Speaker Asylum General speaker questions for audio and home theater.

---

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ Speaker Asylum ]

---

[ Alert Moderator ]

---

RE: Dahlquist DQ-LP1 troubleshooting

Posted by Jeff Davison (A) on January 28, 2008 at 08:34:22

In Reply to: Dahlquist DQ-LP1 troubleshooting posted by SAILLOCO on January 27, 2008 at 10:26:24:

try the process of elimination...
first, swap the left and right interconnect. If the dead channel moves over, then it's the cable,

It could be as someone else mentioned a bad or broken solder joint... those pc board mounted female rca's over the last 20 years or so have been stressed from as many owners, and the solder joints on one may have broken. Reflowing the solder joints on thos rca jacks may be in order.

The IC opamps used areMCM4558. they are now obsolete and mostly unavailable. I think Jamesco Electronics may still have some. but the opamp is an old design and it uses a standard dual opamp package so just about any moder dual opamp will work. I rebuilt my LP-1 using BurrBrown OPA2604's, the cost about $4.50 or so each.

I have heavily modified mine and replaced all the resistors, caps and opamps with the new good parts available today. I also eliminated the summing network as all I use it with is a stereo set of subs and I built an external +/- dual mono power supply. Overkill, but that's how I like it. I also designed, built ans installed a pair of rumble filters to help rid the system of sub-woofer pumping with warped records as I use passive radiator subs that get loose below 18hz. Results have been wonderful.

These things, again as mentioned, are very simple, but having a schematic is the most useful thing to figure out whats going on under the hood.

JD

This post is made possible by the generous support of people like you and our sponsors:

Amplified Parts

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---