SDA CRS+ speakers with vintage receivers
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abescan
Posts: 6
in Electronics
I picked up 4 SDA CRS+speakers at a garage sale a few years ago without the IC cables for $50. What I have set up in my listening room (11 x 14) are 2 Sansui 2000X and 7070 that I got while in the Navy and 2 Fishers, a 800b and a 500b. Currently I am using JBL 4312's.
Will my receivers have any problems driving the CRS+ speakers?
Thanks!
Will my receivers have any problems driving the CRS+ speakers?
Thanks!
Comments
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You need to make an SDA cable or two because you are missing way more than you can imagine.
The CRS+ has a nominal 6 ohm rating, but dips lower. You'd want to use something capable of driving 4 ohm loads without breaking a sweat.
Another thing, with the SDA cable connected you cannot use non-common ground amps.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 -
Thanks!
I was wondering if there is a minimum wattage receiver to use with them. I don't have any modern ones.
My IC cable is the 2 blade connection- I'll have to locate one.
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Thanks!
I was wondering if there is a minimum wattage receiver to use with them. I don't have any modern ones.
My IC cable is the 2 blade connection- I'll have to locate one.
they(blade/blade) are the most common on the used market. -
Would my Sansui 7070 work fine with these speakers?
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yes it would work if you're not looking for rock concert levels.
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My listening room is only 11 X 14 and the volume knob is usually no more than at 10 o'clock.
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I was curious so I looked up your manual and it is rated for 4 Ohm impedance speakers. Interestingly, they rate it for 60 W RMS per channel regardless of 4 Ohm or 8 Ohm. I guess that is cautionary?
George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
Gardenstater wrote: »I was curious so I looked up your manual and it is rated for 4 Ohm impedance speakers. Interestingly, they rate it for 60 W RMS per channel regardless of 4 Ohm or 8 Ohm. I guess that is cautionary?
They might use output transformers like McIntosh does. -
Or it would put out a lot more than 60W per channel into 4 Ohms but cannot do so while maintaining the <0.3% THD specification. In other words, don't turn the volume control up very high into 4 ohms? I'm admittedly not familiar with output transformers in amplifiers. Have to read up on that.
Looking at the back of his receiver there are only 2 pairs of speaker outputs (System A and SystemB) and I don't see different outputs for different impedance loads.
George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
I know just enough electronics to be dangerous
but here's the schematic for the Left Channel and there is no output transformer or autoformer:
George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
I ran my CRS speakers from a 70 wpc Yamaha receiver for years. I thought they sounded fine. Then, I got a 70 wpc high current separate and was amazed at how much better they sounded. Since then, I've gone through a 200 wpc Rotel amp that produced significantly better sound, and now use an even better Parasound A21. The speakers love power.
And, by all means, buy or make an SDA cable. It's what sets SDAs apart. Lastly, consider giving at least one of those sets the 4.1TL treatment. -
Gardenstater wrote: »Or it would put out a lot more than 60W per channel into 4 Ohms but cannot do so while maintaining the <0.3% THD specification. In other words, don't turn the volume control up very high into 4 ohms? I'm admittedly not familiar with output transformers in amplifiers. Have to read up on that.
Looking at the back of his receiver there are only 2 pairs of speaker outputs (System A and SystemB) and I don't see different outputs for different impedance loads.
Amps do not have different outputs for different loads.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 -
Midwest Speaker has the Blade-Blade cable.
https://www.midwestspeakerrepair.com/shop/home-audio/woofers/polk-audio-1/polk-audio-interconnect-cable/"Sometimes you have to look to the past to understand where you are going in the future"
Harry / Marietta GA -
George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
There's no tubes in his Sansui.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 -
Yeah we know that, but invalid posed the question of the possibility that it might have an output transformer, which is apparently common or even mandatory in a true tube amplifier. I was saying that apparently it doesn't because I thought that the back of the amplifier should have different outputs (or at least a selector switch) for different impedance loads. Then I verified that it doesn't have one from the schematic.
The real question that remains unanswered is why doesn't it have a higher wattage output rating at 4 ohms vs. 8 ohms?George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
Maybe you'll figure it out one day.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 -
@abescan Welcome to Club Polk by the way
George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
Thank you- glad to be part of this!Gardenstater wrote: »@abescan Welcome to Club Polk by the way
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abescan, for the record you can safely drive 4 ohm nominal loads the same way you would drive 8 ohm nominal loads. Your Sansui's wpc rating is the same at 8 and 4 ohms because it has a current limiter circuit.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 -
abescan, for the record you can safely drive 4 ohm nominal loads the same way you would drive 8 ohm nominal loads. Your Sansui's wpc rating is the same at 8 and 4 ohms because it has a current limiter circuit.
That's something new I learned today, thanks for the info F1nut. -
It's a nicer receiver than my Technics SA500 that I had as a kid (still have in a closet). High Fidelity did a nice write up and it looks like it puts out about 10W more before clipping than they rate it for:
https://worldradiohistory.com/Archive-All-Audio/Archive-High-Fidelity/70s/High-Fidelity-1976-12.pdf
George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
Thanks for ALL the information!
Hooked the pair of speakers up and listening to them with the RL Led Zeppelin II. Even without the IC cable they sound very good . Will order a cable tomorrow- can't wait to get it!
