SDA 1 Issue

stone of tone

I bought a pair of SDA 1's today in great shape with original SDA cable, tweeters and drivers from midwestspeaker.com. They are local for me here in Roseville Minnesota, so I was able to audition them. Joe at the shop told me they had them for about six months and hunted around for original tweeters and found them! He also repaired the spiders behind the four 6.5 inch drivers in which he said is common for these to need rapair. The passive radiators were fine.

Here is my problem:
The speakers work great with my Integrated Amp as they did with the shops Integrated too. However, when I try to use them with my Emotiva UPA-1 mono block Amps, the left channel engages just fine; but the right channel switches on and lets out a horrible howl and that amp goes into protection mode. I even switched the speaker cable inputs to the mono blocks and still received the howl feedback. The amps are fine, because I did switch them back to another pair of speakers to make sure they are both working properly. Why is the one Amp doing this? Once again, the mono's are fine running another pair of speakers as usual and the SDA 1's are fine running with my Integrated Amp. Furthermore, the three times I trouble shooted and received the LOUD howl from the SDA's the volume on the preamp was turned all the way down.

Thanks in Advance

nooshinjohn

do NOT USE MONOBLOCKS WITH SDA'S!!!!!!!

Very bad things happen to the speakers and possibly the amps as well.
You need a common ground amp, or an AI-1 interconnect to replace the SDA cable. Depending on the model SDA the AI-1 may not work, at least that is my understanding.

Toolfan66

You need a A1 sda cable to run mono blocks, also what SDA 1's do you have? as all SDA's can not use non common ground amps or use the A1 SDA cable as well.

Is your SDA cable a pin blade type or a blade blade type?

stone of tone

Thanks nooshinjohn and toolforlifefan. I read the back of the speakers about common ground, but in my excitement to hook them up and ignorance, it did not click in my brain that mono blocks Larry.....don't have a common ground! UGH! I am lucky I did not damage the Amps or the Speakers.

All is fine. I hope that strain/howl feedback did not cause any harm to the driver's and tweeters......seems to not have. However, doing an ear test on all drivers with safe volume, I feel the SDA tweeters (both) are not putting out anything. The 6.5 SDA effects drivers below each SDA tweeter are functioning with that lower output they do of sound, so the fuse can't be blown to the SDA side if the 6.5's are outputting, right? I could pull the SDA tweets and make sure they are connected? Or are they faint and I'mnot hearing them?

I have the floor standing SDA 1's. So can this model use the A1 cable and how would I obtain one of those if I can use it? My SDA cable is female going into the speakers male two prong.

Thanks again. I'm still kickin myself for what I did..... .

stone of tone

Further clarification: I have the SDA 1.....1984 & 85..........$1700.00. Not the 1A or 1B. I have the two horizontally mounted tweeters across the top with four 6.5's below and then of course the passive radiator below them.

I am loving these right now, even though the SDA tweet's might not be working. The 6.5 SDA's are for sure doing cancelation/functioning. I will pull them (tweets) and have them tested back at Midwest Speaker? I hope I did not harm them. The fuse would have blown.

Stone

nooshinjohn

No harm it sounds like... the sda tweets were not liked by some, so if they sound good to you, I would not worry too much about them. The direct replacement tweet is the SL2000 which can be picked up from Polk Customer service.

stone of tone

SDA Tweets are fine. Of course they worked in the shop. I don't know why I was rambling on about them being faint. When I had them hooked to the Mono's I blew the SDA fuse sure enough on both sides and replacement fuses two on each side were provided by Midwest Speaker....nice touch Midwest. I did not have to wait until tomorrow to get fuses!

My mono blocks are fine (I double checked) and all drivers and tweeters are working perfectly. I like the SDA sound!

I got lucky and saw these posted by happen stance on line this morning and went over to the shop and there they were! Joe found the original tweeters and redid the spiders on the 8 drivers. Walnut in nice shape on both sides and top! Of course he checked the crossovers too. I paid $440 for them.........20% off of $550 today (midwestspeaker.com). I am enjoying them in there full original glory right now with my Dac Magic and Rotel Integrated RA-1062.

Can I use the A1 cable on these? Stone of Tone

stone of tone

I lugged these up two flights of stairs myself. Worth it. I am a no negative feedback tube guy. I have a Decware Torii MK III coming matter of fact. However, this is the best soundstage I have coaxed from solid state-WOW! Stone very happy! Thanks again guys for your online help. Sometimes I just have to laugh at myself for doing what I did. It keeps me humble. All ended well! Now I know what you guys like about these SDA's! Thanks again, Stone of Tone

CNWDI

stone of tone wrote: »

Can I use the A1 cable on these?

From what I can tell in documentation the SDA 1C was the first of the SDA 1 series to be able to use the AI-1 and work with amps that didn't have a common ground--it was specifically written up that way in Stereo Review (as it required significant redesign of the crossover). Probably not going to be able to use these with monoblocks, but it sounds as though you got a good deal regardless.

stone of tone

Thanks CNWDI for the FYI on the AI-1 not working. The mono blocks are going to stick to front mains for home theater duty only, where they belong. These SDA's are moving to my ref. rig and kabling for two channel only. They deserve the respect and output of my new Torii III coming in three more weeks. Stone of Tone

michael1947

With the SDA 1A's let's not take any more chances with amps. You may run them with or without the interconnect cable, they just sound a little bit different with/without and good or bad would be subjective. I have heard Polk customer service will make up a cable for you or you can look around on this forum for some very good designs on a new cable with parts from good old Radio Shack...either will work.

michaeljhsda2

^^^^^ Does this spam strategy ever work? Does anybody really fall for this and actually purchase something from a spam link? Just wondering ^^^^^^^^^^^^^

pitdogg2

sounds as if he has the first incarnation of the SDA cable "my cable has two female that plug into two male"

So your cable does NOT have TWO blades 1 big and 1 small on it? The cable itself has two holes that accomadate two blades on the back of the XO plate that has a little protection boot over the two blades?

Very first SDA1 most likely has two ports for the upper drivers

stone of tone

No more chances with Amps michael1947. I have made sure with the manufactuer(s) about the 3 Amps I am currently switching in and out. Two right now and one on the way as mentioned above. Currently, I am running them in Stereo without the SDA cable connected. Wonderful Speakers. I am using a 2 watt per channel, yes 2 watts per channel, no negative feedback, even order harmonics with SV83 pentodes run in triode at a range of 78 to 84 db SPL.......very musical, with great tone and timbre, and I can't wait to drive them with more power and no negative feedback, coming from my Decware Torii MK III.....coming soon.

michaeljhsda2??? Explain yourself and your comment? Lets have an adult conversation.

pittdogg2, my SDA cable is just as you described. I do have the the very first SDA 1 Series. Go to Vintage Speakers and pull up thread SDA 1's in Twin Cities. A couple of Tweeter's were sold to Midwest Speaker to restore these and Spiders were rebuilt and crossovers inspected.

Stone of Tone

CNWDI

michaeljhsda2 wrote: »

^^^^^ Does this spam strategy ever work? Does anybody really fall for this and actually purchase something from a spam link? Just wondering ^^^^^^^^^^^^^

Just so anyone coming in later understands, the post by michaeljhsda2 was referring to a very SPAM SPAM SPAM post that has since been deleted by a mod...he wasn't impuning or insulting anyone who actually reads the boards. We now return you to your regularly scheduled Polkification.