Is there any point in a valve DAC

[GT]

No, not really unless you use it to add flavour.

Unlike with a tube amplifier or phono stage where the tubes are active devices critical to the functioning of the unit, a dac will nearly always just be passing the output from the solid state signal path through a tube output, usually just a cathode follower. It allows the manufacturer to say it's a tube design, when it really isn't.

Not strictly true. Many DACs that use the older DAC chips like the TDA 1541, output a very low voltage (about 10 to 30mV) depending on the load resistor selected, so the signal will need amplifying up to give the 2 volts output. In this case the valves/tubes provide gain and form a critical part of the output stage. That means they are not just a cathode follower output stage. However, there might be a cathode follower in the output stage after the initial gain stage(s), or if the circuit is cleverly designed you might not need a cathode follower at all...

 

[GT]

Yes, yes, but look on Stereophile and the valve DACs often do produce a lot more distortion.

Maybe the measured distortion is higher, but I very much doubt you would be able to hear that at the levels quoted. Also, as most valve DACs are NOS designs, don't get confused as to what is producing the said measured distortion, the DAC (filter or not) or the valve/tube audio output stage...

 

[earlofsodbury]

AUP prohibits appropriate reply.

No it doesn't - tell us, what are these many designs that you have blessed the World with? You're happy enough boasting elsewhere: -

I couldn't give a flying ****. I AM a rude condescending know it all... and after spending a lifetime at this and becoming one of the best amp designers around I make no apologies whatsoever. I'm almost never wrong ... If I've not said "IIRC", "not certain but..." etc then I'm probably right. It comes with having done this for 50 years man and boy. Hope that's offended you some more.

Oh, and you know where you can shove it

So come-on hotshot, let's have it.

 

[RichardAusten]

That's a deeply flawed premise, from which multiple errors in your long post originate.

I'll shorten it for simplicity -

1) Build an elite measuring system - it is VERY cheap to do this. Find ANY SS preamp/power amp that measures "flat" and has distortion below JNDs - which is most SS - Rotel/Bryston/Adcom/Threshold/Sim Audio/Celeste/Oddysey/Audio By Van Alstine etc can all be found for cheap on the used market. (Around 300-800 USD) - the lower-priced units may lack some power so you need a more sensitive speaker.

2) Buy a speaker Stereophile has proclaimed "measured performance reveals superb speaker engineering" which means it will fall into the range of highly accurate speakers. Stereophile had the KEF LS-50 as such a speaker and it can be found for $500. I had one myself for 4 years. "The KEF LS50 may be relatively affordable, but it offers superb measured performance.—John Atkinson

So you stick on any one of those SS amps from number 1 and you're all set for under $1500. You have the penultimate in accuracy.

3) you then compare in blind level matched conditions against a tube-based system selecting say a SET amplifier that measures bad, a NOS CD player that measures bad, and speakers that don't measure as well as the KEF and you bring your friends (preferably musicians who play acoustic instruments) and you see which system they say sounds more like a piano or a cello or a violin etc.

The Blind test is what determines what sounds the best. There are two kinds of blind tests - one to detect differences - can a person distinguish one cable from another cable blind with an ABX comparator. The other is a preference Blind test - when we know that a SET amp measures lousy and a speaker deviates enough in frequency response then the blind test is for preference not for the difference because the differences would be known to show up. But the preference-based blind test is also important because bias still exists. Perhaps amp A is technically superior to B so one is biased to prefer A when sighted. In a blind test, the person who is biased toward A may actually choose B - if this happens then what? Do you go with the measurements or do you go with what you heard?

 

[DimitryZ]

I'll shorten it for simplicity -

1) Build an elite measuring system - it is VERY cheap to do this. Find ANY SS preamp/power amp that measures "flat" and has distortion below JNDs - which is most SS - Rotel/Bryston/Adcom/Threshold/Sim Audio/Celeste/Oddysey/Audio By Van Alstine etc can all be found for cheap on the used market. (Around 300-800 USD) - the lower-priced units may lack some power so you need a more sensitive speaker.

2) Buy a speaker Stereophile has proclaimed "measured performance reveals superb speaker engineering" which means it will fall into the range of highly accurate speakers. Stereophile had the KEF LS-50 as such a speaker and it can be found for $500. I had one myself for 4 years. "The KEF LS50 may be relatively affordable, but it offers superb measured performance.—John Atkinson

So you stick on any one of those SS amps from number 1 and you're all set for under $1500. You have the penultimate in accuracy.

3) you then compare in blind level matched conditions against a tube-based system selecting say a SET amplifier that measures bad, a NOS CD player that measures bad, and speakers that don't measure as well as the KEF and you bring your friends (preferably musicians who play acoustic instruments) and you see which system they say sounds more like a piano or a cello or a violin etc.

The Blind test is what determines what sounds the best. There are two kinds of blind tests - one to detect differences - can a person distinguish one cable from another cable blind with an ABX comparator. The other is a preference Blind test - when we know that a SET amp measures lousy and a speaker deviates enough in frequency response then the blind test is for preference not for the difference because the differences would be known to show up. But the preference-based blind test is also important because bias still exists. Perhaps amp A is technically superior to B so one is biased to prefer A when sighted. In a blind test, the person who is biased toward A may actually choose B - if this happens then what? Do you go with the measurements or do you go with what you heard?

This is another strange setup, that you seem to consider universally convincing.

A high power SS system, fronted by uncolored speakers will perform very well against fleawatt SET fronted by horns, not to mention price difference, dimensions, power consumption, domestic acceptability, etc.

If listeners actually preferred to buy 4W SETs, they would sell at Best Buy.

 

[RichardAusten]

I design with transistors, mosfets, jfets, op amps and yes valves. Often a hybrid combination of these devices chosen for the attributes they can bring to a specific stage due to their electrical characteristics. BJT's for their large transconductance, triode valves for reasonable linearity combined with high input impedance and moderate output impedance, mosfets where I want a high DC input resistance combined with fairly high transconductance and fast switching speed, jfets for high input impedance with low noise, pentode valves where I want high voltage gain with good internal isolation of input and output nodes and with high output impedance etc etc. Each device type also has its negative attributes, hence I would not use it for a specific stage, whilst for some applications any of the named devices would work pretty well overall but be likely to show advantages or disadvantages in specific areas and hence the choice of device is more of a grey area.

Now the above is actual hi fi... ie electronics... and is a million miles away from the likes of your web site (nothing personal, all such advertorial sites are as bad. I had a look at "Whats Best Forum" and it was hilarious!) where, by and large, people who don't know a resistor from a radish, never mind how an amplifier works, write peons of purple prose praising £1000 USB cables and mains leads which very definitely have no effect (not in this universe with these laws of physics) whatsoever on pages plastered with glossy links to advertisers of things like £1000 USB cables... if any electronics is mentioned (ie whats under the cover, that which IS hi fi, which makes it work) is ever mentioned on such sites it's usually complete bollox which is totally wrong and/or meaningless techno babble of "some of the right words but not necessarily in the right order" often straight from the mouths of the marketing depts of the advertisers!

I do "get it".... it's a whole industry trying to make a profit from selling electronics to people who know little or nothing about electronics and don't really care or want to know either... such things as transconductance and reverse transfer capacitance are "here be dragons", hence it can (and is) made up as they go along!

Placebo and nocebo effects are so strong that people have been known to throw up thinking they are suffering the side effects of a powerful drug when in fact they had the sugar pill... add expectation bias to that and the ever relevant tale of The Emperors New Clothes and we have a scene where people with zero knowledge of electronics believe things like mains cables break the laws of physics and not only have an effect but a favourable one at that...
Since 'It's easier to fool people than to convince them that they have been fooled' (Mark Twain), we get to the ridiculous level hi-fi has now reached in which people who have been taken for a ride and bought things that have no effect will swim through vomit to defend the snake oil sellers who sold them it!

A person's knowledge of the inside workings of a machine is largely irrelevant because the ONLY thing that is being judged is the end result. A racecar driver doesn't need to know how the Internal Combustion Engine works and also be able to design said engine to be able to judge it on its performance on the track. Audio Equipment is designed to recreate the sound on the recorded disc. A great many audio companies hire fully qualified degree-holding engineers and use the best measuring equipment money can buy - even SET amp makers!

I can't speak for other writers. Most magazines hire a large staff of people and some are more objectivist and some are more subjectivist and that means that yes some will fall for what you would deem as snake oil like $1000 USB cables. In my case, I like SET amplifiers - which technically is inferior to solid-state - but I am shielded from the snake oil argument because a SET amp WILL be distinguishable in a double-blind test from a SS amplifier - therefore a difference DOES exist. The difference is established. So in a preference-based blind test - if one chooses the SET because it "sounds better" then it "sounds better." It is then a valid preference. The Audio Note J/SPe speaker was sent to Hi-Fi Choice and blind level matched sessions occurred with a panel of listeners - the AN J is a standmount and they put it in a group test of famous standmount speakers from B&W and others that probably measure better. The AN J won with ease and all the comments noted the bass response was prodigious. So because the Bass was so much deeper and better than everything else in the class - the magazine felt it was unfair - so they put it in a test against those competing manufacturers' floor standers with bigger drivers. The AN J beat all of them as well. The panel all chose the AN J - the magazine bought the speakers to be used as their reference.

Now had they just read the measurements without the blind test there is no way they would choose the AN J - the blind listening changed their minds.

Designers of anything should be doing blind level matched listening - when the famed John Curl designed a loudspeaker he noted that the thing measured fantastic - then he listened to them and disliked them and decided to go back to amplifier design because although he created a technically superb speaker it sounded rubbish.

Lastly, I am an Audio Note owner - they are one of, I should say the ONLY, company in all of audio, that designs and builds their own transformers in house, their own capacitors, resistors, knobs, chokes, circuit boards, casework, connectors, wiring. They are also making their own valves and recording equipment and ADC in the studio.

As a designer yourself you should look at the walkthrough of their plant to see the kind of equipment they have to play with. It's not just some snake oil guy in a garage - again measurements they aren't going to win the owner himself says that their DACs "measure like a bag of nails" but in their listening tests it simply sounded better. Then what? If A sounds better but measures worse what are you going to do? You have to make the thing that sounds better - that's the whole point of buying a stereo system - enjoying the sound not reading the graphs.

Part 1 is with Andy Whittle who heads Rogers Loudspeakers
Part 2 is with Audio Note's lead engineer Andy Grove - who worked with Quad and designed their Anniversary amplifier.

 

[RichardAusten]

This is another strange setup, that you seem to consider universally convincing.

A high power SS system, fronted by uncolored speakers will perform very well against fleawatt SET fronted by horns, not to mention price difference, dimensions, power consumption, domestic acceptability, etc.

If listeners actually preferred to buy 4W SETs, they would sell at Best Buy.

Logical fallacy - according to you because McDonald's sells more hamburgers they must make the best hamburgers.

It's about exposure and the latter systems cost far more to make and fewer people have the financial resources to buy $30 hamburgers of high quality than the slop at McDonald's.

 

[DimitryZ]

Logical fallacy - according to you because McDonald's sells more hamburgers they must make the best hamburgers.

It's about exposure and the latter systems cost far more to make and fewer people have the financial resources to buy $30 hamburgers of high quality than the slop at McDonald's.

It's difficult to understand, why you have convinced yourself that "me and my friends" would choose SET over SS.

My experience has been quite the opposite - tube equipment of various designs and powers, ending with $15K 300B Monos. Then a switch to a modest $3K Emotiva amplification chain and realizing that at least on ET8Bs they sounded better.

And, btw, there has been many very embarrassing events in the realm of blind tasting food and wine - an equivalent of fast-food burger winning over the fancy one.

 

[htsdgrvs]

yes you are right although i can't think of a DAC with valve rectification that doesn't also have a valve output stage

Border Patrol

 

[Arkless Electronics]

No it doesn't - tell us, what are these many designs that you have blessed the World with? You're happy enough boasting elsewhere: -



So come-on hotshot, let's have it.

No it doesn't - tell us, what are these many designs that you have blessed the World with? You're happy enough boasting elsewhere: -



So come-on hotshot, let's have it.

Nice pic of your wife in the avatar there. It flatters her though.

I don't have to prove anything to ****s like you or to anyone else. I have designed literally hundreds of amps and yes I am one of the best amp designers around. Many pfm members have seen and heard designs of mine and some have had home loans of prototypes. A phono stage of mine of advanced design, at a big bake off a few years back, was reckoned at least equal to a TOTR Paradise. The Paradise is widely recognised as one of the top few phono stages in the world. The Paradise is at something like v.6 or whatever after having all sorts of tweaks and improvements etc whilst mine is a v.1 before any attempt to "polish" it or anything.

Whether or not I choose to manufacture any of my designs is purely my business.

 

[Arkless Electronics]

A person's knowledge of the inside workings of a machine is largely irrelevant because the ONLY thing that is being judged is the end result. A racecar driver doesn't need to know how the Internal Combustion Engine works and also be able to design said engine to be able to judge it on its performance on the track. Audio Equipment is designed to recreate the sound on the recorded disc. A great many audio companies hire fully qualified degree-holding engineers and use the best measuring equipment money can buy - even SET amp makers!

I can't speak for other writers. Most magazines hire a large staff of people and some are more objectivist and some are more subjectivist and that means that yes some will fall for what you would deem as snake oil like $1000 USB cables. In my case, I like SET amplifiers - which technically is inferior to solid-state - but I am shielded from the snake oil argument because a SET amp WILL be distinguishable in a double-blind test from a SS amplifier - therefore a difference DOES exist. The difference is established. So in a preference-based blind test - if one chooses the SET because it "sounds better" then it "sounds better." It is then a valid preference. The Audio Note J/SPe speaker was sent to Hi-Fi Choice and blind level matched sessions occurred with a panel of listeners - the AN J is a standmount and they put it in a group test of famous standmount speakers from B&W and others that probably measure better. The AN J won with ease and all the comments noted the bass response was prodigious. So because the Bass was so much deeper and better than everything else in the class - the magazine felt it was unfair - so they put it in a test against those competing manufacturers' floor standers with bigger drivers. The AN J beat all of them as well. The panel all chose the AN J - the magazine bought the speakers to be used as their reference.

Now had they just read the measurements without the blind test there is no way they would choose the AN J - the blind listening changed their minds.

Designers of anything should be doing blind level matched listening - when the famed John Curl designed a loudspeaker he noted that the thing measured fantastic - then he listened to them and disliked them and decided to go back to amplifier design because although he created a technically superb speaker it sounded rubbish.

Lastly, I am an Audio Note owner - they are one of, I should say the ONLY, company in all of audio, that designs and builds their own transformers in house, their own capacitors, resistors, knobs, chokes, circuit boards, casework, connectors, wiring. They are also making their own valves and recording equipment and ADC in the studio.

As a designer yourself you should look at the walkthrough of their plant to see the kind of equipment they have to play with. It's not just some snake oil guy in a garage - again measurements they aren't going to win the owner himself says that their DACs "measure like a bag of nails" but in their listening tests it simply sounded better. Then what? If A sounds better but measures worse what are you going to do? You have to make the thing that sounds better - that's the whole point of buying a stereo system - enjoying the sound not reading the graphs.

Part 1 is with Andy Whittle who heads Rogers Loudspeakers
Part 2 is with Audio Note's lead engineer Andy Grove - who worked with Quad and designed their Anniversary amplifier.

FWIW I consider Audio Note some of the worst gear around. I've yet to come across any AN gear I consider even adequate.
SET's are not even hi fi.

 

[guydarryl]

"Is there any point in a valve DAC"

well it has given us lots to read

 

[earlofsodbury]

Nice pic of your wife in the avatar there. It flatters her though.

I don't have to prove anything to ****s like you or to anyone else. I have designed literally hundreds of amps and yes I am one of the best amp designers around. Many pfm members have seen and heard designs of mine and some have had home loans of prototypes. A phono stage of mine of advanced design, at a big bake off a few years back, was reckoned at least equal to a TOTR Paradise. The Paradise is widely recognised as one of the top few phono stages in the world. The Paradise is at something like v.6 or whatever after having all sorts of tweaks and improvements etc whilst mine is a v.1 before any attempt to "polish" it or anything.

Whether or not I choose to manufacture any of my designs is purely my business.

Nice ad-hominem there - you certainly are a classy guy.

Sure, you don't have to prove anything, but it seems very, very strange that all these amazing achievements are suddenly something you're too modest to share with us.

I mean, it's not like modesty is your thing, is it?

Almost seems like something's not quite right here... What could it be? Hmmmm...

 

[Nagraboy]

This is getting like vintage Wam stuff : popcorn :

 

[Arkless Electronics]

This is getting like vintage Wam stuff : popcorn :

Not my choice.... the site owner has roughly the same opinion of me as twatbury and chooses to leave up multiple attempts over quite some time to denigrate me both personally and professionally by some codpiece hiding behind a user name who is neither a past customer nor has he met me but is being given a platform to pursue a hate campaign. It's no doubt being carefully monitored for me really losing my temper hence giving an excuse for another ban whilst the aggressor is allowed a free hand to "go for it".... yet again...

 

[davidjt]

I'm currently using a MaverickAudio Tubemagic D2. I bought it s/h more from curiosity than anything, but don't find a massive difference between the valve and op-amp outputs. This could be partly because it has the Sparkos Labs upgrade. In one set-up the valves sounded the thinner of the two, the complete opposite of my expectation, but at the moment I couldn't tell you which is plugged in. Given that this DAC was priced in the 'starter' bracket some time back, it may well be atypical. From a marketing standpoint though, a tube-roller's and an op-amp roller's delight! Sounds pretty good, too.

 

[Dowser]

Not my choice.... the site owner has roughly the same opinion of me as twatbury and chooses to leave up multiple attempts over quite some time to denigrate me both personally and professionally by some codpiece hiding behind a user name who is neither a past customer nor has he met me but is being given a platform to pursue a hate campaign. It's no doubt being carefully monitored for me really losing my temper hence giving an excuse for another ban whilst the aggressor is allowed a free hand to "go for it".... yet again...

Jez - what you do know is widely appreciated here. What you don't know, but make blanket and categorical assumptions about, is what really rattles my ****ing cage

Mr. Sodbury is no doubt resorting to the approach that he does as it is so easy to get a rise out of you. Sometimes I suggest you should type your response, then go for a fag, beer or ****, and come back and try and read what you write from any other PFM members perspective. Then re-word it, then post it

Not sure if it helps, but the designer of my SE hybrid monos you so frequently disdain has a similar affliction to you, worse in fact - he would last 5 mins on a forum like this before dismissing everyone as useless twats and being banned - what he does, he does very well though

 

[earlofsodbury]

Not my choice.... the site owner has roughly the same opinion of me as twatbury and chooses to leave up multiple attempts over quite some time to denigrate me both personally and professionally by some codpiece hiding behind a user name who is neither a past customer nor has he met me but is being given a platform to pursue a hate campaign. It's no doubt being carefully monitored for me really losing my temper hence giving an excuse for another ban whilst the aggressor is allowed a free hand to "go for it".... yet again...

Why so mad tho'? All I've done is ask you to substantiate your breathtakingly hyperbolic claims. Seems reasonable given that so many people are entrusting you with the design of their high-end amplifiers, and of course, the repair of same...

Does seem a mite unwise biting the-hand-that-feeds with respect to this forum's owner; if he ignores things you dislike it may simply be that he's too busy to attend to your requirements - perhaps the poor devil hasn't been told often enough how great you are? Perhaps you should PM him and let him know?

 

[Rosewind]

Yeah, bear-baiting is a favourite pastime for some people. I indulged in that in the humungous MQA-threads .... or was I the one being at the receiving end?

I own a DAC with a valve buffer that I like a lot. Before this I had an Ayre QB9 (192/24 version), two Metrum Octave mk.Is (the last one 192/24 capable), an Audio Note DAC 3 (old version with a sweet sound), a Hegel HD12 (briefly) and since 2018 a Line Magnetic 502CA. I like what the LM valve output buffer does to the sound that ends up in my Quad ESL 57s. Still, I could have lived (almost) happily ever after with all of those DACs.

Valves ... I tend to like valves in kit but some valve kit sounds like solid state. So, one more time ... it is all in the implementation and ... in the owner's subjective taste (be it conscious or subconscious bias). That is why most of us recommend the kit we own, or wish we own.

 

[Hooch500]

If forums are so terrible, and your much-vaunted genius so wasted - why are you here - like, all the time, threadcrapping like the aforementioned incontinent seagull?

Likewise, if you're such a merde-chaude amplifier designer - how can you possibly have failed to establish your own brand?

The people I know who are actually good at this have more work than they know what to do with, and spend most of their time on their mega-yachts counting their roomfuls of gold coins and "entertaining" supermodels - what with hifi being such a hugely-profitable scam an' all..

You keep telling us how clever you think you are, so - in the spirit of objectivity, I naturally have to wonder - where's the proof?

Is it, perhaps, the stuff you allegedly designed for Musical Fidelity? Because I've heard a LOT of their kit over the years, and it was uniformly second-rate at best, so...? Some secret hoard somewhere, perhaps?

Even as a mere bodge-wallah, I'm constantly astonished that you have SO much spare time on your hands to boast about your many achievements - all the technicians I know are as busy as hell and wouldn't go near a hifi forum if you put a gun to their temple, and if they did, certainly would waste their time with empty bragging and alienating most of their potential customers...

And yet here you are, desperately trying to be the centre of attention in as many threads as possible... Bit odd that? No?

Yep it’s getting tiresome, Arkless must have been having a bad day or two when he tried to fix some crappy Trilogy monoblocs I owned twice without results. In the end his Zen like knowledge missed the simple fact of a short across worn out and poor quality valve socket.

Though I do have to thank him for urging me to apply myself to gaining some understanding of valve based circuits.

I probably wouldn’t have felt the need to air it if I hadn’t been lumped in with QAnon because I happen to like the sound of an Audionote or Lampizator output stage.