Details on schematic missed, Zap Filter

[Random Task]

Hi Folks,

Getting a used ZapFilter MK2 without PSU (Thx again to Mat...), I don´t care about the missing Supply PCB and go on to figure out the Pinning of the 10 pole Header.
Further I thought this was no problem, the schematic of the Zap was already online.
But it´s only the scheme of the Filter itself.
The Shunts are missing, the DC-Servo circuits and, much important at all, the Relay circuit.
Now, after a few measurements, I do have the pinning for the supply for the shuntregulators, the rest is for the relay circuit.

Am I right, the relaycoils are in series to their supply?
And, is the circuit around the relays only for delaying switching?
If it is so, why so complicated with HEF4060 ?
I would like to use the internal Muting-Function of my CDP, how to do this is no problem.
Never the less, I´d like to have a complete overview of the hole circuits on the Zapfilter PCB..
Ah, and if anybody has a photograph of the BACK of the PSU PCB, well pls show it...

Regards,

Martin

 

[UV101]

I've got one not fitted. I'l dig it out and post some photo's

 

[Random Task]

Hi,

That would be nice, go for it...

Martin

 

[UV101]

Here you go, hopefully you can make the circuit out. If you need me to check anything, let me know. it does look fairly straight forward, +/- rails plus an additional rail with low value smoother to run the relays I guess.

 

[georgehifi]

Here's what I have left in my archives when I was doing them regularly

The Zap MkI pic has the header pin outs

The mk 2 shows the relays only on the outputs and I included the dc servos.

Cheers George

 

[Random Task]

Hi,

Thanx to both of you !

@georgehifi:

A little bit too tiny to have a clear look at it( ZapFilter MK I )...

Never the less, this was helpful.
Thank You Guys !

Martin