I recently acquired this lovely McIntosh PF-2510I-A 6-disc in-dash CD changer. This model was available as an option in the North American market Subaru Legacy and Outback. It is often but incorrectly referred to as the PF-25201 or PF-25201-A.
Fortunately it shares the same connectors and pinout as the Japanese and Austrailasian market Legacys so can be fitted in cars destined for other markets with very little effort. Having said that there are a couple of gotchas. Read on…
American market Subarus have two separate lighting circuits. I’m not sure why this is, however to get the backlights working on a right-hand drive Legacy you need to connect the Illum- pin on the rear connector permanently to ground. The best way to do this is open the unit and solder a small wire directly from this pin (marked on the PCB) to the nearest ground point. Having said that some JDM Legacys already have this pin connected to ground so best to check your car first.
As this is for the American market the FM and AM tuners work in 200kHz and 10kHz steps respectively. In NZ we use 100kHz and 9kHz steps instead. As the frequency range is the same there is no modification required to the tuner, instead we simply resolder a couple of jumpers near the microprocessor to change the area from 1 to 2.
To open the unit up, unclip the front panel first. Remove the screws as marked in the photos below and lift the CD changer mechanism off. Be careful not to damage the ribbon cable; this can be properly disconnected by carefully pulling it out of either connector.
On the front right-hand side of the main PCB are a series of 0 Ohm resistors. Move R209 and R211 to R207 and R212 respectively as shown in the photo below.
Reassemble the unit and test it. Note that changing the area disables the weather band function so the W.B button on the front panel will no longer do anything.
Whilst this unit does not officially have an auxiliary input, you can make one pretty easily. On the rear panel there is a connector for a car phone. Short pin 5 to ground (or pin6) to enable phone mode. The display will show CALL and you can feed mono audio into pin 7. The unit will stay in call mode until pin 5 is released.
The big drawback to this approach is that it bypasses the tone controls. If you don’t mind that then this method works quite well.
For stereo sound input, remove R857 and R858. Connect an input with left to R857 and right to R858 using the solder pads closest to IC801. I strongly recommend connecting a 10μF or so bypass capacitor in series with each input. How you connect your device (e.g. iPod) is totally up to you; for example you could mount RCA jacks on the rear panel or run a flying lead with a 3.5mm jack.
Bass Control Hack
To improve the sound a bit I reduced the frequency of the bass control from the original setting of 100Hz to about 65Hz. The tone control is performed by IC801, a Sanyo LC75412WH.
To do this, solder additional 100nF capacitors in parallel with C837 to C840. Alternatively you can replace them entirely with 220nF capacitors which will reduce the frequency to about 60Hz.
If you want a different frequency the formula to calculate suitable capacitors is shown below (taken from the LC75412WH datasheet).
Like all McIntosh head units, the PF-2520I is compatible with the Clarion EA-1251 iPod adapter if you want to be able to control your iPod or iPhone from the head unit. These adapters work very well, are easy to set up (just plug it in) and the sound quality is excellent.
To switch to iPod, simply push the Disc button until CHR 1 appears on the display. You can then control the iPod like a CD changer, using the track controls.
You can create playlists on the iPod called clarion1 through clarion5. Switching to disc 1 plays all songs on the iPod, and discs 2 to 6 play playlists clarion1 to clarion5 respectively.
Unfortunately these older McIntosh units lack two desirable features for iPod support; they do not display song title information and there is no random/shuffle button.
I’ve also had quite good luck with Anycar Link units. Yatour make an adapter too but it’s not quite as good.
This stereo is designed to operate with the McIntosh EF-1080I power amplifier. It does not have an internal power amplifier so cannot drive speakers directly.
Display and Button Test
I discovered a strange hidden feature on these head units. Turn the ignition to ACC and ensure the unit is off. Hold 1 and 6 and press Bass/Treb.
My stereo displays
100 01 which I can only assume is a firmware version or similar. Turn the volume control one click to enable the display test which will illuminate all elements on the VFD. Use the tune knob switch this to every second element and then to button test mode (display will go blank). Pressing any button on the unit should display that button’s name on the screen.
To exit this mode, switch the ignition off.
Yes, I have the service manual for this unit! Click below to download it.