[glingrem]

Hi, Tom.
Quote:

Originally Posted by thoppa /img/forum/go_quote.gif Hey Glingrem, I finally got around to doing this mod.

Accept my congratulations!

Quote:

Originally Posted by thoppa /img/forum/go_quote.gif However, a good 7912 is hard to find. Most seem to have 70uV of noise and only 60dB of ripple rejection. The case size is a dpak-3 I think and I think 500mA will be enough. Do you or anyone else know a better component ? ]

I think, you got one of best 7912 on a market in D2-pack. Equivalents from TI, KEC, etc. has more noise voltage ( up to 200..300 uV) and few dB low RR.

Quote:

Originally Posted by thoppa /img/forum/go_quote.gif I cut the legs a little so the top sits at the same height as the caps around it so it won't catch/touch on anything when I put the card into the pci slot. I made the rear leg from a resistor lead.

Why don't you soldered IC onto the solder pad on board?
Vitaliy.

 

[thoppa]

Hi Vitaliy,

I'm pleased it works ! Thanks.

It is a shame that there doesn't seem to be any better 7912 regulators than this one.

Unfortunately, the d2pak is just a little too big to fit flat on the board because it completely covers the pad and solder pads and won't fir squarely in the space either. So there was no chance I could get it soldered on like that. The board space is dpak-3 size.

Thanks again.

 

[glingrem]

Hi, everybody!
Today I had make over myself a huge effort to spend
time and carefully read through the entire topic.
I realized one simple thing: You all are walking the wrong way.
You spend hundreds of dollars on the Hi-End analog power supply to reduce its noise, but the main source of this noise is on the card itself.
This source at 14 page of discussion merely observed by thoppa. This are pulsed converters (U25 & U35) of +5V source voltage from molex connector to +/ -12V for power supply of opamps and headamp. The next step in the right direction would be a rejection of the use of these converters and power supply of the card through a molex connector. But neither of you did not this step. This requires a little more changes in the circuit of the card, but gives a much greater influence on the sound. The right analog power supply must contain stabilizers +12 and -12 volts to power supply of opamps and headamp and +5 volt power supply for analog circuit of DAC chip. In this case the set of onboard stabilizers on 78 ** also not used.
That do you think about?

 

[thoppa]

Hi,

I think U25 and U35 are before the regulators ? 7812 and 7805 and now 7912 too - so the regs will be reducing the noise they produce.

Of course, it would be better to build +/-12 and 5V supplies and feed these directly onto the board because it would reduce noise levels at high frequencies (above ~50Khz) which the onboard regs won't do so well with.

However, every mobo produces huge amounts of noise (mV not uV), so the earth is often really noisy, and there are very high levels of emi/rf from the processor, gpu etc. so there comes a point when there is very little more that can be done to improve the sound quality because of the PC environment.

Of course, you could mount the card outside the PC but tbh, it's getting a bit crazy at that stage - it would be better just to use an external DAC with something like the usb asio Teralink X2.

 

[thoppa]

Spam invasion weekend eh.

 

[shimm]

Quote:

Originally Posted by thoppa /img/forum/go_quote.gif So far, the only one I have found is this : ON Semiconductor | Semiconductors | Power Supply and Control | Linear Regulators | Negative Voltage Regulators, On Semiconductor |MC79M12BDTG Do you or anyone else know a better component ?

That guy from russian forum who really did this 7912 mod found that L7912ACD2 is notacible better solution. You may (i hope) see pics here.
They think that *ON* Semiconductor isn't acceptable at all.

 

[thoppa]

Quote:

Originally Posted by shimm /img/forum/go_quote.gif That guy from russian forum who really did this 7912 mod found that L7912ACD2 is notacible better solution. You may (i hope) see pics here. They think that *ON* Semiconductor isn't acceptable at all.

7912A is usually better than 7912B or C but for 7912 it is usually less than 10% better - typically 70uV noise instead of 75uV etc. So who makes the
L7912ACD2 ? Is it Dpak3 or a similar size ? Where can I buy one ? Where can I see the datsheet ?
If you are referring to the ST one, then it is only in d2pak and to220, and it has 100uV noise with similar line and load regulation, transient response, etc. It isn't better.

 

[ROBSCIX]

Cool mods.

 

[glingrem]

Hi, Tom.
Quote:

Originally Posted by thoppa /img/forum/go_quote.gif I think U25 and U35 are before the regulators ? 7812 and 7805 and now 7912 too - so the regs will be reducing the noise they produce..

Of course. But not all noise. You can hear a difference in sound between powering this card from onboard DC-DC convertors and from outside +/-12 and 5V supplies.
One man from russian forum built it and it looks like good. And sounds like good too

Regulators are placed on aluminum cover of card as a cooler.
It connected to the board directly but molex not connected and DC-DC converters doesn't work. It not more expensive as +12/+5 outside supply but sounds better.
Vitaliy.

 

[gwillys]

how about dexa & burson regulators? hope i'm not told i wasted money
improved imaging/clarity/definition.
 
*burson regulator now powered by external psu - opa's @ 16v.
scuse the mess - under construction

 

[h4sy0u]

Hello. Because I also have Essence i am interested in this.
Might this work?
 
http://cgi.ebay.com/60W-Linear-Power-supply-T-AMP-TA2024-TA2020-DAC-/120576189139?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item1c12e6a2d3
together with
http://www.steatite-embedded.co.uk/12v-dc-to-atx-converter-plugs-directly-into-atx-socket-120w-max.html
 

 

[gwillys]

i cant quite figure what your plan is. i dont think those two items would change things much.

 

[spacejay]

i have a few high quality power supplies knocking about that could be utilised in powering the essence. what exactly are the power requirements needed?

 

[serenith]

 
I have a question about filtering / smoothing a SMPS DC output. I have a computer PSU lying around and I was thinking I could join two rails together in series to get a +24V and +10V ouputs. Now, is there any way I could regulate / filter / smooth these DC ouputs down to a clean +12 and +5 ? I know close to nothing about building RC(L) circuits for that purpose so please bear with me.
 
It seems it would be cheaper (for me) then buying / building a dedicated PSU. Also, since i'm not planning to get a soldering iron anywhere near my ST due to my lack of skill, i'm limited to op-amp and psu upgrades.

 

[Psyside]

Hello guys, and sorry to bump this old thread.
 
I got no time neither im skilled/tech wise  to understand all of this stuff, i just bought mine Adam A3x speakers, and now im waiting my STX to arrive in 1 week or so, i just got into the high quallity audio stuff, and would like to know whats this power supply all about? do i need some special PSU in order to get most of the card? or the users who post have medicroe/low end PSU's so they must find a workaround?
 
I own an Coller Master real power pro 1000W PSU, is this good enough? what should i chek for in order to tell if my PSU will offer good and clean power, thanks guys!