huangyong 0 Report post Posted May 25, 2005 Due to the heat problem that the gilmore has, i decided to take it out and send bakc to digi01 to see what can be done. In the meantime, having cash shortage troubles, so thought of this idea to use the casing of the current gilmore and make brand new PSU and amp and sell.. hope to get some $$ for my travel. Here's it, the XP-7 wanna be amp. Birdee View PSU The amp UpSkirt Face Body Butt Share this post Link to post Share on other sites
huangyong 0 Report post Posted May 25, 2005 The amp is using opamp + buffer simple design, specialy tweaked for midrange, using low value resisotr to bring down noise level as much as possible. The PSU is a bit special, using 78/7915 with a opamp for feedback, some source claims that it is as good as battery, so just try out. Overall sounds detailed, good midrange, very good 3D positioning, good soundstage, but not very powerful (of coz not as powerful as gilmore ). Overall, for that simple design, the amp is perfectly good. if interested, see u in classified. Share this post Link to post Share on other sites
jasonhanjk 0 Report post Posted May 25, 2005 Using opamp to feedback the regulators may or may not improve the regulation until further test are perform. If the opamp PSSR sucks than you are in trouble. What I've seen on the web is they put an 18V regulator follow by another 15V regulator. Theoratically you can get -160dB if each regulator gives -80dB. Share this post Link to post Share on other sites
bpribadi 0 Report post Posted May 26, 2005 Good luck! Happy backpacking! Share this post Link to post Share on other sites
huangyong 0 Report post Posted May 26, 2005 jasonhanjk, i've tried the 2 stage regulation you said in my previous preamp for my dad, sounds good, but it will get hot for the first stage regulator. Share this post Link to post Share on other sites
bpribadi 0 Report post Posted May 26, 2005 but it will get hot for the first stage regulator. Don't supply too high voltage. 3 volts higher is enough. If your first stage is 18V, give it's input around 21-22V (rectified 16 volts AC from the transformer secondary). Share this post Link to post Share on other sites
jasonhanjk 0 Report post Posted May 26, 2005 Or you may want to try RC-RC configuration. A 1 ohm resistor follow by 10,000uF cap then another 1 ohm resistor then another 10,000uF cap then your regulator. Super regulation... A -40dB per octave low pass filter @ 16Hz. Share this post Link to post Share on other sites
huangyong 0 Report post Posted May 30, 2005 Bram, what i supply is just 15-0-15 tranny to feed a 15V regulator, then follwed by 12V, should be ok, may be ,my heatsink too small. Share this post Link to post Share on other sites
huangyong 0 Report post Posted May 30, 2005 Using opamp to feedback the regulators may or may not improve the regulation until further test are perform. If the opamp PSSR sucks than you are in trouble. jason, the PSSR of a NE5332 should be better than the opamp in the regulator itself. Share this post Link to post Share on other sites
