GroupDIY

General Discussions => Drawing Board => Topic started by: mrclunk on May 30, 2008, 06:09:36 AM

Title: 1.4V from 30v rail on 1176 PSU (Stereo link 1176SA)
Post by: mrclunk on May 30, 2008, 06:09:36 AM
Hi,
 i'm stereo linking a couple of Urei Model 1A's (basically 1176 rev F circuit)
I've built into one of them the 1176SA stereo adapter circuit but its needs a 1.4v battery for ref voltage.
I'm assuming as the battery expires the units will drift out of alignment so i'd like a regulated supply instead.
going to try a simple LM317 circuit hanging off the +30V PSU rail.

Will this do anything weird to the rest of the circuit?

Or would i be better of matching the fets between units and not bothering with the 1176SA approach.
regards
paul
Title: 1.4V from 30v rail on 1176 PSU (Stereo link 1176SA)
Post by: gyraf on May 30, 2008, 09:16:56 AM
You can't use any voltage referenced to local ground - the whole circuit after the FD300 diodes are hanging "floating" at a trimmed FET-offset-voltage. (look closely at the schematic..!)

Don't worry about battery life - current drawn is close to zero.

Jakob E.
Title: 1.4V from 30v rail on 1176 PSU (Stereo link 1176SA)
Post by: ioaudio on May 30, 2008, 11:07:55 PM
you could use a small 1,4v solar cell powered by leds.
Title: 1.4V from 30v rail on 1176 PSU (Stereo link 1176SA)
Post by: mrclunk on May 31, 2008, 08:08:16 AM
ah ok, i'm being a prat!
I'll just screw an AA battery holder to the back an be done with it.

solar cell ideas cool though!