I just got a 2004 Honda Accord LX V6 and am replacing the factory stereo. I have all the amps, speakers, head unit, EQ and cabling ready to go, but I have this idea, maybe someone in here could tell me if it is ridiculous or if it might work. If it is a completely harebrained idea, please tell me so.
At home I have a Headroom Supreme headphone amp, basically, it is a very high-quality preamp. It runs on 6V DC (4 D batteries). I just upgraded, so this thing is gathering dust. I am wondering if I can use it as a preamp for my car stereo. I can run RCAs from the lineouts on my head unit into the preamp, then on to my EQ. (The benefit of using this instead of just the preamp in the head unit is that this is several quality levels above.) Now, for powering the thing: instead of a battery pack with 4 D cells, a +6V voltage regulator (IC) to step down the voltage from the car battery, I can make a little heat sink for it and attach it under the dash or along the side of the center console.
Does this sound feasible? Any advice would be much appreciated.
GlassWolf, I'm not exactly sure what you mean by the "line driver voltage" of the preamp. If you mean the voltage output, it's up to 28V at full volume. One nice thing is that it has a three-step gain control switch (lo-med-hi), since it is made to power headphones, which have a wide variation in power requirements.
The lineouts of my Clarion DXZ745MP head unit are 4V. The preamp can take from about 2.2 to 6V, supposedly. My EQ is a combo EQ-line driver, I'm assuming it will have no problem accepting what the preamp puts out, within reason. I can just play with levels on the different components to see what works. The preamp is such a sweet piece of equipment, with headphones at least I've had the volume knob up to close to 100% and it refuses to distort at all, so I'm counting on it having some nice clean fun with the music signal on its way to the amps.
I think any line voltage going from preamp to amplifiers over 4V is going to cause problems. you'll overdrive the input stage of teh amplifiers and as a result cause them to clip or distort. stick to car audio for car audio. there are plenty of good preamps for car systems on the market.
I was hoping by running the signal from the preamp through the EQ-line driver, that what finally got to the amp would be a normal 4V line driver output signal. My PPI amp in fact has a switch you flip if the signal is from a line driver.
I also realize that by putting too many unnecessary links in a chain, especially when there is some duplication of effort, you can be asking for trouble, or at the very least you'll get minimal benefit from it.
I think you've convinced me though. Better safe than sorry. Out of curiousity I'll check out some high-end car stereo preamps, but most likely I'll just go with head unit ==> EQ-line driver ==> amp. I know for sure that will work just fine.
Looked online for car preamps. The ones I could find were combination EQ and preamp. I already have my EQ/line driver. Actually, the only stand-alone preamp I found was some company in Indonesia that makes tube preamps -- nice idea, but no thanks, I'd rather stick with the name companies.
You mentioned there were "plenty" of good car system preamps. Can you mention a few names?
most of the EQ functions on car preamps are maybe 3 bands. its no big deal. orion, kicker, audiocontrol, and several others offer good ones. audiocontrol has straight line drivers as well. that headphone pre-amp is most likely made for headphones using an amplifier, and any amplified signal is going to cause noise on a line level input. that's why using the headphone jack of a discman to run to a pre-amp input on a receiver always sounds like crap.