Polk SDA-2 Amp/Preamp/Receiver Advice Requested!

ANY decent amp that is COMMON-GROUND and will drive a 4-ohm nominal load should be fine. This includes the amplifier section of receivers or integrated amps.

"I" would buy used--but then I'm fairly risk-tolerant. As far as stereo music reproduction, there are dozens if not hundreds of amplifiers, integrated amps, and receivers that could meet your needs.

Adding multi-channel decoding for movies or surround music makes everything much more expensive. AV receivers typically have crap amplifier sections and too-small power supplies.

If I were in the market, I'd buy...just about what I have now: An older preamp-processor lacking the latest "features" but with solid build quality and the ability to decode Dolby Digital and DTS movies. There are many brands and models that fit this profile, mine is an Aragon Stage One, which can be had used for $500 or so--sometimes less.

I'd start with a quality two channel (stereo) power amp, as as time and funds allow, purchase additional amps and speakers as desired.

It shouldn't be too challenging to get a used but quality Pre/Pro and a stereo amp for nicely under a thousand dollars; leaving some budget for additional speakers and amps--although total expenditure of $1500 may be tight.

Some of this, of course, is where you are and what stuff is showing on your local Craigslist. Audio Mart, eBay, and Audiogon are additional sources of used gear.

HCA-3500 2 Channel Amplifier:

FEATURES
•Independent power supplies for each channel for true dual-monaural operation
•Massive encapsulated 1.4 kVA toroid power transformer for each channel
•97,600 uF power supply capacitance for each channel
•Multiple polystyrene film bypass capacitors in power supply
•Direct coupled design uses no inductors or capacitors in the signal path
•DC servo direct-coupled audio circuits with 0.5 Hz rolloff
•Output transistors direct-coupled to speakers without LRC networks
•Cascode Class A input stages with matched J-FET pairs
•Hand-picked complementary MOSFET transistors in high voltage driver stage
•High-bias Class A/AB operation provides 15 Watts of pure Class A operation
•8 complementary pairs of 15 ampere 60 MHz output transistors per channel
•High-quality Neutrik XLR jacks for balanced inputs
•Two sets of gold-plated metal structure RCA input jacks for balanced operation
•Two sets of gold-plated 5-way binding posts facilitates bi-wiring
•Multiple protection circuits, temperature sensors and silver-cadmium relay protection
•Glass epoxy circuit boards, double-sided for precision
•Two hand-made audiophile-grade AC power cords-separate for each channel

SPECIFICATIONS
•Continuous Power Output - Stereo:
350 watts RMS x 2, 20 Hz - 20 kHz, 8 Ω, both channels driven;
500 watts RMS x 2, 20 Hz - 20 kHz, 4 Ω, both channels driven
•Current Capacity:
120 amperes peak per channel
•Slew Rate:
> 200 V/µsecond
•Power Bandwith:
2 Hz - 150 kHz, +0/-3 dB at 1 watt
•Total Harmonic Distortion:
<0.025% at full power; < 0.01% at typical levels
•IM Distortion:
<0.03%
•TIM:
unmeasureable Dynamic Headroom: > 1.5 dB
•lnterchannel Crosstalk:
> 95 dB at 1 kHz, > 80 dB at 20 kHz
•Input Sensitivity:
1 V for 28.28 V; 2 V for full output
•Input Impedance:
100 k Ω
•S/N Ratio:
> 120 dB, full power
•Damping Factor:
> 1000 at 20 Hz
•Power Consumption:
1200 watts
•Dimensions:
w 19" x h 7" x d 22", h 7 5/8" with feet
•Net Weight:
85 lb.

HCA-1500A 2 Channel Amplifier:

FEATURES
•Designed by John Curl
•THX certified by Lucasfilm Ltd.
•Independent power supplies for each channel
•Massive 1 kVA toroid power transformer
•60,000 µF computer-grade capacitors in power supply
•Multiple polystyrene film bypass capacitors in power supply
•DC Trigger Auto On Feature
•Cascoded Class A input stages with matched J-FET pairs
•Handpicked complementary MOSFET transistors in high voltage driver stage
•8 complementary pairs of 15 ampere 50 MHz output transistors
•Output transistors direct-coupled to speakers without LRC networks
•DC servo direct-coupled audio circuits with 0.8 Hz rolloff
•High-bias Class A/AB operation
•Gold-plated metal structure RCA input jacks
•Gold-plated looping output jacks
•Multiple temperature sensors and silver-cadmium relay protection
•Glass epoxy circuit boards, double-sided for precision
•Custom designed audiophile-grade AC power cord
•Multiple Protection Circuits

SPECIFICATIONS
•Continuous Power Output - Stereo:
205 Watts RMS x 2, 20 Hz-20 kHz, 8 Ω, both channels driven
315 watts RMS x 2, 20 Hz - 20 kHz, 4 Ω, both channels driven
•Continuous Power Output - Mono:
630 watts RMS, 20 Hz - 20 kHz, 8 Ω
•Current Capacity:
60 amperes peak per channel
•Slew Rate:
> 130 V/µsecond
•Frequency Response:
5 Hz - 100 kHz, +0/-3 dB at 1 watt
•Total Harmonic Distortion:
< 0.03% at full power; < 0.01 % typical levels
•IM Distortion:
< 0.03 %
•TIM:
unmeasurable
•Dynamic Headroom:
> 1.5 dB
•Interchannel Crosstalk:
> 80 dB at 1 kHz; > 60 dB at 20 kHz
•Input Impedance:
33 k Ω
•Input Sensitivity:
1 V for 28.28 V, THX Reference Level; 1.2 V for full output
•S/N Ratio:
> 110 dB, input shorted, IHF A-weighted
•Damping Factor:
> 800 at 20 Hz
•Power Consumption:
500 watts
•Dimensions:
w 19" x h 5 1/4" x d 16", h 5 7/8" with feet
•Net Weight:
40 lb

I couldn't find the 1200II the lowest one they had is this.

HCA-2200II ULTRA HIGH CURRENT AMPLIFIER. Our premiere amplifier created by legendary designer John Curl has been called by Stereophile,"...a benchmark product against which other amplifiers can be measured."

FEATURES
•Two independent 1200vA toroid power transformers
•Independent transformer windings for driver stage regulators
•Higher driver rail voltages and independent regulation to prevent sag
•100,000uF computer-grade capacitors in power supply
•Multiple polystyrene bypass capacitors in power supply
•Cascode Class A input stages with matched J-FET pairs
•Hand picked Mosfets in high voltage driver stages
•24 5OMhz, 15 ampere output transistors, B-matched complements
•Output transistors direct-coupled without inductors
•DC servo direct-coupled audio circuits with 0.3Hz rolloff
•Linear tracking, instantaneous acting DC servos
•Pure Class A operation up to >6 watts output; Class AB-1 thereafter
•Balanced input circuits, XLR connectors, separately switched
•Gold-plated metal structure RCA input jacks
•Multiple temperature sensors and silver-cadmium relay protection
•FR-4 glass epoxy circuit boards, outputs double clad for high current
•Dual mono circuit topology for superior separation past 20kHz
•Proprietary quick-settling bias circuits obviates warmup period
•Silver plated audiophile-grade wiring drivers to outputs
•Precision 1% tolerance Holco and Resista metal film resistors

SPECIFICATIONS
•Continuous Power Output - Stereo
250 watts RMS x 2, 20 Hz-20 kHz, 8 Ω
385 watts RMS x 2, 20 Hz-20 kHz, 4 Ω
385 watts RMS x 2, 20 Hz-20 kHz, 2 Ω
•Continuous Power Output - Mono
750 watts RMS, 20 Hz-20 kHz, 8 Ω
1000 watts RMS, 20 Hz-20 kHz, 4 Ω
•Current Capacity
50 amperes continuous
90 amperes peak
• Slew Rate
>135 V/µsecond
• Frequency Response
2 Hz-95 kHz, +0/-1.5 dB
• Total Harmonic Distortion
< 0.05% at full power
< 0.009% typical levels
• IM Distortion
< 0.03%
• TIM
Unmeasureable
• Dynamic Headroom
> 1.5dB
• lnterchannel Crosstalk
> 84 dB at 1 kHz
> 74 dB at 20 kHz
• Input Impedance
100K Ω/RCA-unbalanced, 200K Ω/XLR-balanced
• S/N Ratio
> 114 dB, input shorted, IHF A weighted
• Damping Factor
> 1000 at 20 Hz
• Dimensions
19" wide x 7" high x 15" deep
• Weight
60 lbs. net
• AC Power Requirements
1000 watts

BigPondSmallFish wrote: »

drumminman wrote: »

I think you're better off getting a good 2 channel amp, like the Parasound, than a 5 channel. It'll have a much beefier power supply than a 5 channel (typically).

Unless I'm greatly mistaken, the HCA-3500 should be a 2 channel amp, and a bit beefier than the 1200ii or 1500?

If I'm not mistaken he was probably talking about the Theta you mentioned earlier.I have the 2b's also and I think the Parasound 1200,1500 will do just fine.If you get them for the right price you can always upgrade at a later point.It seems like some of the 3500's are common ground and some are not so maybe go with the one you know is common ground to start with.The rabbit hole has no bottom so I hope you enjoy the ride.

I toiled over the HCA-3500/common ground question myself earlier this year. I did the multimeter test across the negative speaker terminals and I get continuity, which, according to the test, is supposed to indicate common ground.

I still haven't tried it yet with my SDA's, but intend to shortly, relatively confident after the research that it will be fine.

I'd be curious to hear that Peachtree Nova with your SDA's, myself. I like that idea of simple/practical; minimalist.

The reading was 0.3 ohms, iirc. Been a while, and perhaps I'm forgetting the specifics of what I was to look for in that simple test.

I also spoke with Parasound when I was trying to figure this out. They didn't answer with a specific 'yes' to the common ground question, but instead said that the negative terminals can be strapped. I don't really know what that means with respect to this question.

I'll double-check and see if I can get a schematic to check out.

solarrdadd wrote: »

howdy people, i have a pair of SDA-2's just like the OP's (except with the 2000 tweeters) and i have an amp question. i do not use the interconnect because in the apartment that i live in, i don't have the space to spread them apart as far as they really need to be for an effective use of the array nor do i have the side distance from wall clearance. i do use them in regular "stereo mode" (without the cable) and they sound amazing and i love them. i am thinking about buying a pair of mono block amps for them but just want to be sure if the "common ground" issue with amps is limited to the speakers when in use by the interconnecting cable?

i don't plan on using the cable either i've tried it, but, for me, with the speakers in limited space apart and close to the outter walls, it didn't sound good; too much reflection from the side walls. regular stereo is heaven though.

i know some folks are against not using the cable, but, for me, they just don't sound good with them so close to the side walls. with the reflections. so, blocks or no blocks in stereo only?

thanks to any and everyone who responds.

Original SDA-2s? Dual Horizontal Tweeters? If so, disconnect the dimensional Tweeters, safe-off the wiring harness, re-connect the Interconnect Cable and have another listen. You may be surprised.
The Mono-Blocks will work with the IC disconnected, but are you planning on being in that apartment for the rest of your life? A couple years down the road, you get a bigger space, and you want to use the Interconnect. Those Mono-Blocks will be useless if their original SDA-2s.

westmassguy wrote: »

solarrdadd wrote: »

howdy people, i have a pair of SDA-2's just like the OP's (except with the 2000 tweeters) and i have an amp question. i do not use the interconnect because in the apartment that i live in, i don't have the space to spread them apart as far as they really need to be for an effective use of the array nor do i have the side distance from wall clearance. i do use them in regular "stereo mode" (without the cable) and they sound amazing and i love them. i am thinking about buying a pair of mono block amps for them but just want to be sure if the "common ground" issue with amps is limited to the speakers when in use by the interconnecting cable?

i don't plan on using the cable either i've tried it, but, for me, with the speakers in limited space apart and close to the outter walls, it didn't sound good; too much reflection from the side walls. regular stereo is heaven though.

i know some folks are against not using the cable, but, for me, they just don't sound good with them so close to the side walls. with the reflections. so, blocks or no blocks in stereo only?

thanks to any and everyone who responds.

Original SDA-2s? Dual Horizontal Tweeters? If so, disconnect the dimensional Tweeters, safe-off the wiring harness, re-connect the Interconnect Cable and have another listen. You may be surprised.
The Mono-Blocks will work with the IC disconnected, but are you planning on being in that apartment for the rest of your life? A couple years down the road, you get a bigger space, and you want to use the Interconnect. Those Mono-Blocks will be useless if their original SDA-2s.

thanks, i've never heard of the disconnecting the array tweeter, but, i'll give that a try and get back to you. while i may or may not live in that or another apartment for the rest of my life, (cause there is nothing wrong with living in an apartment) mono blocks will never be usless, perhaps not usable with interconnected SDA-2's but never useless. i was also really just wondering about buying some blocks i saw at a great price and wanted to know about using them with my non interconnected SDA-2's having read you can't use them with the cable connected.

i'll disconnect the tweeters and re connect the cable and let you know what i think. thanks for your suggestion. also, they sound amazing as is just running as regular stereo speakers. i watch movies and even game on my 2 channel system with them and they sound amazing no matter what i'm doing.

westmassguy wrote: »

I'd didn't mean to infer they were useless, I was referring to their use with your particular model 2s

oh i know, we're cool. i was just curious about the blocks in a stereo only mode. they are such a good price that even if i only used them for a couple of years, i will have gotten my money's worth out of them. also, the 2 channel setup i'm using is fully balanced quad differential (oppo 105 XLR out to emotiva XSP-1 XLR in) the blocks are emotiva XPA-1L and they too are fully balanced quad differential mono blocks. so i'd love to have that quality of signal path to my SDA-2'S and like i said, i'm perfectly happy with them in stereo mode no problem.

of course it was suggested that i disconnect the array tweeter in each speaker and then put the interconnect cable to it and give that a listen with the 2 channel amp i currently have, so, i am going to give that a try and see how i like it. who know's, it might blow my mind and i'll just keep it that way!

i'll keep you posted. check back in the next couple of days.

Glad you're enjoying them. They'll grow on you.