplifiers which have been the heart of my personal system the last two years. When the time is right, we plan on replacing them with the Ypsilon Phaeton integrated. Both of these are exceptional products with many great reviews. I'm sure I will go back to monoblock amps one of these days when I can, as I'm just a monoblock kind of a guy. But having heard the Golden Ear Award winning Phaeton, I am sure I could be just fine with that for the time being and in any case I have to put my family before my stereo- so there it is. My loss is your gain and all of that.


These are our personal amps, we do not have a store, they have been professionally operated and well cared for. Rest assured, they are under warranty for 2 more years and in perfect condition. This is not like where you buy some beat up piece of demo gear out of a store! Beyond the use in our home, we have brought these amps to 2 audio shows. Both times we won best room of show / best sound of show! Batting a thousand, as they say.


These amps are just incredible. New, the Aelius II Amplifiers retail for $39K,
today you can purchase them for $25K plus freight.


See below for more info and links to reviews, a video from the LA Audio Show 2017 room, shown above, where we won multiple awards for that setup (Aurender servers, Ypsilon electronics, Perfect8 loudspeakers).

Here is a view of the artistically beautiful top of the Aelius II which also keeps it nice and cool as part of our setup at T.H.E. Show 2016 where we featured Ypsilon Electronics, Acoustic Zen speakers, Aurender music server, Verastarr cable loom.

In our home, we use the Aurenders and proudly sell those too. We would be happy to help you integrate one into your system. In many cases we will pay, or help to pay, to digitize your CD collection if you buy your Aurender from us.

The only amps I know definitely beat these Aelius II's are the Ypsilon SET 100 Ultimate monoblocks. But for $125,000 a pair of course they do!

(Ypsilon SET 100s seen above supporting the Perfect8 Points and below, as seen from above)
Feel free to contact us at 575.535.2280 or through email if you are in the market for the best Single End Triode Monoblocks we have ever experienced.

That said, while the Ypsilon SET 100's are our best selling amp for those who have the money to get whatever they want, the Aelius II's have much more power. They drive the most difficult speakers with ease, 1 ohm impedance loads are no problem at all. These are just exceptional amps.

Every piece of Ypsilon gear is personally tested by their founder and CEO before it ships out. He listens carefully. If something doesn't meet his standards, he rebuilds it. We know of no other company that pays this much care to what they are doing. And the results are simply magical. Not one of our clients who have bought Ypsilon over the years has ever left the brand! They have sometimes upgraded to newer gear from Ypsilon. But they never got rid of theirs without getting new first. That says a lot. No other brand we sell that we could ever say this about. Just extraordinary. If you want the absolute best electronics you can get, then Ypsilon is it. Best for the money. Best in terms of sound quality. Best in terms of reliability, knock on wood.


This pair of Aelius II's were specially built for us and have some custom upgrades. I think they are the only pair ever built with these upgrades, definitely the only pair in the US. They were built and tuned with Synergistic Research top of the line fuses in them instead of the stock fuses. They have had NOS Mullard rectifiers added to them.

And saving the best for last, they have an extra set of binding posts (very expensive binding posts, made by WBT I believe) for true bi-wiring of your speakers. So I can run the amps with 2 fully separate pairs of speaker cables going to my speakers. But of course, if you don't want to do that you can also just use a single pair as normal. Either way, this feature will add value to the amps for you and permit different system configurations to be used in your home.

The Aelius II's are a huge upgrade in technology over the original Aelius or Aelius I amplifiers. You see a lot of the Aelius I's for sale and of course those would sell for less than these Aelius II's which are perfect, dealer demo amps that are under factory warranty, come with all original items and factory wooden crates in great shape, plus have thousands of dollars in custom upgrades built into this pair alone. But aside from the Aelius I's being much older, the cost to upgrade to Aelius II would be very large due to the major changes they implemented in the amps. Of course you could just buy Aelius I, if that was your budget and not upgrade it and that is a nice amp for sure, nothing against it. It's just not a balanced design as these are (it does have XLR's, but the circuit is not balanced) and it lacks the refinement and upgrade on the Aelius II's. This is an opportunity to get about 1/3 off a demo pair and still get the latest model and warranty.


Another big advantage is that you can enjoy these immediately, they are already fully broken in. Because of the transformers used in Ypsilon gear they take much longer than most gear does to break in. The time is certainly worth it and I encourage you to give Ypilon a try whether you buy these or brand new. But definitely, this is one of those few cases in life where the cheaper item actually IS better because it will sound better much sooner and has the other unique upgrades. I think there are about 5 pairs of Aelius II's in the US and these are one of the only ones that were originally built as Aelius II, not upgraded from an older amp. Plus, some of the other ones are not even broken in yet as that does take so long.


So these can be yours for $25,000 plus freight. If you want a full system of Ypsilon as many of our clients have, then just talk to me and I will see if I can earn your business for the whole system you need whether you need a preamp, phono stage, DAC, CD transport, or whatever. If you need speakers or items from another brand, let us know. We offer installation throughout North America and can arrange shipping worldwide. These amps are 120V but we can have the voltage converted if need be. Please call or email us for more info or if you'd like help with any system design questions, etc.


Here is some of how Ypsilon founder and CEO Demetris Backlavas describes the design of the Aelius II's and the substantial upgrade they represent over the original model.

"Aelius II is a push-pull hybrid monoblock power amplifier using only two gain stages with no overall feedback, providing power to drive real world speakers with unmatched transparency and musical involvement.

"The first gain stage is implemented with a tube, operated in single-ended class A, transformer coupled to the output stage. By using a transformer we avoid using an additional gain stage, so transparency and purity of the signal is preserved.

"For this purpose a wide bandwidth (10-75 KHz) transformer is made, developed under extensive listening tests and measurements. The bandwidth of the transformer defines also that of the amplifier.

"In Aelius II, a recently developed input transformer is added that extends the purity of the signal path even further. It also gives the opportunity of a balanced input in the amplifier, adding versatility of using longer interconnect cables.

"The output stage uses components of the same polarity (N-channel), working in the same topology. The output of the amplifier is symmetrical so both output connectors, plus, minus, carry signal in opposite phase.

"Great attention was paid also in the power supply design. It uses high current inductors for smooth and quiet filtering.

"Aelius II is most certainly a revolutionary product having a unique set of features, refinement and transparency, sound purity, endless power, outstanding design, unmatched build quality."

While the Aelius II amplifiers include improvements to the original Aelius, the foundations which made Michael Fremer report the following, remain intact:
"The Aelius amps were just right if you like a tight, fast, nimble top-to-bottom ride, if you like sounds so transparent it's almost alarming, convincingly yet not analytically precise transients, and three-dimensional imaging—all without paying the high price of too-sharply-defined edges or a clinical, soulless, harmonically bleached sound.
"The Aelius is yet another spectacular sonic and technological achievement from Ypsilon Electronics. I remain impressed by everything they do.
" (full review here)


At the LA Audio Show 2017, Ypsilon Electronics were paired with Perfect8 loudspeakers and Aurender servers. (see top of the page photo) During the show, we had the pleasure of hosting Jason Victor Serinus of Stereophile for a listening session and his review includes the following: "Especially impressive was a 24/96 track of mezzo Jamie Barton singing Sibelius, where the system conveyed the huge expanse and changing dynamics of her stunning voice better than any other system I've encountered. When Barton opened her one-in-a-million, Golden Age voice to full capacity, you could literally hear it expand in the room. Wonderful." .... "It is no wonder that two of the Ypsilon products have received Class A ratings in Stereophile's recommended components."


Ypsilon Electronics are by far the best electronics that we have had the privilege of listening to and working with. Feel free to visit our web page where you may listen to and watch a video of one of our LA Audio Show's award winning rooms, as well as other video related to Ypsilon Electronics.

The retail price for a new pair, without the upgrades these have, is $39,000. This pair of Aelius II's are available to you for $25,000 + freight. These Aelius II's have thousands of dollars worth of unique extras on them. The fuses and NOS tubes you could easily add for a price but the extra outputs which allow for true bi-wiring are really great and make a huge difference in this pair vs. any other pair.


Because of the long break in time for Ypsilon gear, typically at least 6 months though it will depend how you use it, this really is one of the rare times in life that saying "better than new" actually applies. Because if you order new Ypsilon, not only do you pay more but you wait at least 3 months to get it, sometimes up to 6 months, depending on the line ahead of you, and then you wait for another 6 months to break it in. So, you're at least 9 months behind getting to the sound quality you could have a week or so from now if you bought our amps. This pair is immediately ready to bring your system to a new level.

These amps are functionally perfect obviously, have never been fixed or had issues of any kind, never blown a fuse, etc. They are packed in original custom boxes and crates in nice shape with manual, etc.

These amps will come with 2 years of factory warranty, though I should mention that Demetris is known for taking care of people even after warranty and if you ever needed anything, we would of course go to bat for you personally on that. We handle all service requests within 1 business day and we take care of repairs at no markup for the life of the gear because we don't want to profit if anyone ever has trouble with a piece of gear we sold him. And we've never known any Ypsilon to need repair, but if it ever does, we will be there for you. From what clients tell us, our approach to service is pretty unique.

As mentioned above, this pair of Aelius II’s are available to you for $25,000 + freight. If you choose to pay via PayPal, we’d ask you to cover the fee which is 3% for Domestic and 4% for International. We are also able to receive funds by Bank Wire and would be happy to help you arrange that. Please feel free to call us at 575.535.2280 or email us if you have any questions. Thank you.

Ypsilon Electronics AELIUS II Push Pull Hybrid Monoblock Power Amplifiers


200W rms @ 8 Ohm
350W rms  @ 4 Ohm


11Hz -75Khz  -3db 


0.25 Ohm 


47K Ohm 


x30 (29.5db)




250W @ idle 


17” W x 17” D x 19” H


100 lbs (each)


High End Zone strives to provide quality gear at exceptional prices to all of our customers. Because we are a small company and we have a wide range of experience being both the client and the dealer, we choose to meet our clients with respect, share our knowledge, and provide reasonable recommendations to meet our client's needs.


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