This is the thread to discuss real obscure portable gear. I’m not talking p6 pro, caying C9, or even mass kobo 428. I’m talking the bakoon HPA-21, a battery powered dac the size of a xi broadway or maybe the analog squared paper TUR-08, (afaik) the only portable tube true preamp on the market. What have you discovered recently? Any questions of gear you’ve stumbled across?
Ok, so I made this thread mostly to discuss how utterly intrigued I am by the TUR-08 (and a couple other amps, but those for later). The creator has confirmed to me that he does make a version that has a true pre-amp function ontop of already being a 4wpc transportable tube amp with a non-feedback class a power amp stage. Tbh, I realy, realy can’t explain how absurdly tempted I am by this. With a rrp of under 3k usd too it seems like not all to bad of a deal. This + broadway/428 could (theoretically since I’ve never heard it) an astonishing combo by making up for the fairly unrelenting 428 sound sig while maintaining its astonishing grip and texture. It even at least holds the posability of doing stuff like the 1266 and sus some modicum of justice as well given its power specs.
Unfortunately I do not speak Japanese and I am fairly certain the creator uses Google translate to English so getting propper technical information can be a bit of a difficulty
Have you seen anything from swan song like the cygnet or mini black, or their more limited runs like their portable speaker amps and whatnot, neat stuff, that’s fairly obscure
I guess some of the other things I’d find obscure might be too normal for this thread, as they are just not well known, rather than super weird
Second amp I want to bring up is the Tsurunagi by Brise. They are a totl cable manufacturer as many of you will know but what really draws me to this amp is 2 fold. 1st, its current dive, and 2nd, it is tuned for both iems and over ears with a fair amount of power. Unfortunately the pre-orders are all sold out already (and they were expensive) and the amp won’t be out for several more months here but I will be following this one closely
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My intention for this thread wasn’t just wierd, but more of just stuff people may not have run across. I think we on the forum as a whole wax and wane about the p6p and 428 enough that they don’t fit and the broadway and c9 feel fairly mainstream. Basicaly anything else (and even those above that don’t have dedicated threads yet) fit imo
TBH current drive is interesting and all, but it’s really not great with iems from my experience, most iems will not take to that well at all, completely fucks them up, so I will have to see how well they can get this done. But even if it was done well, it’s still a problem of iems not reacting well to current drive, most things with a crossover get completely fucked up. Will be getting my hands on one eventually though, so should be fun
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Well I do like vorzuge amps, they have some pretty nice stuff, some of it with bass boosts/eq which is nice so I think they should get a nod. Anything from orb or kojo tech I’ve really enjoyed but they do lack drive for most headphones tbh. You’ve already mentioned the bakoon stuff. I used to enjoy some of the cypher labs and ray samuels portables but those have fallen off.
Also I think this counts, I owned this and actually really enjoyed it, but holy shit is it expensive for what it is
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I do know of the swan song mini! Never seen any reviews or comments on it though. Their headphones also interest me a bit purely because they are so strange tbh.
I would love to see sinsentive iems start to make a comeback though. Honestly, something as simply as the audeze I4, imo, is prety cool even if execution isn’t great. A current drive portable amp may open up that world a bit more.
That’s why you just need to use the mad24 that don’t have a crossover 
But realy, how did you even do current drive with iems? Bakoon portable? I thought that one in general was just aimed at over ears if I’m honest
Bakoon portable, my re/leafs as well. Also keep in mind the nature of current drive typically leans pretty dead neutral and clean which some may not like
The re/leaf monoblocks will run iems? I didn’t realize that. Just assumed they wouldn’t do well. As for the dead neutral nature, is that always true though? I was under the impression the 13r leans a bit dark but is also current drive. That said, I have 0 technical understanding of current drive topologies nor have a heard any myself.
I have been tempted by some of the portable Ray Samuel’s stuff if I’m honest, bit that wierd balanced plug keeps making me heistsate. Iirc he still had a couple of each portable amp left in stock last time we spoke. But the utter lack of commentary on it post 2015 has made me skeptical tbh.
I’ve actyaly stumbled across this before. Iirc its just a flat out dac, yah?
They do fine with some, bad with others
Yes, but that’s kinda an exception from my experience, so who knows, there’s really not enough out there to
Given he was one of the first people making some of the higher performing portables he kinda decided to go with that before things were standardized
No, it powers headphones
Those look like guitar pickups
Hence the current drive issues with iems you mentioned…
I am just currious if this “current drive is linear” is similar to “class a warm” where its not true, there just isn’t much out that breaks the trend.
Oh, 0 blame for the choice, it’s just an added inconvenience i don’t feel like tackling tbh.
There is truly just 0 info online about this this. Clearly this was the first true NOS portable. Assuming you think it stacks up disfavorably to p6p?
Also, side rant here. I fucking detest sources that don’t have any form of BT input. Sp1k being a perfect example. I want to listen to music not on my SD card right now but am out and about. That means 0 ability to use mad16. I dont even care if its shitty right now. But instead of shitty BT with mad 24 I’ve got tws og galaxy buds from my phone which are just objectively way worse
I’d assume that’s some of it, but also the nature of current drive will generally alter the signature of dynamic drivers for example because it can almost ignore the impedance peaks and dips in dynamic drivers (if I understand it correctly). I mean it also totally fucked with the utopia for some reason, made it sound all bassy and flabby
Yes, but I do think it’s closer than it really should be in some cases lol, it’s amp is it’s limiting factor, but the dac is real nice inside there
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Thats… very wierd… I wonder if current drive makes output impendnce not behave the way we expect? Flabby bass to me tends to mean to low of damping factor at least.
Boo! Let me hate the bullshit! But seriously, any idea if he does any models with LO?
Well it is typically in the hundred or so as mentioned previously for current drive designs, but that doesn’t seem to bother most planar, and with the utopia I have heard it sound good at that high oi on other amps, so I think it’s more how it ignores those impedance spikes and dips that makes the headphone almost lose it’s tuning.
No, and even if he did, you would still be locked to wav which is irritating, that is if you can look past the lack of a ui at all lol. It’s not really that usable, so that’s why I sold mine, it’s lack of features actually was too much this time
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I didn’t know that. I seriously want to learn more about current drive topologies but holy hell is there just 0 info out there…
Tubes mostly I would assume? Tbh I kinda want to get utopia again specificaly to try on tubes.
Oh, now that would be interesting actualy. If that’s the case I wonder if you could make a higher end dynamic headphone and have an easier time tuning if you pair it with a specificly designed current drive amp (think like a solitaire system but current drive amp and dynamic driver). Tbh there are so many cool techs in hifi that I feel are under utilized. Multi-driver systems are another. They can be so, so, so good with iems why aren’t more people exploring for over ears?
Yah, ui is shit but I honestly just use my p6p on shuffle only anyways. I did forget about wav only though. Idk I even have 1k wav files total tbh
Maybe because it only changes where the feedback is taken.
Note: That is off course oversimplified since your amp needs to adequately react to the feedback it receives, be stable when feedback and input are phase shifted, etc.
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This is going off of current drive designs I’ve tried
QES: typical output impedance of around 150-200 ish ohms for their amps
Bakoon: fun fact the output impedance of the hpa-21 is 2.5 million ohms in current drive, not sure about the other models, but expect it’s high
Re/Leaf: not exactly sure but iirc it’s somewhere in the hundred or so
Austin Audio Works Black Amp: got to demo, I think around 50 ish ohms oi? Lower than others
And then a few one offs/diy that also had impedance within the hundreds
Yes depending on the amp
Likely possible
Ehhhhh, there’s a difference from something being awesome in theory vs actually getting a worthwhile result in practice. For example, multi driver headphones are neat and all, but almost always fail, and it makes sense why. Why would you go out of your way to bother with multiple different drivers and crossovers and whatnot if one singular driver can give you all you need. It’s just a case of complicating things for no reason imo, and you end up with a worse result than you started. This is for headphones though, not counting iems or speakers (because it’s harder to get away with one driver solutions there). So the multi driver things for headphones basically doesn’t make sense and isn’t something that I would assume is worthwhile to explore for most manufacturers.
When you introduce multiple drivers you now have to adjust the entire headphone design itself from a physical space and acoustic perspective, you now typically want to introduce crossovers which increases complexity and is typically where you would have signal quality loss that otherwise wouldn’t happen + the space that takes up, you now have to closely match drivers for fr, timbre, time alignment stuff, etc. And this also would likely change the way it reacts to amps a lot so now you need to account for that, and more. Doesn’t make sense to me at least
Same I only use it very basic. With the wav thing it’s great if you are editing audio in an uncompressed format, otherwise just takes up space for no real good reason
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