SDA CRS problems

irishaz

Hello all,

Just picked up a pair of SDA CRS, my second set of SDA's, off ebay. Well today the little brown truck arrived and I couldn't wait to hook them up. I have them hooked up to an Adcom GTP-450 and Doro's GFA-5400. Well, I was all excited to hear them, turned on a Robert Cray CD and boy was I disappointed. I don't know if it was the guys in brown or if the seller was less than candid but these babies have some problems. The only thing working on the left channel is one tweeter (SL2000) and as far as the right channel goes, the two 6503's are working but one of the SL2000's is not working at all. I checked the wiring/polarity several times, but still no sound at all from the above-mentioned parts.

I am going to contact the seller about filing a claim/getting refund, but in case that doesn't go so well, I am looking for some help. I removed the woofers (passive and a 6503) from the left channel and it appears that everything is attached/hooked up properly. I did notice that on the two 6503's on the left channel, I can turn the magnets (if that makes a difference) rather easily. I am wondering what I can do (with limited technical knowledge) to see if this is a wiring problem or if the speaks are a total loss. Should I remove the "working" 6503's from the right channel and hook them up to the left to see if they work? Ditto for the working SL2000's? I am just wondering if the crossover is bad as well as the components themselves. I should mention that there is no sound coming from the two woofers and one of the SL2000's on the left and no sound from one of the SL2000's on the right.

Any help/advice would be appreciated. I've waited a long time to get a pair of these at a reasonable price ($220 inc shipping) and right now I feel like I got the short end of the stick.

Thanks guys....

F1nut

As for the two 6503's, it seems like transportation issue. If they are jarred or dropped the magnets can come unglued. Time to buy 2 new drivers. As for the tweeters, remove the dead ones, hook them up directly to your power source at very LOW volume. If they play the problem is elsewhere, if they are still dead it's time for new tweeters. You can usually find used SL2000's for $20.00 or so.

You do have the interconnect cable between the speakers hooked up, right?

trubluluc

What Jesse said.

You didn't mention it, so I'm just wondering if you have the SDA cable for these speakers? Owing to the fact it's your second pair I'm assuming you know this but:
If not, you won't get all drivers and tweeters working without rigging up an interconnect.

Also, the CRS have a tendency for the crossover plate to come lose from the mounting and rattle around inside. Could have happend during shipping.
Have a look see.
And yes, you can swap drivers to check the crossover or use a meter.

-Luc

heiney9

FYI, the Acom GFA 5500, 5800, 5802 all have secondary windings on the power transformer therefore they are Non-common ground amps. IIRC, the 5400 doesn't have secondary windings but I can't remember for sure. This may be part of the issue though it doesn't sound like a non-common ground issue. If you end up determining all the drivers work properly your next step is to call Adcom and see if the non-common ground is an issue with the 5400. If it is the negative terminals can be tied together.

If I have this issue (non-common ground) wrong in regards to the SDA CRS someone please chime in. Jesse?

H9

schwarcw

Greetings! The guys have some good advice. F1's suggestion to remove and check each speaker with the speaker wire at low volume will determine if it's the speaker or some other component problem. One step at a time and you can narrow down to where the problem is. Good luck and let us know what you find!

irishaz

Thanks for the responses guys. Yes - I had the interconnect hooked up. I checked the working 6503's in the left channel and they worked fine, so I had to assume that the trip from OK to MN did the damage. I was pleasantly surprised by the seller. All he asked me for was an estimate of what it would cost to get them working again. I told him $ 20/tweeter and $40 for each 6503. He was really cool about it and I think I will end up alright on the whole deal.

But - one quick question. To hook the tweeters up to the source, do I just remove them from the box and put the + in the positive on the GCD-700 and the - in the negative? Would bare wire be OK or should I hook them up to spades or plugs? Never done this before so I would appreciate some advice.

Thanks guys, looks like I am on my way to my 2nd set of SDA's.

thanks for everything - Hap

F1nut

Straight wire will do the trick, no need to terminate it. Be careful not to short out anything.

Dennis Gardner

H9 is correct..............the 5400 will eventuallly fry since it isn't common ground. Al (dangerboy) lost his last year.

Just so you are aware.

heiney9

Dennis Gardner wrote:

H9 is correct..............the 5400 will eventuallly fry since it isn't common ground. Al (dangerboy) lost his last year.

Just so you are aware.

My guess is with the 5xxx series the front-end (input side of amplifer is run by Class A power mosfets which need a fair amount of current even while idiling hence the need for a secondary (or multiple secondary) windings as opposed to another seperate tranformer. It seems the whole series runs this way. The older bi-polar amps 5xx series don't have this problem except the the 535 is a dual mono design (not sure if it's common ground or not) and the 585 is considered a dual mono design but with only one main power transformer.

My suggestion still stands, call Adcom and explain the situation about using SDA's, etc and ask if the negative terminals can be tied together to make it a common ground amp with out damaging anything. I believe you can, I just don't want to say for sure. If you continue to use the 5400 with SDA's that need a common ground amp you will fry the amp and may even damage the speakers.

Good luck

H9