AND everyone....keep on mind, the current draw is tiny for phantom!!!! Run the numbers.....worst case would be XLR pins 1 shorted to 2 to 3.
With 6k8 resistors, that means 3k4 Ohms across a 48V supply, or 48/3400 which would be approx 14 mA! Bottom line from my "racking up world" is that the SMALLEST "Power One" 48V linear module (0.5A rating) can "juice" approx 35 DEAD SHORT Circuits hehhe....and a normal mic has to pull less than a dead-short. The deal that bugs me (and others....) with the "stock" JLM design is that the specified "3-legged 317" part is NOT fully "bullet proof" on a 48V rail. If YOU NEVER MAKE A MISTAKE with internal wiring, perhaps the 6k8 "phantom" resistors might avoid a failure/breakdown of the "stock" LM-317. Shrug...I never assume anything...and hence would select any of the "higher voltage" parts. Pennies difference.... For eons...I have been using 35V or 50V parts that "hang" across 15 or 18 rails...hence a TL783 or a LM-317HV in this 48V instance. Bri ---- Brian Gibson <[email protected]> wrote: > Hi, > > I think the voltage regulator number you are trying to remember is TL783. > > Max input voltage up to 150V and output 125V max. at 700mA > > Regards, > Brian G. > ----- Original Message ----- > From: eliya gwetta > To: [email protected] > Sent: Saturday, July 04, 2009 10:37 PM > Subject: Re: NEOTEK: Power for Series IIIc Pre's > > > Hi Matt, > > Yes! I remembered the LM317 not being the right regulator for 48V, a TL583 > would be a drop in replacement or I would have to change other components in > the circuit as well? > > > On Sat, Jul 4, 2009 at 9:25 PM, Matt Syson <[email protected]> > wrote: > > Hi > The JLM circuits are pretty much what you need so you could either 'copy' > the circuit and build it yourself or buy the kit. > I am not too impressed at using a LM317 for the phantom 48 rail, they are > only rated to 39 or 40 volt DIFFERENTIAL (input pin to output pin) , meaning > that if you short the output you stand a good chance of 'blowing it up'. I > presume the 47 Ohm resistor is a lame way of trying not to 'kill' it, hardly > a good engineering solution. > You should substitute it for a TL583 (sorry this number won't come to me, > but there is a similarly packaged regulator that handles 125 Volts). > Matt S > > > Donald Put wrote: > > If you're up to making your own, there are numerous PCBs/kits available > for this type of project. They're set up for dual voltages and 48VDC for the > phantom power. Check out JLM's offerings on his website: > > http://www.jlmaudio.com/JLM%20Power%20Supply.htm > > Cheers, > -- > Don > > > ------ > > View the list online at: http://www.mail-archive.com/[email protected] > > You can unsubscribe at anytime by sending an email to > mailto:[email protected] with "unsubscribe neotek" in the message body. > If you have any difficulties, or questions --please send an email to > mailto:[email protected]. > > The Neotek list is lovingly hosted by Catapult Web. Remember that any > message or reply sent to the list will be automatically forwarded to all > subscribers. > > Vive Le Neotek! > > Thanks. > > > > > > __________ Information from ESET NOD32 Antivirus, version of virus signature > database 4219 (20090705) __________ > > The message was checked by ESET NOD32 Antivirus. > > http://www.eset.com > ------ View the list online at: http://www.mail-archive.com/[email protected] You can unsubscribe at anytime by sending an email to mailto:[email protected] with "unsubscribe neotek" in the message body. If you have any difficulties, or questions --please send an email to mailto:[email protected]. The Neotek list is lovingly hosted by Catapult Web. Remember that any message or reply sent to the list will be automatically forwarded to all subscribers. Vive Le Neotek! Thanks.
