# diy: a/d/s ac-502



## jel847

anyone ever made one, i dont think i will ever find one thats original.
any ideas where i can get help with this?


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## jel847

sorry, it's a a/d/s ac-502


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## sirvent_95

I have a link to get you started, but can't post it. (not enough posts). I will try to PM you with it. It shows a potentiometer that would control the level of a left and right channel. The problem is that it gives no value for the resistance ranges of that potentiometer. If I was doing this I might look at some off-the-shelf potentiometers at radio shack or similar and see what values they're using for line-level signals. 

So what you'd have to do is buy a cable that has the same end as the a/d/s amp does, which I think is a mini-din cable, and you'd have to buy an appropriate potentiometer and wire it based on this diagram.


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## sirvent_95

I have to correct my post. The AC-502 is a DIN cable. That's used commonly now as a MIDI cable in pro-audio. The mini-din is used for multi channel input on a/d/s amps. What you need to buy is on amazon dot com:

HOSA MID320BK standard MIDI cable 20 ft. black

10k audio taper stereo potentiometer

Using the link I pm'd you can build your own AC-502. Note that the diagram is somewhat confusing. The upper left is the ac-502 while the lower right is the mini-din for the input channels. Also, you can ignore the 'illumination' notes as they go with the mini-din cable. 

If you don't feel up to this challenge, I have an a/d/s/ p850.2 I would love to build and test this on. If you'd like me to build you one also, I could do that.


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## jel847

thanks for the help.
i am going to give it a go, i will keep you posted.
jeff


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## sirvent_95

I just made my AC-502 and found out that you can't follow the pin out for the potentiometer in their diagram for the AC-502. You have to determine which pin combinations change resistance when you turn the dial and put your audio plus and minus across those. The pin on each pot. that doesn't change is your audio ground. The pins are different on the pot. I bought from amazon.com when compared to the diagram I showed to you.


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## jel847

very cool! how muchdid it cost yo to build?
i havent had time to try it out yet.


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## sirvent_95

*DIY a/d/s/ AC-502 adapter*

Buying parts thru Amazon.com cost me $24.11 after shipping.

I would think you could source parts locally less than that. The parts were $12 before $12 shipping (nice right?...the shipping was same as the parts).

I bought a MIDI cable (couldn't find it when I called it a DIN cable), and the 10kOhm audio taper potentiometer. I haven't tested it yet but I hope to today.

The only thing I lack is a knob for the pot. I plan on getting this locally. It has a 1/4 " shaft on the pot. It is a round (cylindrical) shaft. I will either 
have to find a knob with a set-screw or I will file one side of the shaft flat 
for a D-shaped knob socket.

I will repost when I have tested it. 

BTW-my project is my 1986 BMW 325 coupe. It still had all original speakers. It's long overdue. I'm using my a/d/s P850.2 in active crossover config. for front components and plan on purchasing quality coaxials for the
rear. My sub is a JL 12W0v2-4 in JL's ported box. My source unit, which I practically stole from a buddy is Pioneer's PRS-8800 I think. It has multiple EQ and crossover options including an auto-setup function with an included microphone.


What are you working on?


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## jel847

2004 GTO have a p-640.2 powerig aura braxials in the doors and aura tweets in te stock dash location.
a/d/s p-2110 powering a pair of 12w3's
stock source with a massive audio flatline and ausio control dqs.


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## sirvent_95

I just tested my "ac-502" and it works fine. A couple things to be aware of 
with the parts I showed you:

The potentiometer seems to work 'backwards'? Meaning that turned completely clockwise is no output, and counterclockwise is full output.

Also, this potentiometer may not be the original value because it only takes approx. 50% rotation from no output to full output. 

If you can get used to twisting this thing backwards and using a light touch when turning it to get the output you want then this would be a working option. 

As for anyone else reading this who wants one I'd be willing to make one just for the cost of the parts. About $20 shipped to you.


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## sakazekillaz

sirvent_95 said:


> I have a link to get you started, but can't post it. (not enough posts). I will try to PM you with it. It shows a potentiometer that would control the level of a left and right channel. The problem is that it gives no value for the resistance ranges of that potentiometer. If I was doing this I might look at some off-the-shelf potentiometers at radio shack or similar and see what values they're using for line-level signals.
> 
> So what you'd have to do is buy a cable that has the same end as the a/d/s amp does, which I think is a mini-din cable, and you'd have to buy an appropriate potentiometer and wire it based on this diagram.


Can you send me the link and stuff too? I wanna try this with my P850. Also, will this work with the 642CSi? The manual states that the 642CSi requires AC500 though. Thanks sirvent!


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## ryanr7386

OR, you can buy one off e-bay! There's one on there now with a 642ix. One just sold a few days ago as well. They pop up fairly frequently.


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## sirvent_95

I can't determine why, but my controller stopped working. I do know that some of my crossover switches and pots on the P850 are dirty. So when I activate the switches in and out I get pretty scratchy sound. I don't know if there is a poor connection in my amp or what. 

Also, I wonder if the function of the AC 502 is dependent on a certain switch's position or possibly a certain gain setting on the amp. I'm not really sure. I can find nothing in the manual about this.

I did find out that radio shack sells potentiometers as "Volume Controls" that are 10k Ohm ratings, so I think the value of my Potentiometer is fine.

As far as a link you're prob. better off sourcing something locally to you because I paid $12 for the parts and $12 for shipping from Amazon.com:

I bought a 

10k Ohm Stereo, Audio Taper potentiometer

and

20 foot MIDI cable. (This is the same as a 5-pin DIN cable)

DIN cables used to be much more common, but I am having trouble finding them now. I guess a/d/s used to use a lot of DIN cables to and from outboard crossovers and everything. 

Also, if you're using the 850 you can make your own DIN cable for inputs 3-8 if you want. You need a 7 or 8 pin DIN for that, though. Be aware if you use these inputs it seems to make these inputs especially sensitive to injected noise. So plan to use extra care routing your signal cables. I actually had my signal cables at the top of a fender well in the trunk and the main battery cable (BMW) was at the bottom of that panel and I was getting noise radiated through that panel apparently because as soon as I moved the signal cables away from that panel the noise went away. Never seen anything quite like that before. It only affected the cables that went into that DIN input connector for ch. 3-8.


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## sakazekillaz

ryanr7386 said:


> OR, you can buy one off e-bay! There's one on there now with a 642ix. One just sold a few days ago as well. They pop up fairly frequently.


I saw that one but need only the controller. I already have a 642CSi that came with a PH12. Thanks for the heads up though!


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## sakazekillaz

sirvent_95 said:


> I can't determine why, but my controller stopped working. I do know that some of my crossover switches and pots on the P850 are dirty. So when I activate the switches in and out I get pretty scratchy sound. I don't know if there is a poor connection in my amp or what.
> 
> Also, I wonder if the function of the AC 502 is dependent on a certain switch's position or possibly a certain gain setting on the amp. I'm not really sure. I can find nothing in the manual about this.
> 
> I did find out that radio shack sells potentiometers as "Volume Controls" that are 10k Ohm ratings, so I think the value of my Potentiometer is fine.
> 
> As far as a link you're prob. better off sourcing something locally to you because I paid $12 for the parts and $12 for shipping from Amazon.com:
> 
> I bought a
> 
> 10k Ohm Stereo, Audio Taper potentiometer
> 
> and
> 
> 20 foot MIDI cable. (This is the same as a 5-pin DIN cable)
> 
> DIN cables used to be much more common, but I am having trouble finding them now. I guess a/d/s used to use a lot of DIN cables to and from outboard crossovers and everything.
> 
> Also, if you're using the 850 you can make your own DIN cable for inputs 3-8 if you want. You need a 7 or 8 pin DIN for that, though. Be aware if you use these inputs it seems to make these inputs especially sensitive to injected noise. So plan to use extra care routing your signal cables. I actually had my signal cables at the top of a fender well in the trunk and the main battery cable (BMW) was at the bottom of that panel and I was getting noise radiated through that panel apparently because as soon as I moved the signal cables away from that panel the noise went away. Never seen anything quite like that before. It only affected the cables that went into that DIN input connector for ch. 3-8.


I bought a bunch of 8-pin 270 degree DIN pugs and cables for a previous project (building input cables for PH12/PH15 amplifiers). I just need info about which pin outs to connect to the potentiometer. As soon as I get the P850, I'm gonna test this. I wonder if this will work with the 850MX as well? Thanks sirvent_95!


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## sirvent_95

*AC-502*

PM sent with pin-out


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## sakazekillaz

Got it. Thanks!


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## jel847

this is great, thanks for the help. i am going to a electronics store today to get the parts. i ordered a midi cable yesterday. 
i will report back with my results.


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## sakazekillaz

ryanr7386 said:


> OR, you can buy one off e-bay! There's one on there now with a 642ix. One just sold a few days ago as well. They pop up fairly frequently.


Just found out that bass controls AC501 are not interchangeable with units requiring AC500 or AC502. Apparently, there were many different AC501 models - AC501CSi, AC501ix, AC501MX. These are not interchangeable as well.


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## labcoat22

So I just picked up an 20th anniversary addition P840.2 
So if you guy had to do it again would would you pic the same parts?

Can anyone get me the pin out diagram?

Thanks

Ry-


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## sirvent_95

I had some issues getting this to work with my p850.2.

it would sometimes change the gain on the 7/8 channel and 
other times it would do nothing. I never found out why and 
I opted to use my deck's level control with a different sub amp.

i do know that some of the switches/pots on mine are a bit dirty.

if I adjust them, sometimes I have to work them back and forth to get
both channels to play properly.

I can email you the pin-out .pdf's I have if you want to try it.

As for the parts, the cable was of good quality and when the control
did work, the pot. I chose was effective.


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## EvilWagn

If you go to directed's website, there is a pdf of the pinouts. 

I have yet to make one, but the need may be arising in the next couple weeks...


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## insane imports

Just curious if anyone has the wiring diagrams for this? I am planning on trying this out very soon. 

Thanks in advance. 
Jon


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