Alpine ipod head unit

vizion · 30th July 2007, 06:46 PM

hello guys,

what is the voltage of pre-outs for Alpine's ipod head unit ? 350mv or 4 volts ? A typical cd player at home would be 1 volt for comparison.

Thanks.

junglejuice · 30th July 2007, 10:55 PM

You would have to assume that it would be 4v like the others...

vizion · 30th July 2007, 10:58 PM

I checked with Tru Technology and Zed Audio. Head units only put out 350 mv loaded. Home cd units put out around a volt. 2 volts and higher are just for measurement. But with music, it's only 350 mv.

junglejuice · 31st July 2007, 12:49 AM

I somehow don't think so, music is very dynamic so 4v head units will put out up to 4v when the output is at it's maximum and I fail to see how a 10000 ohm load can drag that down to 350mv....

Perry Babin · 31st July 2007, 12:59 AM

What load did they use to test the RCA outputs?

No normal amplifier front end has a low enough input impedance to significantly pull down the output of a head unit. Most head units produce at least one volt RMS.

I measured the output voltage of a Pioneer DEH-P3500 I have on the bench (rated at 2v). The following voltages are RMS. The head unit is capable of slightly greater output but the digital volume doesn't allow fine adjustment of the level at full volume. This was done with a 1hHz signal.

Unloaded: 2.07v
Loaded with 10K resistor: 1.90v
Loaded with a 1k resistor: 1.09v
Loaded with a 600 ohm resistor: 0.83.

junglejuice · 31st July 2007, 01:50 AM

Really early head units put out 500mv then they went up to 1v then 2v and then a few at 4v or even higher.
Of course that assumes the programme material is recorded at the maximum level that a cd can handle.
I have an Autosound 2000 test disc that has test tones on it that is recorded at the limit of a cd and used it to measure the output of my 14 year old Alpine 7620 and whilst I can't remember the exact output voltage it was well in excess of 350mv using a cro and a fluke mulitmeter and yes it was loaded with a 14 year old Alpine 3331 equaliser.
Now maybe the sources you contacted are referring to an averaged level of an average music cd but certainly not a cd recorded near to the max.
Just a thought what sort of input level do the Tru and the Zed amps accept?

vizion · 31st July 2007, 03:47 AM

thanks for the input, guys.

30th July 2007, 06:46 PM	#1
vizion diyAudio Member Join Date: Apr 2007	Alpine ipod head unit hello guys, what is the voltage of pre-outs for Alpine's ipod head unit ? 350mv or 4 volts ? A typical cd player at home would be 1 volt for comparison. Thanks.

31st July 2007, 12:59 AM	#5
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	What load did they use to test the RCA outputs? No normal amplifier front end has a low enough input impedance to significantly pull down the output of a head unit. Most head units produce at least one volt RMS. I measured the output voltage of a Pioneer DEH-P3500 I have on the bench (rated at 2v). The following voltages are RMS. The head unit is capable of slightly greater output but the digital volume doesn't allow fine adjustment of the level at full volume. This was done with a 1hHz signal. Unloaded: 2.07v Loaded with 10K resistor: 1.90v Loaded with a 1k resistor: 1.09v Loaded with a 600 ohm resistor: 0.83. __________________ Links >> Basic Car Audio Amp Repair * Basic Car Audio Electronics * New Site * Basic Switching Power Supply Design * Basic Computer Skills << Links

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
I also have an Alpine 7909 head unit...	Nagamitsu	Car Audio	0	22nd April 2009 07:54 PM
Anyone ever repair the smps inside an Alpine V-Drive head unit?	turbo_slug	Car Audio	1	18th March 2008 08:42 PM
Alpine Head Units/Amp	rocko1290	Car Audio	2	15th September 2006 08:40 PM
Alpine 9856 & iPod Connection Errors	blitzstrahl	Car Audio	1	29th April 2006 06:17 PM
Alpine head unit says 4V pre-out but only 40mV?	rth	Car Audio	18	27th April 2005 11:31 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

30th July 2007, 10:55 PM	#2
junglejuice diyAudio Member Join Date: Oct 2001 Location: Brisbane, Queensland	You would have to assume that it would be 4v like the others...

30th July 2007, 10:58 PM	#3
vizion diyAudio Member Join Date: Apr 2007	I checked with Tru Technology and Zed Audio. Head units only put out 350 mv loaded. Home cd units put out around a volt. 2 volts and higher are just for measurement. But with music, it's only 350 mv.

31st July 2007, 12:49 AM	#4
junglejuice diyAudio Member Join Date: Oct 2001 Location: Brisbane, Queensland	I somehow don't think so, music is very dynamic so 4v head units will put out up to 4v when the output is at it's maximum and I fail to see how a 10000 ohm load can drag that down to 350mv....

31st July 2007, 01:50 AM	#6
junglejuice diyAudio Member Join Date: Oct 2001 Location: Brisbane, Queensland	Really early head units put out 500mv then they went up to 1v then 2v and then a few at 4v or even higher. Of course that assumes the programme material is recorded at the maximum level that a cd can handle. I have an Autosound 2000 test disc that has test tones on it that is recorded at the limit of a cd and used it to measure the output of my 14 year old Alpine 7620 and whilst I can't remember the exact output voltage it was well in excess of 350mv using a cro and a fluke mulitmeter and yes it was loaded with a 14 year old Alpine 3331 equaliser. Now maybe the sources you contacted are referring to an averaged level of an average music cd but certainly not a cd recorded near to the max. Just a thought what sort of input level do the Tru and the Zed amps accept?

31st July 2007, 03:47 AM	#7
vizion diyAudio Member Join Date: Apr 2007	thanks for the input, guys.