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Bill Hobba's Killer DAC


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I have opened this thread for discussion again - for those interested in the KillerDAC. 

 

Got excited when i saw the email in my inbox about this. I thought perhaps Bill received his KDac and i was going to get an opportunity to listen to it. Have you got one as well alistairm? Anything in particular you want to discuss?  :)

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No KillerDAC for me, although if anyone wants to hear one through my system I'd be delighted to pull out a good bottle of wine! 

 

That makes two of us alistairm. I have been waiting for Bhobba to get his going since the beginning of this year when he first started this thread. Keen to listen to this and the Lampizator. Bhobba any update on your Killer?

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  • 2 months later...

Hi Guys

 

Its been a long wait but Rawl99 has finally completed my Killer.

 

I will be heading over his place with my Off-Ramp and Mac Mini to check it out.  

 

Will also be leaving my Playback Designs for Rawl to check out. 

 

He wants to actually check it out more with my stuff, and may change some wire etc, so it will remain there for a little while.

 

I can report how it sounds a bit later.

 

The main hurdle is now past and the big DAC shootout date can be set - probably late January - early February.

 

More to follow.

 

Thanks

Bill

Edited by bhobba
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Hi Guys

 

Just returned from hearing it.

 

When I arrived Rawl had his uber transport running via I2S into it playing Dianna Krall - Girl In The Other Room.  Before saying anything else I want to emphasize this transport is wild - really low jitter custom modified Trichord clocks and other stuff that is quite likely even above the uber stuff in an Off-Ramp.  This is no ordinary bit of gear.

 

The amp was an upgraded VAC and speakers ML3 Reference, the same as mine.

 

Very full harmonically rich enveloping sound.  This type of thing is what Rawl and Killer DAC guys refer to as detail - for me its a fuller richer sound - not extra detail - I like it - but its different terminology than I use.  I thought, yes it had the signature of other Killers I had heard and I liked it right off.

 

Next up was via my Off-Ramp using I2S.  My Off-Ramp also uses a heavily upgraded custom built power supply that makes a big difference over the switching supply Steve supplies with it.  It has a switch that engages and disengages the earth - and we found one position significantly better than the other - much cleaner clearer sound so that's what we stuck with.

 

The difference was the Off-Ramp had greater detail, and better, tighter bass, but it lost a significant amount of the harmonic richness.  It was a whiter, more bland sound.  I preferred the transport, but I am not sure that would be everyone's preference.  Knowing Killer DAC aficionados they would prefer the transport. Certainly Rawl much preferred it.

 

OK - I also took on over my Playback Designs, which, prior to the Phasure, was the best DAC I had heard via DSD.  First up we played Harry Belefonte - Sylvie via PCM - OK - but to my ears the Killer was obviously better.  This was expected - the PD is OK via PCM - but a number of other DAC's I pitted it against were better.  Its real strength is DSD.  So next was Sylvie via DSD.  Immediately better - very live real and present.  Now we are talking.  Ok - what about the Off-Ramp via PCM into the Killer.  Sorry PD guys - we have another DAC other than the Phasure that is better.  It simply sounded richer and more life like.

 

We played a number tracks including some classical.  But it was all basically the same - the Killer was clearly better than the PD - and the transport had a fuller, richer more enveloping sound - but the Off-Ramp better detail and bass..

 

The DAC shootout should prove very interesting.

 

And if anyone want to hear it simply drop me or Rawl99 a line.  

 

He will have it for the next few weeks.

 

Thanks

Bill

Edited by bhobba
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Awesome Bill.  Can't wait to hear the Killer (and the transport) and I am glad it has finally been built for you mate.

 

Thanks - much appreciated.

 

Just a bit more info on the transport though.

 

A number of people have compared it to an Off-Ramp and to their total shock it easily bested it - they switched over from computer audio because of that. BTW its the only transport I have heard that can do that - normally I find the Off-Ramp eats transports alive - no contest - especially my Off-Ramp which has a heavily modified power supply - and as you know that makes a big difference.  But, just so everyone knows how wild the transport is, its a heavily upgraded Wadia, which is no slouch to begin with, and battery powered.

 

Convenience wise the Off-Ramp and computer audio wins hands down - but still some want the best they can get regardless.

 

Thanks

Bill

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Thanks - much appreciated.

 

Just a bit more info on the transport though.

 

A number of people have compared it to an Off-Ramp and to their total shock it easily bested it - they switched over from computer audio because of that. BTW its the only transport I have heard that can do that - normally I find the Off-Ramp eats transports alive - no contest - especially my Off-Ramp which has a heavily modified power supply - and as you know that makes a big difference.  But, just so everyone knows how wild the transport is, its a heavily upgraded Wadia, which is no slouch to begin with, and battery powered.

 

Convenience wise the Off-Ramp and computer audio wins hands down - but still some want the best they can get regardless.

 

Thanks

Bill

The only thing thats battery powered is the Clock (trichord also modded)

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The only thing thats battery powered is the Clock (trichord also modded)

 

Thanks for the clarification Mario.

 

But a little birdy told me the version you have with the Killer clocks from Zenelectro is better again.

 

And Rawl is working on an idea to incorporate the Killer clock into the DAC he thinks may make it transport insensitive.

 

Will see what eventuates.

 

Thanks

Bill 

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Thanks - much appreciated.

 

Just a bit more info on the transport though.

 

A number of people have compared it to an Off-Ramp and to their total shock it easily bested it - they switched over from computer audio because of that. BTW its the only transport I have heard that can do that - normally I find the Off-Ramp eats transports alive - no contest - especially my Off-Ramp which has a heavily modified power supply - and as you know that makes a big difference.  But, just so everyone knows how wild the transport is, its a heavily upgraded Wadia, which is no slouch to begin with, and battery powered.

 

Convenience wise the Off-Ramp and computer audio wins hands down - but still some want the best they can get regardless.

 

Thanks

Bill

 

 

To form an opinion on this comparison of sources feeding the Killer it would be necessary to know a number of things for the computer audio alternative including:

 

(1) the configuration of the mac mini used

(2) the audio player used

(3) if it was Audirvana was it run without Itunes and in direct and integer mode? What version of A+?

(4) did the mac have an SSD or a spinning hard drive?

 

Any and all of these has a significant impact on sound quality. There is a thread on CA that even discusses the improvement to be had from booting the mac from a SD card or an external Thunderbolt SSD and demounting the internal drive.

 

I, for one, am not prepared to concede superiority to a CD spinner .... yet.

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To form an opinion on this comparison of sources feeding the Killer it would be necessary to know a number of things for the computer audio alternative including:

 

(1) the configuration of the mac mini used

(2) the audio player used

(3) if it was Audirvana was it run without Itunes and in direct and integer mode? What version of A+?

(4) did the mac have an SSD or a spinning hard drive?

 

Any and all of these has a significant impact on sound quality. There is a thread on CA that even discusses the improvement to be had from booting the mac from a SD card or an external Thunderbolt SSD and demounting the internal drive.

 

I, for one, am not prepared to concede superiority to a CD spinner .... yet.

 

A "red rag" to a Rawl99 bull...I wait the response with interest...Rob

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And Rawl is working on an idea to incorporate the Killer clock into the DAC he thinks may make it transport insensitive.

 

Will see what eventuates.

 

 

Ha...Rawl will be the first to accomplish transport insensitivity across an asynchronous interface if he is successful.  Seriously!!  I've been reading about a US$52k dac that is apparently designed by a wizard but it is still sensitive to the transport.  It's super-duper power supplies, apparently impeccably implemented galvanic isolation of the USB input, vanishingly low noise numbers and perhaps revolutionary arrangement of the dac chips still cannot take the transport out of the equation.  There is a US$17k transport to go with it if you would like.

 

The trouble with the processes involved in galvanic isolation and the asynchronous protocol is that they use electricity and share a common ground with the dac clock and therefore in some way influence the clock and induce jitter.  It is inevitable, and seems particularly important when we are talking high performance femto clocks.  The way I see high-end digital audio at the moment is that you cannot afford to consider the dac in isolation to the transport that serves it.  The ultimate aim is not only to get the right bits to the dac clock in the correct order (which is easy - the asynch protocol does this for us) but to do so generating as little electrical noise as possible (and the right kinds of electrical noise) in both the transport and the dac, which takes quite a bit of thought.  

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Ha...Rawl will be the first to accomplish transport insensitivity across an asynchronous interface if he is successful. Seriously!! I've been reading about a US$52k dac that is apparently designed by a wizard but it is still sensitive to the transport. It's super-duper power supplies, apparently impeccably implemented galvanic isolation of the USB input, vanishingly low noise numbers and perhaps revolutionary arrangement of the dac chips still cannot take the transport out of the equation. There is a US$17k transport to go with it if you would like.

The trouble with the processes involved in galvanic isolation and the asynchronous protocol is that they use electricity and share a common ground with the dac clock and therefore in some way influence the clock and induce jitter. It is inevitable, and seems particularly important when we are talking high performance femto clocks. The way I see high-end digital audio at the moment is that you cannot afford to consider the dac in isolation to the transport that serves it. The ultimate aim is not only to get the right bits to the dac clock in the correct order (which is easy - the asynch protocol does this for us) but to do so generating as little electrical noise as possible (and the right kinds of electrical noise) in both the transport and the dac, which takes quite a bit of thought.

Well ... not quite accurate on the description of isolation Anthony. They won't share a ground reference to both sides of the isolator. Or did you mean that the output of the isolator and the clock share a ground, well yeah they do, but I don't agree that the isolator itself would be the major cause of the noise that effects the clock or that the clock itself would be the major influence in any 'jitter' seen in the performance of the DAC. In fact the normal way of thinking about a signal and a ground as separate confuses and blinds some of the best designers, focus on each loop, the whole loop not a signal and a 'ground' independently. I don't think there is any 'right' kind of electrical noise, but ensuring that we minimise the noise in the freq range that is critical for the load/circuit being focused on.

You're right the transport+DAC together are critical, as we've discussed previously I'm not sure the computer needs to be considered part of the transport but I'm interested to play around and be convinced either way.

I've got a few more ideas that I've come across recently in researching some high speed ADC clocking for yet another project on the long list of unfinished hairbrained ideas I've had.

Sorry for the electronics pedantry guys ... anyway I'm keen to have a listen to this DAC at some point Bill, pretty busy for the next week or so, will be in touch later.

Chris

Edited by hochopeper
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Bill an interesting post on Audiogon about HiRes at the latest CES in the USA, confirms my thoughts on the KillerDac. Makes you think, is hi res all its cracked up to be.

 

Worlds best digital

went to CES this year on my transition to high res digital. I've heard many of the highly regarded players in my room or in others systems in the past. I'm actually very happy with my current CD based sound. As I listened to various DACs playing CD then HiRes, I was not bowled  over. High res was better but only slightly so. The best analog stages (Zandden and Ypsilon). These were without question the most natural sounding digital systems I heard at the show. They made CD sound miles ahead of high res. What Gives.

 

PS I understand the limitations of show auditions.

Edited by stevenvalve
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Well ... not quite accurate on the description of isolation Anthony. They won't share a ground reference to both sides of the isolator. Or did you mean that the output of the isolator and the clock share a ground, well yeah they do, but I don't agree that the isolator itself would be the major cause of the noise that effects the clock or that the clock itself would be the major influence in any 'jitter' seen in the performance of the DAC. In fact the normal way of thinking about a signal and a ground as separate confuses and blinds some of the best designers, focus on each loop, the whole loop not a signal and a 'ground' independently. I don't think there is any 'right' kind of electrical noise, but ensuring that we minimise the noise in the freq range that is critical for the load/circuit being focused on.

Chris

I do mean the shared ground between the dac clock and the dac side of the USB isolation. By no means is it a major source of jitter but when noise levels in the dac/transport decrease to a certain level things like the electrical nose of the USB interface can be heard (think like peeling back the layers in an onion...where the outer layers are the larger sources of noise that influence the dac clock...I reckon the USB interface would be one of the inner layers of the onion...so not so important until the outer layers have been peeled away). Anyway Chris, hopefully this may be one of the things we will be able to measure at some stage...at least I hope so.

Anthony

Edited by acg
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Well ... not quite accurate on the description of isolation Anthony. They won't share a ground reference to both sides of the isolator. Or did you mean that the output of the isolator and the clock share a ground, well yeah they do, but I don't agree that the isolator itself would be the major cause of the noise that effects the clock or that the clock itself would be the major influence in any 'jitter' seen in the performance of the DAC. In fact the normal way of thinking about a signal and a ground as separate confuses and blinds some of the best designers, focus on each loop, the whole loop not a signal and a 'ground' independently. I don't think there is any 'right' kind of electrical noise, but ensuring that we minimise the noise in the freq range that is critical for the load/circuit being focused on.

You're right the transport+DAC together are critical, as we've discussed previously I'm not sure the computer needs to be considered part of the transport but I'm interested to play around and be convinced either way.

I've got a few more ideas that I've come across recently in researching some high speed ADC clocking for yet another project on the long list of unfinished hairbrained ideas I've had.

Sorry for the electronics pedantry guys ... anyway I'm keen to have a listen to this DAC at some point Bill, pretty busy for the next week or so, will be in touch later.

Chris

Mr.hochopepper do you think a simple  resistor swap on the clock power supply would influence the SQ?

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To form an opinion on this comparison of sources feeding the Killer it would be necessary to know a number of things for the computer audio alternative including:

 

 

 

I, for one, am not prepared to concede superiority to a CD spinner .... yet.

great news for me then keep the prices down on wadia 3200 and marantz transports

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A "red rag" to a Rawl99 bull...I wait the response with interest...Rob

 

He used my setup and I have investigated all that stuff, and it was optimized using Audirvana without Itunes.  The only thing missing was a SSD.

 

The power supply into the Off-Ramp made a bigger difference than any of those things.  Acg heard it and can attest to the striking difference it made.

 

Also note what I said - if the Wadia was better would be a matter of opinion - it did some things better, others worse.  IMHO the transport was better - but that's just my view. 

 

I, for one, am not prepared to concede superiority to a CD spinner .... yet.

 

As I said - its a matter of opinion.

 

Thanks

Bill

Edited by bhobba
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He used my setup and I have investigated all that stuff, and it was optimized using Audirvana without Itunes.  The only thing missing was a SSD.

 

The power supply into the Off-Ramp made a bigger difference than any of those things.  Acg heard it and can attest to the striking difference it made.

 

Also note what I said - if the Wadia was better would be a matter of opinion - it did some things, others worse.  IMHO the transport was better - but that's just my view. 

 

 

As I said - its a matter of opinion.

 

Thanks

Bill

 

 

If only Bill, if only

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Ha...Rawl will be the first to accomplish transport insensitivity across an asynchronous interface if he is successful.  Seriously!!  

 

Yes - caught out.

 

Total insensitivity is probably too hard an ask - less (hopefully much less) sensitive is the more likely outcome.

 

Anyway the proof of the pudding will be in the eating.

 

Thanks

Bill

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