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.