2B's back in business, but somethings wrong...

evhudsons

Is there a simple test to make sure the sda circuitry is right? I know there is the SDA test that is performed with the balance dial. My crossovers were well done with the tl upgrade, but I have noticed that before there was a notable change in sound the second I hook up the sda interconnect, now it's not quite as noticeable but certainly present. It was much more noticeable once I bypassed the stock sda jack but it doesn't seem to open up so much as it used to when I first connect the sda cord. Listening close to the dimensional driver it comes on as soon as I attach the sda cord so it's working, I just remember there being more of a difference without having to put my ear to the driver.

heiney9

There is a troubleshooting guide floating around. IIRC, that same guide came in the owners manual with the later generation SDA's.

H9

evhudsons

Thanks, I found it in the sticky for SDA's. My AVR doesn't have a simple balance dial, so I'll use my old Marantz for the test.

heiney9

evhudsons wrote: »

Is there a simple test to make sure the sda circuitry is right? I know there is the SDA test that is performed with the balance dial. My crossovers were well done with the tl upgrade, but I have noticed that before there was a notable change in sound the second I hook up the sda interconnect, now it's not quite as noticeable but certainly present. It was much more noticeable once I bypassed the stock sda jack but it doesn't seem to open up so much as it used to when I first connect the sda cord. Listening close to the dimensional driver it comes on as soon as I attach the sda cord so it's working, I just remember there being more of a difference without having to put my ear to the driver.

The best way is for you to be in the sweetspot and have someone else disconnect the cable. Trying to get up and do it and then sit back down won't give consistent results. If you aren't comparing the two in the sweetspot, then the results will be much less, to non-existent.

You didn't explain your procedure for disconnecting the cable and then how you determined you hear a difference.

jimbo1421

evhudsons wrote: »

Is there a simple test to make sure the sda circuitry is right? I know there is the SDA test that is performed with the balance dial.

There's this: http://www.polkaudio.com/forums/showthread.php?55888-POLK-AUDIO-Speaker-Wiring-Schematics-amp-More-Stereo-Dimensional-Array(SDA)

Last post in the list. It has ohmmeter tests as well as the balance tests.

Jim

evhudsons

cool, thanks! I printed the list up and will test tonight. I'm not sure if my wife wants to help but I'll ask her anyway.

When I was listening for change it's just when my interconnect first touches the jack. Before I would stand behind the speaker and I could hear the speaker "open" up as soon as there was the slightest connection. Now I have to stand in front of the speaker with the ear close to the dimensional driver and reach around to make the connection. I hear it suddenly come on, but it isn't as clear or noticeable from the rear when standing there.

It might be operator memory problems, but I would like to test it to make sure something isn't amiss. It's not enough to get me too worried as it sounds great, but I wondered before if something was slightly awry.

heiney9

IMO, that's not a great way to make a determination if there is an increase or reduction of the SDA properties. The biggest enhancement is in the sweetspot so that's where the judgment should be made. Your procedure makes perfect sense if you listen standing behind one speaker all the time.

Again, IMO and actually in my experience.

H9

evhudsons

That makes perfectly good sense. As I finished my post I was thinking about the changes I had made that might affect my perception. Certainly standing behind the speaker is absolutely the wrong place to make a determination and in front of one speaker. It may be that before the upgrades I heard more coming through leaky holes from the rear that are now fully sealed up and tight.

When sitting in front in the sweet spot which just happens to be my spot on the couch, I can tell a difference between not having the sda and having the sda. But I didn't have a helper. Sometimes sitting there I'm wondering what the heck, and then I check and forgot to put the sda cord back.

I will try the sweet spot test tonight, hopefully anyway.

Thanks!

bmbguy

Play the guitar intros at the beginning of Dire Straits "You And Your Friend" (oh heck, play the whole song!!) from the "On Every Street" album, with the SDA cable off, then with the cable on. As I'm sure you know, the effect is most apparent with material that is mixed to the extremes of the left and right channels. With that in mind, maybe disconnecting one channel of the input source might help too...

And yeah, definitely sit in the sweet spot!!

We need to produce some sort of set of SDA 'test tones' to burn on to a CD for testing/demoing purposes...

evhudsons

Dude, I mean guy, that is a great idea! I know there is an SDA playlist sticky but a SDA test playlist would be killer.

heiney9

bmbguy wrote: »

Play the guitar intros at the beginning of Dire Straits "You And Your Friend" (oh heck, play the whole song!!) from the "On Every Street" album, with the SDA cable off, then with the cable on. As I'm sure you know, the effect is most apparent with material that is mixed to the extremes of the left and right channels. With that in mind, maybe disconnecting one channel of the input source might help too...

And yeah, definitely sit in the sweet spot!!

We need to produce some sort of set of SDA 'test tones' to burn on to a CD for testing/demoing purposes...

evhudsons wrote: »

Dude, I mean guy, that is a great idea! I know there is an SDA playlist sticky but a SDA test playlist would be killer.

I like the idea for perhaps new SDA owners, but since all of our gear and room set-ups are different, meaning each song will have a different degree of SDA or bass or midrange, etc, how will that help trouble shoot an issue? I have heard 1C's exactly like mine in a completely different environment with different gear and I didn't hear the same sound from them.

My MIT cables alone made the SDA properties "pop" and I have certain tubes I roll that enhance the soundstage even furthur so how does that translate to everyone else's rigs? The short answer is, it doesn't.

H9

sda2mike

i find that the songs that thrill you with the most sda 'acrobatics'...are like the frog in the bugs bunny cartoon...when i sit my wife or friends down and say 'listen to this'...wouldn't you know it? the effect stayed home! next session, by myself of course, it returns! it's alot like my golf game...not every session is the same...you can't predict the sda...i have a bias adj. on my tube pre...as i wait for the bottles to warm, i like to change the setting slightly....it's more fun that a way

bmbguy

I think sometimes you get a little 'used to it' too, and have to play some of the more extreme examples just to convince yourself it's still there and working. And it does vary with other things, volume, etc.

Or maybe it's the weather...

That and my too-old ears are never the same from day to day.

Schurkey

bmbguy wrote: »

We need to produce some sort of set of SDA 'test tones' to burn on to a CD for testing/demoing purposes...

Any stereo test disc would do that. Stereophile released several about twenty years ago, they're still available.
http://ssl.blueearth.net/primedia/product.php?productid=2&cat=2&page=1 (all you really need--but the second disc is interesting, too.)

http://ssl.blueearth.net/primedia/product.php?productid=3&cat=2&page=1

http://ssl.blueearth.net/primedia/product.php?productid=4&cat=2&page=1

(I just ordered #3, I got the first two when they were new. Somehow, I missed that they'd released a third disc.)

I'm thinking that any disc that has hard-left and hard-right pink noise, and pink noise in stereo in-phase and stereo out-of-phase should be fine for testing the SDA effect.

heiney9

Watching movies on SDA's (2 channel) is startling sometimes. I've heard people talking in my dinning room as well as doors slamming behind me or other noises behind me. When the lights are off and the movie is playing several times I find myself jumping or atleast looking around the room a little bit when unexpected things happen. It's rather cool because it's a different experience than with 5.1 HT.

H9

heiney9

Schurkey wrote: »

Any stereo test disc would do that. Stereophile released several about twenty years ago, they're still available.
http://ssl.blueearth.net/primedia/product.php?productid=2&cat=2&page=1 (all you really need--but the second is interesting, too.)

http://ssl.blueearth.net/primedia/product.php?productid=3&cat=2&page=1

http://ssl.blueearth.net/primedia/product.php?productid=4&cat=2&page=1

(I just ordered #3, I got the first two when they were new.)

I'm thinking that any disc that has hard-left and hard-right pink noise, and pink noise in stereo in-phase and stereo out-of-phase should be fine for testing the SDA effect.

A noise generated cd would be much, much better than particular songs, but again you run into the differences within peoples rigs as far as gear and room placement. I think something like this is good on a pass/fail basis.

H9

sda2mike

the most nonchalant creatures in my house are the cats....when they wake up, during a session and go into urgent investigation mode, you know you got something good!

evhudsons

Again you make a valid point in the testing part. I think I just love to hear certain songs that do the SDA justice so a test cd makes sense. The SDA playlist is really nice and I think that passage is on there. Maybe there could be a top ten agreed crazy good SDA portion at the top.

We all know Pink Floyd is always going to be in the top ten, but it's nice to hear about other ones you wouldn't think about necessarily. And I do agree each session is different, awesomely so.

I was listening to an old Traffic record on my tt recently and it was just an SDA Nirvana session. I didn't even know I remembered that record, but it was one heck of an album to spin for SDA.

sda2mike

the remastered floyd albums are killer...esp. animals...mark knopfler has some lush productions that the sda's like

bmbguy

And sometimes you just have to put something like that on to make sure and 'refresh' your SDA memory. (Supertramp - School, Dreamer). And yeah, most anything associated with Mark Knopfler just has great sound, period.

Schurkey

heiney9 wrote: »

A noise generated cd would be much, much better than particular songs, but again you run into the differences within peoples rigs as far as gear and room placement. I think something like this is good on a pass/fail basis.

H9

Yes.

The nice thing about pink noise is that you don't get carried away with whether you like or dislike the music. Pink noise pretty much takes the emotion out.

If SDA speakers under test are capable of hard left beyond the left speaker, and hard right beyond the right speaker, and you can tell the difference between speakers that are in-phase and out-of-phase...and hear a difference between pink noise correlated between the channels vs. un-correlated--a person can rule out the speakers and the various cable/wire/crossover connections as a source of polarity defect. If the speakers can put noise in the correct locations and with the correct relationship between the two speakers, if there's still some sonic problem with music, it's either in the components themselves, some goofy recording defect, or in the speaker/listening position room interaction...or, I suppose, that person's ears.

heiney9

I rarely play anything that sounds flat and lifeless or would make me believe the SDA's aren't working, sure there are those great moments where they really "pop" with certain material. But I do some tube rolling so the sound changes a little, plus it keeps things from getting completely stale.

H9

heiney9

But my hard left and hard right could be because of more optimum room characteristics or because of gear choices. Not everyone is capable of reproducing hard right and hard left scenario's because of compromises. That's why I'm saying a test disc might be intense for some and just average for others, ie; too many variables. So is one set of SDA's broken or just limited based on room/gear/set-up choices?

H9

evhudsons

Actually, I use two channel movie as a test to some degree. On 5.1, or 7.1 even, some of the channels don't have the full power they could. When I switch to two channel, the soundstage is huge. I sometimes remark to my wife, "nice surround sound huh?", then I tell her it's only from the two CRS+ speakers. super cool. If it weren't for features I would go back to a simple preamp.

What is tube rolling?

heiney9

evhudsons wrote: »

What is tube rolling?

Swapping different brands, types, years of tubes in and out of my pre-amp. All tubes sound different so I can keep things from getting stale :cheesygrin:

I have my favorites, but I have about 20 pairs of signal tubes and 7 different types of rectifiers I swap (roll) in and out. :cool:

evhudsons

I'm thinking of getting rid of the couch and just putting in a hammock in the living room.



Tube rolling sounds like my next mountain to climb, it must be really nice hanging out at your house!

sda2mike

ev! you live in key west! you can have loads of fun tube-rolling....stay within your comfort zone $$wise...i like the old stock much better than any new attempts...i have some really sweet rca's that have stayed put for awhile..also some nice baldwins i scored on the cheep

heiney9

Other than the EL34 Winged C SED's power tubes I don't listen to any of the new tube offerings. IMO, too unpredictable and inconsistent and plain don't sound good (some exceptions I'm sure exist and people here will tell me). The best tubes, IMO, come from the late 50's and early 60's, there are exceptions of course. The only reason I get the SED's is because the Mullard's from the 50's and 60's cost way too much for my secondary rig. $90/pr for SED's vs. $299-399.00/pr for old Mullards and $199.00/pr for old Tesla's or RFT's.

H9

FTGV

bmbguy wrote: »

Yeah, I probably should have said "way too high". If I was working on a circuit and found 20 ohms between two points that were supposed to be common, you can bet I'd be digging trying to find out where those 20 ohms were, because something wouldn't be right.

Its likely that the designer has tied the grounds of each channel to a common or star ground point through a 10 ohm resistor to provide some isolation between the grounds of each ch..Strapping the negative terminals effectively jumpers those resistors.

evhudsons

It's funny how famous Key West is for it's other type of tube rolling. I'm sure it happens but for the most part they keep it to themselves the fact that it even exists.

I have my baby tubes and they are awesome. It makes me want to get more tubes!