diyAudio (
-   Car Audio (
-   -   Rockford Fosgate type RF X7 (

seankane 9th December 2012 03:21 AM

Rockford Fosgate type RF X7
Hello all, I have RF X7 board number PC-3758-H

The amp powers up and idles fine, no DC on output terminals, and is not in protect.

I tested for output and the output is very low and viewing it through the scope it is low as well and intermittant. I messed with the gain knob and it spikes to full rail on the output terminal when turning the gain pot and the gain pot does not increase the output.

I am going to switch out the gain pot to a new one but my question is, could the pot being shorted or bad cause this symptom or is there something else I might look over as well?

Perry Babin 9th December 2012 03:28 AM

Look at the preamp level signal before it gets to the amplifier section to see if it's good or bad at that point.

seankane 9th December 2012 04:00 AM

OK well if I switch the infrasonic switch it puts over 100 vdc to the output terminals and kicks the protect.

So far I have changed the infrasonic switch and the gain pot.

Why would the infrasonic be putting so much DC on the output terminal?

seankane 9th December 2012 04:05 AM

2 Attachment(s)
Pic #1 of main board and #2 the little control board on which I think the problem is?

Perry Babin 9th December 2012 04:23 AM

I would suspect an op-amp with DC on its output.

seankane 9th December 2012 04:24 AM

Did you read post number 3?

I am suspecting an op-amp as well, just wanting to make sure you read post #3 as well.

seankane 9th December 2012 04:56 AM

OK Perry bare with me here I have been attempting to read schematics again.

U2 and U3 have 11 vdc on their

Signal enters U1 from pins 2&3 and 5&6, then leaves U1 througn pins 1&7 which have no DC.

Enters U2 pins 2&3 out pin 1 to pins 5&6 then out pin 7.

U2 has 11 vdc on pins 1&7

Enters U3 pins 2&3 leaves pin 1 to pins 5&6 then out pin 7.

U3 has 11 vdc on pins 1&7

Enters U4 from there and U4 has no DC on output pins. So switching the infrasonic switch must enable or bypass U4 depending on switch setting?

If U4 is bypassed the switch would send DC from U2 and U3 to where ever it goes next. If U4 is enabled, why is it not getting the DC from the output pins on U3?

Where is the 11 vdc coming from on the output pins of U2 and U3?

seankane 9th December 2012 06:51 AM

Please read post #7 first.

I replaced U2 and U3 the amp works great, but if its not to much trouble could you give a few answers fro, post 7? Was I close on reading the schematic?

I cannot believe how much power this amp has.......its like WOW!!!!

Looks like an over glorified 1500BD to me but I can sure tell a difference in output....WOW!!!!

seankane 9th December 2012 07:04 AM

1 Attachment(s)
Dont forget to read post #7 and #8 Perry!!!

This thing is a beast people, you would not believe the power this thing has, I am truly impressed. I have been around alot of amps and most of what I hear is what I expected but not with this one.....I was OMG!!!!

Thanks for the help Perry.

seankane 9th December 2012 07:18 AM

1 Attachment(s)
You will have to excuse the crappy picture the lighting was horrible and flash made a wierd reflection off of the chrome.

Look at the size difference between the X6 and X7. I thought the X6 was big. The X7 dwarfs a BD1500!!!

All times are GMT. The time now is 12:18 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2