background -

my main amp has been an elekit 8200 that i built in 2018, it uses 2 power tubes and 2 preamp tubes. i got it primarily for speakers. it was my first tube amp and ive never looked back (at solid state) since. over the years, i've rolled a lot of tubes with-it and am pretty sure of the sound i like (warm, 3d/holographic with bass).

earlier this year, i realized when listening to headphones i could use a smaller amp. the main reason is the elekit is like a small space heater and makes my room hot especially in the summer. plus i realized i could trim the tube collection- i had enough tubes to last several lifetimes (this is only half of what i have!). and of course, since i had a bit of cash from the tubes i sold, i wanted to try something new.



i found the ember via a comment on reddit when looking specifically for amps that use a 12au7 or 6sn7gt tube (since i already had them for my other amps). since the ember can roll those plus so many more, it was a no brainer buy. i knew long term it would save money (single tube required)


sound
with the tubes i've tried, in general i'd say the sound is smooth, detailed and refined just like you'd expect from a tube amp with beautiful harmonic distortions and easy relaxed listening. of course some of the characteristics change depending on the tube used but since i have mostly the tubes i already know i like (12au7s and 6sn7gt), it wasnt much of a surprise hearing them on the ember instead of the elekit.

after listening for a few weeks, heres what i tried and took notes on-

1. Tung sol 6sn7gtb is probably one of the clearer more balanced ones i've listened to so far.
2. RCA (red label) 6sn7gtb one of my favorite 6sn7GT tubes, warm lush and wide sound stage
3. GE JG 5814As are one of my favorites, with one of the tubeyest and balanced sound ive heard yet. they're my favorite on the elekit and also on the ember.
4. Amperex 12au7 bugle boys- holographic and well rounded like theyre known for
5. RCA 12au7 clear top- clear airy and transparent with a nice sparkle in the treble
6. Tung sol 12AV7 - excellent bass and midrange with a very smooth, liquidy sound and pleasant vocals. very forward treble and soundstage (higher gain than 12au7)
7. Dumont 12BH7 - a little light on the bass with vocals a little more recessed than others but overall good for some classical (or non bassy music)
8. RCA 6GU7 - thought this tube had a very neutral to average sound, but good soundstage and resolution

the amp sounded great with all of the music i listen to (mostly rock, blues, electronic, classical and jazz), but i think tube sounds mostly do best when real instruments or vocals are present and especially so with live (concert) recordings. with electronic, the tube sound is not always as obvious to me at least.

power
i only have a couple of pairs of regular headphones that i tried it with- ath r70x (470ohms) and avantone planars (32ohms) and with both it has plenty of power and was dead quiet with nothing playing. most of the time i had the volume around 10-11am with the athr70s and the impendence jumper on high. you can switch it to medium or low which will make the volume even louder at the given setting.




conclusion
the ember holds its own against my elekit. it gives me exactly what i wanted as far as the tube sound goes with plenty of options to try different tubes and experience the same music in different ways. in fact, if it had a speaker output, i might even consider selling the elekit.

if youre curious or looking for a headphone tube amp, not sure theres a better option out there with the support, warranty and freedom to try all the tubes the ember supports (and also self biases so you dont have to) and plus you can use it as a buffer or preamp if you want to connect it to your solid state speakers to get a little tube sound there.

for the forseeable future i dont think i'll be changing much if any of my audio equipment. very happy with the elekit, the ember, and of course my more recent foray into stax.

as you may know electrostatics are my headphone and sound of choice.

previously reviewed the es-1a here and now here are my impressions of the kaldas rr-1 conquest.

Sound:
after researching a bit about these and how theyd sound, my expectation was that they would be in between the lambda series and the 007s that i have. and after listening for several weeks and comparing them, i think thats a pretty accurate description.

im not sure i'd call them a baby 007 though since to my ears they sounded closer to the l500s mk2s - without the shoutiness and better bass (non-blutack modded)


Bass:
been on a classical kick recently and listening to bruckners symphony no 7 was a great way to hear the warmth and texture of the bass these headphones can provide. much more substance than the L500s with a natural tone that just sounds realistic - full with life without being overly done or falling flat. (i understand you can blutack the lambdas to improve bass for example but really think headphones should be used as is especially after a certain price)

for electonica recently discovered paloma who's a dj producer out of san diego california. listening to her live set from february 18, 2022 at camino rivera was a wonderful way to spend a few hours imagining i was at the event in person. plenty of bass to make the music feel full and well rounded with melodies and vocals infused throughout the eclectic and international sounding set.

Midrange:
here i gave some acoustic classical guitar a few sessions with andres segovia -art of segovia and the guitar sounds like it would in person. though the rr1 does well here, i think this is where all electrostatics really stand apart from other headphones - with stringed instruments.

Listening to Phish “Harry Hood ” from 5/29/22 finished with another solid jam with a finely coordinated dance between all the instruments they play and are well known for integrated so seamlessly in their sets. again the rr1s sounded great.

as far as vocal music - been a bit nostalgic for some celine dion and mariah carey... and listening to 'because you loved me' and 'always be my baby' brings me back to the good old days when these songs were played all the time seemingly everywhere.

all in all i find the midrange well done and not at all offensive. (unless you like to get offended in which case you can always EQ to fine tune the sound to you liking... )

Treble:
the rr1 treble is tuned very well its not at all like the the L500mk2 (too much shout for me). in fact, i think it's a little in between the relaxed 007s and the es-1a.

i'd say this description is mostly from focusing on the higher frequencies like cymbals, violin and higher notes on the piano or guitar solo from Aerosmiths Crazy or Mendelssohns Violin Concerto Op 64 where i could sense the violin almost reach a point of unpleasant shrillness without getting there where it might hurt your teeth.

Soundstage:
the rr1s do have a much more intimate soundstage. i'd say much more so than the larger stage of the 007 followed by slightly larger stage of the es-1a. part of this may have to do with how close the drivers are to the ears. just from a quick visual inspection you'll notice its much more of a shallow ear cup than both 007 and es-1a, which may explain why (in addition to the driver and size of the driver)


Conclusion:
I'm very happy with these headphones. if i had to choose between these and the L300/500mk2s i'd go with the rr1s.

compared to the 007A and es-1a i currently own they hold their own. if i had never heard those two, i probably wouldnt know what i was missing... but since i have, i know that there's a lot of overlap between these 3 pairs and really only need 1.

curious if you've been in a similar situation, which did you keep and why? lmk in the comments!

Intro
Quick introduction about myself. Used to play the guitar (primarily electric) and a little bit of piano starting in middle school through high school. Back then I mostly listened to rock, rap a little bit of R&B and metal. (to date myself i grew up watching MTV; listening to KROQ and power106 if your’re from LA) Wasn’t until college that I started to expand my music interests. After going to many festivals like Bonnaroo, High Sierra, Outside lands, Gathering of the Vibes, Lockn etc got many chances to explore a lot of different types of music that i now listen to today: jazz, world music, classical, acid jazz, blues, rock and a lot more electronic (house, trance, trap) as well as phish, string cheese and the dead.

I’ve always had headphones in my ears whenever traveling and when possible at work. A few years ago i discovered the 6xx and 7xx drop headphones and thought that was my end game. With COVID and spending more time at home with a change in my living circumstances (cant blast my speakers as often) I decided to see what was out there with headphones this past year.

While trying out some of the top tier headphones (eg DD focal clears, planar (aryas/lcdx, and electrostatic l500mk2,007mk2) and IEMs(mest mk2, monarch mk2, sony ier m9 etc); while they all sound great… the biggest realization was that I discovered i had been missing out with stax all my life. I’d never heard of them before and dont even remember how i came across them the first time…

Life-changing.

the first time I listened to a live phish recording it sounded like I was actually at the concert (course the key is : you got to close your eyes and do this in a dark room).

Anyways having had a chance to experience the L500mk2 as well as the SR 007mk2 was always curious what is 009‘s were but don’t ever see myself paying that much just for a set of headphones. It was already a big step going over the $1k mark as i’m sure many of you have experienced, I never thought I’d do it but had to find out for myself.. And yes, its just diminishing returns beyond a certain point. Plus, I’d rather just use my money for live music and experience it in person.

So here we are with the es-1a. what my research has indicated was that this is in between 007 and a 009 as far as a sound since i knew i’d never buy the 009s I thought why not.

Sound:
I was a bit skeptical and unsure what to expect from all the glowing reviews but have to admit - overall i think this set is tuned perfectly for all types of music and i know you might think… usually jack of all trades aren’t actually good at anything, but i’ll leave that up for your to decide..

Bass:
Fast, deep, dynamic, clean.. Listening to John Summits live set from Ultra 2022 will have you bobbing your head to every single bass note. It’s not as textured as the 007s (which have a palpable oomph) but its there. Same with Above and Beyond “Screwdriver” which has a nice bassy acid mid-section

listening to Lizst piano sonatas (Annees de pelerinage S 160:no6 Valleed’obermann) the piano notes are crystal clear and never muddied or distorted. The es-1a keeps all the frequencies and especially bass well controlled.

Midrange:
Very good performance here, listening to the blues like Stevie Ray Vaughans live set at Carnegie hall “the things i used to do” you’ll really get a taste of his guitar - full-bodied, full of gritty blues distortion while crystal clear and very natural.

The same goes with a listen to Vivaldis “Spring” almost like hearing the sound of the violin for the very first time.

Listening to Phish “Ghost” from 9/1/17 at Dicks will give you one of the many renditions and funky bluesy jams with a fine balance between all the instruments and vocals. Want some more strings? give the string cheese set from 4/22/22 Ashville a listen specifically 'mouna bowa' and 'long journey home'

Speaking of vocals Janet Jackson “That’s the way love goes” and Ella Fitzgeralds “Summertime” both smooth as a babies bottom.

Treble:
the treble is tuned very well. With the L500mk2s i found the treble a bit too much and very shouty. I was a bit concerned it might be similar with these but that’s not the case at all. Some base music was unlistenable with them for example Seven lions remix “you got to go”, but it’s just right with the es-1a.

Imaging and Soundstage:
I think the es-1a really gives you an opportunity to listen to music in a new way. Depending on the recording, sometimes the position eg in front of the stage row 1, or a few rows back can change depending on your source and even DAC (eg comparing r2r vs delta sigma). But regardless, i think certain Symphonies are a good way to experience that like Beethoven Symphony No 9 ‘Choral’ or any of the tracks from Lee Ritenour Rhythm Sessions or Ray Brown Trio Soular Energy

Amp:
I’ve had the chance to listen to these on 3 different amps SRM3, Antares v3, Mjolnir Stax007tA. As they say some headphones (like the SR 007) do scale with a better amp, up to a point… i think these do as well, having listened on a SRM3 and an antares (similar to modded t1) i think the sound is much better on the latter. Not drastically better, but maybe noticeably better if you're 'critically listening' vs background music or listening for fun. i'd say 5-10% ‘better’ if you had to quantify it. And then on a mjolnir modded 007tA) maybe another 2-3% ‘better’. I put ‘better’ in quotes because i think it’s very subjective. i suppose you could also say a different flavor instead of 'better' if that makes sense.
like headphones or anything else in your chain after the source, the amps can give you a different flavor of the music. which flavor you like most is really up to you to decide.

Conclusion:
I was a bit skeptical about the es-1a but after hearing them and being pleasantly surprised, they continue to grow on me and i like them more and more. Now trying to decide if i should keep these and let the 007mk2s go! I can see both the 007mk2 and es-1a as complimentary as many say and easily be the end game (combo or not) for many people.