How to put a clock in a Arcam delta 70.2?

[chlo]

Hello Fin,

There are 2 or 3 Screws underneath the CDP. Just tie them up for transportation I think. I received mine just like that!... The CDP is very good and the laser can be replaced with CDM1/Mk2, CDM2, CDM4/11 and maybe CDM4/31 since they are all same size. I have tried all myself and it worked great. My CDP currently uses CDM2.

Chlo.

 

[Farguar]

Whilst fitting the new clock, I would be tempted to take a look at the Audio board power supply, you will see a really nice discrete regulated supply for the Analogue audio stages, But 78/7905 regs are being used for the TDA1541A core supply these are a prime target for a some LM317/LM337 (Z201+Z204) and will allow for a more stable supply for the core, Beware these will not be a drop in replacement you'll need a resistor net to set the ADJ pin of the reg, a 270 ohm of the output pin with a 820ohm down the 0V and the ADJ pin conected in between, configured as per widely avaliable datasheet on these devices would suffice.

 

[Fin]

Thanks all for this info.

Can't wait to get my hands on this one. It might be a while before I get around to doing anything interesting with it - but I will post some results and probably ask a lot more questions.

 

[Fin]

Originally posted by jean-paul
Delta 70.2 is a different animal with clock distribution and a non standard clock schematic.

Hi Jean-paul

Does a player like this benefit more from a good clock upgrade than a player with a standard clock layout?

Some tips, better late than never. Did you :

* mount the new clock PCB at the back panel nearest to the 74HCU04 ? A shield under the clock-PCB or a metal case around it to avoid radiation is preferred.

* connect the new clock to pin 1 of the 74HCU04 ?

* remove R227/228, C251 and X201 ? Of course you did

* disconnect the pins 5,6,8,9, 10 and 11 of the 74HCU04 and did you ground ( now unused ) input pins 5, 9 and 11 with a wire ?

* use coax cable from the output of the new clock to the 74HCU04 and did you put the coax one winding through a ferrite bead/ring ?

* connect the ground of the new clock its output coax cable only at one point in the cdplayer nearest to pin 7 or ground of the 74HCU04 ? Leave the power supply floating except for this ground just mentioned.

* put the twisted supply wires of the new supply to the clock a few turns through a ferrite bead/ring ?

You see, EMI is my and your cdplayers enemy.

Do you only use one of the outputs on Guido's clock?

Is there any advantage (or is it even possible) to clock any of the main IC's directly from the other two outputs on the Tent clock module?

I agree with you that the Delta 70.2 is quite complicated!. I replaced all elec caps with most Panas FC, 10 Diode for analog and digital sections(11DQ10), 2 OP627 opamps so far. I have difficulty with installing a clock at the moment. However, without Clock it still sounds very encouraging!.

Hi Chlo

What type of difference did the OPA627's make?

There are 2 or 3 Screws underneath the CDP. Just tie them up for transportation I think. I received mine just like that!... The CDP is very good and the laser can be replaced with CDM1/Mk2, CDM2, CDM4/11 and maybe CDM4/31 since they are all same size. I have tried all myself and it worked great. My CDP currently uses CDM2.

Thanks - I contacted the seller and he will now secure the mechanism before sending it to me.

How much of a difference did changing to CDM2 make?

Hi Jean-Paul,
Any other tips to improve this player are also very welcome ( I did see your post that recommended soldering a copper wire under the digital filter chip to improve the grounding).

Hi Dave

Can you direct me to the relevant post?

In the famous thread on the CD723, you mentioned that your Arcam sounds better in someways than your modded 723. Is this before or after modding the Arcam?

 

[Fin]

Does anyone have PCB prints for this CDP?

 

[Fin]

How much spaceis there?

Whilst fitting the new clock, I would be tempted to take a look at the Audio board power supply, you will see a really nice discrete regulated supply for the Analogue audio stages, But 78/7905 regs are being used for the TDA1541A core supply these are a prime target for a some LM317/LM337 (Z201+Z204) and will allow for a more stable supply for the core, Beware these will not be a drop in replacement you'll need a resistor net to set the ADJ pin of the reg, a 270 ohm of the output pin with a 820ohm down the 0V and the ADJ pin conected in between, configured as per widely avaliable datasheet on these devices would suffice.

Is there any benefit in going further and installing an additional transformer to supply the DAC only?

What about adding another Transformer and power supplies for the servos?

 

[Fin]

I replaced all elec caps with most Panas FC, 10 Diode for analog and digital sections(11DQ10), 2 OP627 opamps so far.

When you installed the OPA627 opamps, did you adjust the supplies from +/-12V to +/-15V?

 

[chlo]

Hi there,

I did not touch any regulators, nor do anything complicated as I do not have time, but after changing diodes and opamps the sound improved dramatically. I must admit, every change will improve the sound quality.

Chlo.

 

[Farguar]

Hi Fin.

I would worry about a seperate TX for the DAC although, I might be tempted to investigate a Toroid replacement form the existing Frame TX, you can also by pass this, i.e By pass the mains switch so that the Audio Stages are kept live (WARM) when the rest of the unit is powered down (Dont by pass the mains fuse tho).

Another area that may yeild fantastic results at very little cost would be to replace the current dividing caps arround the DAC these are resonably critical at the original parts are not to special
stick to the original values 220N PEST, my prefrerence would be for WIMA's as a replacement... Locations C233 - C237 and C243 - C247..

Regards

Farguar.

 

[Fin]

Whilst fitting the new clock, I would be tempted to take a look at the Audio board power supply, you will see a really nice discrete regulated supply for the Analogue audio stages, But 78/7905 regs are being used for the TDA1541A core supply these are a prime target for a some LM317/LM337 (Z201+Z204) and will allow for a more stable supply for the core, Beware these will not be a drop in replacement you'll need a resistor net to set the ADJ pin of the reg, a 270 ohm of the output pin with a 820ohm down the 0V and the ADJ pin conected in between, configured as per widely avaliable datasheet on these devices would suffice.

Hi Farguar

I've had a look at the circuit diagram and see exactly what you mean. Replacing the 79/7905 regs will hopefully be easy enough - but I haven't seen the inside of the Delta yet.
Would you recommend copying the capacitor values that are currently used around the LM337 for the -15V supply?

Hi Fin.

I would worry about a seperate TX for the DAC although, I might be tempted to investigate a Toroid replacement form the existing Frame TX, you can also by pass this, i.e By pass the mains switch so that the Audio Stages are kept live (WARM) when the rest of the unit is powered down (Dont by pass the mains fuse tho).

You're obviously talking about Transformer 2 - the 15V + 15V 12VA unit. Well - it just happens that I have a 15V + 15V 25VA Torioal pcb mount unit - that I assume could just replace the original one - space permitting. I've also got a 22V + 22V 25VA unit that could be used with some additional RC filtering.

Any idea where the 74HC74 chips in the clock distribution get their +5V from? Is it the same supply as the +5V for the DAC?
If so, would there be any benefit in giving them a separate supply?

Also - I wonder if the decoder pcb is a standard Philips board as used in many CDPs of that era. Would this mean that the 7210 and 7220 are working off the same +5V reg as everything else?

Originally posted by Farguar
Another area that may yeild fantastic results at very little cost would be to replace the current dividing caps arround the DAC these are resonably critical at the original parts are not to special
stick to the original values 220N PEST, my prefrerence would be for WIMA's as a replacement... Locations C233 - C237 and C243 - C247.
Farguar.

This has been added to the list!

 

[Fin]

Hi there,

I did not touch any regulators, nor do anything complicated as I do not have time, but after changing diodes and opamps the sound improved dramatically. I must admit, every change will improve the sound quality.

Chlo.

Hi Chlo

I've read that OPA627 sounds even better at +/-15V but it would mean tampering with the discrete regulation - and I would need to learn a bit more before attempting that.

Do you know if MBR150 Schottky diodes would be as good as the ones you used?

 

[chlo]

Hi,

I put 4 of MSR860s in the digital section and the sound is more real but abit bright! but I am still using them.

Try to exchange elec caps with Pana NHG type if you can get them as I find it sounds better than the FC type.

My Delta sounds so good and very analog and I am not planning to do any further mods. However, I prefer CDPs with CDM0 or CDM1 transport, I got Marantz CD54 and Philips CD304 with few basic mods and without a low jitter clock, they sound very close to the Arcam.

Regards.

 

[Farguar]

Hi Fin..

I would use the lower voltage Toroid that you have 15 + 15v 25VA the larger supply will drive regs fairly hard once rectified.

Yes the +5V DAC supply does indeed drive the 74HC74 and the TDA1541A if you a really keen you could split the supply using a second reg to drive the Clocking circuit (A point of interrest the player uses a Crown version of the 1541 this is a selected version of the standard with a superior S-N ratio, Philips did produce a Double Crown version this was the best of the best!! I have no known source but if you can find one excelllent)..

The Decoder board was fully engineered by us and is not a off- the shelf Phillips model as used by some other manufacturers arround the same era, the B-chip Filter and the A-Chip decoder run from the same +5v supply, I dont think an extra supply at this point will yeild any sonic improves ments.

A small Ferrite plate on the MAB mech drive micro and A-chip may be worth a punt..

Have fun..

Farguar.

 

[jean-paul]

The Decoder board was fully engineered by us and is not a off- the shelf Phillips model as used by some other manufacturers around the same era, the B-chip Filter and the A-Chip decoder run from the same +5v supply, I don't think an extra supply at this point will yield any sonic improvements.

You gave it away, man

 

[Audiofanatic]

Schematic Arcam Delta 70.2

Hi Jean-Paul,

Would you be so kind as to help me with the schematic?

5 Mb is OK.

Thanks in advance,


Audiofanatic

 

[Fin]

Originally posted by chlo
Try to exchange elec caps with Pana NHG type if you can get them as I find it sounds better than the FC type.

Hi Chlo
What's in there as standard?
On the schematics I can see ELST and ELAL.......

Originally posted by Farguar
Hi Fin..

I would use the lower voltage Toroid that you have 15 + 15v 25VA the larger supply will drive regs fairly hard once rectified.

Hi Farguar

OK - that makes life easy - a direct swap.
OTOH - could pre-regulation with the higher voltage unit bring any further improvement - or the use of a large resistor, before the CRC filter, to lower current peaks etc.

Originally posted by Farguar
Yes the +5V DAC supply does indeed drive the 74HC74 and the TDA1541A if you a really keen you could split the supply using a second reg to drive the Clocking circuit.

I'll look at the layout when it arrives - and probably give it a try.

Originally posted by Farguar
(A point of interrest the player uses a Crown version of the 1541 this is a selected version of the standard with a superior S-N ratio, Philips did produce a Double Crown version this was the best of the best!! I have no known source but if you can find one excelllent)..

Elib has some of these..............

Originally posted by Farguar
The Decoder board was fully engineered by us and is not a off- the shelf Phillips model as used by some other manufacturers arround the same era, the B-chip Filter and the A-Chip decoder run from the same +5v supply, I dont think an extra supply at this point will yeild any sonic improves ments.

This should be interesting to look at and might provide some good ideas to use in my Philips.

Originally posted by Farguar
A small Ferrite plate on the MAB mech drive micro and A-chip may be worth a punt..

Just placed on top of each chip?

Thanks for all this info.

Originally posted by jean-paul

You gave it away, man

Hi Jean-Paul

I'm glad I didn't let it slip

Now all I need is for the Delta to arrive and to get hold of a small PCB for a Tent XO.........Hint!........Hint!


BTW - I have shortened the Service Manual to only include the pages applicable to the 70.2 - and it is now 1.5Mb..............

 

[Fin]

It has arrived.....

Yes - it is finally here and a quick look inside answers a lot of questions - but also poses a few more

I see that all of the electrolytic caps are Rubycon. The recommended replacement is Panasonic FC or NHG - but I wonder if Nichicon Muse KZ would also be good, as I have some of these waiting for a new home?

There are two +5V regs on the decoder board - marked with (D) and (M) respectively. Anyone know what is supplied from each of these regs?

If the (D) means "Digital" and (M) means "Mechanism" - then it should be easy to implement Thorsten Loesch's Ultimate Power Supply Solution as used in his CD723. I know that the CD7xx is a totally different machine - but some of the concepts may still apply:

Originally posted by Kuei Yang Wang

For Players of the CD-720/21/22/23 ilk:-

You really need to add a few extra transformers (they need not be huge size) and build seperate supplies. Working of the original shared supplies is just by far too much compromise. Leave the original supplies to power only Display/Control uP & Remote control circuitry, all other supplies should be build new from scratch and be galvanically insulated, so you can break up several bad ground loops and feed each and every section optimally.

I'd implement as follows:

1) 2 X 15V (seperate supplies only joined to for +/-15V at the DAC's Starground) with a further +15V tapped off the positive supply to null offset and +5V tapped off the positive supply to power the DAC.

All regs. in this supply should be at least LM317 better LT/LM1085, adj pin bypassed and good "audio grade" output capacitor, lower than common value "set" resistor chains to draw at least 50mA standing current through the regulator (more is better within reason).

Diodes Schottky, PSU Cap's small value and raw voltages fairly high, ideally with some added RC filtering, something like 3R3 470uF - 10R - 4,700uF - Reg with a 18V transformer and schottky bridge and the regulators (+15V Op-Amp, 15V Offset Null, +5V DAC each set around 50mA ballast current (27R resistor from Adj to output). Use a Transformer 18V 1A + 18V 1A.

2) 2 X 12V (seperate supplies only joined to for +/-12V at the Servo Motor Drivers Starground)

The regulators are a little less critical, 78XX/79XX types should suffice if on a budget. Due the potentially quite high burst currents when the laser focuses etc the supply should be fairly solid, so put a substantial value capacitor before and after the Regulator. Again, adding some "Ballast resistors" to draw extra current can be a good idea. A 12V + 12V 1.5A Transformer or bigger would be a good idea.

3) 1 X 5V for the Digital Player sections (Decoder, Digital filter etc.). If you use standard type transformers with two secondaries you could use the second secondary to power a clock module. The rest of the supplies I'd arrange similar to those for the +/-15V Analog supply.

I hope this helps.

If you need to due to insufficient space inside the player, you can install all the supplies detailed above in an external case and add a Sub-D25 connector on the back of the player which allows with a short circuit plug the player to run of the internal supply but which otherwise breaks the supply lines to Analogue stage, DAC, Servo and Digital circuitry and connects the external supply.

Sayonara

We obviously don't need to do all of the above as the Arcam has a lot of this inclued anyway and is a vastly superior design - but is any of this likely to bring further improvement for those who want to take the Delta 70.2 to the limit?

 

[chlo]

Hi Fin,

How do you get on with your CDP?. Please tell me how much improvement on swapping T X (2X15 25VA) for the analog supply as I am very keen on this.

I used many types of caps in the past, including: Elna Stargen, SME, Rubycon ZA, ZL,..., Nichicon Muse, and Balck Gate F, and standard type. However, I like the Pana FC and NHG most, the later is better, very open, balance, dynamic, and coherent, quite cheap, and would not take age to burn in as well.

Regards,

Chlo

 

[Fin]

How do you get on with your CDP?. Please tell me how much improvement on swapping T X (2X15 25VA) for the analog supply as I am very keen on this.

Hi Chlo

Haven't tried it yet - only had a quick look inside since it arrived. Things are still very much in the planning/research stage. I will probably keep it standard for a while to get used to its sound, so that improvements can be evaluated properly.

I'm still also thinking about using the higher voltage (2 x 22V 25VA TX) with additional filtering/pre-regs. Not sure if it is worthwile or if there is enough space.

All the parts I bought (Tent XO2 and XO Supply, two transformers, Nichicon Muse caps, regs, opamps, etc) were originally intended for use in a Philips CD624 and a Marantz CD60. Now that this Arcam has unexpectedly come my way, I am trying to work out which players get which parts, and which machine to start on.

I used many types of caps in the past, including: Elna Stargen, SME, Rubycon ZA, ZL,..., Nichicon Muse, and Balck Gate F, and standard type. However, I like the Pana FC and NHG most, the later is better, very open, balance, dynamic, and coherent, quite cheap, and would not take age to burn in as well.

I went for the Nichicon Muse because of price and availability - but a few Panasonics, Os-Cons and Hitanos will probably be mixed in as well?

 

[Fin]

What about a Tent XO2?

Some tips, better late than never. Did you :

* mount the new clock PCB at the back panel nearest to the 74HCU04 ? A shield under the clock-PCB or a metal case around it to avoid radiation is preferred.

* connect the new clock to pin 1 of the 74HCU04 ?

* remove R227/228, C251 and X201 ? Of course you did

* disconnect the pins 5,6,8,9, 10 and 11 of the 74HCU04 and did you ground ( now unused ) input pins 5, 9 and 11 with a wire ?

* use coax cable from the output of the new clock to the 74HCU04 and did you put the coax one winding through a ferrite bead/ring ?

* connect the ground of the new clock its output coax cable only at one point in the cdplayer nearest to pin 7 or ground of the 74HCU04 ? Leave the power supply floating except for this ground just mentioned.

* put the twisted supply wires of the new supply to the clock a few turns through a ferrite bead/ring ?

You see, EMI is my and your cdplayers enemy.

If you were to use a Tent XO2 Module - with three clock outputs - another option is to directly inject the clock from these outputs to some of the ICs - instead of using the distribution for everything?