+24V rail, Zen or DoZ or ???

azira · 9th January 2004, 11:54 PM

I found a brand new complete PS for cheap so I decided buy it now project later. It's output is 24V, 10Amp unregulated. It only has a 4700uF cap in it for filtering so I think I will probably parallel it with at least that amount.
I want to turn it into a pretty simple amp project. At 2-channels with ~5amps/channel and 8-ohms, I could get up to just under 10-watts with a Class-A something or other per channel.
Simple like Zen, or DoZ... What would be good for this PS?
--
Danny

GRollins · 10th January 2004, 02:04 AM

The question becomes whether that 10A is available continuously. It'd be a shame to roast the power supply if it can't keep it up 24/7; a class A amp is a brutal load.
Zens take, what, 3A or so per channel? I don't remember offhand, and it's been quite some time since I looked at the DOZ schematic. At any rate, 6A (for two channels) would hopefully be doable for a 10A supply. If you feel that the 10A is a trustworthy rating, then you could boost the bias.
Yes, I'd consider increasing the capacitance on the power supply, but don't put on so much that the inrush pops something in the supply. You'll have to look over the supply and see how well it's built. With luck, it'll take a couple of Farads and laugh...

Grey

azira · 10th January 2004, 04:04 AM

It's heavy

http://www.acopian.com/single-u-goldbox-24to42vt.html

It's an Acopian U24Y1000, it's listed at $135 on their website and I got it for $25. Pristine condition...

The website says at full load, the expected output voltage can be down by 10%. I think it'll handle the 6A, I don't think I'll bias it up any. I'd still have to adjust some of the Zen components to set the bias right.
--
danny

GRollins · 10th January 2004, 02:13 PM

Sounds like a plan. Give it a shot. At worst, you can always reduce the bias if the supply looks as though it's collapsing.

Grey

EDIT: Might not hurt to do a Pi filter on the power supply, as in:
Power supply->cap->inductor->cap
The ripple in the specs looks a bit on the heavy side and that will help tame it.

Kashmire · 11th January 2004, 12:02 AM

Note that there is a thread specially discussing an amplifier design using low voltage power supplies. A +24 volt power supply would be perfect!

Choke Loads for Zen/Aleph Amps

Nelson Pass · 11th January 2004, 06:25 PM

Arrrr, a small matter to build both power amps, simple they be
sez I, and report back to your mates.

azira · 15th January 2004, 11:32 PM

Ok. So I'll start with the Zen.

What kinds of considerations will I need to take into account for running a Zen at a lower rail?

I was thinking that I will need to adjust some parts to maintain the bias, but since I won't be able to output as much power, maybe I won't need to maintain the bias current.

There is a variable resistor to adjust the base voltage so I don't think I'll need to adjust that area too much.

Perhaps I just get the parts and ... build it ...

9th January 2004, 11:54 PM	#1
azira diyAudio Member Join Date: Dec 2003 Location: Near Seattle	+24V rail, Zen or DoZ or ??? I found a brand new complete PS for cheap so I decided buy it now project later. It's output is 24V, 10Amp unregulated. It only has a 4700uF cap in it for filtering so I think I will probably parallel it with at least that amount. I want to turn it into a pretty simple amp project. At 2-channels with ~5amps/channel and 8-ohms, I could get up to just under 10-watts with a Class-A something or other per channel. Simple like Zen, or DoZ... What would be good for this PS? -- Danny

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Suggested AWG for 6.3V tube heaters rail and 250V B+ rail	eranrund	Parts	0	3rd November 2008 07:30 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

10th January 2004, 02:04 AM	#2
GRollins diyAudio Member Join Date: Feb 2001 Location: Columbia, SC	The question becomes whether that 10A is available continuously. It'd be a shame to roast the power supply if it can't keep it up 24/7; a class A amp is a brutal load. Zens take, what, 3A or so per channel? I don't remember offhand, and it's been quite some time since I looked at the DOZ schematic. At any rate, 6A (for two channels) would hopefully be doable for a 10A supply. If you feel that the 10A is a trustworthy rating, then you could boost the bias. Yes, I'd consider increasing the capacitance on the power supply, but don't put on so much that the inrush pops something in the supply. You'll have to look over the supply and see how well it's built. With luck, it'll take a couple of Farads and laugh... Grey

10th January 2004, 04:04 AM	#3
azira diyAudio Member Join Date: Dec 2003 Location: Near Seattle	It's heavy http://www.acopian.com/single-u-goldbox-24to42vt.html It's an Acopian U24Y1000, it's listed at $135 on their website and I got it for $25. Pristine condition... The website says at full load, the expected output voltage can be down by 10%. I think it'll handle the 6A, I don't think I'll bias it up any. I'd still have to adjust some of the Zen components to set the bias right. -- danny

10th January 2004, 02:13 PM	#4
GRollins diyAudio Member Join Date: Feb 2001 Location: Columbia, SC	Sounds like a plan. Give it a shot. At worst, you can always reduce the bias if the supply looks as though it's collapsing. Grey EDIT: Might not hurt to do a Pi filter on the power supply, as in: Power supply->cap->inductor->cap The ripple in the specs looks a bit on the heavy side and that will help tame it.

11th January 2004, 12:02 AM	#5
Kashmire diyAudio Member Join Date: Dec 2003 Location: Midwest	Note that there is a thread specially discussing an amplifier design using low voltage power supplies. A +24 volt power supply would be perfect! Choke Loads for Zen/Aleph Amps

11th January 2004, 06:25 PM	#6
Nelson Pass The one and only Join Date: Mar 2001	Arrrr, a small matter to build both power amps, simple they be sez I, and report back to your mates.

15th January 2004, 11:32 PM	#7
azira diyAudio Member Join Date: Dec 2003 Location: Near Seattle	Ok. So I'll start with the Zen. What kinds of considerations will I need to take into account for running a Zen at a lower rail? I was thinking that I will need to adjust some parts to maintain the bias, but since I won't be able to output as much power, maybe I won't need to maintain the bias current. There is a variable resistor to adjust the base voltage so I don't think I'll need to adjust that area too much. Perhaps I just get the parts and ... build it ...

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)