bramjacobse
Member
- Joined
- Oct 5, 2024
- Messages
- 11
- Likes
- 38
Linn Ikemi would be nice
-
Welcome to ASR. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!
What CD Player would you like to see tested?
- Thread starter NTTY
- Start date
lini
Active Member
Could be an indicator for a comparable development to how mainstream turntables from the major brands seemed to decline in quality, when the CD had established on the market around the mid to late 80s. Or in other words, I wouldn't be surprised, if some manufacturers have already begun to regard CD players as "legacy compatibility devices", that don't deserve much attention anymore.
Greetings from Munich!
Manfred / lini
OP
- Thread Starter
- #223
Because of the PCM1732 DAC?
lini
Active Member
Oops, forgot to mention that this was supposed to refer to regular CD player models for home hifi use - whereas in case of "Discman" style portables that decline could already be observed many years ago.
Greetings from Munich!
Manfred / lini
Hi Flo @NTTY, what I find amazing about your allways growing list of tests of legacy CDPs here on ASR, is that it becomes so easy to identify cheap decent sounding players and/or perfect transports (most important to me!) on the used market!
Therefore another two suggestions with digital out - just because I have them already on my shelf:
- Sony CDP-XE530 (my only one with CD-text!)
- Denon DCD-435
Therefore another two suggestions with digital out - just because I have them already on my shelf:
- Sony CDP-XE530 (my only one with CD-text!)
- Denon DCD-435
bramjacobse
Member
- Joined
- Oct 5, 2024
- Messages
- 11
- Likes
- 38
Correct ,Because of the PCM1732 DAC?
24-Bit, 96kHz, Stereo Audio DIGITAL-TO-ANALOG CONVERTER With HDCD® Decoder
it looked interesting when i measured it quickly , a few years back
https://www.bramjacobse.nl/wordpress/?p=3552
@bramjacobse
What do you think is implemented with the Xilinx FPGA in the Linn Ikemi? My guess is a custom oversampling filter which might have a proper full attenuation at Nyquist frequency (22.05 kHz for CD player) instead of the usual half-band filter implemented on-chip on so many D/A converter or standalone digital filter chips for processing power saving reasons (among other things). But as Linn has advocated about the relevance to stick with digital filter compliant with the sampling theory only at later years (see here), I'm in doubt and I am curious to know if my guess is correct.
OP
- Thread Starter
- #228
I think it is interesting indeed!
@Vintage02 recently bought a CD player with this DAC. I guess he can measure it.
OP
- Thread Starter
- #229
If they implemented a custom filter, then they disregarded the one of BB that was including HDCD decoding, knowing that the PCM1732 is the sole DAC to include an HDCD decoding filter.
Or they might have used both: if HDCD is identified, the data may be passed through unchanged to the DAC chip having the built-in relevant HDCD decoder; if not, a custom 2x (hence the brand name "2D"?) oversampling is performed in the FPGA?
I am curious.
Last edited:
OP
- Thread Starter
- #232
Could be indeed, in which case we’d only be testing the one of the FPGA.
OP
- Thread Starter
- #233
That’s my plan too, I like Rotel very much.
Yes I bought a Carat C57 where the VAM1202 was out of order, I changed it with another one that I had in stock, now it read CD but still have some difficulties to correctly read NTTY's test CD ... I wil buy another VAM1202 from spare and perhaps it help to read CDR ...
Last edited:
Coming back to the DAP-5500, if you did ever stumble across one, they do have an MSB trim on each of 4x PCM-56's, and they also have an impressive-looking analog filter (see: https://benaudio.nl/images/audio/DE...500_pre-amp_Jaap-De-Jong_modification_36.jpeg). They are only 4x oversampling, so I am not sure the implications for "intersample-overs" performance. Unlike the later DAP-2500, they have no sample-and-hold circuits. In any case, I find this all to be historically interesting and they sound subjectively more enjoyable at 48 kHz than my PCM-1702 players with digital inputs (DCD-S1 or DCD-3000). Thanks again for all the great tests -- happy to see Denon well-represented!
OP
- Thread Starter
- #236
Hi, oversampling introduces a risk of intersample overs, at any rate, unless the interpolator has headroom. None of the early ones that I measured had, I suppose because it was not perceived as a possible issue (no loudness war at the time).
I’m not sure I got you about the sample-and-hold difference.
I’m not sure I got you about the sample-and-hold difference.
It is a separate thought, but I've found it interesting that they avoided a need for a sample and hold "deglitching" circuit that they used in the lower tier 2500, while still claiming a higher 110 vs. 108 dB SNR, which I assumed was made possible by K vs. J chip selection and the superior analog filter. Edit: But the 5500 also uses a SM5804D digital filter vs. the 2500's Sony CXD-1162P.
Last edited:
OP
- Thread Starter
- #238
Oh, ok, I think I got it. The two Denon you mentioned either used the PCM56 or the PCM61 which are essentially the same to the exception of bit-depth.
The datasheet of the PCM56 showed the necessary deglitching circuitry when one DAC was used for two channels, but specifies that when one DAC was used per channel, it met its THD specs without needing a deglitcher.
I guess these SNR figures were only about the analog circuit surrounding the DAC, and maybe measured when the DAC was idle. The PCM56, being a 16bits DAC, could only achieve max theoretical SNR of (6.02x16)+1.76=98.08dB.
The respective common specs of these DACs show:
- PCM61 (18bits): -40dB THD+N @-60dBFS
- PCM56 (16bits): -35dB THD+N @-60dBFS
So, that means respective DR of 100dB and 95dB, former being achieved certainly from 18bits data input (so not Audio CD then).
Only the PCM61 shows "Idle channel SNR" value of -112dB(A) at Bipolar Zero, but I don’t know what it means, except that we probably don’t see that in real world
The datasheet of the PCM56 showed the necessary deglitching circuitry when one DAC was used for two channels, but specifies that when one DAC was used per channel, it met its THD specs without needing a deglitcher.
I guess these SNR figures were only about the analog circuit surrounding the DAC, and maybe measured when the DAC was idle. The PCM56, being a 16bits DAC, could only achieve max theoretical SNR of (6.02x16)+1.76=98.08dB.
The respective common specs of these DACs show:
- PCM61 (18bits): -40dB THD+N @-60dBFS
- PCM56 (16bits): -35dB THD+N @-60dBFS
So, that means respective DR of 100dB and 95dB, former being achieved certainly from 18bits data input (so not Audio CD then).
Only the PCM61 shows "Idle channel SNR" value of -112dB(A) at Bipolar Zero, but I don’t know what it means, except that we probably don’t see that in real world
So, the 2500 and 5500 in question both use four PCM56s, two per channel.Oh, ok, I think I got it. The two Denon you mentioned either used the PCM56 or the PCM61 which are essentially the same to the exception of bit-depth.
The datasheet of the PCM56 showed the necessary deglitching circuitry when one DAC was used for two channels, but specifies that when one DAC was used per channel, it met its THD specs without needing a deglitcher.
I guess these SNR figures were only about the analog circuit surrounding the DAC, and maybe measured when the DAC was idle. The PCM56, being a 16bits DAC, could only achieve max theoretical SNR of (6.02x16)+1.76=98.08dB.
The respective common specs of these DACs show:
- PCM61 (18bits): -40dB THD+N @-60dBFS
- PCM56 (16bits): -35dB THD+N @-60dBFS
So, that means respective DR of 100dB and 95dB, former being achieved certainly from 18bits data input (so not Audio CD then).
Only the PCM61 shows "Idle channel SNR" value of -112dB(A) at Bipolar Zero, but I don’t know what it means, except that we probably don’t see that in real world
The DAP-5500 has:
- SM5804D filter
- 4x PCM56p-K (with MSB adjust)
- 7-pole analog filter
- 110 dB SNR claimed
- CXD-1162P filter
- 4x PCM59p-J (with MSB adjust)
- Sample and hold deglitchers despite 2 DACs/channel
- Simpler filter
- 108 dB SNR claimed
OP
- Thread Starter
- #240
Yep, these SNRs were not achieved with the DACs processing 16bits data, even with two BB per channel. But it is possible that the analog section was at that level.
I was looking at the DAP-2500A, my bad. I sneaked in the Service Manual of the DAP-2500 and there is indeed a funky circuitry with some multiplexers but I failed to understand their utilization. I saw the "DGLC" line coming from the Sony filter, a sync with the clock, so maybe Denon wanted to ensure minimum distorsion/deviation between the outputs of the two DACs, indeed.
I was looking at the DAP-2500A, my bad. I sneaked in the Service Manual of the DAP-2500 and there is indeed a funky circuitry with some multiplexers but I failed to understand their utilization. I saw the "DGLC" line coming from the Sony filter, a sync with the clock, so maybe Denon wanted to ensure minimum distorsion/deviation between the outputs of the two DACs, indeed.
Similar threads
