Denon DA-500 Vintage R2R DAC Review

[Koeitje]

The main cable looks like it would be the first thing to break; cable break after few time moving the device around.

I interpreted the panther the same: the faule (lazy) panther who does not care about measurements at all and want's to chill.
Every time measurement is for educational reasons or others, use this panther.

By that logic you also need an educational-panther.
How about an angry-panther, if the product is bad?

I've never had a cable like that break on me.

 

[audio1234]

Hi,
I have this DAC for years running in my kitchen (before on my desk) and I like the sound quality pretty much. Another aspect I like, it represents the beginning of digital audio and has a R2R ladder dac inside. I just use it with pure low resolution materials e.g. Internet radio etc. The analog stage seem to sound open and neutral. Once I did buy a Teac UD 501 and compare it with the DA-500 (via amplifier and Sennheiser HD580). To make it short the Sound of the Teac (was sounding to me "closed, airless" on the RCA output) and I did return the unit (I know there are good reviews on the UD501, but they use usually refer to the XLR). Even though the DA-500 specification represents the capabilities of the early 90ies this DAC is ok for easy listening while doing the kitchen ;-).

Maybe I will try to connect the I2S output (Raspberry + Hifiberry Digi + Pro) directly with the inputs of the Denon Oversampling chip or PCM 1702 .... lets see.

@Amir can you share with us the "secret" key combination to disable the Alpha Processing?

 

[voodooless]

@amirm doesn't the Alpha filtering mostly clean up the spectrum past the nyquist frequency? Would be interesting to make a comparison there. So look a the filter response with Alpha on and off.

 

[ElNino]

Looking at the service manual, this device may be able to accept 20 bit data. The digital filter SM5845 was a proprietary one-off to Denon, so there's no datasheet, but the SM5843 was able to accept 20 bit data.

 

[PeteL]

@amirm doesn't the Alpha filtering mostly clean up the spectrum past the nyquist frequency? Would be interesting to make a comparison there. So look a the filter response with Alpha on and off.

According to this, looks like it has a good effect in reducing a band limited noise rise around the fundamental tone by a good 20 dB, we see also a reduced distortion in the upper end of the audible spectrum, so clearly, not just a past nyquist effect.

 

[3125b]

Of course I can't quantify it, but seeing how much attention the issue of fake ICs gets it can't be too uncommon.
Fake doesn't always mean that they even work, just that they look right, might just be the same package with fake markings put on.
I guess it can be worth it very quickly if old stock of random chips worth noting used can be sold for a couple dollars each with fake markings on them.
Or if they need to work just get whatever is pin compatible and put fake markings on them, who goes to the trouble of measuring if they work (and perform somewhat close to the expected level).
Almost everything gets faked, in the case of DAC chips it's not much of an issue, worst case you get not so good music reproduction, but looking just a few years back the 2008 milk scandal was a big one for example.

 

[PeteL]

Of course I can't quantify it, but seeing how much attention the issue of fake ICs gets it can't be too uncommon.
Fake doesn't always mean that they even work, just that they look right, might just be the same package with fake markings put on.
I guess it can be worth it very quickly if old stock of random chips worth noting used can be sold for a couple dollars each with fake markings on them.
Or if they need to work just get whatever is pin compatible and put fake markings on them, who goes to the trouble of measuring if they work (and perform somewhat close to the expected level).
Almost everything gets faked, in the case of DAC chips it's not much of an issue, worst case you get not so good music reproduction, but looking just a few years back the 2008 milk scandal was a big one for example.

Yeah I guess I was talking more about specialty chips, with actual engineering, register tables, some logic. Then "Whatever is pin compatible" Is not likely, a serie of chip from a same manufacturer yes. Now, of course, IC packages are standardized, but let's say you have a 28 SSOP packaged dac, even if you have someone else making a 28 SSOP DAC don't mean you can replace one by the other, you have to actually want to make a copy of the other, and that's expensive. But yeah, if we are talking Opamps or shift registers, sure, they are more often than not interchangeable and the design is often not under patent anymore, anything goes in term of ethics.

 

[GXAlan]

Looking at the service manual, this device may be able to accept 20 bit data. The digital filter SM5845 was a proprietary one-off to Denon, so there's no datasheet, but the SM5843 was able to accept 20 bit data.

But the interface for the digital receiver is the Yamaha YM3623B which definitely only has a 16-bit word output.

 

[voodooless]

View attachment 91171
According to this, looks like it has a good effect in reducing a band limited noise rise around the fundamental tone by a good 20 dB, we see also a reduced distortion in the upper end of the audible spectrum, so clearly, not just a past nyquist effect.

True, still would like to see how it behaves all the way up there.

 

[Dmitri]

Excellent review. Many thanks for the educational aspects. I have to admit that I wouldn't mind having that thing paired with a nice vintage class A amplifier and some eighties' large KEF's for an epic retro listening room.

Your definition of “retro” definitely differs from mine. DAC? Huh? What’s that? ; )
God I’m such a dinosaur. Oh look! There’s a comet! How pretty.

 

[AndrewDavis]

This panther reminds me of Joe Camel.

Remember Joe Camel? He was a debonair, penthouse dwelling, smooth talking cartoon camel who interested children and teens (like me at the time) in the "Camel Cigarette lifestyle."

 

[Dmitri]

This panther reminds me of Joe Camel.

Remember Joe Camel? He was a debonair, penthouse dwelling, smooth talking cartoon camel who interested children and teens (like me at the time) in the "Camel Cigarette lifestyle."

Explains my addiction to ASR. This site needs a product warning label.

 

[GXAlan]

can you share with us the "secret" key combination to disable the Alpha Processing?

To Enter Demo Mode on the DA-500
1. INITIALIZE. Press and hold Channel 1, 2, 3 and turn on
2. TOGGLE ALPHA PROCESSING ON/OFF Press Channel 5
3. TOGGLE 48 dB gain (bit shift) ON/OFF: Press INVERT
Power Cycle to return to Normal Operation

 

[LTig]

I just looked it up and apparently this was sold from 1994 to 2000 and cost 700DM (couldn‘t find US pricing).
It‘s a real shame then that many AVRs don‘t do better than this today.

Still it measures slightly better than the Arcam Black Box 3 I bought in 1991 for twice the price. And although the BB3 is older it has a bit stream DAC, not a R2R.

 

[LTig]

Interesting that it output higher than 2 volts. Likely a good number of sales were made compared to other DACs due to higher than normal volume!

That was quite typical for "audiophile" DACs. The Arcam Black Box 3 outputs 2.4 V, and I remember having read in the 90ies a review of a very expensive DAC (Spectral?) which did output 7V . I don't remember if balanced or not though.

 

[infinitesymphony]

The Denon DA-500 was on my watch list for a long time when I was looking to pick up anything with PCM1702 or PCM1704 to get a taste of R-2R. DA-500 uses one PCM1702 per channel if I remember correctly.

I ended up finding a Denon DCM-560 5-disc carousel changer with the PCM1702. It sounded great to me at the time, wide and relaxed. My other devices had PCM1738, CS4398, and AK4396 DAC chips, basically all top or near-top of the line delta-sigma DACs from their respective manufacturers at some point. They all sounded different, and I'm sure the quality of the implementations varied, too. You still see CS4398 being used places like Focusrite's audio interfaces, but R-2R DACs have been gone from mainstream equipment for around 15 years now.

Cool to see this piece of gear finally reviewed. Based on the jitter performance, would it be fair to say that jitter reduction devices might have made a real-world improvement on mid-'90s devices like these?

 

[capslock]

What grade were those 1702? Denon used a lot of -L which is essentially an even lower spec version than the standard U

 

[infinitesymphony]

What grade were those 1702? Denon used a lot of -L which is essentially an even lower spec version than the standard U

This site says:

Denon DA-500 - 2 x PCM1702-J - SM5845AF - YM3623B

From what I can piece together the grading for U chips from worst to best is as follows:

PCM1702U-L
PCM1702U
PCM1702U-J
PCM1702U-K

 

[GXAlan]

@amirm if you haven't packed it up yet, what does Alpha do to the dithered signal? [since you have a high-end digital oscilloscope]

 

[somebodyelse]

Yeah I guess I was talking more about specialty chips, with actual engineering, register tables, some logic. Then "Whatever is pin compatible" Is not likely, a serie of chip from a same manufacturer yes. Now, of course, IC packages are standardized, but let's say you have a 28 SSOP packaged dac, even if you have someone else making a 28 SSOP DAC don't mean you can replace one by the other, you have to actually want to make a copy of the other, and that's expensive. But yeah, if we are talking Opamps or shift registers, sure, they are more often than not interchangeable and the design is often not under patent anymore, anything goes in term of ethics.

FTDI (in)famously updated their USB serial driver to exploit a quirk in one of the fakes to disable them, the problem being that the fakes had infiltrated the supply chain to the extent that manufacturers who thought they were using the genuine article from a reputable supplier were caught out when they stopped working.
It's also an issue with STM32 micros which you might think were too cheap to bother with.