Kenwood DP7090 and ZAPfilter Mk2 connection


2003-03-05 2:19 pm
I want to buy the ZAPfilter Mk2 so please can you help me with connection. Kenwood have 4x PCM1702 so i think this is schematics, where IC12,IC14,IC16 and IC18 are PCM1702 for one channel. So how i connect ZAPfilter Mk2. I presume that IC12 and IC16 connect together and connect to - (or +) input at the ZAP and IC14, IC18 to + (or-) input ZAP and remove all from C202,C200,C198 and C196. Please help, here it is schematics


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2003-12-07 11:57 am
From the circuit diagram you provided, it appears that Kenwood decided to use parallel differential configuration for each channel. So, we have2 X (2 parallel 1702) in differential configuration: (IC12 + IC16) and (IC14 + IC18) in dif. mode.

The only way to implement differential inputs of ZAP filter(s) would be to connect them after IC I to V converters – at pins 2 and 3 of IC24.1 which would be pretty bad implementation of ZAP filter.

Anyway, my experience with ZAP filter is not very positive, but you should try this yourself!

The original analog stage is pretty good one! Only two “IC gain” stages. Maybe you should try with Browndog adapters and use 8066 for I to V conversion, and choose between OP275 and AD826 afterwards. If you like warm and mellow, try 2134’s.

Good luck,
Gasho said:
Good question! Why you can´t connect two DAC outputs in paralel?
Becouse it´s te current output ? I dont´n know te reason:xeye: .

You can, and I've done it that way, the gain will be different, but it does work, and the Zap is the most dynamic I/V and output stage I have ever heard in current input mode, so much so it's scary, you swear there's a DBX unit hidden in there somewhere.

People that bag it are usually ones that have had problems installing it, or have had the odd faulty one, and there has been a few of those, they are fragile to handle all very exposed smd components, so take care with the esd and installation.
I would give Lars at LC an email on this also.

Cheers George