ARCAM Diva CD73

(Diva stands for digital video audio)

ARCAM is a good old UK company from Cambridge. They are famous for delivering value for money and for honest engineering.
My first Arcam is just that - the absolute champion in the value for money department and honest good engineering.
I LOVE IT.
From what I know, all their products are like that.
After seeing hundreds of products inside - I rank ARCAM as my favourite brand.
  It will be documented and lampized in may 2009.





This CD73 looks like nothing, but inside - OH MY GOD. It is made like a dream !

Their PCB is very well made. There are many separate power supplies, with own regulation and filtering. All parts are premium, capacitors, regulators, and the whole PCB is laid out so neatly. That player is made as every player should be. There is nothing made for show, for impressing naive people. Everything seems honest and made for purpose.
Let's take a tour  around the inside.

arcam diva cd73



ar-cam and cam-bridge

The above picture shows Arcam against the Cambridge - very similar players from similar companies. Both silver, understated, and with Wolfson DAC inside.
I like the Arcam better for their excellent PCB design and power supplies. Cambridge has two Wolfsons, Arcam has only one. The stock sound is better from Arcam. After lampization as well - Arcam has an edge.




   
ABOUT WOLFSON  


Wolfson unveils 'best sounding' audio DAC
High-performance 24-bit device offers advanced digital filtering options
By Rich Pell

Wolfson Microelectronics has announced the ultra-high-performance WM8741 24-bit stereo DAC, which combines high-end specifications with advanced digital filtering options that allow designers to shape the subjective quality of the sound. According to the company, the device creates a more "analog feel" than previous audio DACs using conventional digital filtering and conversion techniques.

The WM8741's digital filters include several selectable roll-off and performance characteristics, as well as a selection of advanced digital filter characteristics, including non-half band filters and minimum phase filters, enabling significantly reduced pre-ringing and minimal group delay. The internal digital filters can also be by-passed, allowing the WM8741 to be used with an external digital filter.

Specifications include a 125-dB SNR ('A'-weighted stereo @ 48 kHz), a sampling frequency from 32 kHz to 192 kHz, and operation from 5-V (analog) and 3-V (digital) supplies. The WM8741 supports PCM and DSD formats, including DSD direct and PCM-converted DSD modes.

Other features include fine resolution volume and soft mute control and digital de-emphasis, followed by a multi-bit sigma delta modulator and switched-capacitor multibit stage DAC with differential voltage outputs. The WM8741 supports both hardware and software control modes, and is a drop-in replacement for the previous-generation WM8740 in some PCM-mode applications.

Pricing/availability: The WM8741 is sampling now in a 28-pin SSOP and priced at $6.71, in quantities of 10,000.

Product literature:
WM8741 datasheet(PDF)
http://www.wolfsonmicro.com/aboutus

Other arcams: (from Vassili's list)

ARCAM ALPHA

TDA1541A – SAA7220P/B

CDM-4/19

ARCAM ALPHA ONE

PCM1710


ARCAM ALPHA PLUS

TDA1541A – SAA7220P/B

CDM-4/19

ARCAM ALPHA 5

TDA1541A – SAA7220P/B

CDM-9/44

ARCAM ALPHA 5 PLUS

TDA1541A

CDM-9

ARCAM ALPHA 6

SM5864 – SM5840

CDM-9

ARCAM ALPHA 7

PCM1710

Sony CDM14

ARCAM ALPHA 7SE

PCM1716

Sony CDM14

ARCAM ALPHA 8

SM5864AP – SM5843

Sony CDM14

ARCAM ALPHA 8SE

SM5864AP – PMD100

Sony CDM14

ARCAM ALPHA 9

dCS RingDAC – PMD100


ARCAM DELTA 70.2

TDA1541-S1 (Single Crown)

CDM-4/11 / CDM-4/31

ARCAM DELTA 70.3

SAA7350

CDM-4

ARCAM DELTA 110

2 x SAA7321


ARCAM DELTA 110.2

2 x PCM67P-J


ARCAM DELTA 170

It’s a Transport

CDM-1 Mk II

ARCAM DELTA 270

PCM69AP-J – YSF210B-D (filter)

CDM-9

ARCAM DELTA BOX 1

TDA1541A – SAA7220P/B

It’s a DAC

ARCAM DELTA BOX 2

TDA1541A

It’s a DAC

ARCAM DELTA BOX 3

4 x SAA7321

It’s a DAC

ARCAM DELTA BOX 5

2 x PCM67P-J

It’s a DAC

ARCAM DIVA CD72

PCM1716

KSS-213

ARCAM DIVA CD73T

WM8740

KSS-213C

ARCAM DIVA CD82

2 x WM8740s


ARCAM DIVA CD92

dCS RingDAC 24bit + PMD200

KSS-213

ARCAM DIVA CD93

4 x WM8740s


ARCAM DIVA CD192

4 x WM8740s


ARCAM FMJ CD17

WM8741


ARCAM FMJ CD23T

dCS RingDAC + HDCD

KSS-213B / KSS-240A

ARCAM FMJ CD33

4 x WM8740 – AD1896A

KSS-213

ARCAM FMJ CD36

4 x WM8740 – AD1896A

KSS-213

ARCAM FMJ CD37

WM8741







Above - some capacitors - premium Nichicons. Big plus for Arcam.





Above - the resistors are organized in neat rows like soldiers. All parts are traditional, not SMD. Plus for Arcam again.






Above you see some Cerafine premium parts plus some inductors rarely used elsewhere. (L502, L501). This is the way power supplies should be made.





Arcam transformer is a premium toroid with 5 secondaries. This is very good supply of AC for a CD player.






Arcam mechanism is a Sony - simple and cheap but reliable one and good one. I like it.




That mechanism is Sony KSS213 - reading everything without sweat.





Above you see the fuses protecting all separate circuits.








Above the Arcam is tested with external Lampizator box. I used single ended positive phase outputs only, but later - I added negative phase too.





Test drive - already promising. Sound is very good.





As a transport - Arcam is excellent. It sounds VERY good - like a real transport. The trace is one of the best - super clean S/PDIF.  I admire this.





Above there is the output stage. You may notice three opamps removed. To get clean sound I had to remove them.  After that - I soldered the Lampizator to the resistors which provide the signal to the opamps.






Uuughh what a relief. A good opamp is a removed opamp.






I must have been a sadist dentist in previous life.




Above you can admire some more caps of premium quality - Rubycons.




There is an output stage before opamp removal.





Some more premium caps - Elna Silmic. I am really impressed. NOTHING in this CD can be easily upgraded.





Above you can admire that I soldered the newest wolfson WM8742 in place of the old WM8741. This is the FIRST CD PLAYER in the WORLD WITH wm8742. !!!






UNDER-SIDE OF THE PCB. THE DAC IS THERE - INVISIBLE FROM THE TOP.


























RED ARROWS SHOW WHERE THE VOLTAGE REGULATORS ARE.


















The general view on my lampization job. One tube triode anode follower system with E801CC tube from Siemens.
On the right there is a new lampizator transformer.


Above - the AC power stealing points. The AC after the switch is taken to the Lampizator transformer.

\




As seen above, the signal stealing points should be : R423, R422 for one channel, and R418, R419 for the other channel.
I don't remember the phases but please experiment. If the centre image is spread all over the sound stage - change one channel phases. The centre image should be dead accurate in the centre.






My Siemens E801CC (equivalent of ECC81)  is perfect.
The schematics is this:

Power is 150 V DC anode
Anode resistors from power to anodes is 15K / 2W
Cathode resistors are 330 Ohms. (150 Ohm to 400 Ohm)
Grid to ground resistors are 360 K (200K - 500 K)
The positive signal from DAC is wired to grids via 1K.
Negative signal from DAC is wired to the tube cathodes via 10K
All four signal phases are coming through the capacitors : 1 uF (or more) by any voltage.
The tube output comes from Anodes, via 2,2 uF caps or more, by 200  V or more voltage rating.
The RCA outputs are newly installed sockets in place of old cheap ones.
Output should have resistors to ground to eliminate  Boom after cable switching. These resistors should be between 200K - 500 K.



The end result:
In this system, Arcam plays like a dream. So much better than with stock opamps that it is hard to believe. The music is fantastic, energetic, powerful, spacious, musical, rhythmical, etc. I absolutely love it. Of course - with original DAC - WM8741 - it would be equally good. The 8742 is just newer but not better.


2 years later

I installed my new baby - Mikrolampizator in a similar ARCAM CD73 and equally loved the result.

Just look:












Above - Left Ch. stealing point
Below - R Ch. stealing point.