Take it easy on me - SDA 1C Question

Saftgeek

Hello all...

I am really excited to be picking up some SDA 1C's this Saturday. I have read every single post on hooking these up to a home theater system. I currently own an older Onkyo TX-898. I also have an Onkyo power amp operating my subwoofer. I spoke with the techs at Onkyo and they say their amp is not a common ground. I am now searching for the how-to on the AI-1??? The 1C's I'm buying have the interconnect cable. Supposedly these have been stored for the last 30 years... I'm so nervous about hooking these up. I had no idea there was so much to them. I am looking forward to upgrading them but my main purpose for these would be as mains in my home-theater.

Please be gentle. I'm open to any/all suggestions or advice. The last thing I want is to destroy the speakers or my amp. Thank you in advance...

Saftgeek...

Mystery

Welcome to Polk forums Saftgeek!.
I'm pretty sure all general public A/V receivers are common ground but wait for more comments.

nhhiep

are you sure that Tech understood your question?

Saftgeek

Not really. He sounded like a minimum wage phone answering guy. I swore I was talking to the guy from the Capital One commercials. He said he would put me on hold to contact the engineer but I could still hear the same background noise.

Thank you for the welcome. I am a huge Polk Audio fan from my Navy days. We did our A school in North Chicago and would go to the stereo stores to look at all the high-end components. I still remember hearing Polk for the first time. I couldn't afford the big stuff but I managed to scrape together all I could to buy a used pair of monitor 10's. Loved them but soon went crazy and replaced them with Infinity. These SDA's are my mid-life crisis. I have a feeling this may get expensive...

Saftgeek-

EndersShadow

Saftgeek wrote: »

I have a feeling this may get expensive...

Saftgeek-

Truer words never spoken. Especially if you stick around here long enough :biggrin:. Larrys rings, Gimpod's boards, X-over upgrades, Pepster SDA cables, A1 transformer..... yeah its a rabbit hole, but one worth going down from what I hear

chumlie

Welcome to CP. Hang on to your wallet. Hope you weren't stuck at Great Lakes during the winter, because it really sucked.

Saftgeek

Oh yeah... All winter! We made due by going to Waukeegan, Kenosha, and other WI destinations. Having a 19 year-old drinking age boosted the local economies back then. One bad thing was the amount of clothes the girls wore. They had a lot more opportunity to say no before you ever got to see any skin. Fun times!

Saftgeek

Schurkey

Saftgeek wrote: »

I also have an Onkyo power amp operating my subwoofer. I spoke with the techs at Onkyo and they say their amp is not a common ground.

Unlikely. Possible. Test it with an ohmmeter. < 1 ohm between negative terminals of opposite channels = good.

Saftgeek wrote: »

I am now searching for the how-to on the AI-1???

http://www.polkaudio.com/forums/attachment.php?attachmentid=26698&d=1186346846
Gives basic instructions, but the transformers listed are all discontinued (replaced with different part numbers.) No matter, the transformers are much too small for best sound quality.

Better is to search on "Dreadnought" for the 800-to-1000 VA transformer version of the AI-1. There will be a dozen threads to study. Currently a group-buy on the 1000VA transformer--unless it closed while I wasn't paying attention.

Saftgeek wrote: »

my main purpose for these would be as mains in my home-theater.

They'll be wonderful. That's exactly what I'm doing with my 1Bs.

Saftgeek

Thank you very much for the info. I still haven't seen the backs of the speakers I'm buying so the whole pin/blade thing is a little fuzzy. I'm sure this will be similar to my golf motto, "better golf through aggressive spending". Really getting jacked up to bring these home. If anyone has a list of issues to look for when buying I would appreciate that as well. So far I know to look at the cable, tweeters and cabinets.

Saftgeek-

gdb

Congrats and handle them with EXTREME care to avoid the dreaded magnet shift/MW paperweight syndrome !!! JB Weld the 6.5" drivers at your earliest convenience.

Saftgeek

Magnet shift??? JB Weld??? Now what is this all about? I am very venerable to some hazing. I keep waiting to be sent out for a glass of liquid steam... I will search and read. I do not want to mess this up. I wasn't this nervous about bringing my kids home from the hospital when they were born... Wow! Overload...

Saftgeek-

gdb

Yeah lousy glue can allow the magnets to slip loose and lock up the voice coil. Result?......most times a paperweight!

nspindel

Hello there Saftgeek, welcome to Club Polk.

Schurkey is correct, I am in the midst of assembling a group-buy for the 1000VA isolation transformers that are used to build a Dreadnought, which is basically an AI-1 cable on steroids. Here is the link to the group-buy thread, your participation would be most welcome. We need a minimum of 10 for an order, we're currently up to 8:

http://www.polkaudio.com/forums/showthread.php?134643-Group-buy-Avel-Lindberg-1000VA-isolation-transformers-for-DreadNought

chumlie's offered you the advice to hang on to your wallet. That won't be easy around here!

heiney9

If they have been stored the past 30 years, then they aren't 1C's. Perhaps your statement was an embellishment. The only reason I even mention it is because prior to the 1C's (and then only certain 1C models) you can't use the AI-1 cable. So if in fact these were stored for 30 that would mean they are from 1982.

Again, perhaps you were just approximating, but in the scope of AI-1 it's important to know for SURE which SDA's you have.

H9

pitdogg2

lay them on their backs to transport.

nspindel

Excellent point.

Saftgeek

I am sorry... I did do an approximation. I re-read what I was sent and he bought them in 1990. Not sure where 30 years came from. The serial number on the rear right is 8618. Not sure if this helps. He is asking $600 with cable. I am hoping to get them for $450. I'm looking forward to the back-and-forth for the $150 in the middle. I'm not sure how to post pics but I'll figure it out and hopefully show them off next week.

Again... Thank you all for the great welcome and advice. I can tell you are all passionate about this stuff.

Saftgeek-

nspindel

$600 if they've not been upgraded is way too expensive for 1C's. I'm about to sell my modded 1C's for $650, and that includes $200 worth of new tweeters, several hundred worth of new caps, Cardas posts, and Erse inductors. Seriously, you want him to cut that price in half.

When I purchased my stock 1C's a few years ago I paid $250.

heiney9

Saftgeek,

You are sure they are 1C's? They would have been discontinued by 1990, but I'm sure dealer stock would have still been available back then. Each speaker will have it's own serial number and they can vary widely.

H9

Saftgeek

Wow... I think I'll just buy your 1C's Mr. Nspindel. How far away are you from Mo. Like I said earlier, the serial on the right is 8618. Not sure about the left. I may print out this post with the replies so he can see why $600 is too much. I guess I may be doing a lot of driving on Sat for nothing... I hope not. I hate to beat anyone up too bad but I equally don't care to overpay myself. With the cable is $450 too much??? It sure seems so if I can buy modded ones for $650...

-Saftgeek

nspindel

$450 with the cable is too much, in my opinion. You'll find the sda cables for sale here from time to time for about $35.

nspindel

I actually have a spare cable that I'll be selling when I get round to listing all the parts I ripped out of the CRS+'s I'm modding right now.

littlewoodboats

Saftgeek wrote: »

Magnet shift??? JB Weld??? Now what is this all about? I am very venerable to some hazing. I keep waiting to be sent out for a glass of liquid steam... I will search and read. I do not want to mess this up. I wasn't this nervous about bringing my kids home from the hospital when they were born... Wow! Overload...

Saftgeek-

I think the liquid steam deal is more for the Navy. It was when I served anyway. I got to avoid the pink belly by being forewarned that it was a glass of water. (one would be surprised how many people do not know that when the word steam is used)

My biggest problem is trying to source a replacement for the Blue Smoke I keep hearing about that leaked out of my cabinets. There are many very smart speaker people here who can be helpful. One step at a time and you will get where you want to go.

The only advice I can give is be patient. SDA's are awesome speakers but the right set is worth the wait.

nspindel

Saftgeek wrote: »

I will search and read. I do not want to mess this up. I wasn't this nervous about bringing my kids home from the hospital when they were born... Wow! Overload...

Saftgeek-

Saftgeek, first of all, I want to thank you for your service to our nation. We all have brave people like you to thank for the freedoms we enjoy, and too many take for granted.

As far as the SDA's go, my first bit of advice is to take a deep breath, and don't let this stress you out. Bottom line is this is supposed to be all about fun - if you're stressing yourself out about this, it sort of defeats the point. You are not in any sort of rush here.

Here's my two cents on how you should proceed:

First step, obviously is acquiring the SDA's in the first place. I don't know anything about the speakers you're looking at and may purchase on Saturday, but do yourself a favor and don't overspend. That extra cash will come in quite handy as you travel down the upgrade path with them. If he wants $600 for these speakers, at a minimum I would hope that they come with replacement tweeters. You can easily tell the difference. The original tweeters have a clear plastic dome. The replacement tweeters, the RD-0194, have a black silk dome. You don't even need to ask, it's an easy visual inspection. Each speaker has two tweeters, and they're $50 a pop. So if these 1C's you're looking at come with $200 worth of replacement tweeters, they're still a bit pricey, but not off the charts. I would still try to talk him down by $100 or so if they do have the new tweeters. If not, try to talk him down to the $300 range. If that doesn't work, thank him for his time and wait for the next pair to come along. Keep your eyes on Craigslist, these come along all the time.

Next step is to understand exactly what you've bought. As H9 correctly pointed out, not all SDA's can use the AI-1. Such a speaker would be flat out incompatible with a non-common ground amp, as you've been told your Onkyo is. If the SDA-connection between the two speakers is a "pin-blade" type, where the cable has one round and one flat connector, then it is compatible. If the SDA-connector is a "blade-blade" type, then it may or may not be compatible. In this case, to determine if it is compatible, the best way to do it is to remove the passive radiator (the big round subwoofer at the bottom of the speaker) and look inside to examine the wiring of that SDA connector. If you see one of the two blade terminals with an internal wire connected to the ground (black) binding post, then they should be AI-1 compatible.

Again, assuming the Onkyo tech support person was correct in telling you that amp is not common ground, then it is very important for you to get this part right, because the only way you can use 1C's that can't use the AI-1 is with no SDA connection at all. Without the SDA connection, well...., they're not really SDA's any more.

Assuming they are AI-1 compatible, and your Onkyo information is correct, then you're off to build a dreadnought. With a non-common ground amp, I'd probably advise you to build a dreadnought before any other mods, since you really can't do much without it. So you can fork that cash that you save by talking your seller down over to me and get into the group buy:biggrin:

After that, I'd say the next thing you'd want to do (assuming the speakers don't already have them) is to upgrade the tweeters. This is an easy mod to do, since it's just a straight swap - pop the old tweeters out, pop the new tweeters in. You'll call Polk customer service, and order four of the RD-0194 tweeters. You should mention that you're a Club Polk member, you will get a discount.

From there, you can get started with the crossovers. I won't go too into that, let's take this one step at a time....

Keep us posted, we'll make sure you're going in the right direction.

heiney9

Neil,

Great advice but the AI-1 compatibility is not as cut and dried as pin/blade; blade/blade. The first serial number he has given is compatible no matter if it's a Left or Right speaker. If he could find out the other serial # then he should be set on the AI-1 compatibility.

H9

factorz

Saftgeek welcome to the club and believe these guys when they say get ready to spend. I first picked up a pair of RTA-12C that I fully upgraded and it was not long after that I picked up some 1C's as well. I paid $175, but they need a little work. Have fun and read lots as there are some really smart people here.

nspindel

heiney9 wrote: »

Neil,

Great advice but the AI-1 compatibility is not as cut and dried as pin/blade; blade/blade. The first serial number he has given is compatible no matter if it's a Left or Right speaker. If he could find out the other serial # then he should be set on the AI-1 compatibility.

H9

I thought that any pin/blade is AI-1 compatible, and blade/blades with one blade shorted to ground is as well. Blade/blade not shorted to ground is incompatible. Or am I wrong on that one?

FTGV

May I ask the model# of the Onkyo amp?

heiney9

nspindel wrote: »

I thought that any pin/blade is AI-1 compatible, and blade/blades with one blade shorted to ground is as well. Blade/blade not shorted to ground is incompatible. Or am I wrong on that one?

Yes, actually you are 1/2 correct, only certain serial number 1C's (pin/blade) can use the AI-1 without further modification. Blade/Blade no matter what model can't use the AI-1. 2B's need internal mods and only certain CRS+ and SRS2's can use the AI-1.

nspindel

Interesting, because my 1C's were blade/blade, although we all determined mine were made from a pile of spare parts. Remember this thread?

http://www.polkaudio.com/forums/showthread.php?70442-SDA-1-vs.-SDA-2B

I use a Dreadnought with my 1C's and it works great.

nspindel

Saftgeek, have a look at this thread I did on my 1C upgrades:

http://www.polkaudio.com/forums/showthread.php?70931-Meet-my-new-SDA-s&