Precision PS - 100% Radial Caps ?

[ToneMerc]

Anyone used all radial caps in the precision power supply? What's the negative effect if any of using radial caps instead of the two larger axials at the first node?

TM

[martin manning]

You are probably still going to need to use two in series with balancing resistors to get the voltage rating requirement down. A quick look at the dimensions of 220uF, 300+ volt units shows that they are about 50mm (2") tall and 25mm (1") in diameter, so unless you have an unusually deep chassis you'll have to lay them down and then secure them to the board with silicone adhesive. Other than that, I see no reason why you couldn't use them.

MPM

[glasman]

Anyone used all radial caps in the precision power supply? What's the negative effect if any of using radial caps instead of the two larger axials at the first node?

TM

I have been using radials in that position for a couple of years. I think they sound pretty good. I think Andy Fuchs as uses radials in that position. These days I think the you have a better selection of caps in radial varieties than are available in axial, but that is OMO.

The picture below shows a Glaswerks using radials on the power supply board.

Gary

[martin manning]

Nice compact all-in-one PS board! First filter is 4x120uF (?) radials, with two paralleled pairs in series?

MPM

[glasman]

Nice compact all-in-one PS board! First filter is 4x120uF (?) radials, with two paralleled pairs in series?

MPM

4x100uf. 350v

[talbany]

I gave them a shot on a couple prototype transition amps making the switch over to PCB...To me it gave the amp a kind of sterile feel and stiffer/faster attack than the larger radials.... I tried 4 @ 100 350 on 3 prototypes...I don't personally care for them on the plates and screens but think they are fine for the preamp.. IMHO... Just to use to the bigger radials I guess..


Tony

[BobW]

Nice compact all-in-one PS board! First filter is 4x120uF (?) radials, with two paralleled pairs in series?

MPM

4x100uf. 350v

Gary, are they Nichicons?

[glasman]

Nice compact all-in-one PS board! First filter is 4x120uF (?) radials, with two paralleled pairs in series?

MPM

4x100uf. 350v

Gary, are they Nichicons?

They are Xicon XRL series. I use Nichicons in a couple of other products.

Gary

[Colossal]

They are Xicon XRL series. I use Nichicons in a couple of other products.

Beautiful amp Gary. If you don't mind my asking, what values do you use for your balancing/bleeder resistors?

Thanks.

[Structo]

Look like they may be 270K.

[glasman]

Look like they may be 270K.

They are 270K in that amp. I use various values on what I am looking for in the amp.

[ToneMerc]

Thanks guys, radials it is then.

TM

[Colossal]

Look like they may be 270K.

They are 270K in that amp. I use various values on what I am looking for in the amp.

Thanks Gary.

[mlp-mx6]

They are 270K in that amp. I use various values on what I am looking for in the amp.

Gary,
Can you describe the impact that the different bleeder values make in the amp?

Thanks,
Michael

[glasman]

They are 270K in that amp. I use various values on what I am looking for in the amp.

Gary,
Can you describe the impact that the different bleeder values make in the amp?

Thanks,
Michael

The bleeders have an effect on the touch of the amp. The classic rule of thumb in power supply design is 1K resistance per volt of supply (ie 440K for a 440V supply). Going smaller helps to regulate the supply a bit better and makes it tighter and going larger (say 470K for each balancing resistor) will loosen up the supply regulation and add some squish to the touch of the amp.

Let your ears decide.

Gary