The true experimental tweak thread

[BigGuy]

1 hour ago, sandyk said:

Big Guy

 

With the 12V 50VA transformer you will be dropping around 7.5V , and with a 2A load that's 15W of heat to dissipate !

With a  9V 50VA transformer you will be dropping around 3.6V , and with a 2A load , dissipating around 7W of heat.
 If the regulator is an LDO type ( Low Drop Out) type, the Input/Output difference voltage (headroom) will be O.K. and more than likely O.K. with a normal type voltage regulator too, especially if it uses low voltage drop Schottky Diodes for rectification.

 

I have looked at the S12 PSU before, and the only thing against it is the price.
It will do the job very well.

 

The 5Amps Voltage Regulator-Module-Out-1-5-32V-Based-on-LM338 will also do the job, but it will not be particularly low noise.

 

Regards

Alex

Appreciate the evaluation by someone obviously knowing his way around power supplies and regulators.

 

I may opt for the S12 despite its being more expensive.

 

Thanks!

[elan120]

13 minutes ago, sandyk said:

 

 Incidentally, with both types of PCBs, it is also possible to replace the Current Limiter section with an LM317T without any PCB modifications, and just a couple of small components under the PCB.

 I have done this to give 2 separate very low noise +5V supplies for my PC's 2 SSDs from the internal +12V SMPS  . The bottom photo is before heatsinks were fitted. It was made for a local C.A. member.

Click on the images for  larger images

This looks to be a good, simple way to get up to 1.5A.  Thank you.

[lmitche]

33 minutes ago, BigGuy said:

Appreciate the evaluation by someone obviously knowing his way around power supplies and regulators.

 

I may opt for the S12 despite its being more expensive.

 

Thanks!

I have three Sigma 11 based LPSUs here one at 12 volts and two at 19 volts.  They are just fantastic.  You can buy premade sigma 11 regulators at ymb.com. Integration with a case, toroid and iec and dc connectors isn't too bad if you are handy with drilling metal.

[sandyk]

2 hours ago, BigGuy said:

may opt for the S12 despite its being more expensive.

 

 For those that would like to try this PSU :

 

Quote

 It is designed to be
relatively easy to build, but it is not recommended as a first-time project for the beginner.

 

[MikeyFresh]

9 hours ago, Cornan said:

I got right to it and butchered my Gotham Audio GAC-1 Pro Spdif cable

 

A necessary sacrifice, nice job on this!

[Cornan]

1 hour ago, MikeyFresh said:

 

A necessary sacrifice, nice job on this!

 

Thanks MikeyFresh! ?

I was going to change the Gotham out to a QED Signature Audio 40 (butchered), but after hearing how good it sounds I might just make the Gotham as short as possible and be happy.

The sad part is that I'm moving in February next year and we are taking photo's of our appartment on Monday. The estate agent thought that one setup was enough (or rather two setups was one too many), so I'll have to quickly merge the two setups into a clean KISS style speaker/headphone setup and make the A setup corner into a reading corner that is possibly more attractive for potential buyers. Most of the things will have to go into boxes until February. Hopefully I can atleast get it to sound good enough until then. ?

[Solid-State]

7 hours ago, lmitche said:

I have three Sigma 11 based LPSUs here one at 12 volts and two at 19 volts.  They are just fantastic.  You can buy premade sigma 11 regulators at ymb.com. Integration with a case, toroid and iec and dc connectors isn't too bad if you are handy with drilling metal.

https://www.ebay.com/itm/100VA-Ultra-low-Noise-100W-LPS-R-core-Linear-power-supply-DC-5V-24V-With-display/131867485038?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

 

 

[Solid-State]

9 hours ago, sandyk said:

Big Guy

 

With the 12V 50VA transformer you will be dropping around 7.5V , and with a 2A load that's 15W of heat to dissipate !

With a  9V 50VA transformer you will be dropping around 3.6V , and with a 2A load , dissipating around 7W of heat.
 If the regulator is an LDO type ( Low Drop Out) type, the Input/Output difference voltage (headroom) will be O.K. and more than likely O.K. with a normal type voltage regulator too, especially if it uses low voltage drop Schottky Diodes for rectification.

 

I have looked at the S12 PSU before, and the only thing against it is the price.
It will do the job very well.

 

The 5Amps Voltage Regulator-Module-Out-1-5-32V-Based-on-LM338 will also do the job, but it will not be particularly low noise.

 

Regards

Alex

 

"especially if it uses low voltage drop Schottky Diodes for rectification."

 

This one 

 

https://www.hifituning24.de/downloads/STPSC1006D.pdf

or

http://www.st.com/content/ccc/resource/technical/document/datasheet/3d/8a/38/9a/6c/a8/4b/c6/CD00180034.pdf/files/CD00180034.pdf/jcr:content/translations/en.CD00180034.pdf

[Speed Racer]

Is this pretty good?:

 

 

[Solid-State]

10 minutes ago, Speed Racer said:

Is this pretty good?:

 

 

which one

[sandyk]

1 hour ago, TubeMan said:

"especially if it uses low voltage drop Schottky Diodes for rectification."

 

This one 

 

https://www.hifituning24.de/downloads/STPSC1006D.pdf

or

http://www.st.com/content/ccc/resource/technical/document/datasheet/3d/8a/38/9a/6c/a8/4b/c6/CD00180034.pdf/files/CD00180034.pdf/jcr:content/translations/en.CD00180034.pdf

 

Schottky diodes can come in many different forms. The 3A 1N5822 for example looks like any other 3A through hole diode, and has a forward voltage drop of .390V at a forward current of 1A, and .525V at 3Amps.

 Contrast that with a normal 3A diode such as the 1N5404 which has a forward voltage drop of 1.2V at 3 Amps.

 The 2 you provided aren't good examples, as they wouldn't normally be used with a 2A maximum PSU due mainly to their size and cost.

 

[Solid-State]

ok
so any other suggestion

[sandyk]

23 minutes ago, TubeMan said:

ok
so any other suggestion

 In the photo I posted of a 12V 2A + 5V 2A PSU on the previous page,(p.139) the diodes used on the hand made PCBs using a Dalo pen are 3A 1N5822 Schottky diodes, partly due to their availability too, and reduced rubbish going back into the A.C. mains sewer..

 Note that in the attached PSU schematic, which was designed by John Swenson, he is using Schottky Diodes for rectification.

 

Click on the image for a larger image.

[Solid-State]

ok,
but i seeking something that can handle 7Ah

[sandyk]

24 minutes ago, TubeMan said:

ok,
but i seeking something that can handle 7Ah

 

You don't need 7 or 10A rated rectifier diodes with a power supply of 2A maximum, which is what I believe you were looking for ?

 Incidentally, the maximum Instantaneous forward voltage of a 1N5822 at a forward current of 9.4A is specified as 0.950V.

[Solid-State]

 I am building a LPS for my ATX power of motherboards,
for
12v 2Ah
5v 5Ah
3.3v 5Ah

 

feed by
3 st of R-Core trafos

[lmitche]

5 hours ago, TubeMan said:

https://www.ebay.com/itm/100VA-Ultra-low-Noise-100W-LPS-R-core-Linear-power-supply-DC-5V-24V-With-display/131867485038?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

 

 

Yes, this may be good, but it's not using the original sigma 11 board design shown here: https://www.amb.org/audio/sigma11/

[BigGuy]

12 hours ago, lmitche said:

I have three Sigma 11 based LPSUs here one at 12 volts and two at 19 volts.  They are just fantastic.  You can buy premade sigma 11 regulators at ymb.com. Integration with a case, toroid and iec and dc connectors isn't too bad if you are handy with drilling metal.

Good to hear about the Sigma 11 LPS.  BTW, site is <ymbaudio.com>  Would be nice if the S12 was as good. 

 

May I ask what approx did you pay for the Sigmas?

[lmitche]

6 minutes ago, BigGuy said:

Good to hear about the Sigma 11 LPS.  BTW, site is <ymbaudio.com>  Would be nice if the S12 was as good. 

 

May I ask what approx did you pay for the Sigmas?

It wasn't a commercial deal, just a deal between friends, sorry.

 

Yes, my mistake, ymbaudio.com is right.  Amb.org is the diy site for the sigma 11.

 

What's a s12?

[Speedskater]

On 11/11/2017 at 1:04 PM, Cornan said:

 

@Speedskater 

What is your personal opinion of a starquad XLR cable with 6 conductors plus JSSG? This means 2 hot, 2 low and 2 GND plus 2 floating shields with a JSSG loop attached at all 4 shield ends (not connected to the pins). ?

High & low in one floating shield and GND in a separate floating shield.

As a balanced analog interconnect cable?

That would be a poor choice for a cable.

Why?

a] StarQuad is only useful in harsh electrical interference situations (like near theatrical lighting systems).

b] There is no ground wire (or ground for that matter) in a balanced interconnect system. A cable like that would have high Shield Current Induced Noise.

 

If the cable is for some other purpose, then balanced interconnect rules don't apply.

 

* * * * * * * * * * * * * * *

 

For balanced interconnects, stick with a Shielded Twisted Pair (STP) from a major bulk cable manufacturer.

[Cornan]

4 hours ago, Speedskater said:

As a balanced analog interconnect cable?

That would be a poor choice for a cable.

Why?

a] StarQuad is only useful in harsh electrical interference situations (like near theatrical lighting systems).

b] There is no ground wire (or ground for that matter) in a balanced interconnect system. A cable like that would have high Shield Current Induced Noise.

 

If the cable is for some other purpose, then balanced interconnect rules don't apply.

 

* * * * * * * * * * * * * * *

 

For balanced interconnects, stick with a Shielded Twisted Pair (STP) from a major bulk cable manufacturer.

 

Thanks! ?

I will keep my shielded Supra starquad XLRs for my active speakers since they do sound better than my two other STP XLRs. Maybe a starquad XLR with JSSG is not a good idea after all. ?

[Speed Racer]

11 hours ago, TubeMan said:

which one

 

 

 

The bottom line is the measurement threshold of the Audio Precision Analyzer.

The middle line is the VDC noise at idle.

Top line is VDC noise at maximum output.

 

Is that good? How does it compare to linear power supplies you like?

 

 

[sandyk]

10 hours ago, TubeMan said:

 I am building a LPS for my ATX power of motherboards,
for
12v 2Ah
5v 5Ah
3.3v 5Ah

 

feed by
3 st of R-Core trafos

 

The Cree C3D06060A would work well there if you are using a Bridge Rectifier. I use them in my Class A Amplifier, and as another DIYer reported, they do sound better than normal Schottky Diodes.

CREE C3D06060A.pdf

[ted_b]

What have folks found as the best way to stabilize these LT3045 setups, especially when in series and/or have dc adapters hanging off them?  I have found more than once having these unprotected in the pc case or even hanging off power supplies they can come undone, even though I have been somewhat diligent with tightening down the screw terminals, etc.

 

 

Discussing with a few others I'm thinking bare PCB boards underneath, hot glued or something? 

[BigGuy]

8 minutes ago, ted_b said:

What have folks found as the best way to stabilize these LT3045 setups, especially when in series and/or have dc adapters hanging off them?  I have found more than once having these unprotected in the pc case or even hanging off power supplies they can come undone, even though I have been somewhat diligent with tightening down the screw terminals, etc.

 

 

Discussing with a few others I'm thinking bare PCB boards underneath, hot glued or something? 

Assembling this without the regulator board I used 3/1 shrink tubing to stabilize back to back barrel connectors.  Not sure if the 3045 needs to be ventilated but you might be able to use shrink tubing on either side to cover the screw block and part of the board which would allow deconstruction as necessary.  You could even buy GREEN shrink like I did for the JSSGs.