I have the XLR plugs but they seem to be sealed dont know how I'm to short the pinany ideas ?
You don't want to 'short' the pin, if by short you mean short circuit. You want it open circuit (not connected to anything).
Measure the continuity (resistance) between pins 1 and 3. If they are connected together (zero ohms) you have a problem. If it's open circuit you're good to go.
1 should be connected to outer part of RCA
2 should be connected to centre of RCA
3 should be connected to nothing
Even if pin 3 is connected to ground (pin 1) you won't be shorting the op-amp output directly to ground as it has a 75 ohm restistor in series (also the output cap). You won't damage anything anyway, but driving such a low load may possibly change other circuit parameters and add noise to the power lines which are shared amongst the op-amps. It may still sound better than going straight from the RCAs. Try it anyway, it won't hurt.
Hi guys.
I am writing from Argentina and my name is Matias. I tell the reforms which were made to my Cambridge DacMagic.
* 5v Reg DIY for the DACs.
* Tracking Preregulator DIY 15v.
* DIY 15v *- Preregulator Tracking.
* PM Flea circuit (thanks Ray) with Tentlabs Xo.
* Total recap (OSCON, Elna, Panasonic FC, Nichicon).
* 8 OPA627AU in BrownDogs adapters (SOIC, SOIC)
* Bias in class A with JFET's.
* Toroidal PSU
I want to thank DIYAudio users because this post was an inspiration to me.
I leave my project links to a forum published in Argentina, it is very difficult to do again in this forum.
Any question or doubt I am available as needed.
Thanks
Matias
www.forodvdmania.com • Ver Topic - DIY - Upgrade Cambridge Azur Dacmagic
www.forodvdmania.com • Ver Topic - DIY - Regulador de bajo ruido 5v - Reemplazo 7805
www.forodvdmania.com • Ver Topic - DIY - Regulador de bajo ruido 15v - Reemplazo 7815 - TP
I am writing from Argentina and my name is Matias. I tell the reforms which were made to my Cambridge DacMagic.
* 5v Reg DIY for the DACs.
* Tracking Preregulator DIY 15v.
* DIY 15v *- Preregulator Tracking.
* PM Flea circuit (thanks Ray) with Tentlabs Xo.
* Total recap (OSCON, Elna, Panasonic FC, Nichicon).
* 8 OPA627AU in BrownDogs adapters (SOIC, SOIC)
* Bias in class A with JFET's.
* Toroidal PSU
I want to thank DIYAudio users because this post was an inspiration to me.
I leave my project links to a forum published in Argentina, it is very difficult to do again in this forum.
Any question or doubt I am available as needed.
Thanks
Matias
www.forodvdmania.com • Ver Topic - DIY - Upgrade Cambridge Azur Dacmagic
www.forodvdmania.com • Ver Topic - DIY - Regulador de bajo ruido 5v - Reemplazo 7805
www.forodvdmania.com • Ver Topic - DIY - Regulador de bajo ruido 15v - Reemplazo 7815 - TP
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An externally hosted image should be here but it was not working when we last tested it.
Hi Fivetide
The reform did was extreme because they were few original elements in the signal path. The results are also in the sound ends.
The only comparison I did was sound against a Marantz SA-11S1 and DacMagic surpasses it. I could not make more comparisons but I have no friends with best players. The sound is very detailed, the highs were shortening and becoming more pristine as the project progressed. I have a Fostex FE206E horns and the soundstage is superlative! never "saw" anything like it. This is my Fostex Project link
www.forodvdmania.com • Ver Topic - DIY - Horns de alta sensibilidad
A hug
Matias
hi all, is it still safe to use 35v capacitor in C76, C77, C402, & C403? i'm aiming for higher capacitance (1200uF each), hence lower voltage rating is necessary. i know that the adapter supplies 12VAC to the DAC, which means after it gets rectified the voltage will raise up to approximately 16v, which makes 35V voltage rating should be safe already. but maybe there are something i beyond my understanding? hence i'm asking for inputs
sorry for the noob question
sorry for the noob question
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I would not change the value of the voltage for the capacitor without measuring the voltage coming into the capacitor and adding a 20% safety factor for power surges (40% for peak AC). Adding more uFs is not a substitute for the amount of voltage a capacitor can handle. Note the voltage is not the amount supplied but can handle coming in. For example if the voltage running through that part of the circuit is 60V and you put in a 40v capacitor the results could be a small bang.
yes, i know that the voltage rating is the one that handle voltage coming in. i just want to know the rectified voltage supply of the dacmagic, that way i will be able to predict what voltage rating specs needed.
but i'm still not sure whether the dacmagic really rectified the 12VAC into 16 VDC or it does another rectifying method.
Use a voltmeter, measure the voltage, and take into account that the voltage coming into your house could vary.
I have attached the schematic for the power supply section you are looking at. Those capacitors are used as RC filters. The 35V probably will be ok but upping the capacitance may drop the voltage too much in the filtration circuit. You will need to get the voltage coming in and then calculate the voltage drop for the RC filter before and after. If you drop too much the regulators may not work.
Alternatively you could leave the caps in as they are not in the signal path and add the tantalum capacitor mentioned earlier in the thread. You can also look to change out the 7805 to a DEXA regulator. The 5 volts is more critical then the 15 volts as it is used to power the ICs. Having redone several power supplies, I don't think you will hear much of a change by replacing these caps as they are followed by voltage regulators which could add or subtract noise.
I have attached the schematic for the power supply section you are looking at. Those capacitors are used as RC filters. The 35V probably will be ok but upping the capacitance may drop the voltage too much in the filtration circuit. You will need to get the voltage coming in and then calculate the voltage drop for the RC filter before and after. If you drop too much the regulators may not work.
Alternatively you could leave the caps in as they are not in the signal path and add the tantalum capacitor mentioned earlier in the thread. You can also look to change out the 7805 to a DEXA regulator. The 5 volts is more critical then the 15 volts as it is used to power the ICs. Having redone several power supplies, I don't think you will hear much of a change by replacing these caps as they are followed by voltage regulators which could add or subtract noise.
thanks for the reply, Ajcrock!
i missed the tantalum capacitor thing, i'll look to that again alter *edit: wow, it seems tantalum capacitor brings out more good than replacing a bunch of elco capacitors? it's definitely worth a try
For a bigger change try replacing the 7805 with a DEXA Clocks 5.0v Dexa UWB " Series" Regulator (Positive) (78xx Series). Also don't forget the 6 coupling caps with Elna Silmic II Capacitor 470uF 16V 12.5x25 mm. The point is to try and make changes that have the biggest impact. Namely critical components and the signal path. Look at what other companies are offering as upgrades to the Dac Magic. Also consider replacing the op amps. However these are surface mount and take some skill to replace (cut the legs off the olds ones to remove them and then clean the pads and add the new ones). Earlier in the thread I mention the op amps replaced which were also done by the person that mentioned the tantalum capacitor.
i measured the dc offset single ended output, i got 3mV & -0.07mV, hence i decided to just bypass the 6 coupling capacitors
i have no problem in soldering surface mount components, but i pretty like the sound of ne5532 (i've tried LM4562 in my previous dacmagic), hence i'll try to modify the digital and analog supply section first
wish me luck!
ermm..is the dc offset will likely to fluctuate? if it doesn't, i think 3-10mV dc offset is pretty much safe for about any amplifier out there.. CMIIW
as for the balance converter, i already did that..and yes, it does sound better through the balanced out
When you measured the DC offset had you already shorted out the coupling capacitors? If not you measured the result of them doing their job. You need to short them out first then measure. As to it always being the same amount of DC offset I cannot comment. The Elna Capacitors are on $1.25 each. I am willing to bet your amplifier is worth more then $7.50.
yes, i have shorted all the electrolytic coupling capacitors before measuring it. what's the point of measuring the dc offset anyway when i haven't done anything to it yet
I have now replaced the 4805-regulator with a Belleson superpower, and shorted the output coupling caps. I could not measure any dc on the outputs at all, it was 0.
It is to early for me to say anything about the sound difference, it is still breaking in. I did it to a new unit. My experience is that the dacmagic changes sound a little bit after break-in. More bass and less treble after a week or so.
It is to early for me to say anything about the sound difference, it is still breaking in. I did it to a new unit. My experience is that the dacmagic changes sound a little bit after break-in. More bass and less treble after a week or so.
was the improvement of replacing 7805 with DEXA Clocks really bigger than replacing 30 electrolytic supply caps? it's a $40 regulator, not including shipping. i have to think about it carefully
i did the capacitor mod, changing around 14 decoupling capacitors already (yes, i haven't replaced the big capacitance analog & DAC supply capacitors), and i heard no significant improvement *i do hear difference (smoother sound, more open), but the improvement was just not worth the hassle. LOL
but again, those mod are cheap, still below $10. it was still worth a shot if you know how to DIY, and willing to do it
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I did the changes in stages. First I added the tantalum capacitor and Elna coupling caps and noticed an ok change. I then changed out the regulator and noticed a huge change much more delineation and clarity. More open airiness. I then changed out the op amps and and got much more richness and depth of soundstage.
I just ordered another Dexa regulator for my Sony NE999ES SACD/DVD player. I am also replacing the op amp in it with a LME49720.
So yes I think the DEXA regulator is the easiest change you can make. Having done several power supplies, I would doubt you would notice much change from swapping out the electrolytics unless you go high quality/technology change like upgrading to something like a ruby gold or mundorf with film caps in parallel. None of which will fit in the space allowed.
I just ordered another Dexa regulator for my Sony NE999ES SACD/DVD player. I am also replacing the op amp in it with a LME49720.
So yes I think the DEXA regulator is the easiest change you can make. Having done several power supplies, I would doubt you would notice much change from swapping out the electrolytics unless you go high quality/technology change like upgrading to something like a ruby gold or mundorf with film caps in parallel. None of which will fit in the space allowed.