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AR-3As: Marantz 2270, 2250 or Pioneer SX-850 Receiver?

I use to power 4 or 6 AR-3a with two Mac MC 3500's, and never had an issue. Just stack them on either side of the Stage or in the Orchestra pit and go for it. We usually used Ansermet recordings for Ballet works. The third 3500 powered the Capstan motor on my 300-2 and a friend of mine with perfect pitch helped me set the line frequency to get the correct pitch while changing the tempos during rehearsals. Then we would dub the tape to another 300 for an repeatable on speed master tape. What griped me was when the Ballet director wanted to change the tempo during the performance. Placing the AR-3a's in the orchestra pit face up gave the impression that there was actually a live orchestra in the pit. As I remember one performance hall held about 750 and the other about 1100 audience members. I don't know how you measured your AR's but I consistently had uniform bass output below 30 HZ. But as AR's have delicate tweeters I would use Mac 2125, or other models with Power Guard rated around 125 watts per channel. If I were you I would be looking for Some Mcintosh XRT 18's or XRT 28's line arrays to control the room acoustics.
 
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My JVC amps have no problems driving my 3's, at quite loud volume for long durations when I'm in the mood.
lbella heard them and her 3a's. My amps are somewhat rare, but well worth the wait while monitoring the usual on line sources.
 
KentTeffeteller said:
Not recommended unless it can drive a reactive 4 ohm load which is known to dip as low as 2.5 ohms. That Yamaha would likely be emitting smoke doing that.
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Flip that impedance selector to the up position. Just checked this earlier tonight on my RX-V3000 with a similar scenario.
 
Can it handle a 4 ohm load which dips to 2.5 ohms? 130 or more watts/channel into that tough load and severely high current? If not it is simply NOT AR3a suitable. Yamaha does have separate power amplifiers which can and do fine, receivers, NO! Clipped amplifiers and their nasties don't treat those very difficult to replace drivers kindly. Also neither will the AR3a sound right on a AVR of anybody's.The bass especially won't sound correct.
 
leesonic said:
Anything NAD or Proton. These are legendary at driving low impedance or difficult loads.

Lee.
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Not AR3A! Not enough current, power supply too cost cut. Remember 130 or more watts/channel into a 4 ohm load which dips to 2.5 ohms. And demands very high current. Both of those don't do that.
 
KentTeffeteller said:
Not AR3A! Not enough current, power supply too cost cut. Remember 130 or more watts/channel into a 4 ohm load which dips to 2.5 ohms. And demands very high current. Both of those don't do that.
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Sorry, but you have no idea what you are talking about. I get tired of doing this, maybe it should be a sticky, but here goes :

When the NAD 3020 was introduced, it was their turning point for providing well designed equipment at a reasonable price. There is no doubt it was cheaply made, but it contained some well regarded components : Motorola or RCA output transistors, Hitachi drivers, and Philips or Siemens small signal transistors. It was very austere looking, as was all their subsequent equipment, but there were no chintzy looking fonts like Marantz or McIntosh. When Stereo Review magazine tested it, they measured peak powers of 42, 75 and 102w into an 8, 4 and 2 ohm load respectively. Yes, you did read that right, into a 2 ohm load, not bad for a 20w amplifier. There used to be a trick at HiFi shows where they would connect four pairs of speakers in parallel to the output of the 3020, and it showed no signs of distress. They also tried it driving the infamous (for low impedance) Linn Isobarik speakers, and it had no problems. Here is a link to consider :

http://www.tonepublications.com/old-school/nad-3020-integrated-amplifier/
http://www.tonepublications.com/old-school/nad-3020-integrated-amplifier/
Now consider the big brother 3140. Rated at only 40w, Stereo Review tested it and found it clipped at 73, 94, and 112w into 8, 4, and 2 ohm loads. Once again, the peak power was even higher, testing at 103, 152 and 201w into 8, 4, and 2 ohm loads respectively. This might explain why people have found that a "NAD watt" is more effective in the real world than other brands. Stereo Review commented that "The NAD 3140 is called a 40w amplifier, but measurements and listening leave no doubt that it can easily hold its own against most conventional 100w amplifiers".

And this is without even looking at the 2600 and 2700 series power amps, which have the Power Envelope circuitry. YouTube posts have confirmed these peak way above their 100w rating, the same goes for the Proton 1150 and 1200 power amps.

Lee.
 
I like NAD provided the soft clipping is turned off. And people don't expect their 40 watt amplifier to deliver 112 watts into a demanding load which demands severely high current. Use the NAD within the wattage it's rated at, at the impedance it is rated at. Don't expect NAD to deliver more continuously as a daily habit. The parts NAD uses are as good as the price point allows you, and are better than most in their price. They sound great.

But peak power is not full time power into a demanding load. Want more power full time, get a bigger amp, and you have fewer issues. I have service customers with NAD which hardly ever have issues with them, but their 3020 receivers drive efficient speakers which are easy to drive, and don't have major impedance dips. And they're responsible, careful adult listeners who don't abuse their gear.

The ones who expect their 3020 to put out 100 watts a channel full time and play it severely loud, they have more issues and who use more difficult to drive speakers. The 3020 is a legit classic. The 3140 also is. But run them conservatively. Don't ask more than it can deliver.

AR3A demands more amplifier, and more current and needs it full time, not just peak bursts. Lee, I respect your viewpoint. But AR3A is not an NAD job. Unless it is a bigger NAD.
 
I just hooked up my 2275 to my ar 3a's and it handled them fine. It is in a smaller room and about 11:00 position was louder than normal listing. Prevously I had tried a sansei 5000x and they did clip costing me a new tweeter.
 
Here are some specs on the NAD 2700 :

150 watts per channel.
Rated distortion (THD 20Hz - 20kHz) 0.03%
Clipping power (maximum continuous power per channel) 200W
IHF Dynamic headroom at 8 ohm +4.3dB
IHF dynamic power (maximum short term power per channel) 8 ohm 400W (26 dBW)
4 ohm 600W (28 dBW)
2 ohm 800W (29 dBW)

Damping factor (ref. 8 W, 50Hz) >120
Input impedance 20kW / 820pF
Input sensitivity (for rated power into 8 ohm) 1.2V
Frequency response 1Hz - 80kHz / (+0, -3dB) THX
Signal/noise ratio ref. 1W 100 dB
ref. rated power 122 dB
THD (20Hz - 20kHz) <0.03%
Bridged Mode
In exc cond.
Continuous output power into 8 ohm 400W (26 dBW)
IHF Dynamic headroom at 8 ohm +5dB
IHF dynamic power (maximum short term power per channel) 8 ohm 1.2 kW (31 dBW)
4 ohm 1.6 kW (32 dBW)

Exactly how much power do these overpriced ugly looking speakers need? Even if you have to buy two 2700s and bridge them, you'll still be spending less money than other brands.

I think these anti-NAD postings are actually part of a deeper anti-British bias here on AK...

Lee.
 
Specs are, well, specs.

Real time daily use with power hungry speakers is another game.

This ^^^^ later NAD model should do the trick, but IMHO the 3020 : no.
I'm sold to British stuff BTW
 
I've experienced speakers that were also very hungry. They were made by Dunlavy when he resided in Australia. They are called Duntech "Black Knights". I resolved the problem quite easily, although at a little bit of a cost and that was by purchasing a used Krell KSA100. They will accept loads down to 1 ohm. They are rated at 100 watts per channel into 8 ohms so doing the simple math will tell you what they're pumping out at 2 ohms and they'll do this all day long. The sound from these things is strong and clean and they'll wipe the floor with anything suggested so far.
They also double as a great room heater in winter and moving them requires 2 people!
They are still selling in very good condition for around $4K AUD so I would think they would sell for considerably less in the USA. By the way, I drive my Krell with either a Marantz SC6 or 3600 preamp.
 
Sorry Ibella that the boys here get into pissing matches about their favorites. A couple have answered without drama. I have to ask what do you listen to and do you enjoy high volume? Any bass heavy music played loud will take a receiver or amp that handles 2ohm dips.

If not, the Marantz 2270 would work at around twenty watts or lower. I have 3a's that have been redone and have suffered with the 3a's shutting down my receivers at higher volumes.

Also....do you have these set up in a foyer as forty foot ceilings in a room is very rare.
 
I have my 3a's hooked up to a 2275 and enjoy playing it loud (volume dial never gets past 11:00). It is in a smaller room but I have had no problems. I did have it hooked up a sansui 5000x that caused me to recap the speakers, the tweeter went out but luckily it was crossovers not tweeter. I have a sx1250 I think I will try next
 
lbella has been quiet. I did have a conversation with her in December to see how the search was going, and suggested becoming a subscriber for access to BT. There was a restored Pioneed receiver I sent her the information for onBT. Not sure if she contacted the seller about it.
 
I don’t know if vintage power is a requirement, but I’ll share my experience with powering these speakers. I run a Bluesound Powernode integrated amp/preamp/streamer that delivers the same 60wpc into 8 and 4 ohm loads with class D power. It weighs 4 lbs. It powers my AR-3a beautifully with absolutely no strain and no heat. Anything over half volume is too loud for me in a 24x12 room.

I started out in this hobby with a love for vintage receivers, and they still occupy a soft spot in my heart. But I learned pretty quickly that these “monsters” are anything but when presented with anything other than a very easy load. It’s an excellent lesson in current vs power and the wimpy power supplies found in vintage receivers.

Now, I can see why someone would want an equally pretty vintage piece to power these pretty vintage speakers. But for sound quality, reliability, flexibility, and peace of mind, there are much better options. And considering the cost of vintage receivers these days, may be considerably cheaper!
 
Well I hope she found what she's looking for. I know this is kind of an older thread but I'll throw my 2 bits in here. I have had first hand experience with both of the receivers and the speakers questioned in the original post, in fact I purchased and brought up to snuff a 2270 specifically to drive a pair of AR3a's and it did not like them at all. I always run everything flat with tone controls bypassed and no loudness contour engaged yet the 2270 ran out of steam very early on during bass heavy passages and wasn't handing the load well even during easier to drive sections of music. I had two other 2270 receivers at the time (both in perfect condition) and they did exactly the same thing. They don't like hard to drive loads like the AR3a, something that was changed with the 2275.

By contrast I had a Pioneer SX-850 at the same time which had absolutely no problem whatsoever driving my AR3a's very well, in fact I used it to do so for years. I still have it but I replaced it with an SX-950 only because one became available and the extra few watts come in handy. The SX-850 and SX-950 have no problem driving tougher 4 ohm loads and I can tell you this from experience. The AR's get driven daily (sometimes quite hard) and neither receiver has a problem with this. I have had them apart since then to do other work on them and the power amp sections and power supply were right up to spec with no signs of overheating emitter resistors or regulating transistors / resistors where you would typically see signs of stress. Pioneer receivers from the SX-850 and up have four TO-3 output devices per channel (not two like many others do) and a very well designed power supply which explains why a receiver rated at 65 WPC is so much more capable than one rated at 70 WPC.

Long story short, don't use the Marantz 2270 to drive AR3a's, but the Pioneer SX-850 and higher is absolutely fine for driving them. If you are talking Marantz 2275 that's another story but not the 2270. Actually I think it's fairly well documented around here, wish I had known that all those years ago before I bought the 2270's but they were cheap back then and I got my money back!
 
She's got her sights on the Pioneer receivers when we last spoke.
I can see if she can chime in here if anything has changed, or if she found a receiver.
 
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