Hi, Mates
You hooked another one
I've just got my first 63SE (aka: victim #1) and unmodded its sound a couple steps above my old Carver TL-3100 or cheapo Dell computer Also,
the analog output beats the digital output thru my Audio-DG Compass, which probably means the Compass's days are numbered.
So, while gathering supplies I've got my first question for the experts.
I couldn't find any info on this by searching, but it seems everyone is removing the power switch link, O25G, and its connector on the pcb. Is the anything to do with the jumpers U251-252? I take it that this mod will leave the unit on all the time? Should I connect the 63SE power cord to a dedicated power strip/circuit breaker to use as an on/off switch?
Thanks all.
You hooked another one
I've just got my first 63SE (aka: victim #1
) and unmodded its sound a couple steps above my old Carver TL-3100 or cheapo Dell computer Also,the analog output beats the digital output thru my Audio-DG Compass
, which probably means the Compass's days are numbered.So, while gathering supplies I've got my first question for the experts.
I couldn't find any info on this by searching, but it seems everyone is removing the power switch link, O25G, and its connector on the pcb. Is the anything to do with the jumpers U251-252? I take it that this mod will leave the unit on all the time? Should I connect the 63SE power cord to a dedicated power strip/circuit breaker to use as an on/off switch?
Thanks all.
This is the best way to fit 7805's in my opinion.
Then your regulator is regulating against the ground potential at the gnd pin of interest on the consumer, not the ground potential of the ground plane on the other side of the board, which may be a long loop away. Mustn't think of gnd as being 0V and the same everywhere.
The reg's output isn't "+5V", it's simply "5V more than its GND pin". The GND pin is only a reference point for the regulator, no real current goes through it in a series regulator (unlike a shunt regulator).
You want the gnd pin connected close to the gnd pin of the consumer, so moving the lytic to where the ceramic was, and putting the ceramic underneath it, leaves the site of the lytic open as the perfect spot for gnd and o/p of the regulator. The only thing I would add is that if the input to reg is coming a long way you should add a small cap between gnd pin and input pin, as per data sheet, although you usually get away without it on a 7805.
Matthieu has it spot on I think.
(just my opinion of course)
That's how I've done it too.
Right, now for something different: Anyone on here tried transformer output?
I've had a go, and I have to say the gains have been incredible (in more ways than one). This isn't done properly, and I expect that a proper audio transformer by Lundahl or Sowter will do the job better, but jeez it's dynamic
It sounds live.
I currently have the filter section of the DOS, feeding into a single opamp with the output going into a transformer.
Only thing is the transformers are large. About 300va toroids to be honest about it.
Lee.
Right, now for something different: Anyone on here tried transformer output?
I've had a go, and I have to say the gains have been incredible (in more ways than one). This isn't done properly, and I expect that a proper audio transformer by Lundahl or Sowter will do the job better, but jeez it's dynamic
It sounds live.
I currently have the filter section of the DOS, feeding into a single opamp with the output going into a transformer.
Only thing is the transformers are large. About 300va toroids to be honest about it.
Lee.
I want pictures!
Men we may thanks Marantz for having given us (and the gangsta companies named before...) such a player full of promises
Simon, the fuse bypass, I want to know more, sound & danger.
As I have a TX for many 5V, a TX for the clock and no fuse there I was wondering about a fuse included in an IEC socket and no more for the driver and left 5Vs. Sounds good to you?
And yes Glenn, I'm at least no more asking what is an op amp like in my very early posts
Matthieu
Men we may thanks Marantz for having given us (and the gangsta companies named before...) such a player full of promises
Simon, the fuse bypass, I want to know more, sound & danger.
As I have a TX for many 5V, a TX for the clock and no fuse there I was wondering about a fuse included in an IEC socket and no more for the driver and left 5Vs. Sounds good to you?
And yes Glenn, I'm at least no more asking what is an op amp like in my very early posts
Matthieu
Will do. So far though, it sounds utterly brilliant, although I suspect the opamps may give up soon, lol. I'm not sure exactly how it's working, but the opamp may be driving a tricky load.
Piccies coming soon...
Lee.
Haha, well I don't think it makes it particularly dangerous, but it will make it sound better as they present a resistance on a power line with a lot of current draw. I don't recall ever having done the mod in isolation but Brent assures me the +-12V resistor bypass increases dynamics and bass impact. This tallies with my findings, albeit when mingled in with other mods.
Simon
You hooked another one
I've just got my first 63SE (aka: victim #1
the analog output beats the digital output thru my Audio-DG Compass
So, while gathering supplies I've got my first question for the experts.
I couldn't find any info on this by searching, but it seems everyone is removing the power switch link, O25G, and its connector on the pcb. Is the anything to do with the jumpers U251-252? I take it that this mod will leave the unit on all the time? Should I connect the 63SE power cord to a dedicated power strip/circuit breaker to use as an on/off switch?
Thanks all.
Hi, and welcome to this thread.
What link are you referring to? I don't know of any O25G in a CD63, where is it located? The mains switch is fitted on the main PCB. Jumpers U251 and 252 are only there for mechanical support and have no electrical function.
Regards,
Ray
MMM! I'm still perplexed as to how many volts you'll have p-p on the output!!! I'm not sure how your pre amp input stage will be coping. If you have a ratio of approx 1:7, if you have 1vpp on the output, that step up to 7vpp on the preamp input!
When do those 1:1 tx arrive? I've got a couple of 24v:115v which should give me a ratio of about 1:4.8 which will be less than the tx's you're using. Funny cos I've blown the dust off my 63 and had it working again albeit with 317 regs all over the place as I used all the decent ones in my phillips player! I'll hook those TX in tomorrow! If those RS ones are any good, I could pick a couple up on Tuesday!
I've also looked at audiocom, they do the same mod using audio consulting TX's at about £300 a pair for copper! Looks like they still use the op amp stage for filtering because they list opamps and OP TX's in their L4 upgrade.
I'd be interested in any comments on impedance figures, or how to calculate for this sort of application!
Last thing - does anyone know the freq for bit clock op on the DAC? Thanks Ian
For anyone who fancies trying transformer outputs, read this thread, from this page onwards:
http://www.diyaudio.com/forums/showthread.php?t=137976&pp=25&page=8
It revolves around trying various audio transformers on the output of Crystal CS4397/CS4398 DACs, but they are differential voltage-output DACs also, so should be transferrable I imagine.
http://www.diyaudio.com/forums/showthread.php?t=137976&pp=25&page=8
It revolves around trying various audio transformers on the output of Crystal CS4397/CS4398 DACs, but they are differential voltage-output DACs also, so should be transferrable I imagine.
Which 10k do you mean Lee? There's no 10k resistors in the DOS.
The original 10k's in the player should be removed, if that's what you mean.
Regards,
Ray
If you take the left channel as an example, LO is at +2.5VDC and LON is at +2.5VDC so no DC will flow in the transformer primary. There might be a few mv of difference between the two (probably) but not enough to cause problems I'd have thought.
Aha. I'm playing about with it now. I tried hooking dac straight into tx and got distortion, hopefully that's down to load so I'm playing with various resistors to see if I can eliminate it. I've tried with the dos filter, but am getting strange results as I've had to lower the 2k4 input resistors and I think it's messing with the filter slope.
Lee.
Lee.