I'm the original owner of SDA-1C & finally (30+yr) at the point I can afford a great AMP.

FraSerK

What are some recommended 300-500+W AMPS that are compatible with the SDA 1C?

Thank you,
FraSerK

Nesmith98

Holy toaster ovens Batman, that's allot of wattage. Half of that range would be sufficient.

Tony M

Krell amps.

Moose68Bash

For years the last several years I've used a vintage Perreaux PMF3150 amp with the SDA 1Cs I purchased in 1989, and I still love their sound.

A few years ago I did the full range of modifications one them, including spectacular new crossovers by Vr3 Mods. These speakers "sing" beautifully with the old Perreaux.

When I first purchased my 1Cs, I also purchased a Perreaux PMF2350 amp, which is 200W/channel. The PMF 3150 is from the same era and delivers 300W/channel. The increase in power brought out even better sound from the speakers.

BlueBirdMusic

Look at this recent thread too. It is about SDA 2Bs, but applies to 1Cs.

FraSerK

thanks for all the suggestions Krell, PMF3150 Vr3 rebuild etc.. and of course the comments - toaster over LOL - my 1989 SDA 1C are AMP hogs and in reality only start to partially "wake up" at 200W. current driving with/since 1998 my Denon AVR5700 at 170W/170W - I am ready to take them to the next level 300-500W to each L/R.

motorstereo

Mcintosh MC2500 will light them up, sound great at low volumes and has the important power guard circuit.

Tony M

I've loved how my NAD C370 integrated has powered my 4 ohm SDA-SRS2s over the years.

I STILL might buy this one below soon just because it's so damn good!. It would be my second one.

There's a GREAT one for sale right here, right now too.
https://forum.polkaudio.com/discussion/187002/nice-nad-c370-w-remote-power-cord-and-manual#latest

BlueFox

Also think about upgrading the speakers, or at least rebuilding them. Everything wears down over time, especially mechanical/electronic gear.

audioluvr

FraSerK wrote: »

thanks for all the suggestions Krell, PMF3150 Vr3 rebuild etc.. and of course the comments - toaster over LOL - my 1989 SDA 1C are AMP hogs and in reality only start to partially "wake up" at 200W. current driving with/since 1998 my Denon AVR5700 at 170W/170W - I am ready to take them to the next level 300-500W to each L/R.

200w is more than enough with the right amp. Heck that NAD @Tony M mentioned would wipe the floor with your Denon AVR and its only 120wpc.

BlueFox

Stereo power is like money. The more, the better. You can never have too much. Of course, it must be good, clean power, but don’t be misled by low power advocates. Even at very low listening levels, power is important.

txcoastal1

Bryston

BlueFox

Plus Bryston has a 20 year warranty on their analog gear.

F1nut

FraSerK wrote: »

thanks for all the suggestions Krell, PMF3150 Vr3 rebuild etc.. and of course the comments - toaster over LOL - my 1989 SDA 1C are AMP hogs and in reality only start to partially "wake up" at 200W. current driving with/since 1998 my Denon AVR5700 at 170W/170W - I am ready to take them to the next level 300-500W to each L/R.

The 1C's are not even close to power hogs, 6 ohm nominal - 90dB 1 watt/1 meter. I've driven them extremely well with a 75wpc tube amp.

BTW, your AVR is rated at 140wpc, not 170.

tonyb

It's not about watts, it's about current. Amperes peak to peak.....and your receiver doesn't have it in spades like a dedicated amp would.

FraSerK

What are some recommended 300-500+W AMPS that are compatible with the SDA 1C?

ok...I'm slightly on defense...being a new member & my first post...when seeking some recommended 300-500+W AMPS compatible with the SDA 1C...I get called out for misrepresenting my decks power...too many ways to skin a cat in audio/video specifications... rabbit hole...

Over the decades I have experienced the SDA 1C driven from several different AMP sources, each progressively rated higher in power, with exception to drop in power when adopting Dolby tech.

I agree the SDA 1C can be in accordance with Polk factory spec driven by 50W-500W sources. My past 3 decades, I've sourced at 50W, 100W...etc... By electrical circuit design the SDA 1C are empirically power hogs, reference schematic two (x1 ea. L/R) 16mH air coil inductors, low base SDA circuit, empirical current (AMP) demanding base circuitry. By electrical & mechanical design the SDA 1C circuits & speakers can handle 500W, so be it in accordance with Mathew Polk.

And personally I have never listen to any 1kHz audio source at one meter, however the DenonAVR5700 spec is 170W+170W (8ohm @ 1kHz with 0.7% T.H.D.) So conservatively the DenonAVR5700 is pushing 200W/200W (SDA 1C 6ohm @ 1kHz with x.x% T.H.D.)

The Polk Audio SDA 1C are spec rated min 50W ~ max 500W and (from memory) I have used... (I preface from memory because I am almost certain some fact checker will find tooth comb the follow...)
circa 1989 Yamaha RX-396 50W/50W Stereo 8ohm
circa 1990 Adcom GFA 545 II 100W/100W Stereo 8ohm
circa 1995 Denon AVR 2500 85W/85W Stereo 8ohm - transition into Dolby ProLogic
circa 1997 Adcom GFA-6000 100W/100W Stereo 8ohm - expand into Dolby PL
circa 1999-2019+ Denon AVR5700 *8ohm - transition DD THX5.1 DTS.
*140W+140W (8ohm 20kHz ~ 20 kHz with 0.05% T.H.D.)
*170W +170W (8ohm 1kHz with 0.7% T.H.D.)
*140W x5 ch (8ohm 1kHz with o.7% T.H.D.)
SDA 1C are 6ohm... so conservatively I stated 170W/170W (6ohm 20kHz ~ 20 kHz with 0.05%~0.7% T.H.D) stereo. 170W+170W (8ohm @ 1kHz with 0.7% T.H.D.)

Fortunately at this time I can leapfrog the 200W+ price point AMPS and get on with it at 300W~500W+.



now back to business...to reiterate I'm the original owner of SDA-1C & finally (30+yr) at the point I can afford a great AMP. What are some recommended 300-500+W AMPS that are compatible with the SDA 1C?

The recommendations listed - with follow up questions, comments etc...

Krell - Tony M thanks for the idea... I know of Krell... long forgot about them... no offense I have not followed up (yet) on your recommendation. funny your first to reply and I have not got to it yet. I'm pretty sure Krell will be on the short list...just need to do some research... will get to it soon. I planned to look into Krell this weekend then all these current replies dropped in lately... so I was reading each and compiling some reply thoughts...figured I need to get that behind me otherwise by tomorrow I will have forgot what I was thinking about. Krell recommendation research suffers...

Perreaux PMF3150 - moose68bash - I had not heard of them before (I'm under a rock?) thanks for the input - found one in Europe for sale - the price point is in range - very impressive...these spec out nice on paper I would love to hear / have one - too distant for this buy - keeping this on the short list if one becomes local.

NAD C370 - thanks but I'm not considering spending $300-$400. and I am already within (*or possibly surpassed) the NAD power, performance wheelhouse. *Possibly surpassed, but I have never listen to this combo, so it is impossible for me to pass judgment. I do remember NAD equipment from back in Stereo era days (pre Dolby ProLogic etc..) it was impressive...just outside my budget range then otherwise it just possibly could have been part of my history.

McIntosh - motorstereo thanks for your recommendation Mcintosh MC2500. Currently on eBay, local pick up a purchase there is a 100% functional MC2300 (cosmetic 9+/10) for sale at $2,900 (too expensive) . seller had two, one sold already. This fits within my price point and at 300W 8ohm I figure 350W+at SDA 1C 6ohm + connected to the 4ohm MC2300 out. I agree the MC2500 will light them up...I am not in any hurry...the MC2500 is on my short list of options for sure.

Bluefox the McIntosh T.H.D. VERY LOW <0.25% vs. extremely low 0.05%, 0.007% etc... of other AMPS. So when you state "Of course, it must be good, clean power" would you consider 0.25% not meeting the SDA 1C clean power expectations?
Also I am sold the SDA 1C fidelity with 300W-500W source at low (& party) listing levels will be magnificently mind blowing. Same (or better!, cross fingers) than my 50W/50W... 100W/100W... 170W/170W... past experienced iterations have been.

Peachtree Nova - anonymous, (Peachtree Nova will research AMP in near future) & Bluefox & moose68bash...I'm going rebuild the crossovers, binding post, patch cord, speaker mods, etc...the complete rabbit hole of upgrades,... but only after I characterize the AS-IS frequency spectrum response of the factory shipped SDA 1C + Denon AVR5700. Subsequently after the new AMP, rinse and repeat...after new crossovers (keeping the originals complete for reference), replace the SL2000, cabinet mods, rabbit hole...
I figure if I start now, the project could be finished before I retire in another decade+.
My only son will be the benefactor of this journey.

Bryston - txcoastal1 (& BlueFox) thank you...very interesting... relative lower price point relative to power and impressive specifications, vs. others on market... I had not heard of them before (I'm under a rock?) thanks for the input. Definitely on the short list of purchase options.

ken

I will now turn off my PC in 10, 9, 8,....seconds 0.

Tony M

Hey Ken.

Thanks for your synopsis to our recommendations.

Here's some specs on that c370 from a Stereophile mag. review.
https://www.stereophile.com/integratedamps/633/index.html

Sidebar 1: Specifications
Description: Remote-controlled integrated amplifier with seven line-level inputs (including two tape in/record out); preamp out/main in, and a second preamp out with up to 12dB attenuation; NAD Link; Soft Clipping and Bridging switches. Output power: 120Wpc (20.8dBW), continuous average power into 8 ohms, both channels driven. IHF dynamic headroom into 8 ohms: 3dB. IHF dynamic power (8, 4, 2 ohms): 210W, 340W, 450W. Frequency response: 20Hz-20kHz, ±0.3dB. THD: 0.03%. S/N Ratio (A-weighted, ref. 1W): 94dB. Damping factor (ref. 8 ohm 1kHz): >150. Preamp output impedance: 100 ohms. Headphone output impedance: 220 ohms.
Dimensions: 17 1/8" W by 5 ¼" H by 13 13/16" D. Weight: 26.5 lbs.
Serial number of unit reviewed: HOZC37005157.
Price: $699. Approximate number of dealers: 350.
Manufacturer: NAD Electronics International, 633 Granite Court, Pickering, Ontario L1W 3K1, Canada. Tel: (800) 263-4641 (North America), (905) 831-0799 (worldwide). Web: www.nadelectronics.com.

Read more at https://www.stereophile.com/content/nad-c370-integrated-amplifier-specifications#boYIhOAcYiGm41Qt.99

mhardy6647

THD is a relatively useless specification for amplifier output power, I would opine. The magnitude of total harmonic distortion is far less important than the spectral distribution of the harmonic distortion products (speaking of cans of worms).



A direct radiator loudspeaker (i.e., one not using approaches to acoustic impedance matching such as horns/waveguides to couple the speaker's drivers to the air in the room) will have harmonic distortion levels (especially at lower frequencies) on the order of a few percent. Horns do a little better, since they require much smaller diaphragm excursions for a given SPL output, but still the speaker is far more important to audible harmonic distortion than is any "hifi" amplifier's performance. The difference between, say, 0.25% THD and 0.05% THD from an amplifier is thus quite likely to be inconsequential, all else being equal.

Also probably worth mentioning that, from a sound quality standpoint, other forms of signal distortion are likely much more significant than is harmonic distortion (if for no other reason than that the industry learned to measure and control THD very early on in its history).

Bottom line: there is more to amplifier "synergy" with a loudspeaker load than the sensitivity of the speaker & the "RMS" output power specification of the amp. I don't know what the impedance curve of the OP's SDA-1C looks like (although @F1nut says they're a fairly easy to drive load), but I would imagine that, as @tonyb mentioned, an amplifier with a fair amount of grunt (current delivery capability) would be "best". This requires appropriate design and a beefy power supply (again, for best results).

Just my opinions, albeit honed over four-plus decades of fiddlin' with this stuff, offered "as-is" and FWIW. YMMV, etc.

HTH, as they say.

pkquat

@FraSerK You will find (and there are many posts on polk's or just about any audio forum) that all "power" is not the same. Power ratings, and especially at single frequencies tell only a minor fraction of what the amp actually can do when playing music, and more importantly how it sounds. More "power" does not equal better sound. As a starting power reference though a 20Hz-20kHz is a better realistic measurement, and what people commonly use.

I have 1C's and have listened to them with various receivers, amps, and preamps.
Before I get into that, here is a post of a new users members experience.
https://forum.polkaudio.com/discussion/187100/parasound-2250-with-polk-rti-a9s

I am pulling some of the specs. from memory and the power is per channel in stereo. They are ballpark, but as mentioned really only a general gauge. All equipment is original and not upgraded unless noted. All the stand alone amps went through a Parasound P5 preamp.

Yamaha HTR 5960 100 watts 2006
Kenwood KR6400 ~ 45watts 1970's
Hafler DH220 115 watts 1985
Krell KAV-300i 150 watts 1997 (refreshed to new 2012)
Parasound NC 2250 250 watts
Parasound A23 125 watts

The list is in order of best sound at any volume with the A23 being the best over all. With the Yamaha used as a preamp, it sounded better than the old Kenwood in "pure direct" mode which turns off all necessary electronics, but it was still a weak point. Comparing the Yamaha receiver amp to the Kenwood, the Kenwood had more punch over all. Amplifier ratings were different back then too, but if you look at the transistors and power supply, is about the same as the Yamaha. The Yamaha is a "voltage" amp. The stand alone amps are all current amps. All of them rocked the 1C's and could bottom a speaker cone depending on the content.

I with the Yamaha though I could hear a little distortion at high volumes, so I really only did that once. The Hafler was a big step up. I could hear the difference between the Yamaha as a preamp and P5 at normal and loud levels. The P5 had better detail, clarity and separation. Although it was not a big step it was noticeable. From there each amp had better detail, clarity and separation with the P5. They all had different sounds as well. The Hafler is warm, and inviting. The Krell is crisp and detailed, but can sound a bit harsh. The Parasounds are the best of everything. This is for average to loud listening.

All but the Yamaha could reach extremely loud. And TBH at that volume it is more rock concert than critical listening. At loud to extremely loud the Krell was actually the weakest of the stand alone amps, there may even have been some distortion in the highs. It lost some of it clarity and detail. The Hafler did much better. While at lower volumes the Hafler didn't sound as good, it didn't change much at extremely loud. The bass dropped just a little, but still had great impact and punch, and the highs were clear. The Hafler bass is richer, and IMO the most pleasing sound for bass out of all the amps. The Krell had good bass impact at extremely loud, but something was missing. The Hafler did a better job.

The Parasound 2250 didn't break a sweat. The room got overloaded. The A23 however, has the better sound overall and doesn't break a sweat either. Once you reach the extremely loud level, there are too many other factors, and detail and separation get lost.

B&K is another good option for amps, and since no one has mentioned them yet, Parasound is too. Many people here think Parasound pairs well with polks. As @mhardy6647 often mentions "synergy" is key thing in the audio experience. When people say a certain component or cable sounds better, but another person tries it in there system, they can get a different result, because not everything is the same. Some components sound harsher, and others too warm and muddied, but a combination of the right components can equal things out. This is where people can get picky about sound and amplifier brands, and even models. It becomes relative, but relative to what?

Tube amps, generally have lower power, but higher current for that power, and often rated higher distortion than solid state amps. The "warm" sound is often associated with that distortion, so they should sound bad, right? How could you hear that detail, and get the clarity with all that distortion? Yet I have heard things via tube amps that I never really heard with my SS amps using the same speakers. I can now hear them with the SS amps, because know they are there, but I have to concentrate more. With the tube amp they appeared almost effortlessly. This was not with the 1C's. These speakers don't get as loud. About 75-80% is their max with the Hafler compared to the 1C's. The ~40W tube amp didn't break a sweat driving them, and drove larger more demanding speakers louder and with better detail than my Hafler could have.

pkquat

TY for the correction @DSkip. I am not that familiar with the tube world. I had assumed since people at talked about many tube amps more easily driving speakers with tougher or lower impedances the output to the speakers was more current based. While noted, I may still get this wrong again in the future.

F1nut

now back to business...to reiterate I'm the original owner of SDA-1C & finally (30+yr) at the point I can afford a great AMP. What are some recommended 300-500+W AMPS that are compatible with the SDA 1C?

Since wpc specs seem to matter most to you get a Crown pro amp.

motorstereo

^^^^^^OMG!!! Something in the air or water just isn't right east of Mississippi today.........Jesse recommending a pro amp????

F1nut

Don't worry the air, while a bit humid, is fine here.

krazypolk

F1nut wrote: »

now back to business...to reiterate I'm the original owner of SDA-1C & finally (30+yr) at the point I can afford a great AMP. What are some recommended 300-500+W AMPS that are compatible with the SDA 1C?

Since wpc specs seem to matter most to you get a Crown pro amp.

Ouch!

FraSerK

F1nut wrote: »

now back to business...to reiterate I'm the original owner of SDA-1C & finally (30+yr) at the point I can afford a great AMP. What are some recommended 300-500+W AMPS that are compatible with the SDA 1C?

Since wpc specs seem to matter most to you get a Crown pro amp.

And it's you again...what matters most is "compatibility"...so I simply seeking advice from club polk... the club with a "heart" symbol in the logo... so show me some love my "polk" brother.

txcoastal1

http://www.renohifi.com/PassUsed/PassUsedInStock.htm

Pass Labs X-250 stereo class AB power amp

Refurbished, excellent condition, one year transferable factory warranty, all factory accessories, new factory double-boxing. Satisfaction Guaranteed, S/N D-3141 $2795.

FraSerK

Hey Tony M - I see the NAD has that feature IHF dynamic headroom into 8 ohms: 3dB. looked into the IHF, it appears this unique IHF electronic circuit provides, when triggered, a 10mSec burst of power. This sounds like a great feature in itself and I would like to hear the NAD IHF drive something some day. The SDA 1C themselves have their own unique electronical circuit, the SDA circuit. I am not sure if the unique IHF 10mSec burst circuit could afford the unique SDA circuit what it needs. maybe so maybe not.

thanks for the recommendation.

as for the Denon5700, this deck is not your run of mill modern era Best Buy Denon.
It's 50lbs of beast and has the electronic guts one would expect to see in discrete AMP... I copied this image off the net...soup can sized CAPs,
etc...

FraSerK

hey Tony M the Denon5700 comment and picture was to address some others who made comments...not maid by yourself, however related to the NAD.

pitdogg2

Did someone say soup cans ??? How about BEER Cans with a massive torrid transformer.... and 16 mosfet output devices per channel ….pffft NAD dynamic headroom MINE has REAL HEADROOM

FraSerK

sweet pic...are those "Foster" beer cans...they look like "Fosters". What model Adcom is the BEAST? possibly I put a pumper sticker on my Denon, my other AMP is an Adcom. sponsored by "Fosters" beer.

pitdogg2

Gosh those were the days a couple of oil cans after work and all was good.

Adcom 5802