SET Shootout China VS The USA

One thing I've learned in audio is there's always something better ~~~~~~~~~~~~~~~~~~~~~~~~~~~ WEll sure I mean if we bring Kronzilla and Wavac into the discussion, Jadis has to take a distant 2nd place. There are other UK designers also employing the 833 and other super massive exotic SET type tubes. But in its price category, Jadis reigns pretty high up there in craftmanship. This is my point, Jadis eraned and well deserves its reputation. Is my point. I did go a bit hyperbole when i said **THE most** when in fact truth is, **among the most mucical in that price group..*

Ok I read the who thread.

Wow!

Merry Christmas

Dac chips until this thread. So thank you for that if nothing else. ~~~~~~~~~~~~~~~~~~~~

 

. I’ve had the DAC now 9 months.

Yesterday was a very wet 100% humidity and cool. I’ve noticed during a rain , next day, DAC needed **drying out time**, Yesterday was the worst...So what i am doing to help prevent this longgg dry out time,, is 1) placea paper bag over top of unit where there are vent holes placed along top, 2) turn DAC on early in the AM< WITH bag left in place, this way heat builds up and drys out any excess moisture. Beats using a blow dryer, which did not help all that much... , Also I could put back in the window my 5k btu window AC and run it at night, like a dehumidifier. If I have to I will. I note the pops are more frequent while in play, with all my jazz /pop cs which have some marks on the surface,, my classical cds are near mint have less pops. So the entire Shamling drive + DAC together are being sensitive to excess moisture + cds in avg condition. This issue only happens on certain super high moisture days. 100% humidity + rain + cool front which makes air highly energized wind = static energy. This Jadis DAC is loaded with chips + the Class A JFET opamps, loaded with tiny cjips. All make for highly sensitivite DAC setup to moisture.

Why are you supporting China's economy? ~~~~~~~~~~~~~~~~~~~~~~~ Look I am completely with you on this one. Chinese intellectual theft is real and affects us all here in the USA, in one way o more. I don't like what the chinese do, robbing our technology and then branding it and we buy it. Its theft. But in this case, I can't afford the other high end manufacturers ofg FR speakers nor the higher end amplifiers made in the EU and USA. Also are there any USA manufacturers designing a 2A3 PP amplifier at the moment? At a price I can afford. In this case, hats off to china for bringing me wonderful components which fulfill my long quest for a beautiful musical soundstage.

Someone text me say his UX250 SET has no issues driving his vinatge Realistic Nova 7’s and Grafyx SP10’s, both double stacked,, thats SIX WATTS...so just **what** do I know...

ahhh you know what, Here is where his Colbalt out trans kick in with a bit of slam power,,, vs the Yaqin’s Z11 weaker trans. So it is possible he is having some **success* driving LOW EFFICIENT xover types with a SET, Cobalt trans.

 

Few of us have cobalt trans in our low powered amps.

So that caveat aside.

basically this topic OP has been altered.

Its not about a chinese designed amp vs a USA amp design.

The new OP Q is

KT series tubes PP

vs

Low SET type tubes PP (300B,2A3)

 

For all low sensivity speakers/xover types, KT series , EL34,88,120,150 are the ideal tube for giving dynamics to a highly INefficient speaker.

These speakers demand power, Which the KT has to offer.

 

In high end HIGHLY efficient speakers such as FR. lower powereed tubes such as the 2A3 is the superior choice. Lets say **marriage made in heaven*.

So I will not commit to say the lowered powered tubes, are superior in soundstage/musical sound field..only that witha FR the best and ideal choice is NOT the KT series.

I’m closing out this year with 2 major discoveries in my experiemental journey ~~~search for high fidelity.

 Discovery  of FR as my dream speakers, DUALs at that.

and this Yaquin 2A3 which i had no idea what it was all about,, how it would perform.

It was intended as a low watt SET for light chamber/solo piano. Sort of backup amp.

Now the Defy has taken a distant 2nd place.

Yaqin wears the crown jewels.

2A3 does things a  KT series tube can't do.

 

@mozartfan

What you’re referring to as "SET tubes" are technically DHT(Directly heated triode) true 3 element tubes (45, 2A3, 300b, PX 25,211,845, 805,50 and so on). Your reference to "KT type tubes"  are IDHT (Indirectly heated ) with most of these tubes being pentode, 5 element constructed tubes. You are discovering the world of DHT tubes. Welcome😊, there’s a ton of information available via search that can go into as much detail as you care to explore and learn.

Charles

You are discovering the world of DHT tubes.

 

~~~~~~~~~~~~~~~~~~~~~~~

 

**another world**. Bigger.

 

Another universe. As you were typing this message,,

I was on the Inet searching these *DHT** tube designs. I’ve heard amazing things about the **45**, and other DHT tube circuits Just unreal. WOW factor off tjhe charts. Look its high time we get off discussing KT series tubes. Audiogon past 20 yrs has been ALL about KT series tube designs. I;’m sick and tired of of the old standard fare, like stale bread./

Yes a KT is a nice sounding tube. But it ain’t nothing special such as these DHT’s deliver. 2 **completely** (hyperbole necessary) different soundstages. You guys know how far I’ve gone in hypeing FR speakers as not only the best choice, but,,,well I refuse to finish the sentence... Again here with the **DHT** Universe discovery,, the sound fields lifts you off the earth into a new unknown (KT exp well known /explored) planteary system.

For months I was perplexed as to what amp design will open up the magic of a FR system..

I searched all and evey KT offer. Close to addinga 2nd KT series, like a EL34 low watt amp,,, By sheer luck (man do I need a break on luck in my choices lately)) I hit on this 2A3 PP rare gem. So as we close out the year, i am going to add to my prognostication (big word I know, but have a bit of that old spirit with me,, a bit I said, not to the degree of the old masters). FR as speaker choice, 1st system, wearing crown jewel And these DHT SET/PP as the preminent place among audiophiles choice in amplification power. Its comming, I can see it, but its still some years off. Sterophile, 6 Moons still pumps out massive does of propaganda fopr the big KT power tube designs and the speakers that go with these sheer power blocks, the low sens/low efficient blood(fidelity) sucking xover type speakers. Neither of which is going away anytime soon as 1st picks.

 

~~~But a time is comming~~~

KT amps will be offered at *dime a dozen* prices on used retail sites. Rock bottom. Whereas you’ll be lucky to find a good deal ona used SET/DHT type amp. = Minisclue discount. maybe 10% off list. vs PP amps, now nearly 30%++ off list. jadis DPL Linestage, with takman, Mundorf and Teles, Jadis Defy, Takman, Mundorfs, Teles,,, I gave jadis all the best,,But its no match fora DHT PP 2A3 design.

The future is

~~~FR + DHT~~~

 

and here ya go

WOW factor off the chart.

These designs are blast off rocket ships to a   magical musical universe.

Your music will never be the same. 

Will never have sounded this good.

You will RE discover your favorite music. 

As in,,**WOW I never knew this singer/ band had such talents..**

http://www.triodelab.com/45-triode

 

 

Correction

IDHT and pentode tubes are not synonymous. Pentode =5 element construction. IDHT is a triode =3 element construction.

Charles

The 45 tube is a fantastic tube to many DHT enthusiasts it's their favorite. However because of the exceedingly low power it's not for everyone and proper speaker matching is essential. I prefer it and the 2a3 both to the 300B tube as a general rule but obviously that's amp dependent there are tons of good 300B amps out there.

@jond 

 

Yes my tech speakers often of this **45** tube.

Looking at a  pic,  tube looks super.

have a  feeling its the one Im after, Yes very low watt as  mentioned in Triode's web site and mentioned *speaker choice is critical..** Mentioned something like 100 db sens speakers..

Mine are dual FR + dual T's. 

tweets 91db and FR 95 and 93.

with the ohm load, might have to stay with DHT PP circuit, for a  booost in power/dynamices

Actually listening to a single tube SET UX50, , now this PP2A3, I prefer a  PP DHT design.

I love the dyanmics of this dual tube circuit.

Not sure when the Defy will IF ever get tubes,,,,, man, the wrong roads we travel down....costly....never  taken much interest in DHT's due to alotttt of , half baked , misleading nfo I read here on audiogon decades ago concerning SET amplifaction. Another reason i never took a  interest in DHT's is  lack of exp with a  FR speaker.

All this is completely new to me.

Seems I am saving the very best amplifier for,,,last. 

Like a  good old rare Bordeux. 

The new OP Q is

KT series tubes PP

I've been exploring SETs for nearly 30 years. I started with 300bs, then it was the 2A3, finally the type 45. Then I decided to see how a PP 45-based amp would sound and it ran circles around the SET version- smoother, more delicate, greater resolution, more grunt, better bass- no downside whatsoever.

Of course I was measuring these things too. What I found was the distortion signature defines any amplifier. Its what we call the 'sonic signature' since distortion is very audible as tonality.

Since SETs express a certain type of distortion (quadratic nonlinearity) and a fully differential amp expresses a different type (cubic nonlinearity) and since PP amps with single-ended circuits express both, I set out to see if I could build a PP amp using small power pentodes that could outperform SETs of the same power.

This little amp makes 5 watts and is class A. It uses EL95s which are a little brother to the 6AQ5. The tube is meant to be very easy to drive. I set up the output section in ultralinear, using cathode bias so it would have a substantial differential effect on the output section, giving it greater linearity. I then built a 12AT7 differential amplifier to be both the input voltage amplifier and driver. So the amp is fully differential and thus has a cubic nonlinearity.

A cubic nonlinearity expresses the odd ordered harmonics since the even orders are cancelled. A quadratic nonlinearity expressed both even and odd.

The ear treats the 2nd and 3rd harmonics the same- they are relatively innocuous. But they are also useful as they serve to mask the presence of the higher orders. That is why an SET sounds so smooth, despite making more of the higher orders than any other kind of amplifier!

Because the 2nd is suppressed, this little amp makes a fraction of the distortion that an SET of the same power makes- its about 0.5% at full power and vastly lower at any other power level, and because the 3rd harmonic is able to mask the higher orders, its very smooth. Its actually smoother than any SET I've heard, while also being more detailed and transparent. It also has wider bandwidth, being full power to 100KHz and good down to 5Hz.

Having heard it, there is no going back to an SET. I wanted an amp small enough that it would be good in a desktop or bedroom system, also good for headphones or a main system if you have speakers of sufficient efficiency.

Put another way, this isn't about KT vs 2A3; IME its about design. You can make a bad sounding PP amp and you can make a good sounding SET. But you can also make great PP amps that go places no SET can at any price: smoother, more detailed, more musically involving, IF you know what you are doing with the design.

 

Hi @atmasphere ,

Why did you use EL95 in ultralinear mode? Why you didn't use 2a3 or 45 tubes for your push-pull amp?

Regards,

Alex.

chips + the Class A JFET opamps, loaded with tiny cjips. All make for highly sensitivite DAC setup to moisture. ~~~~~~~~~~~~~~~~~~~~~~~~~~~ This may have contributed to the pops while cd plays,, but then I played same jazz cds with ceiling LED with dimmer OFF, and pops completely disappeared. DAC did not like 100% humidity + cool temps + static energy in air/cold front energy + LED ceiling with dimmer. No pops and just was able to upload another video.

Put another way, this isn’t about KT vs 2A3; IME its about design ~~~~~~~~~~~~~~~~~~~~

 

man I want one of THOSE amps the EL95 you describe. wow. Sounds just like my perfect cup of tea. I am about to upload a video after I post here. In the video, I make the claim the KT88 does not render the music such as I am hearing via the 2A3. Although both techs here threw tomatoes at Jadis Defy design,, neither can pin point exactly whats wrong,,excep there are ONLY 4 bias pots for TWELVE!!!! tubes, Jadis cheated on that mess up. This amp needs 12 bias pots accessible from top panel. Come on Mr Jadis,,just wwhat were you thinking,,,ohh yeah French asethetics, beauty,,GOT it, Give me 12 bias pots top panel please, I;’ll ship it back, you pay ship both ways to france.. Design?

 

Every KT amp I’ve heard, about 5 , EL34,88,120 all sounded about the same. To me it comes down to 88 vs 2A3. The sonics are in the tube, much less the design. Although I will say i prefer AU along with AX in front end as superior pre section , this way I can get Teles in the sound. Got to have Teles in pre. My tech’s UX50 has 12AU7 and some other taller pre tube,,which I am thinking is the reason i prefer this Yaqin over his UX25. Teles are simply magical. I’m not saying design has no influence, just saying it really boils down to power tube vs power tube.

I could not tell much dif twix a EL34, 88 and 120. Whereas DHT’s have a **signature** character. This is what i am trying to say.

Not saying all DHT’s sound same, just all have a  signature midrange  linear magic.

But I’d bet the KT170 Jadis sounds not much dif from their EL34 designs. Speaking of only midrange, not bass, not highs.

vs the liquid, magical mids of DHT’s.

Every cd I’ve tested sounds like new music vs the KT88’s **signature sound*. Again not that all KT88’s sound the same. I did not like the ever popular Gold lions, Svets were better,,hoping the EH’s beat out the Svets so I can decide either to keep the KT88 amp or sell it (= dump it) Can the reputation of Electro Harmonix 88 save this amplifer?? But why listen to a midfi amplifier when I can listen to hifi amplifier???? Makes no sense. KT88 mid vs 2A3 high.

Why did you use EL95 in ultralinear mode? Why you didn’t use 2a3 or 45 tubes for your push-pull amp?

@alexberger

I’d already built the PP 45 amps and they were rather large. One problem of DHTs is you have to run DC if you want the output section to not make hum. So that means a DC supply which takes up room. The EL95 amp is silent on ’phones with AC filaments- its also a stereo integrated amp (2 inputs with volume control) and has a footprint smaller than a sheet of notebook paper. I did actually want this amp to fit easily into the space I have for it in my bedroom...

Its far more practical than any SET of the same power. For now anyway, the tubes are cheap and you can leave it on all night without it getting into trouble or worrying about the life of the tubes (they’ve held up just fine over the last year). Despite being class A it really doesn’t make much heat.

When people compare PP amps to SETs, one variable is that they are often using different tubes with far greater power (apples and oranges)! So this exercise sought to eliminate those variables, first by using the same DHTs in PP with the same components and tubes as used in the SET version, and the second by comparing an SET to a PP amp that made the same power at clipping.

If I had to describe the little EL95 amp, its very nimble compared to SETs of anywhere near the same power. Its not subtle. One problem with it was that when I was done it had too much gain. Since it used a differential amp for the input and since the inputs were all single ended, that allowed me to use the unused input of the differential amp for feedback, which was used solely to reduce the gain. IMO/IME this is the only legitimate use of feedback unless you can run over 35dB at all frequencies.

BTW there’s nothing special about this amp unless you think that attention to the kind of distortion it was going to make might be considered special. There is a reason SETs went the way- despite improvements in things like coupling caps and power supplies, they are simply an antiquated technology that can be easily surpassed IF the designer is paying attention to the distortion issue and understands how that interacts with the human ear. IMO its a tell of the sorry state of affairs in high end audio that there are SETs that actually do sound better than their PP brethren- it really shouldn’t be that way!

The opinions expressed in this video I take full responsibility  and in no way  wish to disregard the KT88 tube in a  design.

Its a  wonderful sounding tube   (tongueincheek),, but at the end of the d,,listening session, there can only be one sharp shooter left standing ,,as you know,, only 1 gets The Cigar.

.Midrange,,although I will say this lil 7 watter has soem kick in bass. Highs super. 

IMHO the KT series tubes, EL34,88,120,150, 170 is midfi after you hear a  Direct Heated Triode.

 

 

OK Miles Davis with the Yaquin 2A3 + DavidLouis duos

vs

this Jadis JA30's w KT150's  + Sonus faber Guarneri

 

Now you tell me which you prefer, have same track as in my upload

 

I'll take Sonus Faber for $500 Alex!

Neither sounds particularly good. I think that is supposed to be piano playing at about the 8 to 9 minute mark of the first video. It is pretty tough to tell for sure though. Bright and splashy with overall poor timbre. The Sonus Faber have a somewhat more realistic piano, but is closed in and dark sounding. If I am forced to choose between them, it would be the Sonus Faber but only because it is less bad.

IMO its a tell of the sorry state of affairs in high end audio that there are SETs that actually do sound better than their PP brethren- it really shouldn’t be that way!

@atmasphere

For a number of listeners this is their conclusion. You give rationale explanation as to how push pull topology could easily equal (Or surpass) the sonic presentation of a good SET amplifier. Problem is very few manufacturers commercially are following the recipe you propose.

Most happy SET owners migrated from the world of transistor and push pull tube amplifiers. Very rarely is SET the first amplifier choice for newbies. Rather it’s a choice discovered after ownership and exposure to non SET amplifiers. So most of these converts are seasoned listeners and owners of High End audio components.

 

Upon introduction to a good DHT SET some listeners find a purity, aliveness, transparency and most importantly a genuine deep emotional connection with their music listening experience. These traits were found lacking to some degree with their previous non SET amplifiers. Some do return at some point to other amplifier types, but many do not. So perhaps other manufacturers should heed your guide lines for improving their push pull amplifiers.

Charles

The Sonus Faber version sounds better but it's impossible to know if it's the system or the quality of the recording. Neither sounds great but that's YT for you.

1. I have three single end tube amps. A 2A3, a 45 and a 6BG6. The 2A3 is a Sanei 260A made-in-Japan. It uses all Tango iron, including a Tango choke! Plus a front panel volume pot and a headphone jack! It was an eBay auction win for me one December! The Japanese seller gave me free shipping too! The 45 SET was a custom build by Will Vincent in Idaho. He built it on a Dynaco ST70 chassis using Emcron output transformers, two 6C6 pentode input tubes and a 5V4 rectifier. Beautiful white powder coat on the chassis. I paid $1600 + shipping. With only 1.75 wpc I don't have any speakers to use with it after selling my Heresy's.

2. The 6BG6 is another custom build from eBay. It uses a single 12AT7 as input to two 6BG6 tetrodes, along with a 5U4 rectifier. About 6 wpc, so a bit more useful than the 45 and 2A3 amps. Now I wish I had kept the vintage Heresy's! I think I paid about $200 for it. The circuit is built upon a square piece of chrome metal diamond pattern flooring, with all four sides encased in wood pieces. Power tranny on top rear center, 12AT7 front center and a 6BG6 in front of the power tranny on left and right sides. Underneath are the two output transformers. 5U4 in center in front of the power tranny. All the circuit wiring underneath.

I am thinking that this would be an easy build. Wonder if there would be enough interest in it for some sales? The 6BG6's are still available NOS. They take the plate lead out by a top cap. About 6 wpc of tetrode power! Again, best with higher sensitivity speakers!

Upon introduction to a good DHT SET some listeners find a purity, aliveness, transparency and most importantly a genuine deep emotional connection with their music listening experience. These traits were found lacking to some degree with their previous non SET amplifiers. Some do return at some point to other amplifier types, but many do not. So perhaps other manufacturers should heed your guide lines for improving their push pull amplifiers.

@charles1dad 

They're not actually my guidelines- just good engineering practice. I think there's too much 'by gosh and by golly' going on in this sport where real engineering just isn't being done- instead you see an awful lot of rehashed circuits from yesteryear. I know a lot of audiophiles look askance at measurements but the simple fact is that if you have the right measurements you can tell how an amp will sound if you also have an understanding of how we perceive sound.

 

I’ll take Sonus Faber for $500 Alex!

 

 

~~~~~~~

I think that SF model goes for like $2500 vs my FR duo @ under $1. I’ll take my FR/Duo’s all you get with the SF is a 6 inch mid and a tweeter, Neither has the fiber to voice the super duper critical 2khz-3khz band width. Breakup in both drivers in this extremely important fq zone.

I know a lot of audiophiles look askance at measurements but the simple fact is that if you have the right measurements you can tell how an amp will sound if you also have an understanding of how we perceive sound.

I believe many experience audiophiles/music lovers have a healthy appreciation for measurements. They just have come to learn that you have to listen to an  audio product to really know if it's for you. People realize there is no better way to select these products.

Charles

I have three single end tube amps. A 2A3, a 45 and a 6BG6. The 2A3 is a Sanei 260A made-in-Japan. It uses all Tango iron, including a Tango choke! Plus a front panel volume pot and a headphone jack! It was an eBay auction win for me one December! The Japanese seller gave me free shipping too! The 45 SET was a custom build by Will Vincent in Idaho. He built it on a Dynaco ST70 chassis using Emcron output transformers, two 6C6 pentode input tubes and a 5V4 rectifier. Beautiful white powder coat on the chassis. I paid $1600 + shipping. With only 1.75 wpc I don’t have any speakers to use with it after selling my Heresy’s

 

 

~~~~~~~~~~~~~~~~~~~~~~~~~~ WOW you really have some gorgeous sounding amplification. Down the road I may be interested in the 45, would be fantastic with my FR.

These online comparisons using YouTube are rubbish.

OK so we know the KT88 tube in a 12 tube amp, ain;t working for me vs the incredible sound froma 2A3 PP

 

,,,so what do we do in this case???

1st wish to say

glad these 88’s are not new,, i’d be stuck with them...they have 4k hours,,,so what we do is to consider what other tube this picky Defy will accept... that MIGHT just be a game changer,,,and after thinking,,,thinking, pondering,,I found the answer.

Not going to tell you which tube.

Only going to say, specs look close, but IMHO the 88 has a bigger mid voice.

And with dual FR, I don’t want/need/wish for a midrange that **blooms** as is so often said about the 88.

The mystery tube I’m guessing has a tiny bit less pronounced midrange X’s 12 88's   = now we have a massive alge bloom midrange , polluting the waters.

So if the mystery tube, a tube that has completely totally been thrown under the bus, then steamed roll over (= its all about 88,88,88,,,88,88 = Popular Vote, = which goes against my modus operandi),

 

Hint

the plant was bombed, russians picked it up and made the tube superior.

This is the tube that might very well save the Jadis from being nothing more than a museum piece.

 

2A3 PP low watt amp

vs

100 (real/true) watt amp + Mystery tube

shootout.

There’s still hope for Jadis

Yeah I know Jadis lovess the Svet Kt88, only due to popular demand.

 

Stay tuned.

 

 

If you're speaking of the Genalex Gold Lion KT77 repros yes they are far superior to the KT88 tube and most EL34 variants as well.

Genalex Gold Lion KT77

 

~~~~~~~~~~~~~~~~~~~~~~~

 

This tube more than likely will not work in the Defy as pe my tech’s opinion. He did grant approval on the mystery tube as acceptable in the Defy’s circuit. Bombed plant is dead giveaway

 

btw if someone says **mystery tube has even more midrange vs the 88...** I’ll dismiss.

The 88 is well known as **bloomy** midrange.

Which again, xover type speakers need the 88  to ENRICH that 1800hz-3500hz region.

FR , especially dual concoction/scheme,,has already too much,,well actually with the right tube ina PP, just perfectly rich enough.

a single FR would (might) bore me to death.

@mozartfan 

I think that SF model goes for like $2500 vs my FR duo @ under $1. I’ll take my FR/Duo’s all you get with the SF is a 6 inch mid and a tweeter, Neither has the fiber to voice the super duper critical 2khz-3khz band width. Breakup in both drivers in this extremely important fq zone.

The $500 Alex comment was intended to pay homage to the lat Alex Trebek. The current version of the 2-way Sonus Faber Guaneri is $18,000/pr IIRC. Stands included.

 

Your speakers are probably quite a bit more sensitive.

 

current version of the 2-way Sonus Faber Guaneri is $18,000 ~~~~~~~~~~~~~~~~~~~ EMoji of complete shock.. A few months back there was a older version of the Guarneri on ebay,, bidded over 2500,,, could not believe it,.,,,now you say,, 18G's. huh? 2 way 6 inch Scan speak made especially for the Guarneri with a incredible Neo Dymium magnet motor,,and a high end tweeter,, is this the 2 way you are refering to...?? 18GGGGsss. Emoji of disbelief.

Now the shootout is

France vs China

Defy7 with highest end Mundorf, F&T's,  Philips, aero space silvercopper internal main cabels, 4 @ 8 gague.

Takman Rey resistors.

Vs 

Stock China 2A3 PP .

I do not wish for this Defy to  be a  closet piece, collecting dust.

The 88's are just a  pinch too thick in midrange.

I need something that is more evenly distributed. 

And that tube is none other than,,,,the mystery tube.

Will the Jadis come up to the Yaqin's magic?? 

Lets say this, if the record has something that requires depth, dynamics, complex passages, demanding,, the 2A3 just might not match what the Defy delivers in this more strigent, demanding power requirements. Such as Ravel's Daphne and Chole. 

This  Q can not be answered til I find the cash for the 12 mystery tubes + Richard will install new bias pots, .

Stay tuned,,, maybe late April (not mid summer as previously stated).

 

 

 

Why bother with the Defy 7? Get a pair of nicely restored Heath W5's. Peerless iron. Add a quad set of Gold Lion KT66's and four vintage 12AU7's for the input/driver stages. 28 PP watts per mono amp. Sonically way better than any Chinese amp! I have a pair. Sell that Defy 7!

Regarding speakers: a pair or two of Quad 57's plus a pair of Heath W5's is audio nirvana! That's what I use!

Why bother with the Defy 7? Get a pair of nicely restored Heath W5's. Peerless iron. Add a quad set of Gold Lion KT66's and four vintage 12AU7's for the input/driver stages. 28 PP watts per mono amp. Sonically way better than any Chinese amp! I have a pair. Sell that Defy 7! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Man o man, dont you just sound like both techs here in the area,,**you really ought to dump the Defy*** why all the hate for the Defy.. show some love.. Richard speaks very highly of the ~~legendary, famous~~ Heath Kits. KT66's. ,,, not much attention on these rarely employed tubes. My gress is like EL34's in tones..?? WEll I have too much cash invested in ~~upgrades~~ in the Defy,, wife will not let me sell it,. Has corrosion on some tiny points top chassis, (New Orleans 100% humidity and stuck ina closet for 10 years,,have 5 cats, but its not from the cats pp). + added mods, NOT STOCK, one just sold ebay $2500 top big $200 ship. I have over 1500 in upgrades alone. I'm betting all my chips the new mystery tube is going to deliver the CORRECT sound stage for this amplifier. fact of the matter is, I followed the crowd going KT88's. Great tube for a 4 tubed amp. And a absolute necessity for all you audiophiles with CONVENTIONAL xoverlowsens LOUD`speakers.. For a single FR, the 88 will only work ina 4 tube amp. When we get up to Defy's 12,, the tiny big added midarnge X 12, makes the mids ~~bloated~~. The mystery tube I am speaking of has a tiny bit more recessed mid vs the 88. I'm guessing the Defy will arise like the Phoenix from the fires, into a new beautiful soundstage. When cash become avaliable I will tube the Defy with the mystery tube and upload about 10 YT videos. If its not a success, I will not upload any videos. I'm guessing my modded Defy vs stock Jadis, with mystery tube, which jadis DOES not rarely employ as per clients request,,, will elevate this Defy beyond all Jadis' amp,ifiers when a 88 is in the socket. Dual FR + 12 88's = bloated midrange = yucky. Still think about it. China 2A3 $1500 vs Defy+ DPL = over $10G's. 2A3 in most classical gets the Cigar. RFavel's Daphne awaits the test. Which one can handle the massive swings load of fq's, wins the cigar. The 2A3 might show some distortion at say 65SPL, vs the Defy/Mystery tube might show distortion at say 85++ SPL. I listen at 65/70SPL.

Regarding speakers: a pair or two of Quad 57’s plus a pair of Heath W5’s is audio nirvana! That’s what I use!

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~ Quad57’s, Legendary, Richard mentions Q57’s are the Gold standard by which all xover speakers are measured.(yeah I am putting words in his mouth,, but thats pretty much how he talks about this Legend))

Now will they hold up against my Dual FR’s???/

Let me go to YT now on the Q57’s.... see what I hear....

 

Remembera  Legend ary speaker is only as good til a  new kid on the block comes along.

Do the 57's have a  sweet spot,, = beaming??

If yes, grate my nerves. = reject. 

Do the Q57's require some special power amp/db sens??

If yes, not for me.

Joao Gilbert at 3 minutes

Sorry not my cup of tea.

a bit tioo much resonances, like all paper mid woofers have same identical coloration. 

Bass is UNREAL...

You will not know just how colored the Q57 is until I bring in my Dual FR.

 

Thuis is the way this game works, One speaker smacks down another.

Last speaker standing wins.

My Duo has no competition(exception high end horns, which all speakers fail against) in certain regards. 

 

 

 

This thread is like a slow motion train wreck. You yell “look out” and then no matter how hard you try you….can’t….look….away. Ugh.

I listened to ESL57 speakers in 3 different homes and liked these speakers a lot!

@atmasphere . One of my friends built a number of SE and low power push pull amplifiers on EL84 and 6V6 tubes. He mostly used similar quality parts for both SE and PP. But he preferred the results he got with SE by a big margin. He used classic schematics. He runs his amplifiers without feedback and with feedback. The question is why you and my friend got so different results? What is the difference of your schematics to classical EL84 PP schematics?

Do you use balance input "+" for input and input "-" for feedback? Did you publish your schematic?

Regards,

Alex.

 

 

I have not heard the Heathkit amp, but, I've heard a number of amps with Peerless trannies, and I am a big fan of the KT66 (and similar sounding 6L6) tube so I bet the amp is quite nice.  A good modestly powered tube amp feeding Quad 57s makes for a terrifically musical and enjoyable setup. 

If it sounds like crap on YouTube, guess what: everything SHOULD sound like crap on YouTube.

@alexberger

But he preferred the results he got with SE by a big margin. He used classic schematics. He runs his amplifiers without feedback and with feedback. The question is why you and my friend got so different results? What is the difference of your schematics to classical EL84 PP schematics?

Because when all is said and done it boils down to the desires, taste and preferences of an individual listener. Someone will prefer the push-pull and another will prefer the SE. Neither is hardly  wrong . No one has "golden ears" and thus the final arbiter on what sounds best. This is rightly so, up to each listener to decide. No absolute proclamations can exist in an endeavor so thoroughly and innately subjective and personal. That’s what makes this all fun and an adventure.

They just have come to learn that you have to listen to an audio product to really know if it’s for you. People realize there is no better way to select these products.

Yes- heaven forbid that audio companies actually publish spec sheets that told you how the gear sounds! As a result the only way to know if something works for you is to play it at home.

@alexberger

He used classic schematics. He runs his amplifiers without feedback and with feedback. The question is why you and my friend got so different results? What is the difference of your schematics to classical EL84 PP schematics?

Do you use balance input "+" for input and input "-" for feedback? Did you publish your schematic?

I think the problem comes in when you combine single-ended and PP circuitry at the same time! Thru algebraic summing you wind up with a more prominent 5th harmonic. Seems to me Norman Crowhurst wrote about this in some of his tomes back in the late 1950s- so this shouldn’t be a revelation (although I’ve come to suspect many designers are ignorant of his work). Back then the solution was to add feedback, which causes the circuit to be brighter due to added higher ordered harmonics (so to me does not seem like a solution). Crowhurst also wrote about this too, so none of this is new.

What strikes me as odd is, when these things have been known for so long, why do people persist in making what to me seems the same mistakes, over and over?

I am suggesting that your friend possibly made this mistake also. IME if you really want to hear what PP can do, you can’t combine it with single ended circuits or you’ll shoot the project down before it gets off the ground.

You do one or the other, but not both!

I didn’t publish my circuit, (which is very simple; two stages of gain including the output section which is a simpler signal path than most SETs), but I did publish an in-depth description over on audioasylum.com in the DIYtube section- search on ’EL95 amp’. The description allows anyone to build the circuit if they have the know how to build amps from scratch. The only tricky bit is I used some very effective constant current sources for the differential voltage amp which is something you don’t usually see in tube circuits (and so leaves performance on the table). To this end the Voltage amp also ran on + and - Voltages of the same value.

You are correct- the audio input is the + input and the feedback is on the - input. In that way there would be no intermodulations introduced at the feedback node. I got such good linearity out of the circuit I didn’t need the feedback at all; it was only used to reduce gain. IMO/IME if you are applying smaller amounts of feedback (like 15dB) that is really the only way to do it.

 

Hey mozartfan, are you by any chance related to a guy named Jeff, AKA LowMu or LoOhms? Just wondering............

 

BillWojo