Aegis DIY Headphone Amp

https://redirect.viglink.com/?forma...-tube-headphone-amplifier.399473/post-7354944

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Ah, the Aegis, is this kit actually coming out soon, so still in the no man's land of final prototyping? oop. can't read. this just came out today and the BOM is here!

haa anyone had ears on one of these?

 

There is no kit. You basically source the parts and get going. He has provided the BOM and the build guide, where he has given detailed, step-by-step instructions.

@shotgunshane @jexby could you please rename the title to ‘Aegis DIY Headphone Amp’?

 

I tried to edit the title, but no dice.

 

LordGwyn has been one of the last vanguards of true DIY on Head-Fi, and has done some REALLY nice work. So I'll be interested to take a closer look. But man, US$2k with the weak ass Canadian dollar plus shipping on heaps of heavy stuff? Almost certainly makes it a non starter for me.

 

Yah, two grand for parts, half of which is the Lundahl tranny's/chokes, is a lot for a diy project, but imagine the price if it was a commercial venture. Yeeeow!!

Actually, as I understand it, LordG had originally intended just that, but got too busy to build them.

 

I'm all in on this one. Lundahls and pcbs are ordered. Considering the BH Mainline kit is over $1400, a project with this kind of iron starts looking more reasonable at $2k.

 

The schematic is available so there’s no reason why you couldn’t choose to use cheaper transformers. Particularly for chokes

Elekit is well known for offering their kits with a stock transformer and premium Lundahls. That’s what’s great about DIY, you can do whatever you want

 

Damn this looks like an awesome project, been going through the manual and the design from a practical perspective seems top notch. Once again need and want are in contention.

 

Ahh yes: Need vs. Want. The eternal battle.

 

A few months ago I saw that L0rdGwyn had posted in the DIY section of Head-Fi of a new amp he'd been working on. I was really curious and kept going back to the thread. I remember him building a Bottlehead Crack, then a Crackatwoa, then ended being a Glenn OTL owner like myself. After, he really dove into upgrading his amps and learning about different circuits. You can say this is the culmination of his experience.

Since I had all of equipment needed to put together an amp from previous builds I decided to dive in.

Aegis amp build information:
https://www.diyaudio.com/community/threads/aegis-diy-tube-headphone-amplifier.399473/



Chain:

PC --> Bifrost 2 OG | X-Sabre Matrix Pro --> Aegis | Elekit TU-8600s | Cavalli Liquid Crimson

Aegis Tubes compliment:
Driver Tubes: JJ 6SL7, Tung Sol 6su7gty, Tung Sol 6SL7 (BGRP), Ken Rad 6C8G, National Union 6C8G
Power Tubes: Mullard EL34, TAD EL34, Gold Lion KT77, Svetlana 6L6GC
Rectifier: RTC 5R4-GYS

Elekit tube compliment:
Driver Tubes: 2 x JJ 12AU7, 1 x Electro Harmonix 7025EH (replacement for the 12AX7)
Power Tube: 2 x Psavne ACME 300B, 2 x EML 300B

Cavalli Liquid Crimson tube compliment:
Driver Tube: 1 x WE396

Headphones:
ZMF Atrium
ZMF Verite Open
ZMF Auteur
HD650

Impedance switch:
Low - 5 ohm
High - 17 ohm (currently set to this)








Build/Price:

L0rdGwyn makes building this amp as easy as possible. He created 135 page PDF with clear instructions and pictures to follow along. There's a BoM on what and where to buy with alternatives. Even for starters this is an easy build and for anyone that's built a Bottlehead Crack it's like hopping right back on a bike. All in all, the total for materials came out to roughly just a little above $2,000 and took me about two days to complete. This is a great price-to-performance value compared to other amps on the market.

Amp topology:

L0rdGwyn, "At a high level, the power supply is tube rectified, CLCRCRC filtered. The circuit features a choke-loaded 6SL7 input stage, capacitor-coupled to a triode-strapped pentode output stage. The output topology is a transformer-coupled cathode follower, which at this time is the only headphone amplifier of this topology that I am aware of. There is no silicon in this circuit, it is an "old school" tube amplifier design featuring Lundahl transformers and chokes. The amplifier includes a high and low output impedance switch for the purpose of matching high and low impedance headphones.

Tubes for the amp:

-Rectifier - 5V / 2A types; GZ34/5AR4, 5V4/GZ32, 5R4, 274B. 5Y3 can also be used with lower current output tubes like 6V6.
-Inputs - pair 6SL7
-Output - pair power pentodes; 6V6, 6L6, EL34, EL37, KT66, KT77, KT88, 6550. Others as well, compatibility list in progress."

Sound:

I want to preface this and say that sound is very subjective. My ears have gone through a little bit of abuse. What I may find too warm may sound fine to you or what I may find neutral may sound too bright.

To help you triangulate how the amp sounds I'll compare it to other amps. I'll take the two amps: the ZMF Pendant and the Glenn OTL. I'd say that this amp sits close to the middle of those two amps. The Pendant, being an ultra-linear amp, has a more aggressive sound that's closer to a solid state. The attacks of drums and cymbals, for example, are sharper on the Pendant while the Aegis leans more on the delicate side. This sounds is in line with what's expected of a triode SET amp. I've rolled several tubes and this characteristic is similar on each roll. You can move it closer to the Pendant with specific tubes but in the end it's not going to be as crunchy. The Glenn OTL can sound bombastic with serious punch and a wide/deep sound stage. The Aegis shares this pedigree but not to the full extent of that amp. This amp has more clarity than the Glenn while still having great weight to instruments and notes. I've never heard another amp with such a deep sound stage that the Glenn OTL but the Aegis gets close. The Aegis has more clarity than the Glenn from memory.

The Elekit TU-8600s can be dropped between the Pendant and the Aegis. It has a more solid state attack compared to the Aegis. It's a good tube amp for the price but the gain is ridiculous for headphones. Which, in all fairness, it should as it's primary function is running very efficient speakers. You have a little bit of play on the knob between 8 and 9 o'clock which borders on loud. Also, if you're not going that high on the knob, you'll hear channel imbalances. It's easier to have a preamp to manage the volume than to use the volume knob it comes with. That's an added cost. The headphone out was definitely an after thought. Sound stage wise both are wide but the Aegis goes deeper with a stronger holographic effect. Also both are similar when it comes to how tall and big instruments sound.

Bass:

I'm going to throw in the Liquid Crimson to talk about sub bass extension. Both the Elekit and Aegis reach low but it's not going to have the reach that solid states have. The Crimson goes low and surprisingly gives the Verite Open a much enjoyed sub bass rumble. The two other amps sub bass extension can be heard but not really felt. I want to point out that the Elekit, out of box, will not be a good match for low impedance planars. Something like the Mod House Tungsten, with it's 155 Ohm impedance, may be a different story. The Aegis doesn't have this problem unless running something like the Susvara.

Mid Bass:

The Aegis is satisfyingly punchy. Great body to notes while not smearing mid bass into the mids. How good is the mid bass? I had the Atrium sitting there collecting dust, then I plugged them into the Aegis which made me sit up and smile. Great synergy with the Atrium and made them come alive. Pairing it with the Elekit or the Crimson never made them sound that good.

Mid:

Mids are open, with the wide sound stage and you can easily follow what instruments are where. This is what I expect from a good tube amp. Tube wise, what you can expect from the EL34 tubes is a more mid-forward sound. The 6L6 is more neutral across the boardwhile the KT77 tube is more mid-foward than the 6L6 but less so than the EL34 tubes. The impedance switch in the back also from low to high brings the mids slightly forward as well. Spice to your flavor.

Highs:

Here's where I wanted to spend a little bit of time talking about the treble. Using EL34 tubes I find that the amp leans to the darker side. There' s roll off at the top with Mullards, TAD, and KT77 power tubes. There's the typical old school tube amp roll off at the top. You can add more energy to the treble with the driver tubes. For example, a good mix I found were the EL34 tubes paired with the Tung Sol 6SL7. If you want even more extension the Svetlana 6L6GC are by far my favorite tubes in this amp. There's great extension while not being sharp. You sacrifice a bit of the punch for more treble extension and clarity.

Holography:

Listening to something like Flaws - Disguise, that song is just all encompassing with notes floating in the air. Great separation and layering in that song. The Svetlana 6L6GC are new tubes that do a great job with a holographic sound stage compared to any of the new production tubes. The NOS Mullard EL34 do a hell of a great job with this. You get the spooky 3D effect but you're paying for this as these tubes are expensive.

Resolution/Microdynamics:

The amp performs at the level of the Elekit. I do wonder what how much more we could pull if I was to install the VCAP Tuft caps into the Aegis. It's not to the level of Crimson but that's a different story but it will perform as well as any $3000 amp.

Blackground:

It performs in line with most tube amps at the $3k price range. In line with the likes of the Pendant, Amp and Sound, Eddie Current amps. You won't have a blackground compared to a solid state or the Crimson/Nitsch DSHA-3F. Those amp are ridiculous in that sense.

Synergy/Pairing Consideration:

ZMF headphones with this amp especially the Atrium. The Verite Open I find that I like it paired more with the Crimson. The Auteur is a toss up on either amp. If you have cans with high treble energy then any EL34 with the RCA 5691s/JJ 6SL7s will work. Headphone examples: OG Utopia, HD800, and Hifiman 1000SE will be great pairings. If you have darker headphones you can pair them with the 6L6GC tubes and a pair of Tung Sol 6SL7s. If you find the Atrium too dark you can always remove the metal screen on them for more treble. I would not pair something like the Meze Empyrean or DCA Aeon 2s with this amp. It'll be too overly thick and dark. Because of the somewhat forward nature of this amp, I wouldn't consider something like the LCD-5s as it may be too much. Not sure since I haven't tried the pair but have heard the LCD-5 before on solid states. It still a forward sounding headphone even on neutral amps.

The other consideration is the DAC. The OG Bifrost may be too warm for some people since it's a bit thick. The 6L6GC tubes take care of that or you can go with a DS DAC. I found that the Matrix X-Sabre Pro worked very well with the EL34 tubes since it adds more bite to the sound without it thickening up instruments.

Tubes:

Neutral pairing/Clarity:
Svetlana 6L6GC + Tung Sol 6SL7s
Svetlana 6L6GC + JJ 6SL7 (cheap and also a great pairing)

Warm and detailed:
TAD EL34 + Tung Sol 6SL7 or Mullard ECC35

Warmer, holographic, and detailed:
Mullard EL34 + Mullard ECC35
Mullard EL34 + Tung Sol 6SL7

Warmer yet:
TAD EL34 + RCA 5691
Mullard EL34 + RCA 5691

Conclusion:

I really enjoyed building and listening to this amp. I believe it's a steal at $2,000 and rivals amps at the $3000 price range. With tubes it comes out to $2200 give or take while still giving you a great sound. The Elekit with it's compliments of tubes, VCAPs and, Lundahl transformers will set you back $3000+ and that's on the cheaper end. If you like the Triode SET amp sound, with a big sound stage, and punchy this is a great amp to consider building. If you're more in line that you like more of the Ultralinear sound then the A&S amps are great in that aspect. So now I guess I have to make another thread putting up the Elekit for sale. I can't find a reason to keep the amp unless we decide to move soon and I get enough space for some nice and efficient speakers. This is currently not wife approved until I get a man cave.

 

I know this is the DIY Aegis thread, but I thought it should probably become the place to post about the new ZMF Aegis as well. I just got mine today, and after a couple of hours of listening, I’m very impressed.

First of all, it’s quite the statement piece as far as looks are concerned. I understand its aesthetic may be polarizing, but I personally think it’s beautiful and entirely unique. It’s a massive amp. I think it’s about 55lbs.

I have acquired a number of tubes to eventually roll in, but for now I’m sticking with the stock setup. I want to get a good baseline before making any changes. I’d also like to give the amp a week or two to settle in. Let me just say, the stock tubes, even with only a few hours of use, already sound incredible.

The ZMF version has a few useful features not found in the DIY amp. It has three output impedance settings, as opposed to only two on the DIY. It has a 4.4mm jack with a voltage divider to work better with IEMs and very sensitive headphones. I’m also happy to have a 5-year warranty on such an expensive piece of equipment.

I’ll post in more detail about the sound once I’ve had more time with the amp. I’ve briefly listened to all 3 of my main headphones tonight, my Atrium Closed, Meze Elite, and OG Autuer. So far I’ll say it is highly resolving with a smooth and natural presentation. I’m going to try to do some comparisons with my Mjolnir 3 in the next few days, but my initial thought is I might be saying goodbye to the MJ3 in the near future. The Aegis might just make it unnecessary to keep, and I really need to scrape together some more cash to help pay for this monster.

More to come…

 

Well I said I was going to wait a couple weeks before swapping out the stock tubes. Turns out I have very little self control and didn’t even make it a week. Typical…

Right now I’ve got the following tubes rolled in:

Input: RCA red base 5691
Output: Mullard EL38 *with adapters
Rectifier: RCA JAN 5R4GY (brown base, early version with slanted double D getters)
​

After a day or so in the amp, this tube combo has really started to show its stuff. I’m not going to be great at pointing out all the specific sonic attributes that changed from the stock setup, but it can be summed up as sounding more real with a more three dimensional soundstage. I’d say bass, mids and treble all improved too though it’s hard to pinpoint in what specific ways. Vocals are particularly superb now.

The big surprise was how amazing my OG Auteur sounded with this tube roll. I plugged the Auteur in the first or second day I had the Aegis, but I didn’t have a strong impression at that time. It sounded really good, but it didn’t “wow” me. It might be a combination of the amp burning in and the more synergistic tube combo, but I’m really glad I didn’t sell my Auteur like I tried to do recently. This is the best they’ve ever sounded. They offer a unique tuning that complements my Atrium Closed and Elite really well.

I kind of wish I didn’t have so many more tubes to try in the Aegis. This first combination sounds so good that I just want to stick with it indefinitely. I know my curiosity will get the best of me eventually. As many of you know, it’s hard to leave well enough alone with so many choices. Then again, every once in a while you can stumble upon a magical combination and feel like it was worth all the effort. Tubes are a blessing and a curse!

Here’s the new tube roll:

 

Just finished up a DIY Aegis build today. I've been listening as it warms up and have been very, very impressed using Atrium Open.

Having been absolutely addicted to Atrium Open and DNA Stratus for the last few years, nothing has come close to having me consider letting my Stratus go...besides this amp.

It does so many things so well, and a few better than Stratus. Aegis mostly impresses me with its clarity and resolving power. Hearing more in the mix here. Bass is also very tight, well controlled and goes LOW with authority. I prefer high impedance and find the bass quantity just right.

Treble is very clean and extended. No nasties at all. Slightly cleaner treble than Stratus even.

Headstage is very wide. I'm also impressed by the imaging and layering. Instruments are very easy to place. Also has a lovely 3D effect like Stratus.

The amp doesn't sound bright or warm to me. Just sounds accurate but with a slight inner 'analog' warmth. Everything sounds natural and effortless.

Looking forward to tube rolling and tweaking.

This is a killer amp if you are patient while waiting for parts and don't mind getting your hands dirty in the world of DIY.

Edit: Since these first impressions sounds too positive, one drawback is that Aegis is less forgiving than Stratus. Recording quality on albums and tracks is actually easier to distinguish on Aegis, for better or worse. Stratus is a bit more forgiving where poor recordings still sound goodish.

(The above is not true with good tubes...)

Also, FWIW, this is a new build with less than 5 hours on all components, tubes and caps. I expect things to open up and also relax over the next 50 to 100 hours as it burns in.

 

Tease! Let's see what you're packing under that skirt!

 

Ugh. She's kind of ugly. I left the wires all long for when I can order a landfall chassis. Here ya go!

 

Nah, that looks pretty bloody good to me. Top work!

 

Excellent impressions, TYVM! This is pretty much what I'm hearing with a ZMF loaner I'm lucky enough to have on hand. I'm not great with parsing the sonic attributes of amps, but I think you basically nailed what I'm hearing so far.

 

Agreed. Good work! I'd maybe tie the wires down if you ever plan on moving it.

 

I did not have the confidence to build my own Aegis, so I’m always impressed when I see someone take on the challenge. Your build looks great to me!

What tubes have you tried so far? I went a little crazy and bought a bunch to try in the Aegis. I’ve pretty much settled on RCA red base 5691’s for the input tubes and a 1940’s RCA JAN 5R4GY for the rectifier. I have lots of output tubes that I like in the amp. I’ve got Mullard EL38’s, Tung-Sol 6550’s (smooth gray plates), Ei KT90’s, RCA smoked glass 6V6GT’s, RCA 807’s, and GE 6BQ5’s. Quick note, the EL38’s, 807’s and 6BQ5’s all require adapters.

Now that the amp has a 100+ hours on it, I’ve found almost every tube combination sounds excellent in its own ways. I think the amp circuit is the main star here, so the tube choices aren’t super important. It’s more about finding the best fit with the rest of your setup for your preferences. I have lots of good options now, so I really need to resist buying any more tubes!

I’ve currently got Ei KT90’s rolled in the output positions, and it’s a very nice listen.