Re: 8 Channel, 3U NEVE 1073 completed
« Reply #2180 on: March 16, 2017, 05:25:38 PM »
I notice the PCBs for this build are currently out of stock. Anyone have an idea when they might be selling more?


TillM

Re: 8 Channel, 3U NEVE 1073 completed
« Reply #2181 on: March 17, 2017, 07:51:29 AM »
That was fast :D
I get an E-Mail a week ago, that they back in stock.
Holy cow ... i'm sure that in the next weeks new PCBs will arrive.

Re: 8 Channel, 3U NEVE 1073 completed
« Reply #2182 on: April 03, 2017, 12:55:11 PM »
So I've been thinking about the best way to efficiently power my 8 channel 1290 preamps and right now I'm thinking about buying one of these switching mode power supplies (http://www.ebay.com/itm/292065772914), then adding some linear voltage regulators to bring it down to 24VDC and decoupling capacitors to reduce the ripple in the ouput voltage. Has anyone tried using this type of power supply? Are there any other problems or drawbacks that I should be aware of?
« Last Edit: April 03, 2017, 02:07:16 PM by mattmartin831 »

useme2305

Re: 8 Channel, 3U NEVE 1073 completed
« Reply #2183 on: April 03, 2017, 04:31:20 PM »
what do you mean " bring it down to 24VDC"?  it's already 24VDC as far as i can see.

i'm using a 48VDC switching power supply in conjunction with a JLM TREX (little PCB that puts out 24VDC from an 48VDC input) for my two channel unit. works fine and sounds great!

in an 8 channel unit this would mean ALOT of heat though! i don't think it's possible without alot of venting and at least one fan.

Re: 8 Channel, 3U NEVE 1073 completed
« Reply #2184 on: April 03, 2017, 04:42:03 PM »
what do you mean " bring it down to 24VDC"?  it's already 24VDC as far as i can see.

i'm using a 48VDC switching power supply in conjunction with a JLM TREX (little PCB that puts out 24VDC from an 48VDC input) for my two channel unit. works fine and sounds great!

in an 8 channel unit this would mean ALOT of heat though! i don't think it's possible without alot of venting and at least one fan.

The power supply I ordered has 28VDC output with up to 5A of current with around 120mV of ripple. I would think most the heat in your situation comes from  the 48V to 24V voltage drop across the linear regulators, so since I will only be dropping 4VDC across them, and I also plan to limit the current going across each regullator to about 500mA, hopefully that will minimize the heat coming off of them.

useme2305

Re: 8 Channel, 3U NEVE 1073 completed
« Reply #2185 on: April 03, 2017, 05:20:56 PM »
my bad. i thought you wanted to use a 48VDC PSU and i didn't see that the one you wanna buy has 28VDC but i instead read 24VDC and thought you probably wanna go the 48V to 24V route.

EDIT:
why didn't you just go with a 24VDC external PSU? why the hassle of regulating the 28VDC to 24VDC?
« Last Edit: April 03, 2017, 05:27:58 PM by useme2305 »

Re: 8 Channel, 3U NEVE 1073 completed
« Reply #2186 on: April 03, 2017, 05:28:55 PM »
my bad. i thought you wanted to use a 48VDC PSU and i didn't see that the one you wanna buy has 28VDC but i instead read 24VDC and thought you probably wanna go the 48V to 24V route.

No problem man, I'm glad to hear from someone who has made it work. Makes me feel more confident in my plan, so thanks!

EDIT: I chose the 28V psu because I realize there is a lot of ripple voltage coming out of the switching mode power supply. I wanted to minimize this ripple voltage so I decided to use LM317's to regulate the voltage and turn the expected 120mV of ripple into something in the scale of micro or nanovolts.
« Last Edit: April 11, 2017, 06:40:30 PM by mattmartin831 »

Re: 8 Channel, 3U NEVE 1073 completed
« Reply #2187 on: April 19, 2017, 08:41:59 AM »
Hey Guys, maybe someone can help:

can I use 630Volt Polystyrenes instead of 50Volt?

Thanks.

Whoops

Re: 8 Channel, 3U NEVE 1073 completed
« Reply #2188 on: April 19, 2017, 08:46:50 AM »
Hey Guys, maybe someone can help:

can I use 630Volt Polystyrenes instead of 50Volt?

Thanks.

Yes, it just means the capacitor can whitstand an higher voltage without burning.

But it would be bigger, might not fit the pcb and it will be much more expensive also

« Last Edit: April 19, 2017, 03:48:05 PM by Whoops »

Re: 8 Channel, 3U NEVE 1073 completed
« Reply #2189 on: April 19, 2017, 08:48:53 AM »
Thanks Whoops!


Whoops

Re: 8 Channel, 3U NEVE 1073 completed
« Reply #2190 on: April 19, 2017, 03:48:52 PM »
Hey Guys, maybe someone can help:

can I use 630Volt Polystyrenes instead of 50Volt?

Thanks.

why do you want to use 630v caps?

Where are you located?

Re: 8 Channel, 3U NEVE 1073 completed
« Reply #2191 on: April 21, 2017, 04:29:32 AM »
why do you want to use 630v caps?

Where are you located?

Have some laying around here.
Just ordered a bunch at Banzai.  8)


PS: I'm from Bremen

Whoops

Re: 8 Channel, 3U NEVE 1073 completed
« Reply #2192 on: April 21, 2017, 08:35:15 AM »
Have some laying around here.
Just ordered a bunch at Banzai.  8)


PS: I'm from Bremen

Banzai, Farnel and Mouser
all of them have those

I think Mouser is cheaper