goldenreference low voltage power supply

[wink]

If you used smaller electrons, you wouldn't need such a wide insulation gap.      

[johnwmclean]

8 minutes ago, wink said:

If you used smaller electrons, you wouldn't need such a wide insulation gap.      

Yes but you need bigger electrons to let moar basses through.

[JimL]

I remember years ago when Monster cable was promoting their original multi strand interconnect with thick wires for the bass and thin ones for the treble, Frank van Alstine was speaking to a Monster rep and suggested an experiment where he would take the small wires from the interconnect, solder them to an AC plug and have the rep hold on to the wires while he plugged it in.  Much to his surprise, the rep declined.

[G600]

I have just completed a pair of split GRLV for the Grounded Grind.

Powered by 25 VAC secondaries.

I used 750V resistor for +- 15V, instead of the 1.5k for +-20V.

But I'm getting +-20V, so where am I wrong ? Only one 1.5k resistor has to be changed ?

Edited March 2, 2017 by G600

[johnwmclean]

R8 and R9 from memory have to be 750ohm.

[Pars]

Yes, you only change one of the two resistors.
((R8+R7)/R7) x Vref
((750 + 1500)/1500) x 10 = 15


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[G600]

Briliant, thanks !

[Pars]

I know the thread is 15 pages, but this info is in here multiple times.


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[Mirko]

Hi guys, just built the GRLV plus version but I have encountered some problems.

It is configured R8=860R, R7=1500R which would give me roughly 15,4V. But here is the problem VAC is 16 and im getting 17.8V DC..

Red led D1 is not lit but D9 is. Checked the leds and transistors, everything seems to be working.

[MLA]

So, I would start with reflowing all solder joints and also double check that your R8 actually is 860R. Pic of the board would help trouble shooting.

Edited March 5, 2017 by MLA

[wink]

On 28/02/2017 at 4:20 PM, johnwmclean said:

Yes but you need bigger electrons to let moar basses through.

With the bigger electrons you don't get the same volume of sub-bass.......  

[Craig Sawyers]

On 2/28/2017 at 5:20 AM, johnwmclean said:

Yes but you need bigger electrons to let moar basses through.

Go for muons instead. 200 times heavier than electrons. They only live for a couple of microseconds for an added sense of speed 

[Mirko]

3 hours ago, MLA said:

So, I would start with reflowing all solder joints and also double check that your R8 actually is 860R. Pic of the board would help trouble shooting.

My bad the R8 is 820R and not 860R, as I did not have 750R at hand for the desired 15V. Checked the solder joints and everything seems fine.

[Pars]

That sounds similar to a problem I had with one of mine (2 pages back in this thread) when I brought it up on a variac. D1 was lit, but D9 not. Input voltage was too low and the opamp was locking up. Is your transformer actually putting out 16Vac? That should be plenty for a 15Vdc output.

 

Edited March 5, 2017 by Pars

[wink]

15 hours ago, Craig Sawyers said:

Go for muons instead. 200 times heavier than electrons. They only live for a couple of microseconds for an added sense of speed 

I had considered neutrinos.   They give the ultimate in sound transparency.       

 

But, being vitrually massless, bass reproduction suffers considerably.......   

[JimL]

7 hours ago, wink said:

But, being massless, bass reproduction suffers considerably.......   

FIFY.  Being massless, they are the ultimate in speed.

[wink]

Jim,

http://www.pbs.org/newshour/rundown/what-is-a-neutrino-and-why-should-anyone-but-a-particle-physicist-care/

Particle physicists originally believed that neutrinos were massless. But in the 1990s, a team of Japanese scientists discovered that they actually have a smidgen of mass. This tiny bit of mass may explain why the universe is made up of matter, not antimatter.

 

http://hyperphysics.phy-astr.gsu.edu/hbase/Particles/neutrino.html

This elusive particle, with no charge and almost no mass,

 

https://en.wikipedia.org/wiki/Neutrino

The neutrino is so named because it is electrically neutral and because its rest mass is so small (-ino) that it was originally thought to be zero.

Mass	≤ 0.120 eV/c2 (95% confidence level, sum of 3 flavors)[1]

 

http://particleadventure.org/neutrinos.html

Because neutrinos were produced in great abundance in the early universe and rarely interact with matter, there are a lot of them in the Universe. Their tiny mass but huge numbers may contribute to total mass of the universe and affect its expansion.

 

There are about 100,000 of them passing through every square centimeter of the earth every second.

If you had a bar of lead 1 light year long and fired 2 neutrinos down the centre, one would pass through and the other would have a 50% chance of passing through.

 

Hope this helps...... 

 

btw, just recently some scientists believe that they have discovered a fourth flavour of neutrino.

https://www.sciencedaily.com/releases/2010/11/101102185722.htm

[Skooby]

Fascinated neutrino facts!  Just wonder, due to their abundance, would their mass's enough to account for the universe "missing" mass without the need of "dark matter"?

Sorry for hijacking the thread...we need a general thread on physics.  

[sorenb]

17 hours ago, Skooby said:

..we need a general thread on physics.  

more like a psychiatrist and pharmacist it seems

[JimL]

On March 6, 2017 at 9:24 PM, wink said:

Jim,

http://www.pbs.org/newshour/rundown/what-is-a-neutrino-and-why-should-anyone-but-a-particle-physicist-care/

Particle physicists originally believed that neutrinos were massless. But in the 1990s, a team of Japanese scientists discovered that they actually have a smidgen of mass. This tiny bit of mass may explain why the universe is made up of matter, not antimatter.

 

http://hyperphysics.phy-astr.gsu.edu/hbase/Particles/neutrino.html

This elusive particle, with no charge and almost no mass,

 

https://en.wikipedia.org/wiki/Neutrino

The neutrino is so named because it is electrically neutral and because its rest mass is so small (-ino) that it was originally thought to be zero.

Mass	≤ 0.120 eV/c2 (95% confidence level, sum of 3 flavors)[1]

 

http://particleadventure.org/neutrinos.html

Because neutrinos were produced in great abundance in the early universe and rarely interact with matter, there are a lot of them in the Universe. Their tiny mass but huge numbers may contribute to total mass of the universe and affect its expansion.

 

There are about 100,000 of them passing through every square centimeter of the earth every second.

If you had a bar of lead 1 light year long and fired 2 neutrinos down the centre, one would pass through and the other would have a 50% chance of passing through.

 

Hope this helps...... 

 

btw, just recently some scientists believe that they have discovered a fourth flavour of neutrino.

https://www.sciencedaily.com/releases/2010/11/101102185722.htm

Interesting.  Last time I studied physics was in the 1970s.

[wink]

Physics has been an ongoing passion/affliction of mine for as long as I can remember........

[Kerry]

Just got the boards back for the GR78/9xx boards.  They look good.  I'm hoping to have them built up next weekend.

[cspirou]

Very nice! I assume it would work with the Dynalo Mini in place of the TPS7Axxxx regulators?

[Kerry]

They should, though the spacing is for a T0-247 and not a T0-220, so you'd have to just be careful mounting them.

[Pars]

I'm curious why the BOMs I see show Elna Silmic caps for the 220uf caps on the PSU? Usually audio grade caps are spec'd for coupling caps (Pass seems to like them), but for a PSU? Some reason that I am missing? I used Pana FM/FR for the ones I built.

 

 

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