Vintage SDA-SRS Revival & Restoration (Return to service)
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Mrwolf
Posts: 11
Please let me say in advance, thank you to anyone who proves to be helpful.
I have just had an amazing experience that is best explained with a metaphor.
"My crazy uncle and I were cleaning out his barn and we found a vintage muscle car stored behind a random stack of crap. He told me to take it, just get it out of the way.
In this situation you don't just give it a shot of starting fluid and a battery jump, hop in and take it on a road trip. There is a process of changing fluids, belts, filters etc before it is road worthy."
With this thinking in mind I recently stumbled onto a cache of vintage electronics, including a left and right pair of Polk SDS-SRS Speakers.
The speakers appear to mechanically sound.
There are no cracks or fractures in what appear to be butyl surrounds and the cones appear to be in good shape. The cabinets and grills do not appear to be abused other than being very dusty from sitting unused in the back of a garage for ~15 years
The speakers have not been exposed to water but in Indiana there is plenty of humid summer days.
The ambient humidity has corroded some of the speaker mounting screws. This is not a specific issue other that to help define the storage environment.
Soooo,,, with this being said I think there is likely some advice (or opinions) to be had related to a "Return to a service protocol".
How do I start to use these marvels of analog tech without running the risk of killing them prematurely? I am specifically concerned with the elasticity of the speaker surrounds and vic coil bellows.
I am thinking to use low level white noise for several hours (if not days) to flex the moving components gently for a while to restore flexibility. Further I would be interested in any pre power-up electrical test I might do with an ohm, inductance or capacitance measurement.
As a last point, I do not want to take unfair advantage of my friends generosity related to these speakers. Does the community have any thoughts related to the "As Found" monetary value of these speakers?
As a retired engineer of 40+ years I am looking forward to a mutually beneficial relationship with this forum, thanks in advance for your time and your thoughts.
I have just had an amazing experience that is best explained with a metaphor.
"My crazy uncle and I were cleaning out his barn and we found a vintage muscle car stored behind a random stack of crap. He told me to take it, just get it out of the way.
In this situation you don't just give it a shot of starting fluid and a battery jump, hop in and take it on a road trip. There is a process of changing fluids, belts, filters etc before it is road worthy."
With this thinking in mind I recently stumbled onto a cache of vintage electronics, including a left and right pair of Polk SDS-SRS Speakers.
The speakers appear to mechanically sound.
There are no cracks or fractures in what appear to be butyl surrounds and the cones appear to be in good shape. The cabinets and grills do not appear to be abused other than being very dusty from sitting unused in the back of a garage for ~15 years
The speakers have not been exposed to water but in Indiana there is plenty of humid summer days.
The ambient humidity has corroded some of the speaker mounting screws. This is not a specific issue other that to help define the storage environment.
Soooo,,, with this being said I think there is likely some advice (or opinions) to be had related to a "Return to a service protocol".
How do I start to use these marvels of analog tech without running the risk of killing them prematurely? I am specifically concerned with the elasticity of the speaker surrounds and vic coil bellows.
I am thinking to use low level white noise for several hours (if not days) to flex the moving components gently for a while to restore flexibility. Further I would be interested in any pre power-up electrical test I might do with an ohm, inductance or capacitance measurement.
As a last point, I do not want to take unfair advantage of my friends generosity related to these speakers. Does the community have any thoughts related to the "As Found" monetary value of these speakers?
As a retired engineer of 40+ years I am looking forward to a mutually beneficial relationship with this forum, thanks in advance for your time and your thoughts.
Comments
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I'd start with original windex and a very soft cloth and clean all the drivers and surrounds. Making sure the rag stays wet and do not spray the drivers only the rag. Use one had to hold driver to support and go around the driver gently. You will be amazed at the gunk that will come off them. They are a coated driver and should be somewhat sticky DO NOT try and scrub that off it should be there. This is the reason the rag needs to be wet to keep from dragging and sticking to the drivers. Turn the rag often and you may need several rags. Do not use a rag that will leave a lint coating on the sticky part of the cone. Microfiber might be a good candidate. I've used several thick folded paper towels in the past kept good and wet. Use your best judgement. There will be lots of brown stuff maybe dont sweat it just clean until it is no longer coming off onto the rag. Do not scrub gentle movements.
Good luck be extra careful with the big passive radiators you'll have better luck winning the lotto than finding a set of those.
Do not clean the tweeters like the drivers just leave those alone -
You will need jumpers on the binding posts. You cannot use a non-common ground amp, mono block or dual mono amps. Other than that just hook'em up.
Do you have the SDA cable?Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
I am sure others will chime in, but after they are cleaned up a bit I don't think there is any reason to not hook them up to an amp and give them a go. Those 6 1/2" drivers have rubber surrounds and last a looooong time. Many folks here, (me included) have vintage Polks that are 40 years old, that still have the original mid bass drivers. You don't have to blast them, but just see if the drivers are all working. These big SDA's need some power, minimum 100watts per channel. And the amp needs to be common ground . You should also consider rebuilding the crossovers, as the old capacitors are well past their useful life. Many upgrades and "mods" for those girls can be found on the forum and lots of very helpful and knowledgeable people.
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You can blow some canned air on the tweeters to get the dust off. The instructions for the drivers should be read as “damp to moist” and not “wet”. I would pull the crossovers and look at the condition of the components on the boards as well. These are of an age now where the crossovers should be refurbished.
As you clean them, push the driver gently inward to make sure they move freely. Also press the passive radiator and watch the driver movement. They should all move smoothly. Holding the radiator in, watch how long it takes for the drivers to settle back to their rest position. It should be about 3 seconds.
Use an amp that is common ground and fire them up. About 45 minutes should be all that is required to inspect and clean them up. Start slowly thought with the volume.The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD
“When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson -
Welcome to the forum @Mrwolf ! I just picked up an identical set as yours, not too long ago. Not stored in the garage, mind you. The above comments are exactly right, and your caution is well thought out.
Not sure if you mentioned you got the interconnect cable (blade/blade), but that is essential to bring them to life with an expanded soundstage! I replaced the tweeters on mine, and eventually will do the complete XO upgrade.
These bad boys are awesome! The best speakers I've ever owned!
Once you get em running, you'll be on the upgrade journey for sure!
Again, welcome to CP!Basement: Polk SDA SRS 1.2tl's, Cary SLP-05 Pre with ultimate upgrade,McIntosh MCD301 CD/SACD player, Northstar Designs Excelsio DAC, Cambridge 851N streamer, McIntosh MC300 Amp, Silnote Morpheus Ref2, Series2 Digital Cables, Silnote Morpheus Ref2 Series2 XLR's, Furman 15PFi Power Conditioner, Pangea Power Cables, MIT Shotgun S3 IC's, MIT Shotgun S1 Bi-Wire speaker cables
Office: PC, EAR Acute CD Player, EAR 834L Pre, Northstar Designs Intenso DAC, Antique Sound Labs AV8 Monoblocks, Denon UDR-F10 Cassette, Acoustic Technologies Classic FR Speakers, SVS SB12 Plus sub, MIT AVt2 speaker cables, IFI Purifier2, AQ Cinnamon USB cable, Groneberg Quatro Reference IC's
Spare Room: Dayens Ampino Integrated Amp, Tjoeb 99 tube CD player (modified Marantz CD-38), Analysis Plus Oval 9's, Zu Jumpers, AudioEngine B1 Streamer, Klipsch RB-61 v2, SVS PB1000 sub, Blue Jeans RCA IC's, Shunyata Hydra 8 Power Conditioner
Living Room: Peachtree Nova Integrated, Cambridge CXN v2 Streamer, Rotel RCD-1072 CD player, Furman 15PFi Power Conditioner, Polk RT265 In Wall Speakers, Polk DSW Pro 660wi sub
Garage #1: Cambridge Audio 640A Integrated Amp, Project Box-E BT Streamer, Polk Tsi200 Bookies, Douglas Speaker Cables, Shunyata Power Conditioner
Garage #2: Cambridge Audio EVO150 Integrated Amplifier, Polk L200's, Analysis Plus Silver Oval 2 Speaker Cables, IC's TBD. -
Original SRSs with blade/blade connections? As-found condition?
I say $700--$900 if all the drivers work. Start deducting for non-functional or otherwise damaged drivers, nicked corners, damaged veneer or grilles, soggy chipboard, etc. -
Once you get them cleaned up and running look into gluing the magnets on the MWs. Older Polk drivers such as yours are prone to magnet shift which can happen if they get bumped, lots of info here on that subject. Welcome to the Polk familyYamaha RXA1030, Yamaha CD-S2100, Yamaha AS-2200, Bluesound node 2i
Polk SDA2btl highly modded
Polk SDA 1C modded
Polk CS350 LS x2
Kimber 8TC
Sony 55" Bravia
Wish list SVS sub -
One thing is also, if these are bone stock is that they will have a polyswitch in the crossovers. These are problematic and will cause the high end to cut off earlier and earlier as they go bad. They were meant to protect the tweeters but don’t hold up. If the high end goes away at volume and comes back if the volume is turned down. The switch is the culprit.Main System
Marantz AV8802A PrePro
Marantz MM7025 Amp rear surrounds
McIntosh MC7205 Amp center, ceiling and mid surrounds
McIntosh MC300 Amp front mains
Oppo 203 Bluray
Polk SDA-SRS with VR3 monastery crossovers
Polk FX1000 Mid surrounds
Klipsch RP-440C Center channel
Klipsch RP-15M Rear surrounds
SVS prime elevation ceiling surrounds
Rythmik F15HP sub
Samsung 8500 curved screen 65" LED 4K
Mac Mini Server
Office System
Musical Fidelity M6s dac/preamp
Oppo 103D Bluray
Polk SDA-SRS 2
Parasound HCA-1500A
Polk PSW 650 sub
Microrendu
Roku Ultra
Mac Mini Server -
Here's a treasure trove of info, including those measurements you mentioned, authored by a great, generous member here.
http://vr3mods.com/uploads/SDA_Handbook_2011_Rev2.pdf
Also, review the stickied topics in the Vintage Speaker forum.
Congratulations on your good fortune! -
Dr_Wu,
Thank you for the document, it is appreciated.
I believe it will help me identify the specific model of my speakers as well as provide needed technical information.
However, can anyone identify the model from the photos posted above?
Thanks again to all for the comments and advice. -
Yours are SDA-SRS, first series.The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD
“When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson -
nooshinjohn wrote: »Yours are SDA-SRS, first series.
If I am not mistaken isn't a "identifier" for the first series the amount of bolts on the front plate?
Reason for the quotes being the random variations and left over parts used for later models.Just a dude doing dude-ly things
"Temptation is the manifestation of desire which equals necessity." - Mikey081057
" I have always had a champange taste with a beer budget" - Rick88
"Just because the thread is getting views don't mean much .. I like a good train wreck doesn't mean i want to be in one..." - pitdogg2
"Those that don't know, don't know that they don't know." - heiney9
"Audiophiles are the male equivalent of cat ladies." - Audiokarma Member -
codycatalist wrote: »nooshinjohn wrote: »Yours are SDA-SRS, first series.
If I am not mistaken isn't a "identifier" for the first series the amount of bolts on the front plate?
Reason for the quotes being the random variations and left over parts used for later models.
You are correct. Polk often used up existing stock in support of the newer models. IIRC, the XO faceplate was indeed used on some very early SRS gen 2's.
Another way to verify is to look at the mid-woofers (I did on mine just to be sure). They should be 6503's.
Either way Wolfie my man, you got yourself a sweet set of speakers!
Here's my journey:
https://forum.polkaudio.com/discussion/183597/the-sda-srss-have-landed-at-verbs-house/p1Basement: Polk SDA SRS 1.2tl's, Cary SLP-05 Pre with ultimate upgrade,McIntosh MCD301 CD/SACD player, Northstar Designs Excelsio DAC, Cambridge 851N streamer, McIntosh MC300 Amp, Silnote Morpheus Ref2, Series2 Digital Cables, Silnote Morpheus Ref2 Series2 XLR's, Furman 15PFi Power Conditioner, Pangea Power Cables, MIT Shotgun S3 IC's, MIT Shotgun S1 Bi-Wire speaker cables
Office: PC, EAR Acute CD Player, EAR 834L Pre, Northstar Designs Intenso DAC, Antique Sound Labs AV8 Monoblocks, Denon UDR-F10 Cassette, Acoustic Technologies Classic FR Speakers, SVS SB12 Plus sub, MIT AVt2 speaker cables, IFI Purifier2, AQ Cinnamon USB cable, Groneberg Quatro Reference IC's
Spare Room: Dayens Ampino Integrated Amp, Tjoeb 99 tube CD player (modified Marantz CD-38), Analysis Plus Oval 9's, Zu Jumpers, AudioEngine B1 Streamer, Klipsch RB-61 v2, SVS PB1000 sub, Blue Jeans RCA IC's, Shunyata Hydra 8 Power Conditioner
Living Room: Peachtree Nova Integrated, Cambridge CXN v2 Streamer, Rotel RCD-1072 CD player, Furman 15PFi Power Conditioner, Polk RT265 In Wall Speakers, Polk DSW Pro 660wi sub
Garage #1: Cambridge Audio 640A Integrated Amp, Project Box-E BT Streamer, Polk Tsi200 Bookies, Douglas Speaker Cables, Shunyata Power Conditioner
Garage #2: Cambridge Audio EVO150 Integrated Amplifier, Polk L200's, Analysis Plus Silver Oval 2 Speaker Cables, IC's TBD. -
Thanks for the input, I will confirm in the AM.
Looking forward to getting started on the project, -
Without a doubt they are first-generation SRS because of the blade / blade interconnect socket which is unique to this model. The 1.2 and 1.2 TL socket is pin/ blade. Polk never manufactured a blade blade 1.2 or 1.2 TL.SDA SRS 2.3TL's
Silk Audio MS-90-BT integrated tube amp
Yaqin MS-20L integrated tube amp
SDA 2B TL's -
I was looking at the serial number on the back...The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD
“When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson
