Tube DIY Asylum

Do It Yourself (DIY) paradise for tube and SET project builders.

Return to Tube DIY Asylum

Message Sort: Post Order or Asylum Reverse Threaded

Powering on a PS without a load. .

184.99.186.144
Posted on December 11, 2014 at 11:39:05
John PA
Audiophile

Posts: 4019
Location: The lower 48.
Joined: August 27, 2000
 I have a few power supplies that I have used in the past for my preamp (yes a few, I bought an extra, a friend gave me one as he took the Full Preamp apart and made the same amp but in point to point and I got another one from somewhere). They came from the Quicksilver Audio Full preamp. Very nice ps's they are. Fully regulated with two voltage outputs of 560 and 720 volts that are obviously knocked down to the working voltage on the main circuit.

Being that they are regulated, do they need a load to be powered up to check voltages and working condition? I once asked Mike this and he said he thought they should have a load but wasn't sure. Since they are regulated to a set voltage out, it would seem to me they don't need a load but what do you think?

I put this in the tube DIY because this is a dual 6X4 rectified ps.



iBasso DX300MAX Ti. Focal Utopia and Stellia. iBasso SR2. Mr. Speakers, Ether II, Voce stats. Manley, Absolute headphone amp. LTA MZ3, Z10e electrostatic amp. Many other headphones, amps, cables etc.

 

Hide full thread outline!
    ...
RE: Powering on a PS without a load. . , posted on December 11, 2014 at 12:56:09
Tre'
Industry Professional

Posts: 17293
Location: So. Cal.
Joined: February 9, 2002
 "Fully regulated with two voltage outputs of 560 and 720 volts that are obviously knocked down to the working voltage on the main circuit. "

If they are truly fully regulated then they do not need an external load. They have a load, the regulator is a load.*

I have to point out that it makes no sense (to me) to fully regulate a PS and then "knock down" the voltage. That leaves your circuit operating with a non-regulated PS voltage.

*To me "Fully regulated" means that the voltage will stay constant (within reason) from no load to 2X idle current load.

Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"

 

RE: Powering on a PS without a load. . , posted on December 11, 2014 at 13:14:45
JKT
Audiophile

Posts: 612
Location: Midwest
Joined: November 26, 2002
 That will depend on the design of the supply. The current source fed shunt reg. that I use would fail run no load as the shunt device is not heat sinked to dissipate all the current under no load conditions. You can use a resistor to load the supply. A 10W wirewound should safely dissipate 10mA @600V. So 60K would be a good value. These are just ballpark numbers.


"It is better to remain silent and thought a fool, then speak and remove all doubt." A. Lincoln

 

I understand but that is how the ps is built. . , posted on December 11, 2014 at 14:56:07
John PA
Audiophile

Posts: 4019
Location: The lower 48.
Joined: August 27, 2000
 and if you have a resistor in the network after the regulation, then depending upon the current draw, the voltage could change. Seems to work well though and I would have to float a 12AX7 pretty high to use 720 volts. :^)


iBasso DX300MAX Ti. Focal Utopia and Stellia. iBasso SR2. Mr. Speakers, Ether II, Voce stats. Manley, Absolute headphone amp. LTA MZ3, Z10e electrostatic amp. Many other headphones, amps, cables etc.

 

RE: Powering on a PS without a load. . , posted on December 11, 2014 at 15:30:02
Caucasian Blackplate
Industry Professional

Posts: 8313
Location: Seattle
Joined: June 18, 2004
 I would agree with this. A regulated supply may be counting on a load to ease the thermal load on the regulator.

If you have a tube rectified regulated power supply, the rectifier tube may be giving the rest of the circuit time to warm up and draw current as the high voltage rail comes up. Otherwise, there's the chance that parts in the regulated supply can take some thermal stress at turn-on, but then cool off and run happily when everything is warmed up. (Even the lowly 0D3 has notes about this)

If these are external supplies, with umbilical, it's possible that protections are built into the cabling interface to prevent abuse.

If these supplies are tube series regulators, you should be OK.

 

RE: Powering on a PS without a load. . , posted on December 11, 2014 at 17:10:28
Tre'
Industry Professional

Posts: 17293
Location: So. Cal.
Joined: February 9, 2002
 I think I was putting to much "faith" in the word "Fully".

My CCS feed, shunt VR tube regulated supplies (one for the preamp and one for the driver stages of the power amp) will stand up to a no load condition.

I'm not saying I'm right, but I somehow expected a commercial regulated PS to do that.

Your points show that I could very well be wrong in my expectations.

Thanks.

Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"

 

RE: Powering on a PS without a load. . , posted on December 11, 2014 at 17:33:11
Caucasian Blackplate
Industry Professional

Posts: 8313
Location: Seattle
Joined: June 18, 2004
 Yeah, the 0D3 can do 100ma for a warmup period. If you assume a DHT power amp is being regulated, warmup could be quick!

I think a lot of commercial high voltage regs are OK with no load, since sometimes people forget to put the tubes in.

 

This is dual regulated and . . , posted on December 11, 2014 at 19:46:01
John PA
Audiophile

Posts: 4019
Location: The lower 48.
Joined: August 27, 2000
 the 6X4's are in series but even with a load, they never lasted a long time and would arc something known about the preamp and Mike later went to 5AR4 but it doesn't sound as good as the 6X4 model. I tried resistors to slow the surge and draw on the rectifiers and it helped some. I have over 100 NOS 6x4's now, most likely more, so I am well supplied but I want to get my preamp running again, after being stored for 10 years. The front end tubes are battery biased and for some reason I left them in. Nope, they aren't in too good of condition but they didn't hurt anything. .

The Full Function preamp did not have an umbilical. for my preamp I have a 5 foot umbilical and the power supplies sit in a beautiful rosewood base.




iBasso DX300MAX Ti. Focal Utopia and Stellia. iBasso SR2. Mr. Speakers, Ether II, Voce stats. Manley, Absolute headphone amp. LTA MZ3, Z10e electrostatic amp. Many other headphones, amps, cables etc.

 

Thank you for your input . . , posted on December 12, 2014 at 07:30:23
John PA
Audiophile

Posts: 4019
Location: The lower 48.
Joined: August 27, 2000
 I can always put a resistor in as a load and then test the supplies.


iBasso DX300MAX Ti. Focal Utopia and Stellia. iBasso SR2. Mr. Speakers, Ether II, Voce stats. Manley, Absolute headphone amp. LTA MZ3, Z10e electrostatic amp. Many other headphones, amps, cables etc.

 

Page processed in 0.019 seconds.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]