ZMF Aegis Official Thread

[theveterans]

FTFY....[Reg. TM; © bcowen: 2021.]

Might be too low of plate resistance for Aegis though

 

[SunRa Fan]

.... then how does one get this advice?

Only making light

 

[theveterans]

@theveterans Cool. I read your earlier post about how you're enjoying those EH 6CG7, and I may eventually look at that them too. Happy you were able to settle on your roll relatively quickly. That's always advantageous to one's wallet. I've gotten the RCA 5R4GY DD from a kind member on this forum already, and it's the first tube I've started to roll in Aegis. I moved from the JJ/Sovtek stock tubes after about 3 weeks of continuous listening, onto the TAD bundle now, and am currently breaking them in. I went back to the TAD 5U4G rectifier from the RCA simply to give all the tubes in the TAD bundle more time to burn-in and settle. Another two or three weeks and I'll start doing some serious rolling. By then, my Bokeh Opens ought to have properly burned-in as well.

Looking forward to your thoughts soon! Especially when you find that special sound that’s specific to your liking!

 

[iamoneagain]

Now just get a couple of backups of each, and ride off into the sunset.

. . ."swear I'm done now.". . . If I had a nickel for every time . . .

As far as backups, seeing the Mullard can last well over 10,000 hours and the RCA 5691 even up to 20,000 hours. The EI have the shortest lifespan of under 5,000 hours. So not sure if I’d buy again since find the Gold Lion kt88’s that sound almost identical in current setup.

I have said I’m done a few times but mean it this time. I had the Audio Technica L3000 & DHA 3000 headphone/amp combo that I lived with for over 10 years. Only moved on once the amp started having trouble and then still stuck with the L3000 for a few more years. Find enjoying the Caldera Open even more. So once I find what I’m looking for I stick with it.

 

[betula]

Chilly early summer morning here in Minnesota, and everyone else in the house remains asleep. I'm on my second cup of coffee and in the mood for some music. Listening to Medeski Scofield Martin & Wood's fabulous Out Louder record on Aegis and my Bokeh Opens.

So, a general question for the collective. After reading hundreds of pages of tube impressions and suggestions and combinations, I'm curious about this. For those who have had their Aegis for a while--whether its a DIY or from ZMF (looking at you @Wes S, @Toonartist, @theveterans, @ckhirnigs113, @betula, @AnyDave, and any others) is there a specific tube roll you keep returning to?

Now I get it: One of the wonders of Aegis is the nearly infinite ability to tube roll; and I understand how easy it is to change things up, whether that's due to your mood, getting (a) new tube(s), or perhaps new set of headphones to try, or simply wanting to tweak the sound that particular day. However, all that said, after such day-to-day variations, if you find yourself returning to a particular combination of tubes, care to share what's your go-to roll?

Hope everyone is enjoying the weekend. Happy listening.

My preference seems to align with @Wes S's a lot. I use the same rectifier (Mullard 5U4G slim base, welded black plates and pan getter); to me this easily bests all the rest. My second choice would be the U52, but still behind the Mullard. I feel I am done on the rectifier front.
I am also pretty settled on input tubes: Mullard ECC35 slim base. This for me also easily bests the others I owned (TungSol VT229, RCA 5691 red base) by being more 3D, higher resolving yet tonally very pleasing. I am interested in trying the F7F tube family at some point, just my motivation is not as high as it used to be, already owning the ECC35s.

I think, the biggest variation comes with power tubes, where it is less easy to pick one that rules them all. There are many equally good, just different choices. After trying EL34, KT66, KT88, KT90, EL38, EL39, 6V6 I feel pretty settled with some 4654/EL50 variants. To me this tube family bests everything else I heard previously and the three pairs I use, still offer enough variation within the same 'house sound'. My RT 4654 red base, solid plate is the most technical with awesome clarity/detail/dynamics but still with a lovely tone. If I want even sweeter/more organic vocals at the cost of a pinch of loss in clarity, I roll in the Mullard EL50s. My Tesla 4654s still have the same 4654 'house sound', but they are a little more neutral and while still detailed, they are smooooth as butter. From the previous tubes I enjoyed the KT90; these are very clean and detailed, but don't quite have the body and texture/tone of some other tubes. They also have a smaller stage compared to EL38, EL39, 4654/EL50.
I also enjoyed the EL39, these are tonally super rich and thick, but lack clarity compared to KT90 or 4654. I feel, the 4654-family kind of gives me the best of both worlds with slight variations here and there: KT90 detail and resolution with EL39 tonal richness and almost EL38 spaciousness.
I am still curious to try some other type of power tubes like EL33, EL37, 6550 or a top-quality NOS KT88, but similarly to the 7F7 inputs I have less motivation to search as what I have already sounds awesome. I think, I am done with 6V6, EL38, EL39, EL34 and KT66 but I feel there is probably more potential in KT88 type than the new production pairs I heard. I am also interested in trying the metal base 4654, which apparently is said to be even more detailed/technical and a bit more neutral than my 4654 variants.

The thing is, other's description is only helpful to a certain extent. Hearing and preference differ for everyone, plus there are the system-chain variations too. You cannot fully judge a tube, until you heard it yourself in your own system.

For two reasons I tend to sell what I don't use often enough: 1, simply cannot afford to store $ thousands in tubes, 2, I don't have endless time just to pick and roll from 20 options for a certain flavour. I keep those few I know I would gravitate towards most of the time. Maybe when I retire, I will build a bigger collection.
Since I am at it, I also stopped panic-stocking backups. These tubes (especially rectifier and input tubes) should last a long time. Even if as an average you listen 4 hours every day, that is 1460 hours a year. That is 3 years+ for a power tube and can be 6 years for inputs/rectifier. Who knows, where I will be in two years. I might want a different amp in 2027 or prefer different tubes. I cannot see much point of stock piling anymore; I will just move with the flow.

 

[AnyDave]

The reality is, that there are a number of combinations I could have and just be happy and done. I only roll things because it's an option and it can be fun to mix things up a bit. And there is no single combination that will replace the occasional itch for something different (which is also why I have more than one amp and sooooo many headphones).

For input tubes, I do often land back on the RCA 5691s (although I have a pair of Mullard ECC35 on the way, so I'll have to check those out). For power, I really like the GEC KT66 tubes. For rectifier, I could live with either the GEC U52 or the RCA 5R4GY DD and be content.

 

[DACattack]

Thanks all for your very interesting feedback. It's fascinating. There are a few commonalities, yet it's certainly evident that everyone has their own individual sweet spot, isn't it? I have one more set and input and output tubes on order, but after those arrive I'm planning to halt my tube purchases for the rest of the year (unless something remarkable falls into my lap). I already have a decent cache of tubes for both my Aegis and Folkvangr, and that should keep me happy and occupied, especially since I'm very deliberate with the rolls I make and always give each one plenty of listening time. Besides I need to start saving up for those flagship ZMFs. I'd love to eventually add a Caldera and Atrium to my collection. I feel fully set on the amp and DAC fronts now, so now it's time to sit back and listen, which is the very best part of this often faintly ridiculous but still awesome hobby.

Once more, thanks all for sharing. You all rock! I'll certainly chime in with what strikes my fancy as I gain more time with Aegis and the tubes I have acquired.

Enjoy the rest of the weekend!

 

[ckhirnigs113]

@DACattack I have a few combos they I can always count on to sound amazing with my headphones. Like @Wes S, sometimes I get the itch to change things up even when things already sound superb with my current tube-roll.

For input tubes, I switch between quite a few: Various 7F7 pairs, Sylvania 6SL7GT/VT-229 (black base), Sylvania 6SL7WGT (brown base), Tung Sol 6SU7GTY (black glass), and occasionally RCA 5691

Output tubes: Mullard EL50 (mesh plates), Ei KT90, Tung Sol 5881/6L6WGB, Mullard EL34 (XF2), GEC VT60, Mullard EL38

Rectifiers: RCA 5R4GY w/DD-getters, RCA 5U4G/VT244’s from 1943-45, and a recently acquired Ken Rad JAN CKR 5U4G/VT244

 

[DACattack]

Thanks @ckhirnigs113. That's a wide variety of tubes for each type. Very nice. I apologize if you mentioned it before in the thread and I simply missed it (there were a lot of pages to parse) but how would you describe the Ken Rad rectifier's sound? (That is, if you've had it long enough to form a lasting impression.)

So far there's a wide enough spread that it there is no runaway consensus for any of the tube types, but thus far here's what has garnered multiple votes:

Inputs: RCA 5691 red base (3 votes), Mullard ECC35 (2 votes), various 7F7 (2 votes)
Rectifiers: RCA 5R4GY DD (3 votes), GEC U52 (2 votes), Mullard 5U4G black plates w/inverted trough getter (2 votes)
Outputs: Ei KT90 (4 votes), Mullard EL50 mesh plates (3 votes), Philips 4654 mesh plates (2 votes)

Of course, what makes it all truly fascinating is how the various tube combinations complement each other. It's rarely 'this is the only tube I use in this slot' (beyond a couple votes for those fortunate to have the Mullard 5U4G grails and @Wes S praise for 7F7 in the inputs).

Appreciate everyone who has shared their impressions so far.

 

[ckhirnigs113]

Thanks @ckhirnigs113. That's a wide variety of tubes for each type. Very nice. I apologize if you mentioned it before in the thread and I simply missed it (there were a lot of pages to parse) but how would you describe the Ken Rad rectifier's sound? (That is, if you've had it long enough to form a lasting impression.)

So far there's a wide enough spread that it there is no runaway consensus for any of the tube types, but thus far here's what has garnered multiple votes:

Inputs: RCA 5691 red base (3 votes), Mullard ECC35 (2 votes), various 7F7 (2 votes)
Rectifiers: RCA 5R4GY DD (3 votes), GEC U52 (2 votes), Mullard 5U4G black plates w/inverted trough getter (2 votes)
Outputs: Ei KT90 (4 votes), Mullard EL50 mesh plates (3 votes), Philips 4654 mesh plates (2 votes)

Of course, what makes it all truly fascinating is how the various tube combinations complement each other. It's rarely 'this is the only tube I use in this slot' (beyond a couple votes for those fortunate to have the Mullard 5U4G grails and @Wes S praise for 7F7 in the inputs).

Appreciate everyone who has shared their impressions so far.

I’ve only had the Ken Rad rectifier since last week and have been out of town for the last few days. I’ll need some more time with it before posting any detailed impressions. At first listen, nothing stood out in a bad way, which is always good.

This particular style of Ken Rad 5U4G/VT244 (JAN CKR w/ three-part top mica and “=“ side supports) was recommended on another forum. I’ll have to see how it stacks up against my go-to RCA’s.

 

[DACattack]

@ckhirnigs113 Cool-looking tube. Enjoy, and I look forward to your impressions of it.

 

[drbusner]

Wow. Just got in some Valvo-branded 4654s w/silver coated glass at an amazing price (<$80), and they sound just magnificent. They produce a greater sense of space and a slightly sweeter, more delicate tonality than the Ei KT90s that I've been enjoying for a while. Looking forward to spending some time with these.
Thanks to @Deyan again for the excellent adapters and quick turnaround.

 

[betula]

I have just realised I have a full Mullard roll in tonight. Apparently, I tend to gravitate towards Mullard sound.
Clean, clear, detailed, dynamic, 3D, yet organic and euphonic.
Mullard 5U4G (slim base, welded plate, pan getter), Mullard ECC35 (slim base), Mullard EL50 (full mesh plate).

 

[iamoneagain]

Oh so even though I said I was done I did one last test with the Gold Lion kt88 vs the Ei kt90. The new Stereolab album - Instant Holograms on Metal Film might be my new go to for headphone testing. It was really easy to now hear the differences between with the Ei kt90 and the Gold Lion kt88, with the kt90 being the superior tube. It’s got better separation and layering, Better control and tighter bass. Same level of richness. The Gold Lion is still a great tube. Nice bass texture, punchy and great rich tone. The kt90 just has this ultra hifi sound, especially with Mullard gz34 fat base. The kt88 is a little more blended and rounded sounding in comparison. Still very close in sound and excellent for a new tube.

 

[timoteus]

4654 is equivalent to EL39, so it's compatible. I can't find a datasheet with triode curves for the 4699 or EL12spez. Highly likely they will work, but no curves available to say for sure. If you find some, send them to me.

Kurves for Keenan: https://patric-sokoll.de/Röhrenmuseum/Datenbank/RöhrenTypen/EL12 Spez..html Lotsa Kurves in the datasheets and application links.