Cambridge Audio DACMagic Modification

Pui, I would recommend the next thing to perform is to add a valve output stage directly after the transformer stage. Right now, the DAC chip drives the transformer directly, and the transformer is connected to your integrated amp's volume control which will cut out some details. Best to have some booster after the Lundahl. I notice that although the DAC chip in the Cambridge is a highly reputable one, it's drive factor still lacks a bit if compared to some of the older good chips like AKM4393 AKM4396 which is japanese stuffs.

cheers.

Is the tube buffer serve the same purpose?

You can try a tube buffer and see - there are plenty of them from china nowadays.

Personally I like the sound of a simple low gain preamplifier stage pumping maximum current to the anode using a constant current source.



cheers.

It is never ending.......as for now, i should stop thinking crazy stuff... enjoy the present gear i have.......thank you wikin.

After 3 weeks with slight rectification on the dac by wikin, I could not be happier to say that it is well worth the money spend on this mod, among my hifi kaki, we do AB comparison with modded marantz 63ki, cambridge produce the sweetness vocal, bass is more weight and well extended, however, ki is more detail sounding and slightly brighter sounding. Those cambridge owner who r into vocal and jazz music may consider this mod, after perhaps we can share our joyful with this little chap.

Last but not least, thank wikin again for the wonderful job.

Wilkin,
Congratulations for a job well done. I also have a DacMagic but it is in a drawer awaiting to be called for service!

wow so much of hardwork,before a fruitation. The cheapest and best tweak may be moving the powersupply onboard away into another box as suggested.lessen the load ...blossom result.

i read some DAC run on battery pack ,more clean DC.

puiyk1973 wrote:After 3 weeks with slight rectification on the dac by wikin, I could not be happier to say that it is well worth the money spend on this mod, among my hifi kaki, we do AB comparison with modded marantz 63ki, cambridge produce the sweetness vocal, bass is more weight and well extended, however, ki is more detail sounding and slightly brighter sounding. Those cambridge owner who r into vocal and jazz music may consider this mod, after perhaps we can share our joyful with this little chap.

Last but not least, thank wikin again for the wonderful job.

You are very welcome
Just IMO, the more detailed/ brighter sounding from the modified Marantz may be the sound of induced distortion. I've heard a KI highly modded with burson audio modules and power supplies, and they sound highly organic; totally not bright at all.

cheers.

DrWho wrote:Wilkin,
Congratulations for a job well done. I also have a DacMagic but it is in a drawer awaiting to be called for service!

Cheers Dr.Who.
I can understand why it's in the drawer

hi5papa wrote:wow so much of hardwork,before a fruitation. The cheapest and best tweak may be moving the powersupply onboard away into another box as suggested.lessen the load ...blossom result.

i read some DAC run on battery pack ,more clean DC.

Yes these are generally the correct engineering work to perform on the DAC.

Still, at the end of the day, we have to rely on the ears to tell if the mods have been correctly implemented to balance out the sound.

For e.g. the battery mod may give good clean sound but because of some DAC chip's stock sound is gentle and weak like the TDA1545 non oversampling, putting batteries may sometimes worsen the sound if the output stage is just resistor and cap coupled. Totally no power and grunt. Highs are missing most of the information.

cheers.

I acquired an old pioneer pds 904 cd player, it is quite a good sounding cd player considering its tech at then 10+ yr ago, vocal is more fatter and rough, considerable bass slam, high is smooth, transport mechanism is unique.

Partnering with my Cambridge, it is totally different sounding, the only downside is that connection is limited to optical.

Now i have one machine with two characteristic sounding.... not bad.

Once i gather enough $, will do next mod on pioneer...crazy....

Hi puiyk1973,

You may want to try replacing the Toslink transmitter in the old pioneer CD player.. if you happen to find out the model of transmitter it is using.~

adrian4454 wrote:Hi puiyk1973,

You may want to try replacing the Toslink transmitter in the old pioneer CD player.. if you happen to find out the model of transmitter it is using.~

Hi Adrian do u know the model? Or alternatively is to tap the signal for mod it to coaxial output. I read quite a number of resource in net modding to coaxial. Interesting.

Hi bro,

I can't recommend coaxial enough; toslink sounds yucky to me.

cheers.

Hi pui,

Neither do I know how to do the conversion; but it is often of the same circuit from the decoder chip, a cap or 2, plus pulse transformer might be needed. You may ask the resident sifu Wikin on this.. he might able to do that for u.. ~

Dont discount off Toslink too soon; pound for pound.. it still the best for the money. Well at least in my case.. There are a lot of highly tweaked digital RCA out there. But 1 look at the cost, u rather like to spend the money somewhere else.

Perhap u can get Wikin to make the BNC instead, but again as much as it is a technical improvement; it doesnt always guarantee good music reproduction~ final tweak always rely on the ear~

adrian4454,

Did the toslink transmitter upgrade make a lot of sonic difference ? Can you describe the difference ? The jitter specs i remember for the replacement transmitter is much lower than the original.

A well implemented Toslink, ie using multi strand glass cable as opposed to fibre cable, could sound as good as a coaxial. It could even better the coaxial if the coaxial is not terminated correctly. To me the digital cable is the most important cable in a system. Get it right the system would start singing

adrian4454 wrote:Hi pui,

Neither do I know how to do the conversion; but it is often of the same circuit from the decoder chip, a cap or 2, plus pulse transformer might be needed. You may ask the resident sifu Wikin on this.. he might able to do that for u.. ~

Dont discount off Toslink too soon; pound for pound.. it still the best for the money. Well at least in my case.. There are a lot of highly tweaked digital RCA out there. But 1 look at the cost, u rather like to spend the money somewhere else.

Perhap u can get Wikin to make the BNC instead, but again as much as it is a technical improvement; it doesnt always guarantee good music reproduction~ final tweak always rely on the ear~

Both coaxial and optical have its own sound characteristics, one may like one to the other, so u c is all down to personal liking and taste. For me, i am exploring the potential of both optical and coaxial since all the while i be using only coaxial. Glass optic cable has gained much popularity among hifi fan recently, and i m curious too, hence just order a glass optic cable (silflex brand, reasonable price) to try.

Hi Carz,

The improvement is minimal.. It seems to show slightly more details... but it was rather hard to assess properly as my setup was still new and wasn't familiar with the sound. Neither was I mad enough to switch back and fore between transmitter(habis la my CDP punya PCB)...

But it does give me a peace of mind(temporary cure to itchy ass syndrome) knowing that new transmitter is of better spec and it's new!. Like changing an exhausted headlight that remain on for 10 years!

adrian4454 wrote:Hi puiyk1973,

You may want to try replacing the Toslink transmitter in the old pioneer CD player.. if you happen to find out the model of transmitter it is using.~

Hi Adrian

Just found the model of transmitter for pioneer pds 904, it is Toshiba TOTX178. Any idea where to buy the replacement? or any better spec for substitution. TQ

Hi PUi,

Here is the link, http://my.element14.com/toshiba/totx177l/transmitter-fibre-optic/dp/1225772

try to search around in it website as well. There are few Toshiba model. Before you buy, u better get the spec sheet on your Toshiba TOTX178. IT should be available in the WWW. Compare with the potential units being offered in element 14. When the solder lead and it functions are same, it should be able to work. I bet u see improved performance on the spec sheet of the latest version in Element 14. U can register as a user and purchase from their webite.

Now, once you did this crazy thing; pls report back on the findings ok! At least, it may help me to prove I am not hearing voicing in my mind ..haha.

adrian4454 wrote:Hi pui,

Neither do I know how to do the conversion; but it is often of the same circuit from the decoder chip, a cap or 2, plus pulse transformer might be needed. You may ask the resident sifu Wikin on this.. he might able to do that for u.. ~

Dont discount off Toslink too soon; pound for pound.. it still the best for the money. Well at least in my case.. There are a lot of highly tweaked digital RCA out there. But 1 look at the cost, u rather like to spend the money somewhere else.

Perhap u can get Wikin to make the BNC instead, but again as much as it is a technical improvement; it doesnt always guarantee good music reproduction~ final tweak always rely on the ear~

Hi Bro,

There are many ways to skin a cat that's for sure in hi-fi; and the only way to assess which method skins the cat the best is to experience it. Every method of sending digital information has it's pros and cons. Toslink provides the best form of noise isolation. Coaxial gives better square wave but if the source has ground loops then that's a headache. BNC is more ideal to reduce digital bounce but the connector is more unique and not flexible with many equipments.

As for me my final solution that I came to, is running a 12feet digital cable terminated with BNC on both sides. Works for me

cheers.

DrWho wrote:A well implemented Toslink, ie using multi strand glass cable as opposed to fibre cable, could sound as good as a coaxial. It could even better the coaxial if the coaxial is not terminated correctly. To me the digital cable is the most important cable in a system. Get it right the system would start singing

Hi DrWho,

From your statement I presume you are now using glass toslink right? Is there a particular brand of glass toslink that was a breathrough? Were there other methods that was done to improve this form of interface?

cheers.

Wikin wrote:

DrWho wrote:A well implemented Toslink, ie using multi strand glass cable as opposed to fibre cable, could sound as good as a coaxial. It could even better the coaxial if the coaxial is not terminated correctly. To me the digital cable is the most important cable in a system. Get it right the system would start singing

Hi DrWho,

From your statement I presume you are now using glass toslink right? Is there a particular brandB of glass toslink that was a breathrough? Were there other methods that was done to improve this form of interface?

cheers.

I did experiment with multi strand glass optical cables and found them to be more superior to the coaxial cable in my HT system. I am currently using a 20 feet 200+ strands optical cable from my AV setup to my HiFi setup. I use this when viewing concert videos. This 20 feet optical is also better than the similar length coaxial cable, but terminated with RCA plugs. Because of the special length, I can't find the brand on the cable but if you are serious to know the brand, I would have to do some digging and will pass you the info later. As you know BNC plugs and sockets come in 50 or 75 ohms and getting the right one makes the different.

adrian4454 wrote:Hi PUi,

Here is the link, http://my.element14.com/toshiba/totx177l/transmitter-fibre-optic/dp/1225772

try to search around in it website as well. There are few Toshiba model. Before you buy, u better get the spec sheet on your Toshiba TOTX178. IT should be available in the WWW. Compare with the potential units being offered in element 14. When the solder lead and it functions are same, it should be able to work. I bet u see improved performance on the spec sheet of the latest version in Element 14. U can register as a user and purchase from their webite.

Now, once you did this crazy thing; pls report back on the findings ok! At least, it may help me to prove I am not hearing voicing in my mind ..haha.

Hi Adrian,

Thank for the website, but there do not offer totx178, only totx177L, toxt178 transmission rate of 6mb/s, where 177 is 15mb/s, is this how to compare the two transmitter, any other date need to take into consideration? i m not a tech man, pls do help, thanks

Hi Pui,

Yes, you need to take some risks here.. of course the original has gone EOL for sure la. Look for the Protocol compliance of ur ori and the new one most important of all they both look physically same externally. And function of each solder lead carry the same function. Mine, I've changed to a current transmitter of the same brand, but new version. And it work wihtout a glitch. Search this forum.. I did wrote my rubbish over this little DIY I did.

It should work without any problem. Certainly the newer version transmitter has a better performance rate. No doubt about it. Don't just compare to the 1 I provided u link, there are quite a few of slight different version on offer. If it doesnt work, just solder back the ori one la..

adrian4454 wrote:Hi Pui,

Yes, you need to take some risks here.. of course the original has gone EOL for sure la. Look for the Protocol compliance of ur ori and the new one most important of all they both look physically same externally. And function of each solder lead carry the same function. Mine, I've changed to a current transmitter of the same brand, but new version. And it work wihtout a glitch. Search this forum.. I did wrote my rubbish over this little DIY I did.

It should work without any problem. Certainly the newer version transmitter has a better performance rate. No doubt about it. Don't just compare to the 1 I provided u link, there are quite a few of slight different version on offer. If it doesnt work, just solder back the ori one la..

Hi Adrian, thank you very much. Put my order for totx177L, hope it work.

Yah do report back on your findings. Something u need to watch out, as you may screw back the transmitter to the side panel, pls hold the transmitter firmly, u need to apply pressure to the screw, as the transmitter screw hole doesnt has screw thread.

Also, try not to over heat the solder joint.~

There are many ways to skin a cat that's for sure in hi-fi; and the only
way to assess which method skins the cat the best is to experience it.

Yea Wikin, I truly believe it that idea too.....

adrian4454 wrote:Yah do report back on your findings. Something u need to watch out, as you may screw back the transmitter to the side panel, pls hold the transmitter firmly, u need to apply pressure to the screw, as the transmitter screw hole doesnt has screw thread.

Also, try not to over heat the solder joint.~

Thank you very much. Accidentally order 2 pcs of totx177L from element14. I successfully added a coaxial output (directly steal the signal right after the decoder chip) for my pioneer pds904. I try both optic and coaxial, optic sound r more airy, bass slam is lighter than coaxial, that all i can hear the difference so far (still using old transmitter, awaiting new one to be deliver). Will try to c what happen next after the new transmitter install.

Hi Adrian, u r right, changed the transmitter, the 1st noticeable is red beam r much more brighter (test by one end in the transmitter and the other end open to a black surface). I told u I were going to change the clock for my pioneer, but I didn't for this particular test. So how does it sound? Lower frequency r substantially improve, more weight (very noticeable from double bass instructment), detail improve, vocal same as before (could not detect any different)...to sum up, a little less than rm10 transmitter could bring substantial improvement is worth an investment.

Maybe these transmitter thingys do wear out and don't sound good compared to a new one. I wonder it these do wear out eventually.

cmboy wrote:Maybe these transmitter thingys do wear out and don't sound good compared to a new one. I wonder it these do wear out eventually.

Is cheap & can change every year

Hi Pui,

Glad to hear that... finally the voices got out of my head...

Mean time, I been reading some writing about direct digital output for SP/DIF from the chip... no capacitor, no resistor, no transformer... haha, gonna get 1 unit of the lousy DVD player to try this one out later.. most likely going to run it on BNC...

adrian4454 wrote:Hi Pui,

Glad to hear that... finally the voices got out of my head...

Mean time, I been reading some writing about direct digital output for SP/DIF from the chip... no capacitor, no resistor, no transformer... haha, gonna get 1 unit of the lousy DVD player to try this one out later.. most likely going to run it on BNC...

Hi Adrian

Give it a try and c what u can discover