So, what is this "something"?
regards,
Douglas
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Are you considering experimenting on the dark side?
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SE gets the 'that's quite different' reaction. It is often just such a difference which can be pointed to as reason to say, "better". I have seen it the other way, listening to a bunch of SE and then plugging my PP amp. Usually it is a combo of things like power and ( IMO ) putting in a better amp in. Clean headroom is not to be sneezed at. A SE design with 3-4 watts is going to be running too close to the edge on a lot ov the peaks...
I am not considerig SE for power just now. Been messing about with phono stage design...and of course the Amp project for Group Build. good news there BTW, some 20W Peerless 20-20 models are on the way to me( and then on to the Winder ).
regards,
Douglas
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Akilesh, do some study before saying stuff like that. Sorry, you were baited.
Thers plenty of really really bad Pp out there too. Try not to generalize.
TC
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>>throw Grenade...
Music reproduction should not be a battlefield.
TC
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For your benefit, please read the statement below:
"Amp designs with push-pull or balanced topologies can achieve lower overall levels of distortion than single ended amps. On the other hand, they achieve this overall distortion reduction chiefly by canceling out even order (2nd, 4th, etc.) distortion byproducts, which leaves behind a disproportionate share of odd order (3rd, 5th, etc.) distortion byproducts. "
Taken from:
http://www.iar-80.com/page2.html
Hope this helps you. My advice would be to read that entire page, it would be well worth your while.
thanx
-akhilesh
"Amp designs with push-pull or balanced topologies can achieve lower overall levels of distortion than single ended amps.
==The author (?) throw in balanced, but I don't understand how that benefits the distortion argument. The author jumps around a bit and creates as much confusion as he tries to clear. Further....
>>On the other hand, they achieve this overall distortion reduction chiefly by canceling out even order (2nd, 4th, etc.) distortion byproducts, which leaves behind a disproportionate share of odd order (3rd, 5th, etc.) distortion byproducts. "
==I don't see how this makes a case for either topology. I read the entire page and it's fairly rudimentary as far as describing various topologies. About the most meaningful statement is this,
"There are many schools of thought about distortion byproducts, with various psychoacoustic theories to support each"
and this...
"There are only a few exceptions, and these single ended amps deserve special praise for bringing overall distortion problems down to acceptable levels (though still detectable, and still higher than push-pull or balanced designs)".
>>In reality it makes no sense to me to argue topology. Fine examples of all kinds are out there. I am lucky to own several excellent kinds of every type of amp including SS and hybrids, otl and SE as well as arguably the worlds finest Pp-otl, the Berning 270. I also have a fine SE in the electronluv, I do prefer odd order distortions BTW. I have heard Lynn Olsens Aurora on my speakers and Paul Weitzels new SS amp, the Firstwatt, and my old Bogen PP. I really liked them all. But when it comes to my money of course SE wins, ultimately. It just sounds better, on my system/room.
To me it makes alot more sense to raise points about tangibles, like craftsmanship, implementations, parts quality and overall design. And what about overall system tuning and synergy between components like manualblock suggests????
Throwing an argumentive bomb to a forum is audio delinquency.
Manualblock makes sense with this regarding various topology debate:
====I have always thought this would be an important part of design theory except that the debate gets too silly with people re-stating the obvious ad nauseum. Or defending their point of veiw or their equipment like there was something at stake that reflects on them as people instead of just helping to advance the cause of better sound for the home stereo.
Or they have some odd or difficult to drive speakers that only sound good with one type of tube or something equally silly.
So when someone is genuinely interested in the musically relevant distinctions between the two circuit types it is side-tracked with all that nonsense.
Just an observation why there can't seem to be a rational dialogue.
>>Well said.
TC
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I think you can make a much nicer sounding push-pull amp for a few hundred dollars than a SET amp, so I think entry level systems might be better off running push-pull. The trouble for DIY is that SET is simple to build but requires more expensive components for good sound quality. A good quality push-pull amp can be made with cheaper components, but it's more difficult to build, and maybe that discourages DIY builders.
I guess I've come to the conclusion that if you have the budget, give SET a go. There are some great SET amps in the >$2K range. Less than that, I'm thinking go push-pull.
BTW, I wanted to let you know that Akhilesh has a PhD and is a professor at Tulsa University, so he's a pretty quick study.
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On the 'SE Sound', I have heard a difference and was curious about moving towards quantifying it. I know my Class A PP amps don't have it...
Its why I made reference to battle, if that is brought to the front, perhaps thinking along those lines would help keep folks from typing frirst and thinking later. A few have made reference to that sort of thing, and there has been no unpleasantness as of this time( that I have read so far ).
more like looking for interesting and passionate discussion.
regards,
Douglas
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Suggesting that level headed grown-ups cannot discuss *ANY* topic under the Sun is an insult to those folks.
It's not like I wanted to know if somebody attended the 8:30 Service or the 10:30 one...or if it was on Saturday or Sunday.
regards,
Douglas
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Even if all things are not equal, at equal volume levels, the SE is working MUCH harder, in relative terms, to push out the same loudness level. Is the SE being pushed into a more non-linear response, thus producing a differnt (better or worse) sound....Colin
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But, if we use similar principles like in SE building - careful selection of linear tubes for the driver and output (DHT), class A operating point with carefully chosen high-quality OPT, LC-style PS with HQ oversized PT(s) (plus maybe additional heater/filaments transformers), MKP (non-electrolitic PS caps), no NFB loop, say - monobloc construction, phase splitter with real balance (CCS), etc. - we can really spend more for PP amp...but, I`m sure that the results will be worth it...
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TC
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I am confident that if you remove budget constraints, you can make any of the popular topologies sound good. But if you make price/performance the goal, I think SET starts losing ground.
That may be why the budget models are probably better off push-pull. Whatever the case, the low end SET stuff just doesn't appeal to me. More expensive SET amps sure do though.
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I want to check out Heart's Kit 2 and Heartbeat amps sometime soon. I hear 6moons or someone is reviewing one of them soon. I kinda like forming my own opinions though.
The current DH Tetrode amps( beam tetrode/Pentode more accurately ) really do it. They have the Peerless 20-20 copies with a few mods for E-Linear operation and cascode Diff amps in front.
I knew I was on to somethig when the chassis ran PP 1619 and didn't glow so well as the Thoriated Tungsten finals I am using now. I can't imagine doing w/o it.
I am going to do a tweak on the front end soon, I have learned a few more things and wish to try them...
regards,
Douglas
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I like to play what I like to listen to. Live Grateful Dead, Pink Floyd, Bela Fleck, and some Allison Kraus get the most time. Led Zeplin, CCR, Iron Maiden, AC/DC and The Who...
If I like listening to it while doing the dishes or folding laundry, it is aceptable test material. Some do stand out, Bela Fleck's album Uncommon Ritual is a nice string piece. From Cosmic Hippo, 'The Flight of the Cosmic Hippo' is always a fav, as is the live cut from Live Art. Little Worlds has a sweet version of 'The Ballad of Jed Clampett'. The SACD of Dark Side has a few favs too. 'Money' and the piece before 'Time'...
the H-E speakers mean I can't stand much noise, either hum or dirt from no place in particular. It is aceptable on a poor man's budget. Heaven helpme if I had to buy it retail...
regards,
Douglas
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Wow. My two SET amps both make thumping bass. I have a 300b Welborne DRD and a 45 DRD Welborne. Both are mono blocks. The 300b is SS rectified and the 45 is tube rectified. I use JBL 4648A-8 twin 15" bass bins that are 100dB efficient. Just a casual observation that many who listen to SET for the first time may not have speakers efficient enough. This does not apply to you Wayne as your Pi speakers are eficient enough for SET. These Welborne amps will play on for a good 10 seconds after I switch them off so maybe their power supplies are also stouter? I have a small stereo 11 wpc 6V6 amp and that has much less bass to my ears than the 300b and 45 SET amps. This amp is used at my apartment on less efficient 93dB@1W JBL L300 speakers. These speakers can exhibit mucho bass with my highly modified 19wpc strapped in triode Dynaco ST-70.
>I think you can make a much nicer sounding push-pull amp for a few hundred dollars than a SET amp, so I think entry level systems might be better off running push-pull. The trouble for DIY is that SET is simple to build but requires more expensive components for good sound quality. A good quality push-pull amp can be made with cheaper components, but it's more difficult to build, and maybe that discourages DIY builders.>
I think you get what you pay for. Cheap iron is not a great start for any DIY project. See the Derek Walton site for plans for the inexpensive version of the JE Labs 300b. The inexpensive angela universal power transformer is actually pretty good. Again with better iron I think anyone will be happier with the results no matter if they are building SET or PP. As for parts count it is a fact that SET usually has a lower parts count. I would love to build the Gordon Rankin designed Baby O' some day. But the silver wound output transformers are about $800 each. Still these amps really look very well designed, and they have low parts count. Low parts count means easier building for dummies like me with a soldering iron.
>I guess I've come to the conclusion that if you have the budget, give SET a go. There are some great SET amps in the $2K range. Less than that, I'm thinking go push-pull.>
There are also some great PP amps in the 1K range like the used Klimo Kent 35 wpc EL34 mono blocks. I paid the princely sum of $995 for my pair on Agon last Fall. Ron Welborne sells some nice SET kits starting at under $1500. He sells built units that use the very good quality ElectraPrint output transformers for a little more loot. Both the kits and the built amps use Electraprint iron. I own 45 SET, 300b SET, EL34 PP, KT88 PP mono block amplifiers. I own a few stereo amps in my HK Citation 11, and two Dynaco ST-70 amps. I listen to both SET and push pull. Both modalities do things that I like. As long as it has tubes and is not made brand new in China I will listen to it. No, some higher end Chinese new gear is rated nicely. I cringe at the folks buying the lowest end Chinese tube gear that just might not stand the test of time. All audio is very subjective at its best. None more so than tube amplifiers and horn speakers. I am a believer in buying vintage tube gear and enjoying it. For example I bought a 20 year old Conrad Johnson Premier 4 that uses 8 Mullard EL34 tubes and makes 100 wpc. Three years later I sold it on Agon to a doctor in MD who loves it for what I paid for it. Same with my HK amp and other higher quality names that tend to hold value. Some like my Fisher FM-1000 tube tuner, and other collectible tube ones can even go up in value. The smart reason for buying better quality used tube amps is you can usually recover your investment if you do not like them. LOL, that is only true if you do not spend to much when you buy it, if it is worth less than you paid for it. Make any sense? Hey, as long as it glows listen to it! Have fun as this is a very short journey we are on in life. I really like the 2-way horns I got for my Dad. The horns are 31" x 31" JBL 2360A. The drivers in them are TAD td-4001. The bass bins are JBL twin 15" woofer 4648A-8. The horns are powered with the 45 mono blocks. The bass bins are still having a/b testing with the 300b SET and the Klimo EL34 push pull. The crossover is a marchand xm-126. It is a lot of fun to listen to vinyl and CD's on his stereo. His speakers at 6' tall are very SET friendely speakers with the 100dB efficiency. I powered both speakers with only 1.8 wpc and it made great sounding music. John C.
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I've heard some really great SET amps in the ~$2K price range, some even hovering closer to $1000 or $1500. But once you get good tubes in the those thousand dollar amps, you're getting closer to the two grand mark. Gently used gear is another option to get the price down.
But what I'm talking about here are entry level tube amps and kits that sell for a few hundred bucks. The low-buck SET's are fun, but not really my cup of tea.
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I have a slightly different idea about loading and output stages, and believe it will be better. It will not look like a chopped, early 50's lead sled...
regards,
Douglas
To cut to the chase, it makes total sense to talk about and understand he limitations of each design. There is no need to keep falling back ion the poor versus good implementation argument, since that is a given.
So I think we are all on the same page.
-akhilesh
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Josh's amps are certainly different from what you'd find at BestBye...
regards,
Douglas
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Minimum primary L requirement at power is still the same, yet one will have to deal with twice the DC. With PP, if the a-a load is right, and you don't overheat things with too much idle DC, you'll be fine if you can keep the two halves balanced.
regards,
Douglas
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I believe the ultimate potential for either topology far exceeds the abilities of %99.9 of the amateur and professional amp buliders out there (and I most certainly include myself in those ranks.)
The primary disadvantage of the SE topolgy is the SE ouput transformer. The comprimise needed to balance DC power handling and good primary inductance is painful. The parafeed connection (and thus no air gap) helps a lot - but it introduces the problems of (some would say the evils of) large coupling caps.
The primary disadvantage of PP amps is that real, honest to god, dynamic tube "matching" is very rare, and possibly fleeting, as the tubes age. CCS's help a lot, but they have their own issues and colorations and complexities.
The good news is that either one can sound great, and that it's a heck of a lot of fun building tube amps! It's fun, because for maybe $300 to $600 you can buid an amp (PP or SE) that, soundwise, kicks the doody out the huge majority of commercial offerings any price.
The amp at the link below has morphed from a simple little 6SL7 SRPP driver to 6N1P (parallel sections) parafeed transformer coupled driver, parafeed output. It sounds fantastic, but it can't match the bandwidth (bass and treble) and drive/punch I'm getting out of my PP amp. The PP amp pretty much matches the midrange.
Fun times, man!
TC
I have gotten an imense help from input gathered at litening meets. Both my own observations and from other participants. Discussion face to face with a shared listening experience is not available anywhere else.
Actually seeing how another circuit sounds is another bit of input. Seperating the small details from gross circuit changes is difficult. If it were easy, everybody would be doing it.
On large coupling caps, how big are they to cause you 'problems'? I like to use big ones in between stages. Moror-run Oilers of 1-2 uF. The current fav is a 1.5 uF MKV rated at 660vac. I got them on ebay for 30 cents each, delivered.
regards,
Douglas
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I use a lot of motor run caps, too, and I think they sound great with a good healthy signal. In a wimpy RC circuit (say 12ax7 or 6SL7 @ 1 or 2 m.a.) not so good.
Craft
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Much less THD, with no regard to odd vs. even order and the different degrees to which people tend to be bothered by them. To say nothing of the fact that gobs of feedback are frequently applied to achieve silly low numbers at the expense of sound quality. Anybody still cherishing a Japanese receiver from the late '70s?
>>SETs have much more esp even order, hence they sound richer or fatter.
There's nothing rich or fat about a properly executed SET design driving a pair of suitable loudspeakers. I don't think gross and misleading generalizations do much to advance our collective state of enlightenment regarding the audio arts. . . .
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A fat tone is pleasant. I think you yourself said that in the post above.
I agree with you...gross and misleading generalizations are gross.... I am sorry you think that describing a design characteristic is a generalization.
I don't want to get into a feedback debate since I am not an electrical engineer and not really interested in debating anyone on this forum. However, if you are really interested, I can point you to some refereed articles in JAES on the subject.
-akhilesh
Just to make sure you understand I am not attacking SETs in any way..in fact I quite like the little things!
-akhilesh
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Just because a subject happens to be something the participants are passionate about, does not exclude them from participating in a gentlemanly fashion( whilst not PC to use such sexist nomencalture, the meaning is not quite conveyed with any other I could think of ).
regards,
Douglas
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Guitar players value tube gear in attaining a particular kind of tone in playing, not reproducing music. That doesn't really do it, either.
I don't think one needs to be an EE to hear the effects of feedback. It's necessary in non-triode amplicification, as most other devices are distinctly non-linear and need a little help. It's necessary when driving long cables. Outside of that, it's a music killer. The Audio Note M2 has switchable feedback. Choose what you like. Without it, the music flows free, full and lifelike. With it, the life is squeezed out of the signal, and the music falls very flat. but I digress; this is about push-pull vs single-ended amplification.
I guess, in the end, I don't see much point in debating this unless the participants can be in the same place listening to gear that embraces the opposing viewpoints, so I'll withdraw.
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As to my system, not surprisingly, since I'm the US distributor for Audio Note, it's all AN. What might be surprising is that I got involved with AN professionally because of the huge effect that purchasing a few used AN pieces had on my system and listening experience.
Anyway, I listen to a Voyd 'table (predecessor to the TT Three), AN 1S arm and usually an IO moving coil cartridge through an AN transformer into an M3 pre-amp. Amps are Quest Silver mono 300B's driving E/SE Silver speakers. Cabling is all AN silver of various levels. On the digital side, I'm waiting for the first of the new CDT2/II transports, which will be paired with a DAC3.1x Balanced.
I'll be building an AN Preamp Kit shortly, (hopefully in time for the Spring New England Valve Fest), and will be building a one-off 2A3 amp using AN parts which will have a dual choked power supply and interstage transformers. 1/2 a 6SN7 per channel input - a stage less than usual to reduce noise as my next speakers will be AN Lexus Signatures - 98dB/w/m efficient w/outboard due to cap size) crossovers.
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It continues to amaze me how well the description of amp charactaristics can be described and shared with a keyboard. Since 'they' don't know what makes an amp sound good, I think we need to step up and become 'them' *AND* find a reasonable answer.
This referal to this mystical 'They' who don't want to make efficient cars, or durable ones, or self maintainable ones...being one of 'Them' is OK so long as I do a better job.
regards,
Dogulas
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I might have to coordinate sending a transport and pre to one of your meets . . . .
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I know it isn't always easy to audition some of the things we discuss here, but really, I'm not sure that there is any alternative. That's why I suggest that folks just take the plunge and give things a try. The best way to know how something well something does is to experience it for yourself. I love having the sound take people's breath away, and watching a silence come over a conversation-filled room when the music starts to play.
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There is quite a buzz on many different levels right now. Lots of people are talking about coming and bringing their equipment, some that are manufacturers or dealers representing a particular product. We may have to roll this into a spring or summer event. It's getting really cool...
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An example of IM distortion: a 1k and 800 signal "mixes" to produce signals of 200hz and 1.8khz. No wonder the music might seem filled out.
One can tell the quality of an amp when a "review mentions liking simple music and not complex, like orchestra. This tells me the IM distortion is very high as it really messes up the music.
Another area is the drive needed for the output signal. Alot of distortion comes from the driver and even before that. This mixes to produce higher order harmonics, although lower in amplitude, that are easier to hear.
Passive parts distortion also plays a major role in the sound. Using passive parts like carbon resistors is guaranteed to artificially "distort/color" the sound.
So the problem with an amp is much more than HD, but IM, topology, parts distortions etc.
Steve
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I have to agree with Ash.. At 2004 CES, The Show, all I heard was fat with one or two thin sounding SETs. I visited those rooms several times, on different days listening to different selections.
As you say, "I don't think gross and misleading generalizations do much to advance our collective state of enlightenment regarding the audio arts..."
Steve
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PP can also have this problem, in a different way, though to a lesser extent.
Take care.
Steve
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and:
but with it's own set of harmonics
Just another way of saying, " I like the distortion spectra of a SET amp".
What I want is a means of measuring the sonic nuance which a good sounding amp has.
And on a more personal note, good amps are not limited to the SE topology.
regards,
Douglas
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