Da-capo issue (John W?)

[JohnW]

Hi Loris P,

I'm sorry I have bad news for you,

There is no problem with the capacitor rework - the PSU rails are OK - it looks like capacitor failure was not your original problem.

At some stage (maybe during the testing of your board after the capacitor rework, the digital filter was removed while the Dacapo was powered up - this destroyed one of the 74AC541 on the bus. I had high hope that’s this was the problem - but after replacing the damaged AC541 still no results.

I then found that the clock line within the Dacapo DAC section is shorted internally to ground (it can be probed from below the board) - as the DAC section is potted, there no way to repair - I guess this has always been your original problem.

I'm very sorry for this bad news,

JohnW

[loris.p]

I'll wait for your new dac
Loris

[JohnW]

Hi Loris,

Do you have the Cardinal? if you do was the Dacapo fitted with the Clock Lock card (with Dual BNC's)?

If you only use the Dacapo with Cardinal, I could directly inject the clock into the DAC section - thereby isolating the non functioning PLL section under the potted box (the Clock tracks can be cut on the underside of the PCB).

This would also improve the Dacapo's performace - but would only allow the Dacapo to be used with Cardinal - I would need to also modify the Clock Lock Card which you could send to my HK office.

I would only need the Clock-Lock card that's inserted into the rear of the Dacapo - no modification are required to the Cardinal.

John

[loris.p]

this is a good new
Now I use the cardinal with an ordinal and the clock lock card.
I can send it to you for modification.
Thanx a lot
Loris

[loris.p]

Originally posted by JohnW
This is slave labour - its 1.39 AM in China - and now I'm going to take a look at you board....

Slave labour I tell you!

JohnW

John, you're a good person

[sq225917]

John, i thought Nelson was one of a kind with his attitude about not talking up his products. but here you are in China with a legacy product on your desk, willing to mod it to keep an old customer's system ticking away.

You are a Gentleman of the first order.

if you want any help with copywriting (sic) when you are ready to start promoting things, let me know i'd be only too happy to pen to paper on your behalf.

[JohnW]

sq225917,

Thanks for your kind words and offer - someday soon I might take you up on your offer...

Loris’s

I will only need your Re-clock card (not the Cardinal) - also Pls. send your Digital filter so I can test as a full working system - I will Email the HK address.

Also, as your Dacapo PCB will be heavily modified - would you also be interested in upgrading the OPAMP’s to a discrete Class A design used on my new products (FOC)? I have them fitted to my personal Dacapo for auditioning... these with the Clock modification makes a huge difference...

Just let me know...

John

[loris.p]

John,
like Jesus you're going to resurrect my dacapo....
so do what you think is best,
I'll pay the mods and shipment.

Loris

[JohnW]

Hi Loris.p,

The repairs are for free - I will just ask for the postage cost,

The HK address is in your Email box,

Thanks,

John

[Studley]

John
You are a prince amongst (mainly) thieves. Hats off to you.
Ian