Cool, thanks guys. I'll run twisted 9v pairs along the front then. Anyone have any opinion on whether 3.5va winding is enough for the DAC digital supply?
I finally got a tiny 3.2va toroid in for the display last weekend, allowing me to remove the KI transformer. It doesn't half run hot though!
I finally got a tiny 3.2va toroid in for the display last weekend, allowing me to remove the KI transformer. It doesn't half run hot though!
This method of direct coupling the output works here because there is 0v DC offset after the 2nd Opamp stage.
You should always check with a meter set to the mV range before you direct couple. DC into your amp could damage the amp and speakers!!!
This morning I managed to fit the four transformers at the rear side of the CD63. See the attached photo. I will connect the wires to the PCB when I have the time. The square encapsulated Tx in blue is for the low jitter clock.
I placed the three toroidal Tx on top of an universal PCB which I hope will make my soldering much more easy when connections are made.
I placed the three toroidal Tx on top of an universal PCB which I hope will make my soldering much more easy when connections are made.
Attachments
I think it should be sufficient as the power drawn by the DAC would not be too much. You should have about 400-500mA supply of current having taking into account of the Tx efficiency.
Obviously it will work but I think Brent used 7.5va 9v for digital and and the same for analogue. We already know that within reason, bigger transformers bring sonic benefits.
Given the almost identical cost of the TX, I know what I'd be doing!!!!
Agreed, the bigger the Tx the more stable the voltage and thus better. I think Ben has space constraints so he tries to use a smaller Tx
Re. the humming issue. Did you connect the CD63 to the main's earth. When I connect the CDP to the mains earth I also got small humming noise but when I disconnect it the noise has gone. The CD63 was designed without the need for any earthing to the mains. Earthing the CDP will create earth loop
@higlander - No, I didn't connect the earth. I can hear the transformer(s) when I put my ear to the case as well. It's not really a big problem - it just bugs me that I know it's there. If I still had muting transistors I wouldn't even know about it.
@Ian - thanks, maybe I'll devote a whole one of these 7VA toroids to the DAC digital then. I bought 5 total. I can probably find a way to squeeze more in.
@Ian - thanks, maybe I'll devote a whole one of these 7VA toroids to the DAC digital then. I bought 5 total. I can probably find a way to squeeze more in.
If the humming is from the Tx itself it means that the Tx is loosely fitted. Try clamping it tight by bolts to the case.
OK, I can try to do that now that the original transformer is out.
I suspect it's a ground loop somewhere though but I've go no idea how to track that down.
From memory there's one unmarked connector to the output section ground that must've had a ground wire go to it from the original KI TX. I'll try to get a diagram.
I suspect it's a ground loop somewhere though but I've go no idea how to track that down.
From memory there's one unmarked connector to the output section ground that must've had a ground wire go to it from the original KI TX. I'll try to get a diagram.
NO, I don't think so. Just leave as it is.@higlander - just saw the pic of your PSU mounting - really nice work!!
Should I have anything connected to this?
Hi Leonel,
I guess you have no soldering experience whatsoever? Otherwise you could open a new thread and we can help you out on-line. Shipping alone would cost you about € 60,- here and back, you can buy a lot of parts for that!
Regards,
Ray
@higlander - just saw the pic of your PSU mounting - really nice work!!
Should I have anything connected to this?
That's a gnd Ben. In the non KI the centre tap of the windings for the audio psu is internally connected, but you could utilise it if you run a separate tx.
I'd start with some other mods 1st. You should swap the local psu caps and fit Opamp sockets so you can roll some different opamps.
You should consider trying LME47920 decoupled with some 470uF Rubycon ZLH. If you've not done it yet, there are a few psu caps that you should swap 1st.
The DOS is very very good especially when used with high quality PSU regulation.
You should consider trying LME47920 decoupled with some 470uF Rubycon ZLH. If you've not done it yet, there are a few psu caps that you should swap 1st.
The DOS is very very good especially when used with high quality PSU regulation.
Hey guys, I've built my first separate PSU for the DAC analogue supplies using a 7VA transformer (2 secondaries @ 3.5VA), some Schottkys and some mondo smoothers. Here I go with another noob question: What do I do with the ground? Anything different? Do the ground pins become separate or the same ground as the rest of the player? I only just realized how clueless I am about this part.