Jump to content

Pioneer DEH 80PRS - Low Preamp Voltage


Recommended Posts

Trying to tune my amp (GM-A6704) with a MM, install is a few years old and it has never sounded great.

 

I can only get 5V or so out of the amp with the gain turned all the way up.   I’m using a 1Khz, 0 db text tone.  I tested the preamp output levels at the head unit and get 0.04 volts! Head unit specs say preamp output is 5V max.  Volume is set to 3/4.  MM is set to 2V AC.

 

I am thinking the head unit is bad but looking for advice.  Could I have something set incorrectly in the head unit to create this issue?

  • Like (+1 Rep) 1
Link to post
Share on other sites

I've read that the 80PRS can go to full volume without signal distortion/clipping, I've also read that there is a pretty big difference from 3/4 to all the way up in terms of output voltage.

 

.04v is crazy low.  Try running the volume all the way up and see what voltage it's reading.

 

Double check and make sure the EQ is set flat and that no xovers are set etc.  I think you have the a level setting as well, but it may only be for the sub output channels, if memory serves (and it often doesn't)  that level setting runs from -6db to +6db so maybe look for those settings as well and see if maybe something was set low at some point in the install's life.

 

If none of that get's you in the 5v neighborhood, then there might be something wrong with the deck, which is a shame, they are really nice.  It might even be worth seeing if you could get it fixed.

  • Like (+1 Rep) 1
Link to post
Share on other sites

Double check your crossovers on your deck. Depending on which channel you are testing from on the deck, your tone might be sloped off.  I agree with what Arthur said above. Depending on how old the deck is if it does turn out to be an issue with the deck you may be able to send it to Pioneer under warranty 

  • Like (+1 Rep) 1
Link to post
Share on other sites
On 6/5/2021 at 6:19 PM, GRS said:

Trying to tune my amp (GM-A6704) with a MM, install is a few years old and it has never sounded great.

 

I can only get 5V or so out of the amp with the gain turned all the way up.   I’m using a 1Khz, 0 db text tone.  I tested the preamp output levels at the head unit and get 0.04 volts! Head unit specs say preamp output is 5V max.  Volume is set to 3/4.  MM is set to 2V AC.

 

I am thinking the head unit is bad but looking for advice.  Could I have something set incorrectly in the head unit to create this issue?

 

I have the PRS, it has a clean output, I set my gains with 2.5-3V to have it the cleanest possible signal, but it can go up to 4.5-5V while being clean.

 

I think you have a crossover sloping your output as said by Cody, check it out.

It may be a Mute parameter also :), must check your settings.

 

On which output RCA are you trying to connect ?

Also are you in normal or advanced mode ? (Small button under the HU)

Edited by Car Audio 83
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Who's Online   0 Members, 0 Anonymous, 92 Guests (See full list)

    There are no registered users currently online

×
×
  • Create New...