Marantz CD-6000 OSE VS Kenwood DP-7090 -which is better?

[torrance]

Hello,

I have followed this tread with great interest since I myself own a 7090. My fingers have this hunger to modify it.

I have already put in the LC Audio LClock - but I want to get my fingers dirty in the analaog section. Maybe one of you have the schematic for this machine??? If I am so lucky you can email i to mat-hansen@email.com. I would be forever grateful

Especially I dislike the "feel" of the op-amps and would like to build a discrete line-stage. I can se the one of you spoke about the Pass D1 - any of you with experience in this field?

One of you also spoke about bypassing the muting resistors - how do I do that?

Best regards - and please excuse my broken english.

 

[Has]

Hi,

Made a few more changes to my Kenwood:

1. removed coupling caps and muting transistors, sounds more dynamic and livelike.
2. compared the original four-DAC-setup vs. a single-DAC-setup, really liked the single DAC better.
3. compared original opamp PSU (+/- 8V) vs. a clean +/- 15V supply, again an improvement.


How you change DAC setups? From 4 to one DAC set up. I want to upgarde with ZAPFilter MK2 and i think it's much easier to do with one DAC.

 

[masi]

Hi Has

I'm not very familiar with the zap filter but i think it can be run balanced or unbalanced. Best performance is probably achieved in a balanced configuration.

For the one-DAC-setup pick two DACs, let's say IC11 for left and IC12 for right channel and forget about alll the others. Now we have a little problem: The data line for the right channel is inverted (IC30, between IC9 and IC12) what has to be changed to get left and right channel in the same phase.
How it's done? Remove bridges W71 to W103 and connect them with a wire. On W71 at solder point closer to the front, on W103 at solderpoint on the right side. That's it

Regards,
Mario

 

[Has]

Ok i think i understand but them i must disconnect power from others dac's and take output from DAC pin11 and connect to zap.

 

[Has]

Well i removed bridges 71 to 103 and 2 problems happend. First i couldn't find bridge 83 and second whem i removed all others i can't power in cd. I soldered back all bridges and cd works. Whath's wrong. Does bridge W83 is problem. Isn't easier to disconnect power supply from other DAC's and leave only DAC 12 and DAC 11. and connect bridge W71 and W103 to omite invering?

 

[masi]

Hi Has

Sorry for not answering sooner.
I'm afraid I wasn't precice enough in my description.
I'm a little puzzled about W83 (where is it located?) I neither removed W83 nor powered down the other DACs. I left the DACs and the IV opamps unchaned. Instead I removed R141/R145/R149 on left channel and R142/R143/R150 on right channel. IC23/24 now are configured as buffer amps and only receive voltage from IC19/20.
Well, in your case with the zap filter, you should omite the data inverting as described in post #23. For a proper connection of the zap filter remove opamps (IC19/20) and its surrounding parts (e.g. C93/C195/R139 around IC19).

I hope this was a little help.
Regards,
Mario

 

[LifeIsMusic]

Maybe someone has new experiences with that player?

 

[Crossy]

Well,
I got my hands on a second-hand DP-7090 - now I'm looking around what tweaks there might available to boost performance..

From the spec sheet, the player looks impressive even unmodded:

8kg weight, 120dB S/N, THD: 0.0013%..

SM5843 digital filter
4x Burr Brown PCM1702 per channel

this thread so far has covered a bunch of mods already. Question now is twofold: first, what are the results of these mods - are they audible ?

And secondly - are the more of them ??

rgrds
CROSSY

 

[vernon.taylor]

Hi Fabian

Could you tell me a bit more about your shifter, please? I've made something similar with inconsistent results.

Could you explain why the first HC164 only shifts by 7.5 BCK - I think this may be where I went wrong because I didn't calculate for any 0.5 BCK shifts.

Thanks

Vernon

 

[Fabian]

Hi Vernon,

I can't give a detailed answer, because it's a long time since I've built this.
If I remember right, it has something to do with with rising and falling edges of the bitclock and when those ICs will shift. I found it out by reading datasheets carefully. Paint a sketch of those clocks and try to understand what's going on. I'm sure you'll find out. That's how I figured it out...

Hope this helps a bit. Regards

 

[vernon.taylor]

Thanks Fabian. You helped me to realise that one needs to re-clock with an inverted BCK if you want your final data valid on the non-inverted rising BCK. I'm going to check my current home-designed DAC to see why it works! I probably made the same mistake twice ;-)

Vernon