Arcam Delta Black Box1 mods

[ash_dac]

Hi,

Picked up an Arcam Black Box 1.Has anyone modded it?

Inside:-

Twin transformer power supply design
Voltage regulator for each main chip
Back end of a CD player (SAA7220P/A, TDA1541a, custom 'black chip' IC programmed for Arcam)
Class A LF411 dc servo output stage
Tantalum capacitors
IEC mains inlet
Phase switch
Phase-locked loop master oscillator

Sound:- nice sound but treble gritty


Ash.

[Jocko Homo]

I had one once..........a "bidnis" contact where you are wanted me to buy some, mod them, and sell them to him. (I won't mention which tube amp company it was...................)

Anyway, it was dreck. One of the worst EMI generators that I have ever brought into my shop. The project was stopped without even trying.

Don't remember a phase-locked master oscillator. I believe that it used a Sony RX chip.

Made for them by TI.

Jocko

[Fin]

It seems that some of it is similar to the Arcam Delta 70.2 audioboard. There are a few threads about modding that CDP - and the service manual is available directly from Arcam.

[Bare]

Firstly I LIKE arcams still have a loved Delta 290 Amp, albeit with it's crappy Pre disabled substituted with a Setpped Attenuator.. Much Better :-0
The Arcan CDP.. which I lusted after for some time.. has fallen far from my wish listr.. replaced by a simple, stupid and disarmingly cheap ($80) Toshiba 3950 DVD player.. Modded to output directly from it's 192 hz 24 bit Burr Brown DAC..
The Arcam is simply outclassed... true.. gotta hear it to believe though :-0.
Suggest you explore this avenue rather than trudging down that dead end road.

[ash_dac]

Jocko,


I see what you mean about EMI!

My black box is ontop of my amp. I turned the black box on and heard a loud pop from the speakers. Looked at the back of the unit, and to my horror the black box was not even connected to the amp or cd player (interconnects) , it was only plugged into the mains.

Some quotes from the manual:-

"Firstly, it is advisable that your system be switched off before connecting it up to the black box. This will avoid all possible damage to your loudspeakers. At the very least ensure that the volume control on your amplifier is turned down, or an unused input selected." (Arcam blackbox handbook, 1989)

"...all mains powered hi-fi components contain transformers which have a certain stray magnetic field associated with them."(Arcam blackbox handbook, 1989)



Kind regards,


Ashley.

[Fin]

So what are your plans for it now?

[ash_dac]

Fin,



First, I will probably examine what is inside the case, and try to get hold of a service manual.

Second, study the information on super regulators on this forum, and think about how to rebuild the power supply.

Then maybe I should build a digital input board with a CS8412 with I2S straight to the dac section as reversible mod!

Or transplant it somehow into a cdp, and tap I2S direct.

I did notice that there was no mains input capacitor like there is on my Arcam Alpha amp.


Kind regards,


Ashley.

[ash_dac]

Hi,

Arcam have kindly provided me with the service manual.

Very detailed.


Regards,


Ashley.

[Jocko Homo]

That isn't what I meant by EMI.

Try putting it next to your TV, if you do not have cable/satellite. You'll find out..........very quickly.

Does it use that funky Sony Rx chip???? I sold my last one several years ago, so don't look to me if it is dead. (The DAC-960 used them.....as well as the LHH stuff. I think......)

Jocko

[ash_dac]

Jocko,


Apologies for my lack of understanding.

I can't see a 'sony Rx chip' in the service manual but they refer to a 'custom IC' that acts as the receiver. No idea of the manufacturer!




Regards,


Ashley.