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,

AFTER TESTING IS COMPLETEED.

Hand on to your horses at the OK Corral. 

Grab a  beer at the saloon, 

sundown shootout at the edge of town. 

 

mozartfan

@billwojo please don‘t go there. After only brief contact, some poor souls have lost their will to think……..

@atmasphere I take it you have a 12AT7 LTP @ +-300V with something like a cascode 10M45S CCS below? Or are we talking fancy pants?

On the subject of vintage trannies my aforementioned PP 2a3 amp uses vintage Eico trannies.  My previous El34 amp used vintage Accrosound trannies, vintage iron really makes a difference!

@pesky_wabbit , well he did say he was tossed from one forum already and his insistent style that only he knows the truth is just very reminiscent of Jeff. I actually haven't seen Jeff anywhere in a long time, no forums left that will allow him to participate or did something happen to him I wonder. I didn't hate the guy but his know it all attitude and bizarre thinking at times got on my nerves. I would welcome him back if he toned it down......a lot!

 

BillWojo

Jond,

I like vintage iron too.  My pushpull 45 runs Accrosound To 330 trannies, my pushpull 349 runs Western Electric 171 iron (input trannies are Western Electric 618).

I like vintage iron too. This is when steel was cheap. Now with high industrialization past 20 yrs has placed critical demands on steel so prices have sky rocketed. Which is why the trans in the Yaqin are no doubt small, at $1300, ,,my tech tapped on the 3 covers,, sounded hollow inside. WEll, no big deal, at $1300 , sounds great, I'm happy. Better trans gives nunace superior bass. Again dual FR pad up the bass 60hz region. Can't complain on certain tracks, I get all the bass i want/wish for.

"Why are you supporting China's economy?" Be aware that not all posters on this site hail from the US. Some of us would rather support Chinese technology rather than US technology for various reasons including political,

I don‘t think the technology is an issue given that it is pushing a century……

Ha yes Chinese advances in 1920's technology are more of a niche sector. 😂

@laoman Then go find a forum like this in the PRC. Where you can speak your mind for the most part and not have to worry about having your front door kicked in.

Why are you supporting China's economy?" Be aware that not all posters on this site hail from the US. Some of us would rather support Chinese technology rather than US technology for various reasons including political,

Look when China techs can put out a  2A3 PP and now I see a  300B PP just out, which most likely i will order as well, as it has a  Pre Out for my Jadis DPL,, might sell the 2A3,,, but look when techs can put out a  SET amp like in this vid below,, there is no way the old KT designs can compete.

I have no idea what this amp lists at, bet its over $15 grand.

Jadis KT170 vs this SET? 

Both at $16 grand

No brainer.

 

Im havinga   hard time trying to figure Ken's amps out, 307 tube,,what is it??

so i googled 307 , yes avaliable for purchase.

WOW this SET world is  a  nother universe.

 

But I do thinik I found the **mother load**

unreal, just unreal.

Yep going to list,,,,,,no,,,no  can;'t sell my Defy,, but certainly  should,... as I don;'t need 3 ,  amplifiers, 

 

 

just revisited the KU 307 video,, love at 1st hearing

Its something I can't even comprehend, the fidelity,, its like its not even real. 

Like a  dream or even a  fantasy.

By sheerrrr luck I hit on KU's page,,I've seen his YT months ago ona   used amp he was selling...but I was very interested ina  brand new chinese 300B PP amp with PRE IN,,and  very confident I would add a  3rd amp,,, so I can use my Jadis DPL with Mundorf caps,,,but hit on this KU 307, 

What I really should do, is list my Defy with $1600 mods (never recoop, all lost), and sell the Yaqin 2A3.

What pain and suffering.....

 

If the idea is that one should not buy products from a country that ranks lower than one's own, based on whatever social metric, this would be problematic for those countries that rank high.  You could scarcely buy anything non-domestic if you lived in Denmark or Finland, for example, but the world is your oyster if you lived in Nigeria or Myanmar.  

I take it you have a 12AT7 LTP @ +-300V with something like a cascode 10M45S CCS below?

@pesky_wabbit Yes, something very similar to that although the CCS is our own design. There's a 'steering diode' so the cathode voltage can't fall below -0.7 Volts; this protects the tube from developing cathode/filament shorts during warmup.

well my dream  of owning this amp via my selling the Defy, , I just canceled the Defy 7 ad , all for 3 hours,, had 50 hits,,, ad canceled, after i RE-visited the KU 307,, I did not let vid finsih BEFORE,, so i just went back and Beethoven was playing,,, hummm, SET's are #1 for jazz, blues, light chamber,,, sym orch,, forget it. 

DHT PP will respond to full orch, but NOT their lil brother the Single DHT. 

Defy ad canceled.

Going with a  3rd amp the 300B PP, contary to my techs advice to stay away from anything *300B*.

 

You shouldnt make decisions, audio or political, based on youtube videos. Also, just because your tech can fix something or tell you how it works doesnt mean he has earned the right to hear for you too. Buy what you want to buy....

@laoman Then go find a forum like this in the PRC. Where you can speak your mind for the most part and not have to worry about having your front door kicked in.

Why are you supporting China's economy?" Be aware that not all posters on this site hail from the US. Some of us would rather support Chinese technology rather than US technology for various reasons including political,

Interesting comment from someone who clearly has no idea of the political landscape, eh Jerry?

because your tech can fix something or tell you how it works doesnt mean he has earned the right to hear for you too ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 

Well although he is a savant in all things electronics/amps/TV’s etc, does not mean his opinions are not *un-biased*, Pun intended. At times he is spot on but can lean a bit to his strong opinions. You know a better OP title could have been KT Series circuits (includes the EL’s) vs Single Ended Triode ///DHT single tube vs DHT PP AS of a few weeks ago, i had no idea DHT PP circuit even existed, to my surprise and de-light. In my very limited exp of these 3 designs, I tend to favor DHT/PP as 1st choice. What we see offered on the market by heaps and gobs are the KT PP series. (KT in a SET design is rarely offered and not of my concern) KT88’s are by far the most offered, most popular, most purchased. Now why is this? Answer:: Speakers. Low sens/xover types require a KT PP circuit that delivers some solid 30++ watts of power.

The USA audiophiles are  so devoted if not  blind eyed, about their xover type speakers, including ZU’s, Tannoys, and such, 

they cant see the forest for the trees,

Whereas the asian, especially the china audiophile almost to the last man, chooses high efficient/higher sens FR type speakers, Thus SET ’s are no doubt purchased more frequently. As I see (hear ) it, seems to me the asian SET/DHT/ with Full range speakers are more advanced in acheiving higher fidelity vs the USA audiophile determined to stay firmly and may i say, stubbornly, planted with both feet , and may I say, rock solid cemented in his stance, to hold on to his dear life , the big PP power amplifiers and the partnered speakers that pairs well with his KT amp, the xover.low sens (aka low efficient read IN-Efficient read IN-effective in midrange) speakers.

So Be IT. each his own I guess. .

I’ll follow the asians on the path to high-er fidelity.

@mozartfan 

I'd say more specifically give credit to the Japanese audiophile/music lover community for reviving the interest and admiration for SET/low power tube amplifiers driving horns-high efficiency speakers. They bought a ton of discarded and ignored old Western Electric old movie theater audio equipment. 

 

Once transistor power became common in the 1960s (More power than tubes for far less money). Tube components were viewed as archaic and useless. It was Jean Hiraga who brought the low power SET/High efficiency speakers movement from Japan to Western society in the 1970s.

The rest as they say is history. Dennis Had (Founder of Cary Audio) was an early American SET manufacturer. Don Garber (Fi Audio) was another early American convert who built SET amplifiers. 

Charles 

I’m glad I stocked up on 307A’s when they were relatively inexpensive. It was inevitable that they were going to be ’discovered’’ at some time. When used correctly they sound particularly fine into special edition Magnequest FS-030’s using the 4 ohm tap. The bottom end is quite authoritative for a SET.

Once transistor power became common in the 1960s (More power than tubes for far less money). Tube components were viewed as archaic and useless. It was Jean Hiraga who brought the low power SET/High efficiency speakers movement from Japan to Western society in the 1970s. The rest as they say is history. Dennis Had (Founder of Cary Audio) was an early American SET manufacturer. Don Garber (Fi Audio) was another early American convert who built SET amplifiers.

 

~~~~~~~~~~~~~~~~~~~~ Hey Charles Thanks for this facinating history of how SETs became part of this hobby. Now I know why the ~~Legendary~~~~ Coral Beta 8 speaker had its birth place in Japan. WE , ESPECIALLY ME of all FR fans in the world,,,, owe our fine high fidelity speakers to this savant in Japan who developed the CB8, Yes I know the original genius was in Berlin, Chicago 1920;s, then we owe alot to Jensen and EV others,, But it is the CB8 where the technology found a new voice in purity, fidelity. I realize the davidLouis VX8, VX6 are direct heirs to this masterful speaker. The Yaqin MS2A3 DHT PP is NOT, NOT new, its been around for perhaps a decade,, as per some comments i see on the Inet. A real hidden gem among a massive pile of KT PP amplifiers. I am not holding my breath on a massive movement away from KT series amplifiers into SET/DHTPP amplifiers , not anytime soon. Most folks are leary about FR speakers, not to mention they can be ,,no in fact are very pricey, Single drivers $5K-$10K a pair, and w cabinets,,, one needs to be close to a millionaire to afford a pair. I remember the days back in early 2000’s the SETs were mentioned ona topic here, speaker shootout, Back then the SETs were pricey, and few offered. Now with chinese tech, machine made, we can all now have access to these highly musical amplifiers. KT series amplifiers hold on interest for me any longer.

 

There are nuances in the DHT tubes which are missing in the voice of the KT series tubes, 34,88,120, 150, 170. Its just not there,,,nice,,but as they say, no cigar. Folks can argue all they want,, **design, trans quality, etc etc** fact of this matter,~~ truth~~ of this shootout,

is the DHT have some magic that KT series are not privy to.

 

If its not there, ITS NOT THERE,,

why lie about it, why pretend otherwise???

The End of The Story

Lights out.

bottom end is quite authoritative for a SET. ~~~~~~~~~~~~~~~~~~~~~~ In the KU307 YT video,, I was wondering if Ken had a ~~~sub woofer~~~ attached to the amplifier,, that deep and powerful. One super DHT tube for sure, Lucky you. Now in a shootout with the highly regarded 45 tube..., 2 super high fidelity tubes in a shootout,,, neither wins,,,correction,,,neither loses, they both win,,,, even draw,,lol

charles1dad,

A nice concise history of what happened.  I would add that another aspect to the story.  When stereo came around, the need to find room for two speakers, instead of just one, meant that smaller speakers gained in popularity.  These smaller speakers, particularly of the air suspension (sealed box) variety were inefficient and required higher powered amps and this favored solid state over tubes.

Mozartfan,

There are many pentode/tetrode tube amps running pushpull that are extremely musical and great sounding with horn systems, fullrange driver systems, and multiway systems utilizing fullrange drivers.  You cannot generalize from hearing only something like the Defy 7 and certainly not by "listening" to YouTube videos.  I have heard terrific 6L6 and KT66 amps and some of my favorites are 350B and 349 amps (the favorite of the amps I own runs the 349 tube).  I also own a pushpull 45 amp (triode tube) and a pair of Audio Note Kageki (parallel 2a3 SET).  All of these amps sound good.  My all time favorite amp is an output transformerless amp that is a custom built amp, and a pushpull Western Electric 59A amp (252 tube) which is something I could never own as a pair is well into six figures.  Even with tubes that I don't particularly like (KT88, KT120, KT150), there are examples of amps that run them that I found to be decent.  I know that there is a strong desire to come to conclusions about various aspects of design or parts choice, but, it really is not that simple to do.  The more I hear, the LESS I am able to draw definitive conclusions in these areas, although I do see rough tendencies.  As to such rough generalizations, I do like quite a few speaker designs that use fullrange drivers in multiway systems (e.g., Cube Audio Nenuphar Basis), a small handful of true single driver systems (Charney Audio, Voxativ), but mostly, I like horn-based systems.

Hi @mozartfan ,

 

Japanese SET audiophiles adore US made speakers like Altec and WE and German Klangfilm speakers. Jean Hiraga used Altec A7, A5 with crossovers designed by himself.
Another Japanese legend - Sakuma used 300B amplifiers and British made Lowther FR speakers. They don’t use Diatone full range speakers! They also preferred German EMT and British Garrard turntables over Japanese turntables.

EV drivers are much cheaper bult vs vintage Altec, JBL, Vitavox drivers.

I prefer horn compression driver speakers over full range for more balanced sound. BUT a few people use FR properly - with front horn and additional low frequency section.

 

@larryi

I know that there is a strong desire to come to conclusions about various aspects of design or parts choice, but, it really is not that simple to do. The more I hear, the LESS I am able to draw definitive conclusions in these areas, although I do see rough tendencies.

I can appreciate @mozartfan’s enthusiasm with his recent discoveries, but do agree with you concerning broad sweeping conclusions. I will say that DHT tubes just seem to produce a very impressive natural sound that I find exceedingly special.

I will be the first to admit however variables such as builder/designer talent, attention to detail and quality parts selection are crucial and vital factors. We all have our preferences. DHTs used and executed properly simply get it done for me.

BTW the 307 tube is not a DHT but is in a fact a pentode tube.

Charles

@charles1dad 

BTW the 307 tube is not a DHT but is in a fact a pentode tube.

 

But it sounded like a SET DHT in the Youtube video!

@charles1dad @larryi and @alexberger well said all around on tubes and the Japanese influence on audio. And @pesky_wabbit what amp are you running?

@mozartfan you're getting tons of great info and advice on this thread but you need to start listening to actual amps and not youtube. You seem to have a good tech maybe you could commission him to build you an amp or two using these tube types that fascinate you?

@jond 

 

well what we are all finding out is that there are such amplifiers as 

 

~~~DHT PUsh Pull~~~

Ner heard such a  design.

All I knew about is SETSETSET.

A SET on a  xover type speaker does not work, I tried it, its  a complete failure. Either high end horn or FR (or Concentric if that floats your boat, Tannoy.

My next experiement is to find out if the KT88 ,,,lets say, how dif in  nuances /midrange is the voicing on a  KT88 vs  a  KT90.

This is my next experiement.

I'm holding out hope for my PP amp.

What can a  KT90 offer paired up witha    dual FR.

The 88's were just a  bit too midrange heavy to work with dual FR.

Its like midrange X's 3.

From what I remember of the EI90's in the JOR, there was magic in the soundstage.

= more recessed midrange.

I think everyine goes for the 88's as their xover/low sens speakers needs all the  voice they can get in midrange.

 

This is why they choose 88's. 

The 90 has been completely totally thrown under the  bus.

Google kt90 on audiogon,,, haha, maybe 5 posts on that tube past 10 years. vs 88's, 100's of posts. 

Its all which 88  is best.

Audiokarma, DIY, all sites, 888888888888.

If I can sell my cayin  cd17 I can get the 90 tubes,,,no bites 3 days,,,,,, priced rock bottom  w mundorfs.

 

 

I have no experience with the KT series other than the KT77 which I think is a great tube. But you are doing it again you're not listening to tubes you're listening to tube amps. So whatever tube it is you do listen to next make sure it's in a good amp.

@mozartfan 

SET on a  xover type speaker does not work, I tried it, its  a complete failure

Perhaps in your one instance,  the complete opposite experience for me. My 3 way 5 driver speakers were built from the ground up to be very compatible with SET amplifiers.  Same brand (Coincident) built by the same person (Israel Blume). Granted the crossover is a minimalist 1st order design (One  tweeter capacitor). I'm referring to the Coincident Total Eclipse II,  94 db sensitivity and a 14 ohm impedance load. 

It pairs exceedingly well with the Frankenstein MK II 300b SET mono blocks. 8 watts of pure music listening joy. It replaced my very good 100 watt mono blocks (6550 or KT 88). So once again it  most definitely depends on what specific amplifier (All 300bs aren't created equally) and what specific multi driver speaker (They aren't all the same). This is my sublime experience the past 12 years. 

Charles 

@jond 

But you are doing it again you're not listening to tubes you're listening to tube amps. So whatever tube it is you do listen to next make sure it's in a good amp.

100% correct👍

Charles 

BTW the 307 tube is not a DHT but is in a fact a pentode tube.

There are a couple of ways to turn it into a ’virtual triode’ with rather attractive plate curves.the equal of many a ’native’ DHT.. ie when configured in this fashion it can effectively be considered a DHT.

Triode strapped 6AV5 didplay remarkably similar plate curves to the 2A3, but are insirectly heated.

@pesky_wabbit

 I don't doubt what you say in regard to the final sound quality.  I just wanted to clear the air concerning the tube's innate 5 component/elements  construction. 

Charles 

I had no doubt of your motives Charles, just thought an explanation was warranted.

I have no experience with the KT series other than the KT77 which I think is a great tube. But you are doing it again you’re not listening to tubes you’re listening to tube amps. So whatever tube it is you do listen to next make sure it’s in a good amp. ~~~~~~~~~~~~~~~~~

 

1) Tube amp design/Circuit

2) what are the pre tubes

3) quality trans 4) power tubes choice/brand (I found Gold Lion a bit dull, confirmed by a member on Audiokhrama)

What I am suggesting is that all power tubes sound awefully close , tiny nunance differences. But a miniscule is all I need LESS IN MIDRANGE with the 90’s vs the tiny bit more full richer mids of a 88. Pre tubes have the most impact, and what brand, I found none beat out Tele , my fav pre tubes are AX, AU, but honestly thats not based on exp, as i’ve not heard a 6SN7 series type pre tubes. I have no idea how they perform. Trans quality allows a superior **cleaner/tighter* bass. Also swaping caps and resistors have allowed some gains, minisclue but worth it. I have 12 Mundorf SESGO .47’s in the Defy @ $50 each + tech fees. Bass has more punch. On swapping caps, it realy only makes a dif if you go highest quality, Supreme EVO SGO. EVO give less impact. All these things go to make a amp’s ultimate performance. Ck out Ken Usegui’s designs. top quality, IMHO Ken is making the best SET’s for the money, 2nd to none. 2nd to none in his price range, Sure we can’t include Kronzilla and Wavac, thats a wholeeee nother price range. But what Ken is doing, 2nd to none. Thing is, he only offers pure SET,,, my thing is DHT in PP design. I need the nuances in dynamics with a DHT/PP vs the super pure linearity of a SET. Suductive, but at the end of the day, I miss the added dynamics of a DHT/PP sound. + a SET will not deliver the power I need for full sym orch,, vs the superior performance with DHT/PP in more complex music.

But as for EL34, KT77, KT88, KT120, Our local tech has run experiements with audiophiles, **guess which tube is in the amp NOW..** and usually its only a lucky guess.

What makes all the dif in allowing nuances of each tube to come through is,,THe Sensitivity of the speaker.

Upgrades were hardly noticed in the Thors at 87db sens. With my Dual FR, any tube swap, I can note the tonal changes. Your xover type speakers are not sensitive enough to allow upgardes to be heard in all their impact. = Big waste of money high end cabels, IC,s Caps, etc, with low sens speakers. A complete waste of cash. Only FR allow the most impact of mods/upgrades to filter through. This is a fact, based on very costly experiences. I’m still in debt with these Thor upgrades. The only thing left now with the Thors are the xovers for the W18’s. Got them sitting on my shelf collecting dust. I really despise all/every xover/low sens speakers, did I not say

HATE.

Loathe,

can’t stand.

my fav pre tubes are AX, AU, but honestly thats not based on exp, as i’ve not heard a 6SN7 series type pre tubes. I have no idea how they perform.

Once you hear what they do there’s no going back. If your SETs don't use 6SN7s there's a whole better world out there...

I agree with Atmasphere--most tube amps, both single-ended or pushpull, benefit from driver tubes with more oomph than the 12AX7 or 12AU7, which often means a 6SN7.  

By the way, Atmasphere is being quite diplomatic by not mentioning the type of amp he manufactures and sells, which are output transformerless (OTL) amps.  If you think your  full-range driver system sounds incredibly alive and vibrant with your typical single-ended triode amp, wait till you hear it with a good OTL amp.

@laoman 

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 We had the same system here in the US but it ended in 1865.

 

Once you hear what they do there’s no going back. If your SETs don’t use 6SN7s there’s a whole better world out there...

Better still stay away from the N7’s madding crowd and stock up on some 7193’s while they are still affordable. No contest IMHO. Kinda cute too - if you're into Mickey Mouse.....,.

@mozartfan if your tech is real hair shirt get him looking at DHT drivers for you amps.....transformer coupling. Enough to keep the OCD going for decades.....

You know what would be a  great new lil topic,, ~~~Post your best pics/videos of some of the coolest looking SET amps you can find on the Inet.

Pics, YT vids, whatever.

Here's one I just found by sheer luck,, ...these  2 tubes have me ~~mezmerized, hypnotized,, spell bound~~~ I've seen the vid already 2x's and can't stop. 

I wish the guy had shut the lights off,, wow factor would have been through the roof. 

And the speakers,, nothing special at all, and sounds just super realistic.

Where's the ADD To CART/BUY NOW button,,haha.

Now everyone post their top pic of **unusual* ( = out this world)  SET tubes amps they can find on the Inet

Pics are ok too, does not have to be a  video

Now go find yours

 

 

wouldnt you just know it,

old HiFi Guy comes through to deliver the **Magma Tube* GM100 SET

 

Wondering after a  few hr session, what kind of heat factor are we talking about?? 

 

 

811 incredible deep voice. Guess its kin to the 845,,now I know what folks are talking about these 8 series tubes.

WOW thats velvery and powerful bass.

Liquid bass.

Unreal.

 

 

@mozartfan

Discovery and exploration is fun.😊

Another 8 series tube is the 805. An accessible and affordable example is the Line Magnetic 805ia/ 508ia which 48 watts of pure class A SET. Those who have heard or owned it say it’s wonderful sounding. Some SET afficianos make the point that the lower power SET amplifiers are more intimate, nuanced, tactile and pure in their presentation.

Obviously opinions and taste vary as with anything and it simply becomes a matter of what one is seeking. The higher power SET amplifiers certainly allow for greater speaker choice flexibility. Always some degree of tradeoffs, so just depends on the objectives of a given listener.

Charles

ower power SET amplifiers are more intimate, nuanced, tactile and pure in their presentation. ~~~~~~~~~~~~~~~~~~~~~~~~~ huummmm I know you mentioned this trade off somewhere else, maybe on this topic.. hummm, looking at adding a 2nd SET or a DHT PP Both lower end amps, under $1600 300B/PP has Pre IN so I can use the Jadis DPL the other 845 w 2A3 as drivers/pure amp w a cd jack/amp has vol knob. Everyone says they love their 845, ,,, but as you say might have to give up up some nuances offered in the #00BPP..... can't ask Richard for advice, he's not going to give thumbs up on either....another amp buy, behind his back. I'm probably going 845 as i already have the 2A3 PP.