SET Shootout China VS The USA

2A3 SET from china arrives any day now.

The tech who loaned me his UX250 (aka 50 Tube) amp, with a  12AU7 in front + a  6BH7 (??) , has incredible pure Cobalt out trans. ($1k+ each back in 2000, now no longer in production). . he will help me set up the  2A3. 

Has a  AX+AU my 2 fav front tubes anda   quad of 2A3's. 

My speakers are pure neutrality, no coloration, no distortion,. 

So whatever amp/ source you plug in, will register the nuances inherent in the circuit.

Will be very interesting. 

USA has pure cobalt out trans which gives the edge in power, but the china 2A3 has a 2 tubes per channel.

Gonna be interesting and will post a  YT upload with comments,


Hand on to your horses at the OK Corral. 

Grab a  beer at the saloon, 

sundown shootout at the edge of town. 



How can a single product from a single company represent an entire industry of an entire country?

Does the 2A3 amp have 2 output tubes (2A3) per channel? ~~~~~~~~~~~~~~~~~


Yes two 2A3 tubes per channel, vs his single per channle UX50 tube (aka ux250) 2A3 3.5 watts x 2 = 7 watts per channel vs his UX50 at 6 watts per channel He has pure cobalt out trans, vs the chinese 2A3 outs which no doubt considering what I paid fo the amp are the low grade Z11 steel. But 2x’s the weight of his cobalt trans. the UX50 hasa 12AU7 + a 6BH7 (?) , lights up like a christmas tree, niceee. I prerfer AX. , So its going to be close. If I find the 2A3 has a bit too much roll off on bass/highs,, I might have to sell and eventually get the Muzishare R100 845, but that will be 2 yrs off. I have the speakers which detect nuances in amplifaction. My speakers register every miniscle going on in amplifaction. Even cd/DAC shootouts. Dual FR are revealing. Also keep in mind we will have stock 2A3’s running. So even if bass/highs are a bit rolledd, there’s always hope the Psvane ACME 2A3’s (like $600 + ship + louisiana Tax, ) might give up some better fq’s in the band width. If so, then we might have a keeper, a winner. I’m definetly a SET audiophile as of now. PP are wonderful amplifaction. Its just that SET’s have a certain magical spell. Its like you got a fix and now you are hooked like a dope junkie. I see SET’s as the future , as 1st choice. SETs get the Cuban Cigar, PP’s well, get the buds.


~~~In 20 yrs~~~~~~

~~~~it will be all SET’s.~~~

~PP will not be in production.

~~No buyers.

~Something like that.

Sitting here listening to an excellent PP 15 watt 2a3 amp and I say nonsense there will be plenty of PP amps around in 20 years.

"My speakers are pure neutrality, no coloration, no distortion"

You are so absolutely full of it. Are you going to say that there is no compression either in those little pieces of crap?,. 


Sorry to burst your bubble, but your new Chinese amp is a push-pull amp, not a single ended amp.

What is a set tube amp?

Image result for set tube amp

A single-ended triode (SET) is a vacuum tube electronic amplifier that uses a single triode to produce an output, in contrast to a push-pull amplifier which uses a pair of devices with antiphase inputs to generate an output with the wanted signals added and the distortion components subtracted.


listening to Norah crooning Christmas tunes thru my  spectacular sounding

1961 push-pull amp….. made in Binghampton, NY….. Wow do i feel old…. 

I am a 1961 Robot in a Scaglietti works body

Sorry to burst your bubble, but your new Chinese amp is a push-pull amp, not a single ended amp. ~~~~~~~~~~~~~~~~~ You know I was wondering about this.. if it was actually a PP...?? Went and ordered in secret w/o telling my tech, ordered on binge late at night,,, hummm, I thought all SET type tubes were SET amplification. hummm, wait til my tech finds out... **I told you soooo*. His famous line. hummm, well, ,,, hummm. uploading new video on the UX250,, Sophie Milman, bass check, Highs check. No roll offs. Goes to show, what we’ve read about FR from decades of **dis-information** is simply just not true. I was wondering,, dual 2A3’s, and I read on descrip of other amps with dual 300B tubes mention of a PP type design. Lets hope we have the super linear midrange in this amp. Yes it is in fact the Yaquin. New upload soon, what you hear in the video is as close as to being in the room. Not sure why folks can’t hear fidelity in my latest FR speaker uploads, vs the older Seas Thor uploads, which indeed had distortion. The Sony cam picked up the distortions of the Seas Excel drivers. But clearly if you can’t hear pure linear, clean mids in the video,, well then I can’t help you



Just cked

SINGLE ENDED. Not a  PP circuit.


@mozartfan  Enjoy it regardless. As you've seen from other replies, plenty of folks enjoying the PP tube amps.

WEll sure, I'm very curious about Jadis' new KT170 tube design. 

I mean stunning.

 Some folks are raving about the KT150, now along comnes the KT170. But honestly, the EL34, KT88 , KT120 sounded near identical to my ears.

Its my guess the 150, 170 ain't gonna be **that** much different froma  El34 soundstage.

But when it comes to SET tube amplifaction, the nuance differences are more platable, more **nuanc-ED*

A 845 is going to  sound dif from a  2A3, ~~~whereas a  KT170, vs EL34, behind the cutain testing,,,can you guess which is which??

In certain recordings with  a very accurate, zero coloration speaker,, perhaps my tech can make the lucky guess.

I could not between his Allen Organ amp (fantastic amp!!) with KT120l s and his EL34 amp he designs.

Both very close,, with the Thor spaekers,, I had not heard both with my brand new Dual FR system...again,, these things need proper testing... 


Defy with new EH88's, vs UX250 vs 2A3,, all these thinsg will have to tested  with some general conclusions.


But it is  common acceptance, a  SET has some lenear magic in the midrange which not even Jadis' KT170 will be able to match.

Of course in dynamics, the KT170 might  surpass a  SET amp such as the big bad 845.

Power vs power. 

any-hoot, Here's my latest, I can tell you there is no roll off witha  good recording.

Plenty of bass, highs in this test. 

SIX lil old watts!!!!!

= are PP dated amplifiction?  now that we have new higher tech FR speakers avaliable. 

THe Coral beta 8 was good, but we have much better now.

Which makes the big power of a  PP amp, not really necessary. 


Just my opinion




enjoying the PP tube amps.





OK yet have these enjoyers of PP amplification, heard a SET amp,,,with the *right* speaker?? This is the Q we must ask.. Let me say this , w/o dogamticism, w/o being pushy and over opinionated... IMHO, in my very limited exp, SETs give a more quieter sound field and a FR also gives a more quiter soundstage, Add these 2 together,,and what do you have?? This is what I am trying to express. Again, my opinion might change as further testing and experimentations continue. I know some of you have 2 systems just for the resaons I stated. But again , seems to my exp, a FR speaker will deliver nuances a xover low sens speaker fails at. My Thor cabinets just went out to the trash. This is the very same speaker that Joseph Audio lists at $12,000. Mine was superior, i had all high end Mundorf caps in the xover,, cost me $1100+ just the xovers. Gone and will never ever conisder a xover low sens speaker ever again in my life. Thus no need whatsoever for a PP amp. back to my original opinion, PP amps are not necessary. I’m stubborn in this belief.

I agree (albeit generally) with the Tech (who is quoted in the video by the video maker) -- PP sounds a bit better when it's limited to a couple tubes per side. I think we lose a bit of mojo when PP uses a bunch on each side. 

Is this you in the video?  How does one reach that turntable? 

I am a 1961 Robot in a Scaglietti works body.

Good robot.

All the best,

@nonoise have to admit , i am more of a barn find…but definitely a 1961. Siblings say i was hatched.

Mozart - yes of course. In particular my main amplifiers are SET = single ended transistor in a cyclotron configuration with no emitter resistors. And the tube ones 2.

Enjoy your quest, it is a worthy one…

i am a Robot carving a line like Senna, in my mind

Is this you in the video? How does one reach that turntable? ~~~~~~~~~~~~~haha Yes the Philips , can’t recall the model # , bought it from my tech’s stash,, have not used it as yet, Bought a whole bunch of INCREDIBLE super rare classical sym/chamber LPs. But have to get with tech , show me how to use the player,, Honestly it was back in the 70’s since last useage of a DUAL turn table.. The player was in fact higher up,, I just lowered it. So I was thinking,,, pondering PP vs SET + what speakers,, OK got it. Here is how i see/hear thihgs. As we know most Audiogon members have ss and PP amplifaction, Very few SET. owners here



What I want to emphasize is a SET amp, absoluet must have a FR speaker. a SET amp will not work with a xover /low sens style speaker. So if anyone is interested going/trying SET amplifaction, ,,I strongly suggest, figure the FR speaker FIRST, but the speaker 1st, THEN and ONLY then buy the SET. Do not put the horse before the cart. man I am hoping for the best with the 2A3 amp, ,,but have no idea how it will perform. Glad you agree with my tech, that a pair of KT’s in each channel is best design for a PP. WOW consider Jadis’ JA200 monos, like 12 tubes per channel!! What would be funnyk, if the Electro harmonix KT88 s perform up to some of the reviews I’ve been reading about that manufacturer.


The Gold Lion KT88’s I found a bit dull in mids. I bought the Svetlana as thtas what jadis initially had in the amp, I sold the NOS off as new for like $350 all 12 tubes.

Lets see if this PP amp has some something to offer with new tubes,,late July on that testing. Have lots of new Mundorf high end caps/F&T’s and Takman Rey resistors. maybe new tubes wll unlock some magic hidden in this amp. that would be unreal. If there is sparkles in the highs and gorgeous lows,, well then maybe i will have to reconsider my opinions on SET’s vs PP. All these things need testing.


~~~~~~~~~~The only thing holding my testing experiements  right now is the ^^^cash^^^ factor.

i am a Robot carving a line like Senna, in my mind.

A very good robot, indeed.

All the best,


btw just looked at another listing of the amp, says its both **SET and PP circuit..** , having my tech figure that one out.

can't be both SET and PP at the same time. ,,huh???

All the best, Nonoise ~~~~~~~~~~~~~~~~ Perfect imagery for how a PP amp channels the music,, PUSH -pull-push-pull, fast on starightaways, slowER on the turns vs a SET's straight musical pathway,,, easy going, pure linearity. As someone imagined the sound field, like angels singing. SETs offera more pure sound field/ PP accents the musical energy = dynamics. But the dynamics can **tend to be** noisey and pollute the quite background. SET sound reminds me of the dark outer space in a desert night sky.

So Mozartfan where have you been the KT170 has been out for a while and the Audio Hungary Qualiton X200 has been shipping with them for a year.

Quite the lovely tube in mu X200. 

@nonoise Senna was the best. I even remember where I was when I heard about his death in 1994 at San Marino. I was shocked he was larger than life at the time.

I am a Fangio Bot. 

So Mozartfan where have you been the KT170 has been out for a while and the Audio Hungary Qualiton X200 has been shipping with them for a year. Quite the lovely tube in mu X200. ~~~~~~~~~~~~~~~ WOW , just found out surfing Jadis;' site,., I had no idea other manufacturers were employing this incredible looking tube. Lucky you. But again, the tube looks to be something like a bigger KT150, which looks to be a larger KT120, and so on, so forth. vs a SET tube, each has quite different characteristics in build and performnace. IMHO there's less nunaces betwix each KT's vs SET tubes voicing. What I am saying if the speaker running a EL34 amp, and then we place the KT170 on the speaker,,, does the speaker pick up the nuances of each tube?? This is my point. The speaker has to be sensitive enough to voice the character dif of each KT type,,,in soundstage nuances. Xover style speakers sound the same no matter which KT tube is in the power slot.

@jerryg123 , I miss him too. Right now I'm still fuming over the treatment Lewis Hamilton ( a big Senna fan himself) got at the final F1 race. That was a hollow and illegitimate victory for Verstappen and Masi has some explaining to do. 

All the best,

My tech is havinga hard time figuring out the yaquin ’s design, is ita SET of PP... , he’s saying stuff I dont understand,,and honestly i don’t think he understands what Yaquin is up to with this circuit.

He says **now you have 2 PP amps***

I don’t believe him, The 2A3 tube is NOT a KT tube.

I bought the amp for

1) not over 60 lbs, my back lift limit

2) in my budget

3) has my 2 fav pre tubes, AX and AU.

we will see.


Just cked the tube data, 

If indeed this is a  PP type circuit,, then I win.. 

Its likea  WIN/WIN amp .

Has best of both circuits, Not a  pure SET , low wattage, neither big power KT PP circuit.

wow, my lucky day

AB1PP says, 

Self Bias , wopping 10 watts per tube x 2 = 20 watts per cahnnel..My tech was say ing before he found out it is PP, last week, *ohh thats a  very low watt tube at 3.5 watts, you may find it lacking dynamic punch..*



My lucky day.


Mozart FYI there is such a thing as a parallel SET amp using two, or more, tubes per channel perhaps that's what your amp is?

jerryg123’s avatar jerryg123742 posts 12-14-2021 7:05pm So Mozartfan where have you been the KT170 has been out for a while and the Audio Hungary Qualiton X200 has been shipping with them for a year



~~~~~~~~~~~~~ Hey Jerry did you note Qualiton’s 833 tube SET and their new 813 SET amps?? wowo, off the charts unreal. wow




Mozart FYI there is such a thing as a parallel SET amp using two, or more, tubes per channel perhaps that's what your amp is? ~~~~~~~~~~~~~~~~~~~~ Yes my tech is trying to explain what to expect. He mentions that my Jadis DPL linestage is SET, and the pre section of the Defy is SET, then out [ut stage on the Defy is PP. so then, there is no such thing as pure SET circuit, neither pure PP circuit. That a PP does have linearity midrange and a SET also can emply dual tubes to become a PP circuit... huh?? well we learn something new every day in this hobby. Tech was saying the other day, I might not like the 2A3 as its only 3.5 watts. Now if we see this amp is a PP circuit this bumps up the wattage to 10 watts per tube on a self bias AB1 circuit. Auto bias says 15 watts, self bias 10 watts..??why?? Got to go over with tech on that one. Or maybe not,,,,,we are going into rocket science now,, haha

@nonoise Not a Hamilton fan and I like seeing Toto lose. It's done and the new Senna, Prost era has begun. Max and Lewis will give us a great season next year, I hope.

Also hoping that the boys in Maranello can get their stuff together.


Sure transformers are important but just as important are quality chokes,

and internal parts like quality capacitors,resistors, wiring,connectors even tube sockets Teflon copper are the best , and many other things.

unscrew the bottom let’s see what’s inside , I have had upgrades to tube gear many times ,most use cheap parts unless spending well over $5 k 

I don’t see any mention of the cost ?

Why, oh why am I doing this...

MF, I just watched your linked latest video where you cue up the oft paraded before the peanut gallery Sophie Milman disc. After 5 seconds of play, you immediately declare that the bass is all there. What bass? This is a typical jazz combo with single female vocalist...probably the LEAST challenging genre (for top to bottom freq. resp.) of anything out there. It would be much more revealing if you hauled something out your mythical classical music vault and slapped that into the transport if you want to demonstrate to the handful of us following this train wreck of a thread the full range capabilities of the DL drivers.

And BTW, I think you confuse percussion with bass. Every time you hear a tom or any kind of drum, no matter what the frequency, you conflate it with bass. There was no real "bass" at the beginning of that Milman cut...maybe some upper mid bass at best. That whole presentation had a decidedly midrange centric quality to it and until you see fit to play something with full range content, you'll never really know what the DL shortcomings are.

SET and FR drivers at their current state of the art, will never be the choice for audiophiles who favor low bass content music like pipe organ, EDM, techno, synth, etc. because they cannot pass muster. Yeah, I know, you're a CM man (though we have no evidence of this) so maybe you're fine with rolled off extremities but your tastes, sir, inhabit the minority.


Hi, well,, I must say,,, actually I need a cold bucket dump,,haha. OK, got ya

WEll, in my limited audio world, thats bass in the Sophie Milman tracks.




Tell ya what, Stevie Wonder has a track on Inner Visions,, where the moog makes the woofers move 2-3 inches of solid slam sub- bass...maybe I will upload a quickie after this post,...I did upload a Elliott Carter score for FOUR!!! Timpini,, but this was with the Seas Thor demo.

Did not come off accurate,, the Sony cam had the timpini all distorted.

I’ll try again with the dual FR.

well, OK, so in my book, 40hz, is rock bottom. I am not least bit interested below 40hz.

So I give up the **real** bass(as you say..)) but I gain super midrange, why?

NO xovers,,WINNER

Higher sensitivity = Winner again

Double win.

PLUS its point source vs a tower like Sonus Faber, Dali, Rockport, Wilson, 3-6 drivers..

FR has decent bass/mids, nice highs all comming froma SINGLE driver.

Niceee sweetttt.

It beats me why FR has not been given their day in the sunshine.

I see Fr as the ultimate musical exp for light jazz, blues, classical.

The genres you mention, perhaps not such as 1st choice.

This is how I hear things.

Rolled off? In a 10x15 room, 60 SPL, near field, all sounds pretty good to my ears.

vs xover designs which I have issues with,, as you guys know. I am xover/low sens speakers most fierce critic

So i expect the same criticisms to come from yoyr camp against FR types.

I get that.


EDIT,,, was off to upload the intro to Stevie Wonders track off InnerVisions,, and realized that 1 UX250 tube went dark.

Trust me if a record has bass , these dual FR’s will deliver the goods.

8 + 6 inch cones, rockin N rollin with bass, as long as its in the actual record.

+ if I really want bass I’ll hook up the Defy with 12 Mundorf SESGO .47 caps, = will shred to confetti the wood cones in both FR speakers.

@ 12 oclock on the vol pot.

If we pushed the Defy hard, it would destroy Wilson’s biggest 8 speaker tower.

The towers would start to walk,, you

’d have to replace all woofers.



Flight of the Cosmic Hippo, that should do it.    I can see the blue plasma … from here…

I am a Flek of Robot in a Bella Universe 

All of the (your) Youtube videos you have linked here sound awful to me, and...


this is coming from someone who has used single wide range drivers (on a meager budget) for almost 20 years now.


If you "really" want the better/type of sound that this approach "can" offer you first need to wake up and smell the coffee.



I have paneling come out basement of lake house if you look for more cabinet material.

I have paneling come out basement of lake house if you look for more cabinet material. ~~~~~~~~~~~~~~~~~~~~~ Thanks for the kind offer,, I'm sure its veery nice old grained wood. But this Tennessee cedar is my fav. Cuts are very rough, 1 cab is 1 inch higher than than the other,, 1 has sides that are IN the front panel/rear panels, and the other sides are OUTside front/rear panels. = each cabinet is different measurmemnets, but close to 50 liters. I'm no cabinet builder,, just a visonary for speaker designs. No one in the world, AFAIK has a dual Fr design system + tweeter,,just ordered another tweeter today, will run dual tweeters. ight,,in fact will build a mini Cedar cabinet to house both tweeters. The Davidlouis seller says no one in china has dual FR in a system. The DIY Association told me it will not work, it will sound just aweful. I don't listen. I really think my speaker offers some of the best midrange sound. You can't do this with AER, Voxativ, nor Cube, all have too high a sensitivity and many other reasons,'can't do this with any speaker brands. Only davidlouis VX8 + VX6 can you combine ia dual system. Nice day

The 6C33C-B tube, when someone includes an amp using this bottle, THEN you will have my undivided attention, hah.  Sorry all, I’m just a parrot!  :)

All of the (your) Youtube videos you have linked here sound awful to me,


I can;’t help that.

Thats your problem, not my speakers problem

"I have paneling come out basement of lake house if you look for more cabinet material."

That may come in handy tubebuffer, kind offer!

By the way mozartfan, it's spelled tympani. And you say that you're a classical music fan? Shame.

unscrew the bottom let’s see what’s inside , I have had upgrades to tube gear many times ,most use cheap parts unless spending well over $5 k ~~~~~~~~~~~~~~~~~~~~~~~~ My tech here, and many other techs as well, believe a cap is a cap is a cap, I’ve proven this to be true in certain uses, and not true at all in other, Take my Jadis Defy 7, each KT88 has a .47 cap attached.. I took out Jadis’s small yellow stock .47 cap and instaalled Mundorf .47 SESGO, bass response registered in a very nice nuance gain. The bass is punchy and solid. Mids also made a small gain. Takman Rey resistors made a minisclue up gain. All the mods/upgardes I’ve made, all togther made for a nice upgrade,~~~

. Upgrade to my xovers in my speakers was a total waste of money.

FR speakers offer a superior soundstage. So again , upgrades, mods have to be carefully considered.

My once beloved Seas Thor speakers (same drivers as Joseph Audio’s $12000 speakers) are now dis-manteled...

, midwoofers sold,

tweeters gave away,

xovers up for sale,

cabinets went out today for the trash.

Adios xover style speakers forever,,,

YOU, too should make the switch.

The 6C33C-B tube, when someone includes an amp using this bottle, THEN you will have my undivided attention, hah. Sorry all, I’m just a parrot! :) ~~~~~~~~~~~~~~~~~~~~~~~~~~ Well this tube ain't too shabby either. 



I own a parallel single-ended 2a3 amp; the two tubes are not in antiphase (pushpull) configuration.  Parallel single-ended puts out more power, and because  parallel operation reduces output impedance, the turn ratio of the output transformer can be reduced.  But, it is quite hard to get good balance in output from the tubes, and one ends up doing most of the work after a while.  I had that happen with my amp.

There is no practical way for an amp to be switchable between single-ended and pushpull operation, the circuits are fundamentally different and the output transformers must be different in design to optimize performance.

it is so unclear as to what is being compared here except that it is two different amps.


Post removed 

Hey Larry, I'll run by, your ideas over with my tech, see whats going on.

OK Acresverde mentioned a  FR system w/o woofer may not appeal to other audiophiles whose music requires a  deeper bass response.

WEll with a  PP type  SET, maybe this will azllow adding a  woofer in the system. But not sure if the added ohm will  be too much on the 2A3's.

I was running dual 8 ohms FR + 8 ohm tweeter,,and 1 of the UX250's went dark, and  is new stock. 

Have to get  with my tech who built the amp, perhaps its not the ohm over load, maybe something other.

But this is what I have to consider here.

can a  2A3 tube handle dual FR + dual this asking too much.

Although the  center trans on the UX250 was not running hot with 3 8 ohm drivers,, maybe the tube was being over loaded.

So its possible  my dual FR speaker may not work with a  SET,,or perhaps this 2 tubes per channel, PP design allows for more ohm load.

hard to say at this point.

My tech even mentioned **yeah go ahead and put a  single W18 mid along with the system..**,, Saying it can handle the ohm load.

All this has to be  worked out. Good thing in this testing is that if a  stock tube goes dark, no big loss. 

I will run the stock tubes for 6 months witha  dual FR, dual tweter, thats 8 phms x4,, and see how the tubes hold up, /heat on center trans.

BEFORE I order Psvane ACME 2A3's which I would not wish to risk early burn out at 600/pair.

If there is trouble, we can try a  single FR/tweeter and use this  amp as for light chamber.

More complex big orchestra like Schnittke symphonies, we can run the Defy  which can easily handle a  bunch of drivers. 

Back to the idea that 2 tubes per channel offers a  better sound vs the Defy's 6. With 6 tubes, you have a  beefier  trans , opening up the path for dual FR + dual tweeters and a  woofer for techno , heavy metal, grunge and any other slam driver music you  care to hear.

So sems  there is a  place for PP power. 

All these things have to be tested and worked out.

Stay tuned.....

Side note the Defy has 2 ohms on top of trans, but somewhere I read , the amp needs to be adjusted to bring it to 2 ohms. 

My tech does not want to make any mods in this circuit.

Again, what may happen  with dual FR + dual tweeters is over load not so much on the center trans, but  may affect/shorten the life of the 12 KT88's, which is not a  good thing, 12 tubes runs me $600. 

Stay tuned.....

Mozart fan what kind of a crap system is that. LOL hahaha well I imagine if the speakers had the name like Wilson Dali Sonus Faber attacjed to the front ,, maybe you and others would buy it hey thats what i am going to do, start up my own speaker retail shop. Lets see what shall I call it oh I know The Frankenstein's. Look if Tekton's are selling their loaded cabinets,, like hot cakes in a alaskan mining town...I think mine are better,,. A bunch of tweeters will not match dual FR;'s in these sma e band width. Trsut me my Frankenstein's are ONLY limited by the amp connected. Whatever sound is in the amp will be channled through the speakers. UNlike xover /low sens speakers which block/distort/pollute the nunances of a Jadis KT170's glorious sound. My dual FR have NO XOVER, just pure muisc from the source + amplifier. I live minutes from the airport, stop by one day. Then make a critique, or insulting comment. Not til you actually heard them live.

"No one in the world, AFAIK, has a dual FR system + tweeter..."

Gee, I wonder why🙄