This amp challenged everything I thought I knew! xDuoo TA-66 review

xDuoo TA-66: US & CA - bit.ly/xDuooTA-66, US - amzn.to/3VWWSYS, AUS - amzn.to/45MagTc, CA - amzn.to/3RMl11N
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xDuoo TA-66 OTL tube headphone amp and OTL pre-amp review including discussions of the tubes used, point-to-point wiring, comparisons with TA-26 and TA-26S, and my favourite headphone pairings.
My top recommended HEADPHONES (prices in USD)
HarmonicDyne Athena - $179 - bit.ly/3QvQdlq
Moondrop Para - $299 - bit.ly/3QvQdlq
Sivga SV023 - $449 - amzn.to/3UKXsZ5
Meze 109 Pro - $799 - amzn.to/3y6l6qi
Sony MDR-Z1R - $1,800 - amzn.to/4dy4szZ
ZMF Atrium - $2,499 - www.zmfheadphones.com/
Meze Elite - $4,000 - bit.ly/3UMIDWb
Focal Utopia (2022) - $4,999 - amzn.to/44xEHvx
My top recommended IEMS (prices in USD)
KZ ESX - $30 - amzn.to/4bpMyxC
Tangzu FUDU - $89 - amzn.to/3UvOrlk
Simgot EM6L - $129 - amzn.to/4a3SLy1
Meze Audio Alba - $159 - bit.ly/AlbaIEM
Thieaudio Elixir - $209 - amzn.to/3ULd9zr
7Hz Timeless - $220 - amzn.to/3QslVA8
Elysian Pilgrim - $399 - bit.ly/3y7N995
Xenns Mangird Top - $530 - bit.ly/XENNSTopLin
Sennheiser IE600 - $700 - amzn.to/44AxcUQ
Effect Audio Pilgrim Noir - $799 - bit.ly/3Wu2k5O
Sennheiser IE900 - $849 - amzn.to/4b66wxy
Westone Mach 70 - $1,400 - amzn.to/3ULUK5P
My top recommended TRANSPORTS (prices in USD)
WiiM Pro - $168 - amzn.to/4bpTDOw
SMSL PL200 CD - $669 - amzn.to/3Wsd0lJ
Eversolo DMP-A6 (Master Edition) - $1,299 - amzn.to/44sBMUR
Eversolo DMP-A8 - $1,980 - amzn.to/3QxRU1B
My top recommended DACS (prices in USD)
Topping E30 II - $149 - amzn.to/3JQyGkd
Topping E50 - $199 - amzn.to/3WucWSO
SMSL DO200 Mk2 - $469 - amzn.to/4a5Di0C
Topping D70 Pro OCTO - $599 - amzn.to/4a8bubZ
Geshelli J2S AK4499EX - $680 - bit.ly/J2SAKM
Schiit Bifrost 2/64 - $799 - www.schiit.com/products/bifro...
Gustard R26 - $1,650 - amzn.to/3QyZ0mB
Schiit Yggdrasil - $2,299 - www.schiit.com/products/yggdr...
Chord TT2 - $5,295 - chordelectronics.co.uk/produc...
My top recommended HEADPHONE AMPS (prices in USD)
Schiit Magni - $119 - www.schiit.com/products/magni...
xDuoo MT-604 - $169 - amzn.to/4bpNYrW
xDuoo TA-26S - $319 - amzn.to/3UJbfzx
Geshelli A3 Pro - $499 - bit.ly/GLA3Pro
Aune S17 Pro - $699 - amzn.to/4a75v7b
Schiit Mjolnir - $1199 - www.schiit.com/products/mjoln...
Burson Audio Voyager - $5,300+ - bit.ly/4a8Mwcq
My top recommended DONGLE DACS (prices in USD)
Moondrop Dawn Pro - $50 - amzn.to/3y2dd57
Simgot DEW4X - $80 - amzn.to/4b68rlK
Questyle M15i - $349 - amzn.to/4doMSyp
My top recommended WIRELESS 'PHONES (prices in USD)
Soundpeats Air3 Deluxe - $40 - amzn.to/3UIXQr4
Soundpeats Air4 Pro - $79 - amzn.to/3Wyj4tj
Edifier Neobuds Pro 2 - $130 - amzn.to/3WwMpEf
Sennheiser Momentum 4 - $379.95 - amzn.to/3WrEqZ0
HiFiMan Svanar Wireless - $499 - amzn.to/4amOhmx
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00:00 Introduction
00:40 Design & price
02:34 Tubes & power
03:51 Sound quality
04:18 TA-66 vs TA-26
09:14 Tube options
10:44 Headphone pairings
#audiophile #audioreview #tubeamp

[@nunoferraz5426]

A Quality delivery.... always a pleasure hearing your review. Secondly, you are being faithful to the hobby by reviewing different price points. Well done.

[@PassionforSound]

I'm glad you liked it. I find there's great enjoyment at all budget levels so I try to share anything I can get my hands on that I think is interesting in some way.

[@CJDilag]

Enjoyed this one as always, Lachlan! Got my TA-66 a couple of days ago and on sale. Eagerly waiting for its arrival.

[@PassionforSound]

Awesome! I hope you love it as much as I do.

[@schoi604]

Thank you Lachlan for another great review!! Cheers from Vancouver Canada

[@PassionforSound]

♥️

[@Nephilim-81]

Lachlan. I love how you are finding value in HIFI at all price points. Well done. ❤.

[@PassionforSound]

There's so much great gear at every level (and some duds too) so it's fun trying it all out

[@Artemis_Prix]

Hi Lachlan, absolutely thrilled to see you caption Tash Sultana on your channel! She is an incredible artist and her music is mesmerizing. Her Tiny Desk concert is truly amazing because you get to see a master at the top of her craft.

[@PassionforSound]

Ooh! I'll definitely check out her Tiny Desk gig. Thank you!

[@mtinhk]

Amazing review. Most tempted to get one to replace my Fosi P3. Got an HE-R9 in the past after listening to your review. Most happy with it. That was a brave one.

[@PassionforSound]

I'm glad I could help here and with the R9. The TA-66 is definitely a really solid choice IMO.

[@MatthewDiFazio]

Love this! I’m a huge TA-66 fan myself, and am so happy with the recognition it’s getting. Thanks for the review, Lachlan. Have you tried the TA-22? It’s another fantastic product from xDuoo!

[@PassionforSound]

I haven't tried the TA-22, but I love most of their products. Whoever designs their gear is/are very talented.

[@datdudeinred]

Lol the intros are getting better & better. 😂❤ My brother lives in Australia so when i visit him i would love to meet you in person too 👊

[@PassionforSound]

I'm so glad you're liking the new approach as I develop it further. I don't have a lot of time to meet up with people, but if you happen to get here when there's a show on like the Melbourne HiFi Show then that would definitely work!

[@richardblaauwgeers4349]

I love the new style!

[@PassionforSound]

That's great! Thanks for letting me know

[@user-cy9og3cy4q]

Thank you for a great review.😊

[@PassionforSound]

I'm glad you liked it!

[@MichaelBrown-oo1ym]

Nice review. You helped me decide on both TA66 and Burson Voyager deluxe . Right now I have ZMF Atrium, HE1000SE and JM Audio modded closed Hifiman. Looking forward to your follow up review of the Burson Voyager with the new power supply

[@PassionforSound]

Great collection! Glad I could help. I hope to have the new power supply and the new Conductor GT4, and Timekeeper Voyagers coming soon...

[@SuperSeltzer]

The secret to TA-66 excellence is in hardwiring design! I love Darkvoice for the same reason. If you like DV you will love TA-66 also. The only gripe is that the transformer hum is more audible than in DV which is very silent.

[@PassionforSound]

I have zero transformer hum in the TA-66 I received

[@andrewgiovannini6613]

In an interview Rob Watts mentioned that the licensing cost to use the 4.4 connector was very high and cited it as the reason for not including it in the Mojo 2 to stay within their target for pricing. I wonder if the cost reduction mostly came from not including it on the TA 66. Nice review as always!

[@PassionforSound]

That's a good point. It's not what's happening here though because the TA-26 had no 4.4mm either and still cost $70 more.

[@OzSteve]

Great review. I ordered one of these last week and waiting on it to arrive. I have the 26 and 26s (and a few others from Xduoo) Be interested in the replacement from tube when you get your box.

[@PassionforSound]

I hope you enjoy the 66! I'll try to do a short video or community post when the tube arrives. 🙂

[@OzSteve]

@@PassionforSound I'm really looking forward to the TA-32. I wonder how much better it'll be over the TA-22. I'll be pre-ordering it when I see it advertised

[@FrantaPo-bc5mu]

Man, this video is visually amazing. Who is clothing you? Great job!

[@PassionforSound]

I'm so glad you liked it! I chose the clothes. Nice to know they look good. 🙂

[@dragonfire61]

Just got my ta-66 yesterday. Using a Voskod 6n2p-EB and a Winged "C" 6H13C power tube. Sound quality is nothing short of amazing.

[@PassionforSound]

Awesome! So glad you're enjoying it

[@chuckmaddison2924]

I'm just listening to a Naim test disc I forgot I had. It's amazing how it sounds. I guess what you feed in makes a big difference to what comes out.

[@PassionforSound]

Absolutely. I sometimes start a comparison test with any old track and think things are similar. I then switch to a high quality recording and that gap often opens significantly.

[@BillyKueekSG]

Great review, again! I still have the original TA-26, just find that having the on/off switch in front for a tube amp makes more sense. The 6N8P replacements are easier. I have the Sylvania 6SN7GT, Ken-Rad 6SN7GTA, GE 6SN7, a Soviet OTK 6SN7 and my favorite being the Tungsol 6SN7GT Mouse Ears. I find it hard to get more options or better replacement for the 6N5P, only managed to get a Soviet Union 6H5C/6080, GE 6AS7 and Thomson-CSF 6080WA and none really delights me yet. I can so resonate with your statement “some nights everything just sounds amazing”, glad I am not alone. Any recommendations for the 6N5P replacement?

[@PassionforSound]

I really like my Tung Sol 6AS7G

[@tek00732882]

Im rocking the TA-20... Xduoo is great.

[@rbhis000]

I know it was only a minor gripe, but there is a great reason for the power switch being on the back. I do that on my builds to keep power away from the audio signal. It’s a little inconvenient, but makes the rest of the build so much easier.

[@PassionforSound]

I can understand that. I'm sure there could be creative workarounds though...

[@russellnedland4569]

This with a pair of Senn 6XX ROCKS!!! As far as tube rolling, you might gain soundstage, but tonaly it’s pretty good.

[@PassionforSound]

I agree. It's really only staging I was wanting to tweak 🙂

[@ancientalien815]

Your mic sounds really good in this video.

[@PassionforSound]

Thanks for letting me know. I've been tinkering with mic placement and think I've got it almost perfect now... 🙂

[@Atomicman123]

Nice Review! Even your given compatibility specs do not fit, do you think it will run a DCA E3?

[@PassionforSound]

The E3 is probably a tough call for it, but it might scrape through.

[@subcoded]

Very nice review! I own HD650 but I don't like them (i find them boring sounding with bad soundstage) Do you think that this amp will drive AKG K701s that i'm planning to buy?

[@PassionforSound]

It should be fine with those

[@SuperSeltzer]

There are lots of tube choices if you like to use the adapter. Any 5751 and 12AX7 would do nicely w/ adapter.

[@vaneast411]

xDuoo making some great tube gear for cheap I have some pricey HP amps but gravitate to the TA-26 for is forgiving and fun musical presentation right up there with the Bottlehead Crack

[@jcisme]

Did you try this as a preamp ? I wonder how this would go into some of the new D class mono blocks like the Fosi V3 mono or some Aiyima offering.

[@PassionforSound]

I didn't, but I have tried the TA-26 and they work great as preamps.

[@caseyodonnell6621]

Interesting. So tube pre and buffer but solid state amplification (and I'm guessing solid state rectifier)? So it's more of a hybrid than a true OTL, right?

[@PassionforSound]

No, it's 100% tube for the amplification. The rectifier is solid state though.

[@progrocker84]

Is the TA66 line-out anywhere close to a Freya+ with stock tubes? Which sounds more "tubey" (as that term is commonly understood)?

[@PassionforSound]

I haven't tried a Freya+. Sorry.

[@tonythearchitect]

Great review and I'm very tempted to get one but I already have a bottlehead crack w/speedball. Curious to know how these two compare either if you have the speedball or maybe from memory. I know my speedball, for iems, is better than my Aune S17 Pro. Thanks!

[@PassionforSound]

I don't have a Crack anymore, but having built a few of them in the past, including upgrading caps, etc. I'm pretty confident that the Crack is the better amp still. Enjoy what you have. 🙂

[@tonythearchitect]

@@PassionforSound Thanks. I hear from Wave Theory that the bottlehead crack has more resolution.

[@PassionforSound]

@tonythearchitect that makes sense

[@spamcan9208]

Wow, having point-to-point wiring that also doesn't look like absolute dog sh!t is a nice surprise. I wasn't expecting that at all. And I'm glad they decided to not chase power numbers. I really like the updated look but I still don't get why they kept that power switch on the back after all the attention to detail. Regardless it's a very nice unit.

[@TheRedMantra]

The 6N5PJ tube can still be rolled. 6AS7G, 6080, 7236, 7802, 5998/421a. Lots of good options from $20-60 USD. Of course some of the ones I mentioned can cost a fortune relative to the cost of the amp, but good tires can make a mid level bicycle ride noticeably better.

[@Alextraz]

Is this a good combo with Sivga P2 pro you have recently reviewed. I felt that those headphones ...at least the way you have described them...might be goos fit for me.

[@PassionforSound]

I would probably choose a good solid state amp for the P2 Pro. They don't really need extra smoothness or warmth. The TA-66 isn't overly rich, but still might not be the best fit with the Sivgas. I'd look at a decent amp from Schiit or Geshelli Labs first. Perhaps a Topping or SMSL option if you're somewhere that's hard to get the USA brands.

[@Alextraz]

@@PassionforSound in that case wonti be ok with my main amp - atoll in200se?

[@PassionforSound]

I don't know that one, but if it's a regular solid state amp it should be great

[@joshchacko7729]

Thanks man.

[@PassionforSound]

My pleasure 🙂

[@mauriceverstraten844]

Just found my Ta-66 came with the Voskhod from the factory, trying an ubranded 6n2 tube from China atm. Furthermore I got some Philips, RCA an a GE 6080 tubes to play around. It’s a nica little amp for the monny imo

[@PassionforSound]

That's a bonus! Enjoy!

[@maroz73]

Nice review , will that work with a Focal Utopia ? Thanks

[@PassionforSound]

Definitely! It won't maximise the resolution of the Utopias, but they'll be plenty enjoyable 🙂

[@hartyewh1]

Would this in general be the best tube amp for the price? Sound quality being the only consideration.

[@PassionforSound]

So long as you're pairing it with headphones of sufficient impedance, I'd say it's definitely the best I've tried at the price (assuming we're talking pure tube and not hybrid like MT-604)

[@boyanddog]

What are the advantages/disadvantages of an OTL amp having two input stage tubes and two output stage tubes over one and one?

[@PassionforSound]

It will largely come down to the specific tubes and circuit design, but more tubes can provide more power (although not a guarantee), can lower output impedance (also not a guarantee), and means you almost definitely have to buy matched pairs of tubes. 🙂

[@markothomas9765]

I've always wanted a tube amp. Would you be reviewing the ta22 as well? That is a dac amp combo, if that one isn't that fun, 66 might be the ideal pick up

[@PassionforSound]

I don't currently have any plans to review the TA-22. Sorry

[@markothomas9765]

Thank you Lachlan! Keep up the great work :D

[@pk.002]

I can give my input as I own the TA-22. It's nothing short of phenomenal and easily the best dac/amp I've ever owned, period. I put two Genalex Gold Lion tubes in mine and the presentation is balanced with warmth, rich, and spacious. The stock tubes are good by themselves but I prefer the Gold Lion tubes. I've also tried RCA clear tops which sound more analytical, and Electroharmonix which are the warmest sounding of the sets I've used. It powers my HD 600, and hungrier planars like the Moondrop Para and Moondrop Venus balanced wonderfully. It also drives them great single ended too. My only cons in my use case about the device are as follows: -The menu is a pain to navigate -Class A amplifier generates noticeable heat, so on hot, humid summer days I have to switch back to another solid state amplfier that's more efficient and runs cooler Overall, it has my seal of approval and has my highest recommendation. Apos offers them refurbished which I bought for $415 which makes it an incredible bargain.

[@markothomas9765]

@@pk.002 thank you Peter, this is awesome insight. I will add it to the top of my plan to buy gear list

[@pk.002]

@@markothomas9765 You're welcome! I'm sure you'll love it once you get yours. It's a fantastic piece of kit.

[@blank-jo1xp]

Do you think the Ta-66 would be a good pairing with 600 ohm Beyers?

[@PassionforSound]

Absolutely!

[@Prxyshj]

What do you recommend for ZMF Caldera Closed? Also are there portables that can power TOTL headphones?

[@PassionforSound]

If you've got the budget, I'd look at a higher level tube amp from Feliks or Linear Tube Audio for the Caldera Closed. There are plenty of portables that will drive those too, starting with the Chord Mojo 2 as a great option.

[@Prxyshj]

@@PassionforSound this may sound silly, but I just don’t like the way the chord looks. It’s a bit … plastic looking. I like the xduoo looks but they might be a bit big for true portability. I assume a Qudelix 5K is underpowered for it

[@PassionforSound]

I'm not sure about the Qudelix, but it's quite possible it would be fine. Being battery powered means it should have decent power output (as opposed to USB only powered dongles). If you're after a better cable option for the ZMFs (which do look and feel a bit plastic), the Apos Flow cables are a great option with ZMFs (if you're in the US, Canada or Australia)

[@Prxyshj]

Given that the point to point wiring is just simple metal, doesn’t that imply that any investment in high end cables is worthless? In fact it made me think that in general even printed circuit board interconnect is just copper so how can high end cabling at the end of this chain make a difference? And yet there are many people on places like Head Fi who genuinely believe their nice cables do alter the sound. Thoughts?

[@PassionforSound]

It can seem contradictory for sure, but the final wire that runs to the speakers /headphones / earphones has influence too over things like the degree to which very small signal fluctuations are transmitted and the timing coherency of the signal which is important too. The internal wiring of the devices also matter and it's why higher priced gear often (but not always) sounds better - because the quality of internal components and circuit boards/wiring is better.

[@JTB--]

Xduoo MT-604 is a great little Amp too. Don't pay attention to the price at $170. It's legit. Drives the ZMF Atrium beautifully adding punch/slam. How does theTA-66 sound the more you crank the volume up? This is usually when the cheaper OTL's struggle. More volume = more distortion

[@PassionforSound]

I agree about the MT-604. I love that amp! I'm not one to test amps at high volume because I don't encourage loud listening due to the danger it poses to our hearing. I heard no signs of any issues at "enthusiastic" listening levels though.

[@JTB--]

@@PassionforSound I agree. But I'm a headbanger!! 🤟 I'll probably be be deaf soon because of it

[@shawnrobinson5242]

My MT-604 with Voskhod tubes wiped the floor with my Feliks Euforia. I couldn't believe what I was hearing. Literally, the only thing the Euforia won at was bass extension. That's it.

[@JTB--]

@@shawnrobinson5242 the MT-604 is going for $84 Bucks on Amazon prime today. What a deal/steal. I'm considering getting another one for a secondary HP set-up

[@PassionforSound]

@shawnrobinson5242 the MT-604 is bunches of fun, but I suspect there might have been a bottleneck somewhere preventing the Euforia from performing its best due to DAC, cables, or headphones

[@Mixail747]

Can it be used with IEMs? Prolly not coz of sensitivity?...

[@PassionforSound]

Yep, sensitivity and lower impedance of IEMs will mean that most aren't a good match for an amp like this one.

[@backrack01]

What headphones would u recommend for this? Thinking 2k or less.

[@PassionforSound]

Any ZMF that suits your fancy or either the Sennheiser HD800S or HD660S2.

[@necrodh]

Any AKG

[@clintonwalker5000]

Hi, I’ve got the original Chord TT DAC/headphone amp. I’ve never enjoyed the headphone output on it my headphones are.Adeez lc closed back. I know you have a new TT so my question is what valve headphone amplifier would you recommend which would really be an upgrade from the TT

[@PassionforSound]

I'm not sure how the original TT and TT2 compare, but if you want an amp that's on the same level of transparency and technical performance, but with different sonic character, you need to be in the territory of a Burson Soloist GT or above. What don't you like about the TT output? (Trying to narrow down the field for your)

[@clintonwalker5000]

@@PassionforSound Hi thanks for replying , I look out for Hi-Fi i’m interested in on your channel I think your reviews are great with amazing detail 👍 my original TT sounds thin ,not holographic and there’s not much sound stage. The other thing is I can only listen to my digital streamer through my TT. I recently bought a Linn lp12 turntable which I can only listen to through my headphones output from my amplifier. Which is Luxman 550 AXll pure class A ,phenomenal beautiful amp headphones output is not good ,but still sounds slightly better than TT with my digital ,can’t listen to my turntable with the TT because it’s obviously built into the DAC, So I’m looking for probably Valve amplifier with a holographic good soundstage transparent and very detailed. I’m not looking for much am I 😁 i’ve probably answered my own question but LTA Looks good. is there a cheaper option that can rival the TT/LTA. many thanks .

[@PassionforSound]

@clintonwalker5000 you could maybe look at something like the Auris Euterpe, but I've not compared them directly to know how the LTA Velo stacks up. I would choose the Velo for its tube rolling options and general design and performance.

[@joshuastephens3926]

I still have been unable to find anyone video reviews of the xduoo MH02. If you ever get a chance to test that, I would love some insight into what you think about it as a budget tube dac/amp.

[@hoiley555]

I second this motion. Looks like a perfect combination of what I am looking for but can't find anyone who's given it a solid test or comparison.

[@joshuastephens3926]

@@hoiley555 I have it and it’s really good but I have no other reference and limited headphones to try it with. I would love to see if it’s as good as I think it is or if there is a much higher limit to greatness I have yet to reach. I also don’t know what tubes should or should not sound like. For $150 though, it’s really nice.

[@PassionforSound]

I think I've actually got it coming up for review. I can't access my schedule planner right now, but pretty sure it's in there.

[@shawnrobinson5242]

I tried it for a few weeks next to my MT-604 and the sound was just as good, maybe better, but there is a catch with it. The MH-02 is an RFI...magnet. I tried all kinds of sound eliminating transformers and power strips. I was never able to eliminate enough RFI to make it listenable, but nope. The MT-604 was sitting right next to it while A/Bing and the 604 has almost no RFI issues, so I don't know what was going on with the MH-02. Regardless, I emailed Xduoo and told them the issue. Hopefully, they fix it, because it has tons of potential.

[@joshuastephens3926]

@@shawnrobinson5242 so keep it away from other amps I guess and it will be amazing. I have it connected directly to my iPad on my nightstand and my Meze headphones sound wonderful.

[@moonabhinav]

Dang is it good upgrade over Mt602 or 604? Or should we continue saving for better tube amps?

[@PassionforSound]

It's a decent step up in some areas, but it's also less versatile because the TA-66 needs higher impedance (48 ohm plus) headphones to be optimal. Depending on your headphones, I'd probably recommend saving up for the TA-20 Plus which is more of a direct upgrade from the MT-602/4.

[@rudyvirupakshaiah5818]

I have both, I like the MT604 better, as it's more versatile about about 99% as good...i find the MT604 is better than the TA66 when it comes to dynamics

[@moonabhinav]

@@rudyvirupakshaiah5818 thanks for your thought on them. I do agree 604 seems to be more useful specifically if you have your speakers at an different angle or distance. However I did not find any significant differences between 604 and some other similarly priced chip based amps. I have yet to experience that tube goodness it's seems.

[@taho88]

Hey Lachlan, you're saying this should work well with 40 ohms and above. Back in the day I had the Bottle Head Crack paired with a Beyer 770 250 ohm and it was great.I have missed both of them dearly. Now I find myself owning the 770x anniversary. At 48 ohms,do you think they would be a decent match for the TA-66 ?

[@PassionforSound]

That should do very nicely based on what I've experienced here. How sensitive is the 770x? The only concern might be noise if they're as sensitive as something like the DT 700/900 Pro X

[@taho88]

​@@PassionforSoundThanks for the reply. They are 98db.

[@PassionforSound]

I haven't tested the TA-66 with such a sensitive and relatively low impedance design so I don't know if you'll hear noise with them. They'll work well in terms of sound performance. It's just a question of the noise floor of the amp and that can also vary with tubes. It's definitely worth a try if you're able to return the amp if it's no good because the TA-66 sounds great.

[@marcusm5127]

The efficency is typically measured at 1000 Hz meaning that bass and subb-bass requires a lot more power.

[@PassionforSound]

That's not accurate for headphones where there's only a single driver.

[@randolphlee3025]

Mr. Lachlan, I have a pair of Grado GH 3, I would like to find a robust amp to drive them I think they are 32 OHM

[@PassionforSound]

OTL amps won't be your best bet. What is your budget?

[@russellnedland4569]

Have you had a chance to demo the Drop/Xduoo TA-84? EL84 power tubes for way more accessible rolling options.

[@russellnedland4569]

$399 (US) w/ stock Psvane classic tubes!

[@PassionforSound]

I haven't tried that one.

[@johnratcliffe6438]

How are you getting on with the Aero DAC?

[@PassionforSound]

Loving it and excited for the review!

[@danisold]

There is a 6sn7 to 6n2 converter on Amazon, i searched 6n2 tube converter. Would that work in the ta66. Anyone have any experience with that?

[@PassionforSound]

I haven't looked into that. Just be sure that the electrical requirements align before plugging it in. Adapting pin layouts doesn't mean the voltage and current requirements will match. 🙂

[@Rezzzn0r]

Hmm maybe I should try it... I've never owned tube amp. Is it compatible with IEM?

[@PassionforSound]

Not really. You're better off going hybrid or transformer coupled for IEMs at this price level. The OTL designs will alter the frequency response of most headphones due to having higher output impedance. They're also likely going to be noisy with IEMs because they're designed more for high impedance headphones.

[@Rezzzn0r]

@@PassionforSound awesome, thanks bro. I will stick with my Mojo2 then ;)

[@RocketLauncherwithInfiniteAmmo]

I like the point to point wiring idea. See if it had been balanced too, that might be asking for the moon on a stick, but I would have had one at the price had it been balanced.

[@PassionforSound]

Balanced OTL tube amps are rare (if not non existent) and generally not necessary. It doesn't improve the sound in any way (assuming both circuits were equally well designed) and it means at least twice as many tubes and the need to buy expensive matches pairs or quads

[@jaybrodnax]

I'd love to know how it compares to Bottlehead Crack (preferably w Speedball)

[@PassionforSound]

Me too, but I don't have a Crack anymore. I suspect the Crack would be comfortably better (and far easier to upgrade with capacitors, etc.)

[@TheMaurob1979]

I wonder if can drive also the hifiman 400 se

[@PassionforSound]

That might be a stretch because the HE400 SE is quite hard to drive.

[@paulyllow]

How is this compare with Schoit Vali 3 or Lyr?

[@PassionforSound]

It's quite different from the Lyr because this is OTL and Lyr is hybrid. I haven't tried the Vali so can't comment there - sorry.

[@progrocker84]

I recall seeing on a forum that the amp hums until the front tube has been properly burned in. I can confirm that tube burn-in removes the hum through headphones. However, I'm still hearing the hum through my speakers even after 50+ hrs of burn in. The hum is only present when no music is playing, however. Does anyone else have this issue? Other than the hum when there is no signal, I love this amp.

[@0rogontorogon]

Thats correct, tubes require some "burn-in" before they reach peak performance. My guess is that your speakers have a far lower impedance than your headphones do. In my experience preamp tubes are a bit of a lottery regarding hum and/or microphonics. If one hums after completing break in time it will likely hum for the rest of its life. If it annoys you, replace the tube and hope for the best.

[@PassionforSound]

Great advice above.

[@michaelorton9887]

Ive always thought the bass was better with tube amps you can here the voice of all the instruments better altjough i like the sound of some of fishers first solid state germanium stuff also ,theirs alot of really good soundingdesigns out their

[@jeffhernandez5098]

Are OTL amps good for lower impedance headphones? Say 32 - 80 ohm.

[@PassionforSound]

You need to be a bit selective as it will depend on the specific output impedance of the amp. This one is good for headphones from about 50 ohms and up IIRC. I'm pretty sure I covered the specifics more accurately at the end of this video.

[@jw-lk1pe]

does the 26 have a dac?

[@PassionforSound]

No. Both of these are pure amp and pre-amp only.

[@marekkordzik7517]

I think Im good with Feliks audio echo mk 2 ....

[@PassionforSound]

Definitely 🙂

[@aRc11-11]

Why do I have an adverse reaction to XDuoo? Maybe the early clunkers from five, six years past. One reason? Is the egg laid with the hummm- dinger, with the very latest co-op with Drop.

[@PassionforSound]

Is that an xDuoo co-op with Drop? I'm not on there at all these days

[@aRc11-11]

They have "dropped" the ball in that organization.​@@PassionforSound

[@Mark-rw3kw]

More direct wiring paths? The electrical circuit design of point-to-point wiring is not different than using a circuit board, unless they are two different amplifier designs. There "may" be other advantages, but often in a simple circuit like this is often less complicated to use point to point wiring, just like is used in many simple speaker crossovers.

[@jaybrodnax]

Does the size of the "wire" matter? If find it kind of amazing how small tiny traces work, especially when people talk up the benefits of better power cables and headphone cables

[@Mark-rw3kw]

@@jaybrodnax Yes, that is a contradiction. But large cables generate a lot of revenue and a talking about them generates a lot KZbin views and ad revenue. I noticed in this amp, the point-to-point wiring doesn't appear to be copper (and not likely silver), and it is not shielded. Looking at the inside of the amp, it looks like the point-to-point wiring is probably the easiest and cheapest solution for such a simple tube design.

[@PassionforSound]

Traces in circuit boards are also not shielded. The wires in the TA-66 appear to be silver-plated copper. Also, by going point-to-point, each wire can take the most direct possible route to the next component. This reduces the length of the pathways which will improve the circuit by reducing the filtering effects that ALL wiring/traces have on the signal. Less wire/trace equals less filtering equals more transparent circuit.

[@Mark-rw3kw]

@@PassionforSound I maintain that you could not hear the difference (in a blind test) if this amp had a well designed printed circuit board (PCB) vs point to point wiring. Properly designed using copper, a PCB can perform just as well as a point-to-point wiring in an amp. But for a tube design this simple it doesn't need a PCB, and using one would make it harder or more costly to build and harder to do revisions. Also, it appears that a lot of so-called point to point wiring in this amp is going to the output and inputs, which would usually be point to point even if using a PCB.

[@PassionforSound]

@Mark-rw3kw I don't really understand the point of this and what you're trying to prove. There's not a debate to be had here.

[@jaybrodnax]

I love Xduoo products, especially their visual design. I HATE blue LEDs though

[@PassionforSound]

Yeah, blue isn't my favourite either. It's nice that it's diffused behind the volume knob on the TA-66 though so it's not piercing and uncomfortable like a direct view to a blue LED

[@masterazlan6999]

Wow it's looks like Eddie Van Halen guitars..wow point to point...2 wow so far..I'd really like Progressions.. Hmm only things I'd to ask frequently..Does it noisey for an iem?..Peace!

[@PassionforSound]

It won't suit IEMs due to being OTL. It's probably noisy and also will alter the frequency response on most IEMs.

[@michaelorton9887]

I hope they keep it at a low price for quite a while so i can save up to buy it

[@PassionforSound]

I've never seen them raise prices of existing products before so you should be fine.

[@jefffeith4201]

I wish xDuoo made amps to drive speakers too.

[@PassionforSound]

That would be brilliant!

[@carminedesanto6746]

GM☕️🦘 I’m still rocking the 604🙂

[@TheVeganVicar]

How’s the weather in Toronto today?

[@carminedesanto6746]

It’s actually pretty decent (now that two days of rain ☔️ have gone )

[@JohnClarkW]

I use the 602 and am very happy.

[@brianliu522]

I live in Toronto too, and I love my mt-604

[@carminedesanto6746]

@@brianliu522 Great! Are you going to Audiofest in October

[@necrodh]

Xduoo is a legit audio brand they dont need to lie like others

[@kentbergstrom3020]

I would probably love the design when I was 17, but now at 67 not so much 😄

[@0rogontorogon]

Sadly tube rolling has reached a pricepoint that makes no sense anymore for $250 6as7g/6080 amps. These tubes are in dire need for new production versions, but sadly nobody makes those. I suspect the factory equipment is not available anymore (afaik new production pentodes are made with the original factory equipment relocated to the new factory, like Gold Lion tubes).

[@PassionforSound]

That's exactly the case. I think there might be one or two factories making 6AS7G/6080 tubes, but it's becoming more difficult to track down good and affordable options. I suspect we'll see a shift to alternative power tubes for future OTL amp designs.

[@artureff3046]

tube rolling is fun....

[@PeterbFree]

The names of these products are so similar it’s hard to follow which one you are speaking about. It would be great if companies gave their products proper names and not codes. So many audio companies go with the code route. Focal and others understand better than Sony etc

[@PassionforSound]

Very true. The affordable Chinese brands in particular seem to love random letter and number combos!

[@Thoughtflux]

Why are tube amps never balanced ever?

[@PassionforSound]

Because it's not necessary for high quality sound and you'd need twice as many tubes and matched pairs of tubes which would raise the price with no benefit other than more power and higher noise floor (not a benefit)

[@Thoughtflux]

@@PassionforSound that is true! Thanks for the response.

[@Prxyshj]

I am skeptical that this is the right way to pronounce their brand name 😂

[@PassionforSound]

I have no idea what it should be so I just go for it with confidence! 😂

[@ThinkingBetter]

Better not buy some US$5,000 RCA cables for this one hahahaha

[@MaxKnoxwille]

Ordered this one few months ago and cancelled the order, cuz I'm tired of waiting. The shipping date was always postponed and I got mad. And I glad I did. Because I really hate how it looks with this blue led freakin' light and totally incompatible grey and red colors. 1/10 for design. Pretty sure it sounds great, but it can't be integrated in my system because of this cheap look and colors. So I ordered Drop + Xduoo TA84 which looks absolutely gorgeous and premium, also packed with a nice features like an internal DAC for those of you who don't have one. I'm really excited and happy that I didn't get this ugly amp. Salut

[@PassionforSound]

I'm glad you're happy with your ultimate choice.

[@kurt120032002]

to be fair, their point to point wire is meh. The advantage of ptp wire is that 1. the path is shorter, and 2nd you got a far better control over the medium that caries the signal. I was expecting a monocrystal copper wire, and that does not look copper to me, and I really doubt it is monocrystal silver wire, and 2nd let down is 90 deg bend. That damaged the crystal of the metal and affects in how the signal arives at the other end. In heneral aplications, the most annoying aspect is raised impedance and potentially heat, but here in Audio world, thing tend to be a little more picky, and that is a really innexpensive thing to avoid, I mean just pay attention when you bend the wire, no extra cost needed, and it takes less wire.

[@hifitommy]

here is a link to Brent Jessee..... www.audiotubes.com/bjtubes.htm#6A%20to%206Z ....perhaps.

[@PassionforSound]

Thank you!

[@paulpaulzadeh6172]

So it means you like distortion color , 😂😂

[@kamertonaudiophileplayer847]

Forget about money, remember only about your ears.

[@BigBoss-kk8hq]

Damn makes me wish I didn't buy the schiit folkvangr

[@PassionforSound]

The Folkvangr still smashes it 🙂

[@TheTastefulThickness]

The catch is the power.

[@russellnedland4569]

Will the Meze 109 pro tolerate the high impedance of this amplifier?

[@PassionforSound]

At 40 ohms it should be ok. The tonality might shift a little, but I wouldn't expect much shift.

[@russellnedland4569]

@@PassionforSound What headphone would you recommend for stepping into high ohm otl tube use around, say $500 or so?

[@russellnedland4569]

I did a bit more homework and realized hd6xx is a good inexpensive starting point. I love your reviews and the fact that you answer fan questions, patron or not most don’t.

[@PassionforSound]

@russellnedland4569 any of the Sennheisers from HD600/6xx/650 and up or the Sivga SV023 would be my choices.

[@PassionforSound]

@russellnedland4569 great choice. Always happy to chat to viewers! 🙂🙂