I need to drive a pair of SDA-CRS speakers

Brusco

I have a pair of SDA-CRS speakers that I'd like to hook up to an amp (I haven't heard them yet). I don't need anything for concert levels but would like a nice amount of headroom. Can anyone recommend a good amp to drive these speakers? I think the amp would need to drive 4 ohms. I have a Dynaco SC80 solid state amp but haven't tried it yet. I think the "front Speakers" on the Dynaco are 4 ohms output. Do you think this will work for the time being? How much do you think I would need to spend to get a decent Vintage SS amp? I would like to keep it under a couple hundred if possible. It will be for a 10' x 12' room. I know it's too small for these but it's the only room I have. Thanks for any suggestions.

Mr. Bubbles

There are lots of goood amps out there and no pinpoint answers for your question. Searching CL usually gets you better deals than E-bay, etc. Some good ones would be Adcom, Carver, Marantz, Proton, Parasound, and many others. A lot of good vintage gear out there, some better than others and some just has differnt sound characterisitcs. Good luck.

Denzel

I have a pair of SDA CRS+ that I drive with an Adcom GFA-545. its 100 watts per channel (8 ohms), more than plenty for the room and speaker itself. However, like the above member said, there are as many options out there as you can imagine. Good luck

Mystery

I use my 7.1 receiver Marantz SR5500 and never have to go below 20 on the volume.

Brusco

I'd be happy with any good amp that could handle a 4 ohm load and had decent EQ controls. I recognize the Marantz name and that's as much as I know about good names to look for. Thanks for the others and also tips on where to look.
I would guess 30W per channel is not much headroom?

Dynaco SCA-80Q Specifications:

Power output: 30W/ch into 8 ohms (stereo), 30W/ch into 8 ohms (quadraphonic)

Frequency response: 15Hz to 50kHz

Total harmonic distortion: 0.5%

Damping factor: 40

Input sensitivity: 3mV (MM), 130mV (line)

Signal to noise ratio: 60dB (MM), 80dB (line)

Channel separation: 50dB (line)

Speaker load impedance: 8 to 16 ohms

Semiconductors: 20 transistors, 10 diodes

Dimensions: 13.5 x 4.25 x 10 inches

Weight: 16lbs

---

F1nut

any good amp that could handle a 4 ohm load and had decent EQ controls.

Amps do not have EQ controls, nor do you want anything that does.

Look on Audiogon or eBay for something that fits your budget. Keep in mind that a couple hundred isn't going to buy you much.

gdb

Common grounding is needed, BTW.

Brusco

No EQ? Are you suggesting a separate unit for EQ? A nice Marantz stereo tuner is not gonna cut it? What are my getting into here? I thought all amps were common grounded? I don't even know how to determine such a thing. I wish I had an electronic geek brain so I would automatically know this stuff.

Big Dawg

Brusco, where are you located? I'm assuming that your $200 budget is for either an integrated amp, a receiver, or separates (unlikely at this price point)?

Mr. Bubbles

I did forget to mention the common ground; it is necessary but no difficult to find. The specs you give do not indicate headroom. RMS power does not indicate headroom as headroom is essentially reserve power for dynamics. (I know this is not exact). Power amps are essentially that; power amps with no controls normally though some have level controls. You may be thinking of an integrated amp that has the pre-amp built into the same chassis as the power amp. EQ's are not necessary and normally not desired for audiophile sound. If you like them use one if you want, but most purists want nothing to do with one.

Per the specs you list, i would personally recomend one with better damping simply becasue of the design of the SDA's. thpugh this is jusd my opinion and many amps with low damping sound great. however they do not offer control over the drivers when cranking the volume that Higher damping does. With some speakers this matters little to none but the drivers in the SDA's have very loose suspensions compared to many others and in my opinion like a little more control from the electronics.

Mr. Bubbles

As others have said $200 is a limited budget. but more likely to find a fit on CL or local ad than web. Where are you located.

Big Dawg

Brusco wrote: »

No EQ? Are you suggesting a separate unit for EQ? A nice Marantz stereo tuner is not gonna cut it? What are my getting into here? I thought all amps were common grounded? I don't even know how to determine such a thing. I wish I had an electronic geek brain so I would automatically know this stuff.

F1nut is suggesting that you forgo all eq controls completely, as they degrade the sound quality. He's correct, or course, but don't worry about it. Just find a nice piece in your price range that is common-ground. If you tell us wher you are, we can help.

Mystery

Brusco wrote: »

No EQ? Are you suggesting a separate unit for EQ? A nice Marantz stereo tuner is not gonna cut it? What are my getting into here? I thought all amps were common grounded? I don't even know how to determine such a thing. I wish I had an electronic geek brain so I would automatically know this stuff.

1st, usually EQ is not recommended for listening music so don't use them and don't buy them.
2nd, suggestions for separate amp here are mainly for the best/optimum performance of CRS+ that you may never need as I have used vintage 45 wpc integrated receivers to 100 wpc and modern home theater receiver ranging from 75 - 110 wpc and it doesn't make any difference at my listening levels and room.
For me, I never need more than 4 watts.
So anything above 30 wpc will work fine unless you have a large room that you can make them a lot louder and if you do, get something with at least 100 real watts per channel.
Don't shoot for perfection and be careful on the volume knob.
Use what you have now and upgrade later.

Big Dawg

If you build your post count up to 100, here's a decent option on our "for sale" board:

http://www.polkaudio.com/forums/showthread.php?146662-Very-Nice-Denon-DRA-635R-80-w-ch-AM-FM-receiver-w-phono-remote-controllable

Nice little receiver for $100, even has pre-outs so that you can use it as a preamp when you decide to add an amp in the future.

westmassguy

Brusco, are they CRS or CRS+. What type of IC cable connects between the two? Blade/Blade, or Pin/Blade?
One tweeter or Two? We need to figure out which CRS you have before assumptions are made as to how much power you really need.

PolkieMan

Here is your new "Electronic Geek Brain", all your answers are in here.
It's a big pdf file so give it some time.
http://vr3mods.com/uploads/SDA_Handbook_2011_Rev2.pdf
Then you can tell us exactly what model CRS that you have:biggrin:

Brusco

I'm in Hatboro PA, North of Phila.
My SDA's are the 2-blade double tweeter version I think. I don't have the interconnect cable. Can I just use 12 guage speaker wire to see if they are working?

I didn't think it would cost more than a couple hundred bucks to have a decent sounding stereo system. I'm no purist but I would spend more if it's going to sound bigger and more dynamic. Does this mean I have to buy a turntable too? I think I read on here somewhere that an underpowered amp is more prone to ruin your speakers than a high powered amp. Is that true?

TennMan

Brusco wrote: »

I'm in Hatboro PA, North of Phila.
My SDA's are the 2-blade double tweeter version I think. I don't have the interconnect cable. Can I just use 12 guage speaker wire to see if they are working?

I didn't think it would cost more than a couple hundred bucks to have a decent sounding stereo system. I'm no purist but I would spend more if it's going to sound bigger and more dynamic. Does this mean I have to buy a turntable too? I think I read on here somewhere that an underpowered amp is more prone to ruin your speakers than a high powered amp. Is that true?

Nice looking speakers. You have what is referred to as the blade/blade IC connectors. You could use speaker wire in place of the IC if you connect if properly. Here is a link to the wiring diagram for your speakers. The only reason you would need a turntable is if you want to play vinyl records.

As far as how much you will need to spend... that depends on your taste in music. Some people are perfectly happy lightening to an AM radio and some people absolutely have to have the best of everything. The sky is the limit on what you can spend. You should try what you already have and see if you like it. Be sure take the time to setup you CRS speakers correctly and getting them working properly before you start spending money or decide you don't like them. Just having the IC connected will make all the difference in the world with those speakers. My CRS speakers don't have the extra dimensional tweeter but I've heard those CRS speakers sound better with the dimensional tweeter disconnected.

Brusco

How are my going to get my post count up over 100? By that time I'll miss out. Thanks for the SDA Handbook PolkiMan. DSkip, that's a nice receiver. TennMan, Thanks for the advice. At this point I'm not picky about differences in high-end audio gear. I'm sure it all sounds good to me. I can appreciate really well recorded music though. I want to hear what Steely Dan Aja sounds like or Dark Side of The Moon, I have plenty of vinyl from the 60's and 70's and I do believe it sounds more dynamic on vinyl.

TennMan

BTW, I think the blade/blade IC is still available from Polk for about $40. At least it was about a year ago. Tell them you are a member here and I think you will get free shipping.

Brusco

TennMan, Schematics only confuse me (A,B,1,2,Black,White, Blue?). It seems so simpler like this> Connect the speaker wire from Left large slot to the Right large slot, and connect the small slots L & R to each other. I will eventually buy the cable if it's available.

PolkieMan

Yes definitely a straight thru connection: wide blade to wide blade, narrow blade to narrow blade.

http://www.alliedelec.com/search/productdetail.aspx?SKU=70152851

gudnoyez

There were a couple of Parasound HCA 1000A for sale on the forum that would be a good match, as far as 100 post count participate
In threads, get your post count up maybe they will be for sale once you reach that magic number. Are the original CRS really 4 ohms? I know the CRS+ are 6 ohm. I have ran my CRS+'s off a Yamaha Avr, a Technics Integrated, and currently off of an Adcom 545, so you should look for a Integrated or an Amp that has 100 Wpc however I did run them off an Adcom 535 for a while and they sounded thier best off of that at low to medium volumes.

Brusco

I just realized I have an Alesis RA100 power amp for driving Studio Monitors. They are hooked up in my recording setup but I can use it temporarily to see how these SDA's sound until I find something better. Here are the specs. Let me know what you think.

Alesis RA100
Output Power: 100 watts into 4 ohms, 75 watts into 8 ohms, per side
THD: 0.05% THD @ 1kHz (8 ohms), 0.19% THD @ 1kHz (4 ohms)
Frequency Response: ±1dB 20Hz - 20kHz
Recording studio reference monitoring
Live sound reinforcement for small venues
Noise: 100dB below full output
Damping Factor: 200 @ 8 ohms
Input Sensitivity: .5 VRMS for full output
Input Impedance: 7k ohms, unbalanced
Input Connectors: 1/4" phone jacks
Output Connectors: 1/4" phone jacks and push clip terminals
Power Requirements: (US Domestic) 120 VAC, 500 W Max
Dimensions: (WxHxD) 19"x3.5"x8"
Weight: 14.25 lbs

F1nut

I'm not big on specs, but couldn't help notice the weight at 14.25 lbs. Is that correct?

My suggestion, before trying to figure out how to drive them, get the SDA cable issue worked out otherwise you're basically playing half of the speakers.

TennMan

Brusco wrote: »

TennMan, Schematics only confuse me (A,B,1,2,Black,White, Blue?). It seems so simpler like this> Connect the speaker wire from Left large slot to the Right large slot, and connect the small slots L & R to each other. I will eventually buy the cable if it's available.

Some people like to see the schematic and some people don't any use for them. I happen to like roadmaps when I go somewhere I've not been before.

Regardless of whether you choose to make it or buy it you definitely need an IC cable for the SDAs to sound right.

Big Dawg

I live in central nj and have a spare blade blade cable you can borrow, and various amps as well. You're welcome to try them out if you'd like.

F1nut

A most generous offer!

PolkieMan

That's the way I got my 1C's off that guy he never knew about the cable or hooked it up of course so he was playing only half ofthe speaker. That amp is a little light weight just don't play them loud till you know where your at. I always check mine for heat and never put one in an enclosed cabinet. Sda Crs and + are 6 ohms. Referenced the Handbook.

F1nut wrote: »

I'm not big on specs, but couldn't help notice the weight at 14.25 lbs. Is that correct?

My suggestion, before trying to figure out how to drive them, get the SDA cable issue worked out otherwise you're basically playing half of the speakers.

Brusco

That's a nice offer Big Dawg. If you were closer I would already have taken you up on it. Let's see if the IC is working then I'll think about amps. Thanks for all your responses.