old school amplifier

Printed From: the12volt.com
Forum Name: General Discussion
Forum Discription: General Mobile Electronics Questions and Answers
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=98422
Printed Date: May 13, 2025 at 6:26 PM

Topic: old school amplifier

Posted By: mecpcert_1
Subject: old school amplifier
Date Posted: October 29, 2007 at 11:44 AM

i was hoping someone out here could help me with the speaker output and remote turn-on pin out of an old (1993-1996) Earthquake of San Francisco amplifier.

these are the colors coming from the board:

brown: ?

white:?

violet:?

red:?

orange: ? ( i think that this one is the remote turn-on)

model# PA 2050 (Hohmann Series)

2x50w rms, 2ohm stable

pulse width modulated mosfet power supply

what i need to know are the polarity's and the bridged application. all info would greatly be appreciated.

thanks in advance. d8^)_

-------------
do it right the first time....less warranty work=more money!:)

Replies:

Posted By: i am an idiot
Date Posted: October 29, 2007 at 6:24 PM

https://ampguts.realmofexcursion.com/Earthquake_PA-2075/inside1.jpg

Red is one bridge wire and brown is the other. Red + and brown -

Posted By: mecpcert_1
Date Posted: October 29, 2007 at 6:26 PM

sure do.

-------------
do it right the first time....less warranty work=more money!:)

Posted By: i am an idiot
Date Posted: October 29, 2007 at 6:32 PM

That was quick I edited that ? out about 2 minutes after I posted it. You will have to click on 2 pictures of this page but you can figure out left right and + and -

https://ampguts.realmofexcursion.com/Earthquake_PA-2150/

Posted By: mecpcert_1
Date Posted: October 29, 2007 at 6:37 PM

hey thanks! i did find the link you just sent me. thank goodness earthquake was lazy and the kept the speaker colors the same! d8^) i was curious as to what you were gonna say.......i guess great minds think alike. posted_image thank you for taking the time to help.

-------------
do it right the first time....less warranty work=more money!:)

Posted By: i am an idiot
Date Posted: October 29, 2007 at 6:45 PM

FYI on this and any other multi channel, bridgeable amplifier, you can find the bridge wires with an OHM meter. There will be 2 wires that are connected together. 0.X OHMS. These 2 wires are NOT the bridge wires. The other 2 are.

Posted By: mecpcert_1
Date Posted: October 29, 2007 at 6:49 PM

that's great to know. i found two wires that tested for continuity from the speaker lead to the transformer on the board. do you know what that is all about?

-------------
do it right the first time....less warranty work=more money!:)

Posted By: i am an idiot
Date Posted: October 29, 2007 at 7:10 PM

Yes the 2 non bridge wires are connected to the center tap of the secondary of the transformer. This is the ground reference for the amplifier section. The shield of the RCA cables should also be connected to the same point. Maybe via a 10 to 100 ohm resistor.

Posted By: mecpcert_1
Date Posted: October 29, 2007 at 7:15 PM

thanks. i guessing your "screen name" isn't all that it's cracked up to be.......d8^)_

-------------
do it right the first time....less warranty work=more money!:)