Bottlehead Amplifier Discussion / Comparison Thread: Crack, SEX & Mainline
Oct 3, 2019 at 5:44 PM Post #1,951 of 2,108
What say you?

I say... Alfalfa.

And yes, the SEX is a good way to go. Don't be surprised that it's not as "tube-ish" sounding as the Crack. Tube hybrid amps can be another good solution - the Cavalli MCTH, Liquid Platinum, Lyr 3, etc. Also, you can try little kits like this, if you like to tinker.
 
Oct 3, 2019 at 5:53 PM Post #1,952 of 2,108
What say you?
The SEX with C4S gave me the tube bug. Made the AFC come to life for me. Sounds amazing with HD800S, TH-610 and even X2. I don’t think it didn’t anything with LCD-3F, surprisingly that sounds better out of my solid state BHA-1.

Sounded good stock but really needed the C4S to handle the full range of my library properly - bass heavy electro sounded slack and muddy without it.

Few build pics here - the paint job caused me the biggest headache, the build took a weekend with plenty of breaks: https://www.instagram.com/p/B0ta5KYJmVR/?igshid=18b0ukgmrah8i
 
Jan 4, 2020 at 9:36 PM Post #1,956 of 2,108
To start the new year, I visited the new Bottleheadquarters (an hour drive) for a listening test(!)—to compare their four headphone amps, and to see what changes each would make to my setup.

Upon arriving, I was warmly greeted by Eileen as we waited for Dan. They both have a very radiant and friendly disposition that made me feel at ease and welcome. I brought them Jones sodas, iced teas, and a variety of donut bites as any decent guest would. Then Dan took me upstairs to the listening room. Before I arrived though, he had carried up all the amps and set them up on one folding table (thanks so much again, Dan, for taking the time and effort to do that), and used a custom RCA splitter box so that all I had to do was plug my headphones into the amp I wanted to listen through.

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For the test, I compared my modded-out Crack (with my prized RCA tubes) against each of the other stock amps (with stock tubes)—S.E.X., Crackatwoa, and Mainline. Then I compared my modded-out Crack vs the Crackatwoa (with both using my RCA tubes). Dan didn’t have a stock Crack on hand, but I’m very familiar with how it compares to my modded-out Crack since I’ve had 3 Cracks since 2010 (stock is basically warmer, mushier, and less dynamic…but overall quite pleasant).

My personal setup for the last 4 years is: PC -> AudioQuest DragonFly 1.0 -> DIY Canare RCA IC -> fully-modded Bottlehead Crack + Speedball w/ RCA 6AS7G & 6F8G -> AKG K240 Sextett MP

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It took me a lot of time to find my synergistically ideal sound. I prioritize spaciousness, midrange presence, body to vocals, and a lifelike bite to crescendos while also not being harsh. This combination transports me to the venues and studios of my favorite musicians, while also riling me up and making me jittery when they deliver their art with aplomb. And every single piece in this chain is crucial to take me there. For example, when I “upgraded” my DragonFly to the newer DragonFly Red, I noticed resolution was increased but the spaciousness closed in on me and I no longer felt transported. When I “upgraded” to Beyer DT 1990 headphones, the mids were scooped out and there was no longer the presence and bite to rile me up. When I “upgraded” to the Tung-Sol RP 6SN7GT, yes, the overall sound was purely refined, but the clear bite of the RCA grey-glass was now dulled and, again, this failed to rile me up. So, for what I like, my setup is the best I’ve matched together so far. In the end, my impressions will be a little unusual as I won’t base them off bass, mid, treble, imaging, and soundstage as reviews normally do. I’m just looking for the specific qualities that make this hobby worthwhile for me, and I hope it’ll help you out or at least be interesting to read.

So, specifically, I will now see if any of these Bottlehead amps will either add to, subtract from, or leave unchanged any of my preferred sound characteristics I mentioned (as well as more general impressions). Nothing else will change in the audio chain besides the amp.

First, I wanted Dan to listen to my setup and see if he experiences the traits I loved about it. I played Hello by Adele (vinyl) and he volume-matched each of the amps. He plugged my K240 back and forth between all the amps and listened critically. I waited in suspense to hear what he had to say, and his first words were… “There’s distortion in the treble. I blame it on the RCA input [tube].” Haha, my heart sank a bit but then I confided in myself that perhaps I just like how the treble sort of nears the threshold of being controlled, giving the impression of the singer putting in so much passion that it’s hard to contain. Despite the AKG K240 Sextetts being from the late 70s, he remarked how the midrange presence is there but how it is scooped out a bit vs his Sennheiser HD6XX. I was surprised by that but didn’t get a chance to listen to the Senns myself. He explained how the highs were less prominent with the HD6XX and how I might just think they’re dull compared to my AKGs haha. For context, he said his preferred sound is “anything that doesn’t fatigue me.” So, while I don’t aim for listener’s fatigue, we do have different tastes. It was really funny after he listened, he said regrettingly that now he may have ruined this all for me by not saying what I would have liked to hear. But he ended with “What I hear doesn’t matter. Of course, it’s all about how it sounds to you.” And with that, I started my listening tests.

I plugged my cans into my modded Crack to touch base yet again with the sound and experience I’ve had countless times. Here comes the crescendo… “Hello from the other Si-iiiiiiiiIIIDEE!” Yep, I again get the jitters, my heart rate climbs, and I feel rejuvenated. Now, let’s compare…

S.E.X. (vs. modded Crack)

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The gist of it: Spaciousness increased noticeably but midrange presence, body, and bite all decreased. I felt transported, but I didn’t get riled up. Treble jumps out more than other ranges. I love the flexibility and layout of this sort of auditory Swiss army knife though—I still want one for speakers and low-impedance headphones.

More specifics: Adele’s voice wasn’t as intense or present, but the treble clarity was better.

Sinatra’s voice in You Make Me Feel So Young (vinyl) soared. When I said this to Dan, he asked me if I had seen any photos of Sinatra recording at Capitol Studios. “No,” I replied. He then explained how they were great recording studios—and that the mics were set up to hang from above and were spaced out from the singer. Here are some photos I found online when I got home to show what he was talking about:

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Although the atmosphere and scale were impressive through the S.E.X., the vocals were a bit too pushed back for my tastes. Also, the lower registers of his voice weren’t as present.

Shostakovich’s Aphorisms, Op. 13 – Mvt. 3 – Nocturne (SACD) highlighted the wide soundscape once again, and the tone of the piano sounded a bit more realistic.

Ray Charles’ Ev’ry Time We Say Goodbye (SACD) sounded clear and relaxing, but lacked the presence and guttural density in his voice.

Crackatwoa (vs. modded Crack)

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The gist of it: Spaciousness increased a bit, midrange presence seems unchanged, body increased, and bite seems unchanged. Bass was more present and alive. The increase in frequency range and body made me think that I’m getting the whole sonic picture (the antithesis of flat and thin). I felt more transported if that makes sense—perhaps as if my suspension of disbelief elevated to new heights—and I got riled up just the same as through my modded Crack.

More specifics: Adele’s Hello was rendered with all the passion I’ve come to love from the Crack, but the body to her vocals was more plump, and the bass notes during the chorus were more explosive. I explained to Dan that I noticed the increased range and power of the bass and he pointed out that it’s because of the shunt voltage regulation, and how it also increases the range of the treble.

Sinatra’s You Make Me Feel So Young gave me the impression of my modded Crack on steroids. The bass in his voice was rendered better and was more prominent. This reminded me of replacing the stock tubes on my Crack to the RCAs…but the Crackatwoa has stock tubes! So, that more sophisticated power supply is really showing its worth.

Ray Charles’ Ev’ry Time We Say Goodbye reinforced the impression of the Crack on steroids. The ache of his passion and the bite of his vocal peaks were really moving…a few notches above my modded Crack.

Mainline (vs. modded Crack)

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The gist of it: Spaciousness seems on par with Crackatwoa, midrange presence is unreal (meaning incredibly real…), body is unreal (lots of “flesh and blood” as Herb Reichert would say), and bite seems the tiniest bit decreased. Here my understanding of being transported was changed… It wasn’t just the spaciousness that did it for me, it was also the staggering sense of realism coming from what was centerstage; the body and midrange presence really grabs your attention as it would in a live space. And tone was eerily realistic. My heart rate climbed and I was excited during crescendos, but just not quite to the same level as the modded Crack or Crackatwoa.

More specifics: Piano is where the Mainline clearly outshone the Crack and Crackatwoa for me. The tone of the two Cracks seemed a little off and artificial in comparison. But it’s a case where I wouldn’t have noticed until hearing the Mainline. It made me reevaluate what’s possible in this hobby. Shostakovich’s Aphorisms, Op. 13 – Mvt. 3 – Nocturne was truly a pleasure to listen to here. I could really sense the acoustic space; the reverberations and the apparent size of the room. And each note seemed uncolored and weighty. As the finger gymnastics ramped up, notes seemed to linger without clouding the attack of the successive notes. I sensed the decay and acoustic space, while easily still following the present twists and turns of the music’s build up. These layers and depth made the experience exhilarating.

Radiohead’s Subterranean Homesick Alien (vinyl) was a resolute soundscape that was uncongested and full of life. I could plunge into this world mind-turned-off like going into a lavender hot pool, or sharpen my senses and appreciate subtle details that were rendered like I’ve never heard before. For example, the melody dances back and forth between the left and right channels, with the reverb decaying in the opposite channel—this has never been easier to follow for me. It’s like calmly looking left and right to observe a display of fireworks, rather than being overwhelmed by them. The impression of life, sophistication, and composure come to mind while listening through the Mainline. Fittingly, the Mainline is intoxicating and it has a confidence about it as if it’s operating in a flow state.

Ray Charles’ Ev’ry Time We Say Goodbye was more affecting, not because of bite…but because of resolution. The longing and breaks in his voice were rendered beautifully. I first told Dan, that it’s more detailed than the Crack but doesn’t quite have the same bite and I found that to be odd…how can it be more detailed but have less bite? He said that’s why he prefers the term “resolution” because it doesn’t imply brightness like detail does to many audiophiles. Ah, I’m learning a lot .

Crackatwoa w/ RCA 6SN7GT grey-glass & RCA 6AS7G (vs. modded Crack)

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The gist of it: Immediately evident is that tubes don’t change the signature as much as with the Crack. With the Crack, the RCA tubes are crucial for me to get the midrange presence and bite; with the Crackatwoa, those traits are evident with the stock tubes. However, some traits of the RCA that I’m very familiar with did carry over, such as bass lines being more clearly separated from other layers in the mix, and the nostalgic analog sparkle in the treble (distortion, as Dan more scientifically called it haha).

Spaciousness, or the sense of space, attained the same analog—like I’m breathing in the venue—quality, and the scale seems slightly increased like with the stock Crackatwoa. Midrange presence seemed the same. Body was weightier and more substantial than my modded Crack (Dan, this is what I personally love about what octals do vs. 9-pin tubes…generally). Bite seemed the same.

More specifics:

Adele’s Hello… whoa, okay, this is the upgrade I think I’m putting myself in line for. A level of power and frequency range are now evident that my modded Crack can’t match. And the RCA tubes dial in the signature and tone that I’m so in love with. The crescendos are the most stirring I’ve experienced.

Sinatra’s You Make Me Feel So Young was a great example of warm tone. His voice is dense and smooth...closer to what I imagine listening live would be like.

Ray Charles’ Ev’ry Time We Say Goodbye exhibited more of the same. At the start when he says, "Ohhhhhhhh, ev'ry time..." I always listen for the little inflections and details when he says "Ohhhhhhhh" because there's a lot of substance there. Crackatwoa with the RCA tubes extracted more weighty tones than I ever remember hearing.

Dan and I discussed and agreed that the basic Crack kit is great for incremental upgrades over time, but if one is willing to spend around the same total amount right at the get-go, then the Crackatwoa is sonically superior even in stock form. Dan stressed the importance of a more sophisticated circuit design and power supply in improving sound quality, versus upgrading a simpler circuit with expensive, boutique parts. Makes sense. But he also said the point of the Crack is to learn and experiment—and I explained my upgrades were always value focused, often $20 or less per upgrade every few months or so after I first got it. So, if I bought a Crackatwoa, the only upgrades I would do would be the stepped attenuators, film output caps, and my vintage RCA tubes. Dan explained how the power supply is so isolated from the signal path that all the power supply upgrades for the basic Crack (like Cree Schottky diodes and power supply film caps) likely wouldn’t be noticeable.

Conclusion

For my setup, the Crackatwoa would be my choice of upgrade if I can afford it in the future. The Mainline was incredible in terms of resolution, tone, and body. But this whole listening test made me realize that, for me, lifelike bite is probably the most important aspect of the sound I like because it elicits physiological responses like heart rate and jitters—literally making me feel more as I listen to the music.

After my main listening tests, I did try out Dan’s HD 800 with the Mainline and that made me feel like an orphan watching a happy family at Disneyland from behind the gates. But honestly, it didn’t have the bite. The treble did, but not the rest of the vocal range…it seemed too distant for me. It possessed other qualities that sounded lifelike though, like its famed super-wide soundscape, and great resolution…but its traits just didn’t align with my tastes.

Dan overall gave me the impression of someone who’s been there and seen it all. I’m a science major, and I really appreciated how to a lot of my questions, he took a moment to clarify things and avoid generalizations. Like my biology professor said to my class, “Avoid blanket statements. We need to make our determinations within an appropriate and thorough understanding of the correlating conditions.” Dan exhibited the same scientific mentality, and that makes sense given his nickname.

Okay, that’s all! Thanks for reading. And thanks, Dan and Eileen, again for your warmth and time. This really was a memorable experience for me—from my drive along the Puget Sound and the pines, to the discussions, and for the chance to listen to equipment I can’t quite afford at the moment as a starving student. I’m happy you’re a company local to me in the PNW.
 
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Jan 6, 2020 at 7:08 AM Post #1,957 of 2,108
Thanks for posting such a nice write up from your visit to BH HQ, I enjoyed reading it.

It would be great to meet Doc and the rest of the BH team just to personally say thank you for many hours of enjoyment their Bottlehead amps have given me.

The dire US to UK exchange rate and import duty adding roughly 25% on top has curtailed my Bottlehead building ambitions for the time being but I am looking forward to building another BH kit again at some point in the future

.
 
Mar 20, 2020 at 11:48 PM Post #1,960 of 2,108
Anyone know how I can confirm what output impedance my sex 3.0 is wired for?
Yep.

Ask Doc on the BH forums.
 
Jul 10, 2020 at 3:57 PM Post #1,961 of 2,108
It's been a while since my last post here hope you guys are all well.

Something for the cap junkies here.

I had been thinking bout trying the Duelund silver foil bypass capacitors in my Mainline for a while now after installing the Duelund Cast Copper capacitors in my Bottlehead Eros phono stage a few years ago and being impressed with the results.

Duelund very recently announced a new versions of both their silver and copper foil bypass capacitors along with cutting the price by 50% due to improved synergy after taking over Jenson who were undertakening the winding of them for Duelund.
The new improved version is called the Duelund JDM (Jenson Domestic Market).

At the new price (£35 each here in the UK) I couldn't resist the temptation to give them a try. After installing the silver foils in bypass configuration onto the 10 uf RTI Teflon Tin foil capacitors I have in my Mainline I have been listening to tunes through them for a few days now.

Current chain
Roon Rock (all SSD) >Oppo205 DAC >Bottlehead Mainline amp> Sennheiser hd800 (balanced cable)

These silver foils are really quiet something the difference has been significant and across the board from top to bottom.

It's hard not to gush but in all honestly it feels like I am listening to a different dac and that's not some thing I expected to be saying or say lightly.

For clarification I purchased the Duelund JDM Silver foil capacitors with my own money from their authorised distributor here in the UK and have no other financial connection with them.

Congratulation to Duelund for making such a superb product available at such a affordable price.

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Jul 10, 2020 at 5:43 PM Post #1,964 of 2,108
Im waiting for my S.E.X. to arrive and Im planning to build some easy-to-drive fullrange speakers for it. But I just got a pair of Stax Sr-Lambda with a SRD-6 adapter and was hoping that the S.E.X. will work for this. Have anyone tried this?
 
Oct 9, 2020 at 7:23 PM Post #1,965 of 2,108
I have an Elekit TU-8600 300B tube amp kit coming in tomorrow. This is intended for a speaker system but i

Trying my luck on replying a year old post. How do you find tu8600 vs mainline?
 

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