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Old 3rd October 2012, 09:59 AM   #61
UV101 is offline UV101  England
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Ty

Got my C3 clock yesterday along with a couple more 22,000uF SI's and some sepc for the mech.
Hopefully the 47,000uF Mundorf will arrive today and I'll get all the on board smoothing sorted.

I've got the psu ready for the clock so that will go in tonight along with a sprinkling of sepc. I'll also start looking at the regulation for the mech to see what I can do there.

I've taken a gamble (kind of educated!!) on some 1000uF cerefine caps too. I've not got any large value BG's and so a coupe of the larger post reg caps will get these. The other option I have is some rubycons ZL's but I'll try the cerefine a 1st and I'm guessing they'll stay in!!!! Lol

Already looking ahead to the caps through the output stage and planning mica based on my experience with the DOS and cd63 in general.

Can someone elaborate on the trim pot that can be used to zero any DC offset on the out put (assuming I've understood previous posts) as I do believe the best cap is no cap ;-)
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When Bitstream came out, I thought, “my God, what are we going to do...?” Ken Ishiwata http://www.hifisounds.co.uk
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Old 4th October 2012, 07:57 PM   #62
UV101 is offline UV101  England
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Been busy the last couple of evenings! Completed the recap of the main board. Now got 1000uf cerefine after the regs, sepc on the dac vrefs to go with the BG FK's and std sprinkled throughout. I'm also now running 47,000uF mundorf smoothing on the main servo rail and 22,000uF on the others. Clock on its own tx and psu (hexfreds, and another 22,000uF mundorf) and this will get one of my regs to pre reg the line tomorrow. The new C3 is quite an eye opener even without a pre reg and additional jitter that will be present due to 2 buffers inline with the clock feed!

Jobs for tomorrow are to bypass the obsolete logic and feed the clock direct after the buffer (ic405) add some more sepc to the mech and fit the low noise pre reg between the clock and its PSU. I fully expect to hear the difference when this is done. I know the clock is not running in optimal configuration at the moment!!!

All I can say is WOW! This is outperforming my audio aero!!!!!!!!!! It's very full and very fluid and very tight!! Still can't make my oasis cd's sound like the sound engineer could actually hear tho!!!! Lmao......

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When Bitstream came out, I thought, “my God, what are we going to do...?” Ken Ishiwata http://www.hifisounds.co.uk
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Old 5th October 2012, 03:54 PM   #63
6h5c is offline 6h5c  Netherlands
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You've been quite busy indeed!

Good to hear it sounds so great already. I'm planning to do some more work on my 8400 soon. These are very nice players to tweak. There's plenty of room in the case and on the board. Only the PCB under the mech is a bit harder to do. I've ordered some OS-CONs to replace the small 22uF SMD caps as well, it will be a lot of work...

Have you considered replacing the four SMD regulators? The Rohm BA-series is not a very outstanding type of regulator... I used LT1963A for them, they are pin-compatible. The package is a bit smaller SOT-223 housing, but they can be fitted right on the board. Removing the original regs requires some patience though, the metal tab can be a bit difficult to unsolder. The difference was quite audible after the first run of tweaks on this board!

Regards,

Ray
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Old 5th October 2012, 11:00 PM   #64
UV101 is offline UV101  England
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Hi ray :-) yep, I'm very excited with the performance in this player indeed (nice heads up lee )
Got the clock psu a bit more sorted this evening and put one of my own 5v low noise regs between the PSU and C3. With respect to the SMS regs on the transport, I've ordered a couple of SPowerD's to try in there as my own regs don't do the low drop out required. They'll go in next week. I started the mechanical enhancements tonight while it was in bits too. Lots of bitumen damping and I've also ordered a 5mm aluminium plate for the base (remember this is not the KI!!!) I've added a few more caps on the transport too (still work in progress). Last thing to report is that I have clocked the DSD chip directly. The feed is now connected to a through hole point near the zero ohm link (r435) into pin 11. The through hole is right next to pin 3 of IC734 on the bottom side of the board. I've disconnected the output of the original circuit at IC405 on the other side of the board.

Listening to it now and it's making me smile lots!!!!!!! Cheers

From this
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To this!!!
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When Bitstream came out, I thought, “my God, what are we going to do...?” Ken Ishiwata http://www.hifisounds.co.uk
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Old 6th October 2012, 07:48 AM   #65
6h5c is offline 6h5c  Netherlands
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You missed a spot! just kidding...

The bottom plate is a good idea, the player can use a more rigid housing. A friend of mine with a SA8400 made one for me back then, he has access to a CNC punch machine at his work. He drew up the whole thing in Autocad and made two plates for us

Be careful with the ribbon cables from the transport. The bitumen material can be quite static as it is a good insulator. I killed the on-board uC once because the ribbon was dangling and touched the bitumen when I was putting it back together. It blew out a few input pins. Replacing that big SMD controller cost me a lot of sweat...

Now if I want to disassemble the player, I take out one ribbon at the time, first at the transport side and then immediately at the main board side.

Ray
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Old 6th October 2012, 10:07 PM   #66
UV101 is offline UV101  England
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Nothing so fancy as something CNC milled for me Ray, but hopefully will look decent enough on the front edge. I'll sandwich another layer of sound deadening between it and the base of the chassis for good measure. I'll be sure to keep my eye out with respect to static!!!!

I've been looking in to the dc offset as suggested a few pages back. Below are the diagrams for both HDAM's. I fitted a 22 turn 5k pot to the emitter of Q612 and Q613 and the wiper onto the +v rail. I was able to trim the DC offset down to about 0.1mV (assuming that my meter is that accurate which is highly unlikely!!!) and bypass the output caps. Nice spot on the HDAMs dannusch ;-)

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I've also added some 0.1uF PPS caps under the board on the DAC too. I can't put it down!!!!!! Lol ;-)
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When Bitstream came out, I thought, “my God, what are we going to do...?” Ken Ishiwata http://www.hifisounds.co.uk
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Old 6th October 2012, 11:09 PM   #67
UV101 is offline UV101  England
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Also meant to ask........
My display is very dim even on the brightest setting. What governs the brightness? Can I adjust one of the rails like H1 or 2 and the -VFT to lift the brightness a bit? I guess the display could be tired and need replacing......could try Charles Hyde in the UK
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Old 7th October 2012, 08:56 AM   #68
6h5c is offline 6h5c  Netherlands
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Yes, that will work. The input stage is just a common differential amplifier with a current sink, so any unbalance there will result in output offset.

I was just thinking the same thing the other day, my display is quite dim too. It's hardly visible during the day in my livingroom. You should not alter the heater voltage, it's a fixed value for that type display. But the -Vft can be lowered a bit (made more negative) and the display will become a bit brighter. The ML9207 display driver can handle -60V so that won't be a problem. DY65 is the component to be tweaked

Ray
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Old 8th October 2012, 08:48 AM   #69
UV101 is offline UV101  England
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Now armed with some zeners to try!!! What would be a sensible 1st step up? 33v???
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Old 8th October 2012, 03:15 PM   #70
6h5c is offline 6h5c  Netherlands
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Yeah, something like that. Just change it a few volts and see what happens. The difference should be clearly visible if you use 33V.

Ray
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