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PCM61P DAC chip info requested from a Dennon DCD-660

garbulky

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#1
I'm trying to figure out if this is a true multibit dac or a delta sigma dac? Burr Brown PCM61P
Context it's from a Denon DCD 660 which says it's a " 20-Bit 8x Oversampling DAC" which I think refers to the oversampling filter.
DAC is a "Serial Input 18-Bit Monolithic Audio
DIGITAL-TO-ANALOG CONVERTER"
more info
www.lampizator.eu/lampizator/LINKS AND DOWNLOADS/DATAMINING/pcm61P.pdf
 

restorer-john

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#2
The PCM-61P is a current output, 18bit true multibit DAC. It used nichrome thin film resistors, laser trimmed and is a pin for pin 18 bit version of the PCM-56P.

The Denon implementation used a bit shifting system not unlike Yamaha's HiBit 16-18bit shifter around the same time. Technics also were bit shifting around the same time with 16-18bit advertising. It was deep in the OS and bit wars of the late 80s.
 

Guermantes

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#3
Good info, thanks John. I have an earlier Denon DCD-820 with 2x PCM-56P chips which I bought around '89-'90.
 

garbulky

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#4
Thanks! I can't believe I came across this. A real multibit CD player. I was offered it free and was about to pass it up until I realized, wait a second it said "20 bit upsampling" which made me start wondering is this from the era of multibit dacs? I haven't listened to it yet.
 

garbulky

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#5
I got a chance to listen to the Denon DCD 660. Just a preface though this was absolutely subjective listneing non level matched non double blind. And I understand that any differences heard would be hard to be taken seriously if at all on a forum like this. So fair warning. I'm not making any claims here. Ahem - your mileage may vary and your skepticism meter will be off the charts. So, rest assured, I have heard the standard protests before, and acknowledge them.

....But I thought you'd be interested in an update anyway.
The gentleman that picked it up said he got it for just five bucks. It's taken some wear and tear from age. The transport tray takes some coaxing to make it fully eject and close. It stops halfway. It skips a little bit especially at the beginning of discs.
I wasn't expecting much in terms of sound considering this was from the late 80's. Its SNR was 95db with a 100db channel separation.
I compared it to my Emotiva DC-1 via digital and used the preamp to switch back and forth.

Well it sounded different and more importantly it sounded great to me. It did some things my DC-1 could not do. Namely in timing. Yes that makes no sense. The timing of these clocks are already at very inaudible levels. But whatever it was things appeared very fast. As in they just appeared. While with the DC-1 there was a bit of vagueness to things. So for instance with a drum and a bass note played together. The drum whacks hard and the bass plays nice and full at the same time. With the DC-1 when they happen together, things sound a little more mushy. In classical music namely is where this thing separated itself. I could follow the melodies of almost all the instruments I heard very clearly. Which honestly I normally don't in classical music.
With the DC-1 I would have to think about what melody lines I'd have to follow. While with this one, all the different melody lines were simply there.
So in a way I didn't have to try to listen to the music and place objects.

Another thing it did was with the way it portrayed all kinds of dynamics. For instance I was listenign to a peice of cello/violin music. The cello was playing notes very fast, at about 1/2 or a 1/3 of a second. Well with other DACs, I'd here these fast notes. But with the Denon, I could hear the variations in dynamics within the bows more easily. I didn't have to focus at all. When the player changes directions on the bow the bow acclerates and slow down within the bowing motion to produce different dynamics and types of timbre very quickly. Well I was able to hear this. While with the DC-1 it was not as obvious. What was obvious was that he was playing a bunch of cello notes.

The DC-1 is the best DAC I've heard. So I was surprised. The DC-1 in comparison has a warmer sound and does produce a bit more depth and room ambience. The 3 dimensional body of instruments feels more rounded and fuller with the DC-1. While with the Denon the body is there but it feels like a different sort of shape. The Denon also produces more sensation of impact on drums.

The Denon's type of sound most reminded me of the Gungnir multibit which also had this canny ability with better timing.
On the cons side both the Denon and the Gungnir suffered from a harsh treble tone. This harshness reduces after leaving the unit on for a day. The Gungnir never really got rid of that tone even after a few weeks. The Denon still has it but it has reduced, but either way there is a peakiness still on the treble in a certain region. This could also explain the difference in sound and speed. But after some thought, I think there's still something else going on.

Either way, I'm having a great time listening to it. :)
 
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Wombat

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#6
I got a chance to listen to the Denon DCD 660. Just a preface though this was absolutely subjective listneing non level matched non double blind. And I understand that any differences heard would be hard to be taken seriously if at all on a forum like this. So fair warning. I'm not making any claims here. Ahem - your mileage may vary and your skepticism meter will be off the charts. So, rest assured, I have heard the standard protests before, and acknowledge them.

....But I thought you'd be interested in an update anyway.
The gentleman that picked it up said he got it for just five bucks. It's taken some wear and tear from age. The transport tray takes some coaxing to make it fully eject and close. It stops halfway. It skips a little bit especially at the beginning of discs.
I wasn't expecting much in terms of sound considering this was from the late 80's. Its SNR was 95db with a 100db channel separation.
I compared it to my Emotiva DC-1 via digital and used the preamp to switch back and forth.

Well it sounded different and more importantly it sounded great to me. It did some things my DC-1 could not do. Namely in timing. Yes that makes no sense. The timing of these clocks are already at very inaudible levels. But whatever it was things appeared very fast. As in they just appeared. While with the DC-1 there was a bit of vagueness to things. So for instance with a drum and a bass note played together. The drum whacks hard and the bass plays nice and full at the same time. With the DC-1 when they happen together, things sound a little more mushy. In classical music namely is where this thing separated itself. I could follow the melodies of almost all the instruments I heard very clearly. Which honestly I normally don't in classical music.
With the DC-1 I would have to think about what melody lines I'd have to follow. While with this one, all the different melody lines were simply there.
So in a way I didn't have to try to listen to the music and place objects.

Another thing it did was with the way it portrayed all kinds of dynamics. For instance I was listenign to a peice of cello/violin music. The cello was playing notes very fast, at about 1/2 or a 1/3 of a second. Well with other DACs, I'd here these fast notes. But with the Denon, I could hear the variations in dynamics within the bows more easily. I didn't have to focus at all. When the player changes directions on the bow the bow acclerates and slow down within the bowing motion to produce different dynamics and types of timbre very quickly. Well I was able to hear this. While with the DC-1 it was not as obvious. What was obvious was that he was playing a bunch of cello notes.

The DC-1 is the best DAC I've heard. So I was surprised. The DC-1 in comparison has a warmer sound and does produce a bit more depth and room ambience. The 3 dimensional body of instruments feels more rounded and fuller with the DC-1. While with the Denon the body is there but it feels like a different sort of shape. The Denon also produces more sensation of impact on drums.

The Denon's type of sound most reminded me of the Gungnir multibit which also had this canny ability with better timing.
On the cons side both the Denon and the Gungnir suffered from a harsh treble tone. This harshness reduces after leaving the unit on for a day. The Gungnir never really got rid of that tone even after a few weeks. The Denon still has it but it has reduced, but either way there is a peakiness still on the treble in a certain region. This could also explain the difference in sound and speed. But after some thought, I think there's still something else going on.

Either way, I'm having a great time listening to it. :)

I can't believe this subjective post has gone unquestioned, here. A sign of the unsubstantiated audiophile 'I can hear it' believers settling-in on ASR with a faux IMO tag. :( Stop the rot.
 
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RayDunzl

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#7
I can't believe this subjective post has gone unquestioned, here.
One of my general rules is "Never argue with text on a screen."

If I do, the next rule is to limit the protest to one post.
 

Wombat

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#8
One of my general rules is "Never argue with text on a screen."

If I do, the next rule is to limit the protest to one post.

?

Those unwritten dang rules, again.

Well, I take the aims of ASR seriously and don't wish to see it backslide. o_O
 
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Soniclife

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#9
Well, I take the aims of ASR seriously and don't wish to see it backslide. o_O
Don't forget this bit, "Come here to have fun, be ready to be teased and not take online life too seriously."

I have a similar personal policy to Ray.
 

gvl

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#11
Anyone here also thinks that multibit sounds different then delta sigma or is it all in my head?
 

garbulky

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#12
Anyone here also thinks that multibit sounds different then delta sigma or is it all in my head?
From what I gather measurably multibit has poor linearity at very low levels which are usually inaudible in music listening. I think this is due to the challenge of having accurate resistors in the circuit. Other than that, I'm not aware of differences that may exist. I've heard talk about "faster impulse" and "better timing" but I don't have a clue if that's just talk or an actual meaningful thing.

Having said that, ...once again completely subjective, prone to error and bias, impressions. No DBT tests done at all, not making absolute claims here etc. Anyway, these are my listening impressions to follow up to your question:

I don't have a lot of experience listening to multibit dacs. I've only listened to this Denon CD player and a Schiit Gungnir Multibit. I thought that they did sound different than my DC-1 DAC which was more or less the best sounding unit I had heard. Right now the Denon is my go to CD player for classical music. I hear as if my delta sigma DC-1 to sound warmer (a sense of more lower midrange) and have more depth, and subtle detail., But it has a slight hazey coloration to it. For some reason this Denon excites my auditory senses in a different way, namely around timing, dynamics, and an ease in recognizing an instruments position and melody patterns in a song. However that sense of 3 dimensions is not quite as good as the DC-1.
I've had enough experience with DACs where I won't come out and say multibit is the only way to go. I've heard several good units that I thought sounded great. However, at this point, the Schiit Ygdrassil is going to be hopefully my final upgrade to my DAC. Unless it's a Holosprings unit! :D But only listening will tell if they stay or not.
 

Wombat

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#13
What has worked for me over the years is to present facts and not respond to subjective posts. They die out quickly if people don't give them air.
I still belong to a forum that is about a US loudspeaker and sound system manufacturer and any information about it and its products up to the mid-eighties when it became a take-over casualty. The forum membership included guys who worked in sales/marketing, design, manufacturing, service and installations. Employees and sub-contractors.

A great practical forum. Then along comes a SET 'audiophile' fanatic(Guru) who has heard how good some of the drivers are for HiFi and have efficiencies that allow 1 watt SET amps to be heard at reasonable volumes. His SET acolytes followed and the forum was inundated with the usual as well as extreme woo. The management let this continue. Long serving knowledgeable members, tired of being called 'old science' supporters and 'not knowing what they were talking-about', voted with their feet and left. By the time management got their act together and drove-off the interlopers it was too late. The forum still exists but is lucky to get one or two new posts per week. Most of the considered, first-hand, input is gone.
 

Frank Dernie

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#14
Anyone here also thinks that multibit sounds different then delta sigma or is it all in my head?
I have been an amateur recordist for 50 years. I have used valve tape recorders, cassette recorders and eventually a Revox B77. I bought a DAT player fairly early on, and it was the first time in my life, by then 20 years of doing it, that I found the output of the recorder sounded the same as the mike feed. This was very early days so an early ladder DAC, probably, and it was already audibly transparent on the type of music I record.
When I auditioned different DACs a few years ago, intending to buy my first DAC capable of higher than 16/48, carefully level matched if there was a difference it was tiny, and I am sure I would be unable to pick one out from the other blind.
I have read about people reporting that a higher sampling rate recording of jangling keys is distinguishable from a 16/44 of the same, but I neither record, nor listen to, keys jangling. For the type of music I enjoy I am content from my own trials that all conventionally engineered DACs are transparent and 16/44 is enough for me (listening). Yes 96/24 gives far more margin for error in setting levels but, frankly, if you have done any recording using analogue systems, you would realise only a cretin would need such extra margin in real life.

IMO if there is a sound quality difference between two DACs one is very probably generating audible distortion, it will probably be unconventionally engineered since a conventional one will not be.
There are DACs out there with no reconstruction filter, which means they don't remove all the spurious out of band grodge. There are DACs with valve output stages and loads of transformers in line (the transformers may behave a bit like a faux-reconstruction filter) and all sorts of others which people may like the sound of. They are not transparent.
 

Frank Dernie

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#15
Then along comes a SET 'audiophile' fanatic(Guru) who has heard how good some of the drivers are for HiFi and have efficiencies that allow 1 watt SET amps to be heard at reasonable volumes.
I had a similar experience. They insisted the distortion of SETs was inaudible but that they sounded better.
When I pointed out that, logically, therefore the distortion was audible, otherwise they would sound the same as a linear amp, and that was what they must like, they went ballistic. Particularly the maker of a mind numbingly expensive SET from Malta.
 

garbulky

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#16
I have been an amateur recordist for 50 years. I have used valve tape recorders, cassette recorders and eventually a Revox B77. I bought a DAT player fairly early on, and it was the first time in my life, by then 20 years of doing it, that I found the output of the recorder sounded the same as the mike feed. This was very early days so an early ladder DAC, probably, and it was already audibly transparent on the type of music I record.
When I auditioned different DACs a few years ago, intending to buy my first DAC capable of higher than 16/48, carefully level matched if there was a difference it was tiny, and I am sure I would be unable to pick one out from the other blind.
I have read about people reporting that a higher sampling rate recording of jangling keys is distinguishable from a 16/44 of the same, but I neither record, nor listen to, keys jangling. For the type of music I enjoy I am content from my own trials that all conventionally engineered DACs are transparent and 16/44 is enough for me (listening). Yes 96/24 gives far more margin for error in setting levels but, frankly, if you have done any recording using analogue systems, you would realise only a cretin would need such extra margin in real life.

IMO if there is a sound quality difference between two DACs one is very probably generating audible distortion, it will probably be unconventionally engineered since a conventional one will not be.
There are DACs out there with no reconstruction filter, which means they don't remove all the spurious out of band grodge. There are DACs with valve output stages and loads of transformers in line (the transformers may behave a bit like a faux-reconstruction filter) and all sorts of others which people may like the sound of. They are not transparent.
I was recently told about the Audio Note multibit DAC. They claim "no filter." I don't believe it. Maybe they are using a transformer as a filter like you mentioned.
 

Frank Dernie

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#17
I was recently told about the Audio Note multibit DAC. They claim "no filter." I don't believe it. Maybe they are using a transformer as a filter like you mentioned.
Lampizator has a devoted following also. They have more models with differing eccentric engineering features too. Audio note's variations tend to be more the amount of silver included.
 

gvl

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#18
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