Sda Crs

BobMcG

Remember, whenever you get bored with the Carvers I'll give them a good home.

Still got my addy??? You know, for shipping...

BobMcG

BTW: Does you buddy (I think his initials where J.M.) still have/use the preamp I sold him or has he moved on and up now?

madmax

I was wrong about the 1C's being the speaker stands for the CRS+. They were actually sitting on the SDA-SRS.

Which Carvers Bob? The 9t's or the Amazings?

JM was close! Actually JW. I believe he is still using the preamp. He didn't turn out to be crazy like the rest of us and try new stuff all the time. He was happy with it and looked no further.

madmax

dorokusai

Bob - I might have some Carver Amazings for you in the near future if you're interested.

BobMcG

Max: Yeah, I meant the Amazings. That's it JW. I had the W upside down that's all. I'm glad he liked it and is still putting it to use. Say hey to him for me sometime if you run into him.

Doro: It depends on the timing, $$$ wise that is, but I'm interested. Thanks.

danger boy

I guess these CRS's near me didn't sell for $495. Imagine that... Hmmmm?

he relisted here for the same amount again.
If he gets his price. i'll eat crow.

fredv

Looks like a trip to South Cal before Memorial Day :-)
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=71571&item=5772587159&rd=1

Any opinions? Looks like SDA SRS not 1.2, right?

-fredv-

Tour2ma

Definitely SL2000's, so yup, SRS's...

Go get 'em...

danger boy

worth replacing the SL2000's in the SRS's?

at a cost each tweeter, would equal how much? $$$ or $

fredv

Originally posted by danger boy
worth replacing the SL2000's in the SRS's?

at a cost each tweeter, would equal how much? $$$ or $

Let see, there are 8x SL2000, and each replacement RD0194-1 cost $48, that will add up to $384.... but I think that can be later since I don't really have the skills to modify the XO and system board to take full advantage.

-fredv-

BTW, I just scored a pair of Peerless 10A for $80 locally. My Peerless problem is solved Happy Happy.

Polk65

Originally posted by danger boy
worth replacing the SL2000's in the SRS's?

Well, if no one wanted to buy them here, you could always sell them on the bay for about 1/2 of what the updated tweeters would cost you.

Then you might get lucky and get $102 for a pair of used sl2000's like some lucky seller did a few days ago: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5769305337

edit: Congrats Fred, I'm glad you got them.

fredv

Congrats Fred, I'm glad you got them.

Thank you, Polk65. I guess dream do come true One week ago, there was no trace of the polks that I wanted, and this week, they start showing one by one, ebay and locally. Now, if there is a pair of SDA SRS for sale in Bay Area ........

-fredv-

Tour2ma

db,
I've not replaced the 2000's in my SRS's, but I've always liked brighter highs. They could be a little overly bright when I ran them off of my old, Yamaha C-2 pre. But my old and current B&K pre's tamed them quite a bit, and the Sunfire smoothed them out even more.

So it's really personal taste and what they're matched with. I'd certainly recommend that you live with them a while before deciding. That said, P-65 is right, you could offset around half the replacement cost by selling the 2000's.

fred,
The RD094-1's are drop in replacements for the 2000's. No x-over mod's required.

Glad your Peerless quest is sorta over. You still need one for repair of your other polks though...

danger boy

last question. then it's bed time.

are those replacements silk tweeters?

F1nut

Yes, rubberized silk domes and they are sweet with more detail.

fredv

Originally posted by Tour2ma

Glad your Peerless quest is sorta over. You still need one for repair of your other polks though...

You are absolutely right. I still hate to see one pair of 10A being handicaped ... However, the urge to find a replacement is greatly reduced. In fact, the Monitor 5 of the LF-14/M5 combo in the bay is Peerless, and there are a pair of Peerless Monitor 7. I almost bid the combo, but the cost is too high - almost $200 shipped. I would rather to contribute the amount to bid for the big SDA.

Kind of off topic a little bit, I have a vintage McIntosh 120wpc power amp, will it be enough to drive the big SDA SRS?

-fredv-

F1nut

Originally posted by fredv

Any opinions? Looks like SDA SRS not 1.2, right?

Both the SRS and 1.2 used SL2000's. The interconnect cable in the picture looks like it's a blade/blade which would mean they are SRS's as the 1.2's used the pin/blade cable. I'd email the seller to confirm that though.

Edit: the Mac will be fine.

Tour2ma

Are Mc's common ground amps? Seem to remember a poster that had issues with a Mc/ SDA setup a while back...

Do you remember that, Jesse? Seems like it all worked out, but can't remember the details.

If yes, the MC2125 (guessing) would get them rocking. Down the road you'd probably go for more amp, but it'd be a good start.

F1nut

Yeah Bruce, I do. Something to do with the Autoformer's they use.

fredv

Originally posted by F1nut
Both the SRS and 1.2 used SL2000's. The interconnect cable in the picture looks like it's a blade/blade which would mean they are SRS's as the 1.2's used the pin/blade cable. I'd email the seller to confirm that though.

Edit: the Mac will be fine.

Just curious, are the SRS and SRS 1.2 very different? From Polk's parts catalog, the diff seems to be the sub-bass radiators. Everything else are the same.

This is why I asked whether my MC-2120 could drive it, from
http://www.polkaudio.com/home/specs.php?category=3&speaker=261&vintage=1

Recommended Amplifier Power 1000 w/channel

Based on the 1.2TL specs, I suppose this should be 50-1000.

-fredv-

Tour2ma

Jesse,
Yeah... Wasn't he running mono-block Mc's, and one had an issue that he had repaired?

After the repair it was like they were immune to the short the SRS's SDA IC creates.

fred,
MC2120... well I had a 50/50 shot...

There were internal bracing differences, MW's and crossovers were different, the nominal impedance was raised from 5 to 6 ohms.

As for amp power... 1000 watts is Polk's maximum recommended level. Most would say that 200 wpc is about what they need to begin to strut, but into the SRS's 5-ohm load, your 2120 will be around that.

fredv

I don't have the manual of the MC2120. So, I don't have the specs at 4ohm. However, I also have a Japanese McIntosh Luxman R-117 receiver that can deliver 320wpc at 4ohm, but it doesn't sounds as warm as the Mac + the
Lux C-5000A preamp. It is a good match to the 10A, though.

-fredv-

BTW, a stupid question, I compared the "newly" acquired 10A to my "old" pair. Their post bindings have different orientation. The old pair has the +ve (red) post on the left, but the new pair has the red post on the right. Is it possible the new pair (actually older, smaller serial numbers) binding posts were replaced and reversed?

Tour2ma

Possible... easiest way to check is swap in your original one that still works and see if the sound goes out-of-phase...

Mac rated their amps prety concervativly. Your 2120's true 8-ohm output is likely 150 wpc or so. So it's 4-ohm is probably in the 180 to 200 wpc range. It has different speaker connection screws for different inpedance speakers... yes?

If the Mac is warmer, you could always let it handle the tweeters and assign the Mac-Lux the bass duties in a bi-amp configuration. It's worth a test anyway.

fredv

Possible... easiest way to check is swap in your original one that still works and see if the sound goes out-of-phase...

---> Good idea, will try it out. It will be really funny if both are reversed :-) The binding post looks like the original crap Polk's.

Mac rated their amps prety concervativly. Your 2120's true 8-ohm output is likely 150 wpc or so. So it's 4-ohm is probably in the 180 to 200 wpc range. It has different speaker connection screws for different inpedance speakers... yes?

---> Yes, and it has Autoformer ... From a few post back, not sure it can be a problem with SDA.

If the Mac is warmer, you could always let it handle the tweeters and assign the Mac-Lux the bass duties in a bi-amp configuration. It's worth a test anyway.

--> Another brilliant suggestion. The Lux has 2 pre-amp outs, but I never thought about bi-amp the Mac and the Lux. I should give it a try with my Dahlquist DQ-12 ....

-fredv-

Tour2ma

LOL.... thanks, I have moments of clarity...

On the speaker phasing, I've read where a sizable percentage of systems are operating 180 degrees off of "absolute phase". Difficult to impossible to tell.

On the Mac... a simple VOM test will tell you whether you do not have an issue, or have a potential issue.... but I'm still remembering the MAc's are immune due to the use of autotransformers.

Need to dig up that old thread....

Tour2ma

A member named "zagloba" was wanting to run a pair of MC300's bridged to mono with his SRS's.... and was able to do.

http://clubpolk.polkaudio.com/forum/showthread.php?s=&threadid=23710&highlight=mcintosh

BobMcG

Tour, I believe in the end he was running the amps in "Mono Parallel" not in the more common "Mono Bridged" mode. His Macs allowed him to do this.

The lucking out part: We discussed this in length probably eight or nine years ago but all that info has probably been lost. I've mentioned it again in a couple of threads this year about using bridged amps without an AI-1 but to recap...
Some people who tried this in the past had rather unpleasent results fairly quickly. However, the damage to an amp can take a couple of weeks to develop. In one instance I was close to, one amp was crippled and the other (same model) was only slightly damaged but was headed down the same path. Damage doesn't have to appear in an instant with results (like sparks or smoke or bad smell) you usually would associate with a dead short. It can sneak up on you!

Tour2ma

Thanks, Bob.

Yup we've had reports of both ways: instant flames and somewhat slower deaths.

In the thread I dug up, I'm not sure zagloba understood what he did, besides leave us hanging.

I think the bottom line is that fredv's MC2120 is going to be compatible with the SDA's... Agree?

BobMcG

I agree with what you stated earlier,

If yes, the MC2125 (guessing) would get them rocking. Down the road you'd probably go for more amp, but it'd be a good start.

I took a quick look at a post about the amp not being familiar with it.

POST: I was in conversation recently with a gentleman on the east coast who sells audio equipment through his store in Boston and on EBay. He has been in this business for 40 yrs. I mentioned that I had this amp and he stated that in his opinion the MC2120 was one of the most underrated power amplifiers available today. Largely overlooked. he felt because of the departure from McIntosh's usual design aesthetic notable with this model. It is a very simple looking amp and does not feature the usual glass and dials of their power amplifier line. Nonetheless this is one of the mintiest amps you will ever be fortunate enough to hear. The music is simply amplified with true accuracy. This amplifier is essentially transparent in every regard other than amplification. McIntosh mc2120 Power Amplifier. Mint Condition. The MC2120 Power Amplifier was produced between the yrs of 1976 and 1982. It sold new for $999. The Amp delivers a conservative 120 w/channel. It is solid state. ELECTRICAL: 120w/ch. (240w mono). Response 20-20kHz (+0 -0.25dB). Distortion 0.1%. Noise and hum -95dB. Output impedance 2, 4, 8 and 16 ohms. (1, 2, 4 and 8 ohms in mono). Damping factor 14 or greater. Input impedance 100k. Input sensitivity 0.75v or 2.5v. Headphone impedance: low. Sentry Monitor. Power Guard. FRONT PANEL: Anodized gold and black panel. Gain controls. Output mode lamps: normal or limit. Power sw: on or off. Headphone jack. BACK PANEL: Output barrier strips. Audio inputs. AC outlet. Input level sw: 2.5v or .75v. Mode sw: stereo or mono. Power Guard sw: normal or out. Fuse.

Sounds like a fine amp to me (being used in stereo mode with the SDAs). I do have to agree that the big SRSs could shine even more sometime down the road with even more oomph.

fredv

First, I want to thank all for the precious info. Now I know I have the gear to drive the SDA initially

I have 2 more hurdles to jump, and the first one is a stone wall from my woman. I was so excited to tell her what I intended to bid, and she was telling me that I would not haul those 180 pounders from LA back home Maybe she is still pissed the 2nd pair of 10A mysteriously appeared in our bedroom ..... Last is I will have to win the bid.

Let see I can convince the one sleeps next to me in the next 7 days - for this part, no advise is needed

-fredv-