jeffbrig

I'm putting a PCX-480 in my '02, and I have one quick question. The amp can handle low level or speaker level inputs (with a 12dB attenuation selected). The manual says to use the 12dB attenuation if your input levels are 4-12V. My Clarion MP3 player has 4V pre-outs (like most good head units), which is borderline, so I'm debating whether or not to use the attenuator. I leaning towards NOT using the attenuator, since it doesn't make much sense to attenuate the signal, then amplify it again. I figure there's enough tolerance there that I won't experience any problems, and I'm not a MAX volume kind of guy, so the amp would rarely (if ever) see a high enough voltage level to cause any damage.

Which setting do you use on your PPI?

Thanks,

Jeff

Alister

Why would you use the speaker level inputs on the amp when you have an aftermarket headunit with RCA outs??

1a-race

same ?

jeffbrig

No, let me clarify that, I am using RCA outs from the head unit. There are only RCA jacks on the amplifier, which can be connected to your preouts or speaker level inputs. If you happen to be using speaker level inputs, you are supposed to solder RCA connectors onto the speaker wires, connect them to the RCA jacks, and activate a -12dB attenuator inside the amp. However, it also states that if you're using a high voltage line-driver for your RCA preouts (specified as 4-12V), you should also activate the -12dB attenuator. Since my head unit is rated at 4V preouts, it's at the minimum threshold where they recommend using the -12dB attenuator. So, the question above holds, would use you it, or not?

Thanks guys,

Jeff

Alister

[QUOTE]Originally posted by jeffbrig
[B]No, let me clarify that, I am using RCA outs from the head unit.

jeffbrig

This should help explain things:



And then #8


I played around with it a little last night. Basically it looks like I can run without the attenuator, with less gain, or activate the attenuator and increase the gain.

1a-race

i dont get it, run the rcas from your head unit to the amp rca inputs.

jeffbrig

As I stated previously, I am, have been, and always will be, running RCAs from the head unit to the amplifier. Let me try to summarize the relevant information for you:

1. Attenuator should be used if input is 4-12V via a "high voltage line driver"
2. RCA pre-outs are rated 4V

Do the headunit's 4V pre-outs fall into the "high voltage line driver" category, requiring me to activate the attenuator?

This is simply a question for others who are using PPI amplifiers, and are familiar with the settings and controls provided. I mainly want to know if I risk damage by NOT using the attenuator. I argue that since the amp can handle anything under 4V without activating the attenuator, I can probably get by at 4V with no attenuator and a slightly lower gain setting.

If you are not familiar with PPI amplifiers, or have no relevant information to contribute, please abstain from responding.

Goldtrom

I have 4V pre-amp outputs on my head unit and have a PPI amp (2001 model)running without the -12db without problems.... I'd say your safe either way...

-- Robert

Goldtrom

Not sure if this says anything... but the new models say >5v before using the -12db...

Push this switch