Jump to content

Thoughts on Amps for 3's


DavidDru

Recommended Posts

As I have gotten into this Vintage Audio thing I of course feel like I am a little all over the place with my various pieces. My biggest concern right now is that I make sure I have a good combination of amp and speakers which are AR-3's and 2ax's. What are you all using and feel is a good combination. I know you need to start with some specs that will work, but follow that up with how it actually sounds with the speakers.

Currently I have a couple Dynaco amps - An St400 with A Pat5, and a ST70 with a Pas2. Both combinations right now are original stock. I also have a Pioneer SA9100. So thats some tube and some SS.

Other speakers I have include some Magnepan MG IIa's. Seems to me what those require in terms of power are not too dissimilar to what the 3's would.

What have you all found to enjoy with your AR speakers?

Link to comment
Share on other sites

  • Replies 256
  • Created
  • Last Reply

Hello David. At present I am using a Marantz 7T preamp and a Crown PSA 2 on a pair of AR 3. A Marantz model 33 and a Soundcraftsmen LA2502 drives another pair of AR 3 , and the same Marantz 33 drives a SAE 220 ( 2200 ) power amp on a pair of AR 3a . In my opinion, AR speakers sounds better with powerful, high-current , very stable SS amplifiers. But my father used to drive his AR 3 in 1966 with a Marantz 7c - Marantz 8b , very similar to Pat2/St 70. At the time I was six year old, but I remember a good, magical sound. But AR speakers tends to offer their best performance - a very big sound, powerful, detailed and undistorted - if you fed it with clean power. Best regards from Rome, Italy. Adriano

Link to comment
Share on other sites

Hello David. At present I am using a Marantz 7T preamp and a Crown PSA 2 on a pair of AR 3. A Marantz model 33 and a Soundcraftsmen LA2502 drives another pair of AR 3 , and the same Marantz 33 drives a SAE 220 ( 2200 ) power amp on a pair of AR 3a . In my opinion, AR speakers sounds better with powerful, high-current , very stable SS amplifiers. But my father used to drive his AR 3 in 1966 with a Marantz 7c - Marantz 8b , very similar to Pat2/St 70. At the time I was six year old, but I remember a good, magical sound. But AR speakers tends to offer their best performance - a very big sound, powerful, detailed and undistorted - if you fed it with clean power. Best regards from Rome, Italy. Adriano

Adriano,

I agree with your thoughts on driving the AR-3, and we've discussed this many times on this forum. Although this speaker worked satisfactorily with some tube-type amps such as the Dynaco Mark III and the big Marantz and McIntosh units, they seemed to perform much better when linked to high-current solid-state designs. The AR-3s perched on top of the AR Music Room on the west balcony in the Grand Central Terminal in New York in the mid-1960s were placed there to provide Christmas music for the entire station, and these AR-3s were powered by a 60-watt (120-watt peak) Dynaco Mark III for each speaker. From what I was told, those amps were driven to near-clipping output levels frequently, but the power was sufficient to give pretty substantial output levels.

The AR-3 (as with many other AR speakers) requires clean, high-current and stable power, and it works better with solid-state amps capable of working well into very low impedances. The AR-3's impedance dips below 3 ohms in places, and it poses a challenge for many amplifiers. I had trouble in the past with some amps driving the AR-3s cleanly; for example, I had a Dynaco ST-120 and an ST-400 that were not happy driving them, and then I used a Marantz 250 that also had difficulty. I eventually began using McIntosh and Crown amps to drive them without any issues.

--Tom Tyson

post-100160-0-54229300-1413388456_thumb.

Link to comment
Share on other sites

Full agreement with Tom on this - McIntosh and Crown give excellent results with any AR speaker, especially ones with the 12" woofer.

I've found the Dyna tube amps to provide a very pleasing result on speakers like the AR-2ax, but there's not enough juice to get the best from an AR-3a, or the like.

I've owned several Dyna transistor amplifiers over the years, and I'm just not a big fan; the ST-120 was notoriously unreliable into low impedance loads, and the larger amps were just too noisy for me.

Link to comment
Share on other sites

It was a pity that no amps drives correctly AR speakers until early eighties, except maybe for the BGW 500D ( 1976 ) ; I remember discussions in hi-fi shops in early seventies between AR fans vs. JBL , E-V, Klipsch and Altec fans, these last ones sometimes wins dues to their great efficiency and easy loads. Do you remember early Phase Linear 's advertisement? A pair of AR 3a ( without badge ), chained. So my father bought a Phase Linear 400 in 1973, first series, beautiful , seductive but unreliable and very harsh. Then a Marantz 250 , good sounding but unable to drive difficult loads because the protections. I 'm not a technician, so I' m not able to understand the reasons that leads Villchur to design a speaker so difficult to drive. But, in every way, to me it's the best speakers I' ve ever heard in 54 years of life, still today. And I' m listening to my Ar 3 now , as ever. Best regards to you all, Adriano

Link to comment
Share on other sites

It was a pity that no amps drives correctly AR speakers until early eighties, except maybe for the BGW 500D ( 1976 ) ...

Best regards to you all, Adriano

If I had bought the 3a model back in the 70s instead of the 5s I probably would have used an SAE or Crown amp. But you are right, Ed Vilchur was ahead of his time.

Now I would be tempted to bi-amp them and use mosfet amps.

Roger

Link to comment
Share on other sites

I am still looking for a suitable amp for my 3a's bought new by me about 1970. I don't recall the amp I used when I first got them but it was never adequate. When I could, I got my hands on the AR amplifier and used that for many years. Still, at 60 watts per into 4 ohms I never thought it enough. I had a friend that had a big McIntosh that sounded great with his 3a's but with a young family I never could swing one of those. Running a mediocre HK receiver now but not happy. Still looking.

Link to comment
Share on other sites

I can't help much with specific high current amp recommendations, but I just gotta say what a great first post from an AR owner of 45 years still looking for better performance from his favorite speakers. Welcome to CSP, der.

Link to comment
Share on other sites

The Soundcraftsmen LA 2502 that I use is a MOSFET power amp, and it sounds really nice, powerful , warm and sweet, beyond suspicion in a West Coast pro amp, and I paid only 350 euros just because in mint condition: probably in the USA its price on vintage market doesn' t exceed 250 USD. However , in my experience vintage pro amps very often offers better performance than domestic hifi equipment. Some years ago I had a '76 Altec 9440A power amp, I paid only 345 euros. Built like a tank, surely powerful but incredibly smooth and well sounding. Then I switched to Crown PSA 2, slightly better, for only 650 euros , from a Recording Studio. Very cheap, a modern lightweight 80-watt integrated amp of British brand, but made in China , will costs more. I 've heard excellent sound by BGW 500F and 750F , and BGW GTA/GTB, very easy to find at cheaper prices. I also still have an original , refurbished AR Amplifier, just because it is in my family since 1968, but it' s only a tiny pleasant integrated , not much more. Surely Ar 3 and 3a deserves much more. Best regards, Adriano

Link to comment
Share on other sites

This is great stuff guys. Last thing I would want is to do all the restoration work on my 3's only to underpower them and not hear what I could out of them.

So when I am looking at amps, what spec should I look at to determine if it is high current? Is there one or do I need to do some conversions?

Link to comment
Share on other sites

Well David, Ar 3 and 3a are capable to receive hundreds of watt of clean , undistorted power. They need no modifications. The problem is only in the power amp. If you want to search in vintage amps, you have to limit your choice to BGW models, Amcron PSA 2 and following models, Soundcraftsmen MA5002 and LA2502, SAE 2401 and SAE X25 , KRELL , every model ( but expensive ). The only Marantz vintage that performs with AR 3 is the model 500 - 500b , but it' s too expensive . Vintage SS McIntosh are dull and muddy in my opinion , and also too expensive. In every way, read carefully the specifications , if the amp has protections or not, and if it's rated to drive 2-ohm loads. Pro amps are normally rated from 16 to 2 ohms load, not so for hifi domestic use amps. You can also decide for a modern amp like an Odyssey Khartago, surely designed for hi-current on low impedance and not too expensive. Creek also is an excellent british brand that makes excellent integrated amps . However , I prefer vintage amps made in USA.

Link to comment
Share on other sites

these old, big, inefficient speakers like lots of good, clean power - tube, solid state, unicorn waves....i don't think it really matters so long as the signal to the speakers is clear, strong, and uninterrupted as an amp is nothing more than a tool to pass the signal from the source to the speaker - it should never have a "sound" as that would (to me) present an unacceptable impediment to the reality of the source signal - i use a pioneer a88x to push either AR-3a's or AR-1's (with Janszen 130's) - it has up to 300 wpc on tap at 4 ohms and the added bonus of a moving coil phono stage (the use of which does, again in my opinion, offer a real upgrade to the vinyl experience) as well as the option to bypass all tone controls and run the signal straight from the mains to the speakers - which can present an interesting tool for comparing different formats and recordings....my cousin has used both a yamaha and sony es to power his AR-3's; each has over 100 wpc @ 4 ohms and each does its job of providing the boxes with the required power to sing with no discernable audio differences between the two...again, its all about the signal

Link to comment
Share on other sites

Yes, I agree, a good amplifier doesn't have a particular sound, and this is true to every hifi component. But, in fact every amp or speaker has its proper, unique sound. I have also AR 3 and 3a , and they sounds different. What is the correct , true sound? To me, AR 3 it' s the only speaker that sounds like natural music, but many people prefers 3a. A friend of mine, jazz musician, says AR 3 and 3a are dull and dead . He likes the explosive sound of my Altec 846b Valencias ( upgraded with JBL 075 alnico tweeters ) that I have just because they are an important part of Audio history, but I use it as stands for AR 3, not as hifi speakers.

Link to comment
Share on other sites

Now discussion is getting interesting. I was actually planning to place question about good vintage solid state amplifiers, but David asked this question first.

Tom... do you know why AR3 was originally designed as 4 ohm model, even later original models with 10" and 8" woofers were nominally 8 ohm ones? In 50´s amps used tubes and you could use suitable output transformer tap for driving speakers... and actually using lower ratio tap (8 ohm or even 16 ohm tap) do offer better coupling between power transformer primary and secondary. There was not too much advantage being 4 ohm model during early solid state era either? I must have missed the point here.

Re power... if something is good, then more of it must be better and if more is better... then too much must be enough. Seriously... I have 4 solid state power amps and 5 tubed ones. Quad 405 and EAR 509 mono blocks are rated for 100 wpc. Others are 15 - 75 wpc. Quad II combo is the only one that has clearly run out of steam with my ATC 100 main speakers. My wife complains quite often that she can hear too well what I do listen inside, while she is in the garden... 100 wpc amplifier with 90dB/w speakers is capable for something like 100dB inside and there is still 10dB safety margin before clipping, slightly less with 85 or 88dB/w speakers. Larger and more damped listening room do need more power of course.

I have not yet any experience how power hungry my AR3aImproveds are... but I suppose that I will respect aging tweeters and listen only with moderate levels. However, I have had no problems driving my AR2x pair with ARC D76A or Quad 405, which was considered capable driving hardly anything...

Best Regards

Kimmo

Link to comment
Share on other sites

My father had Quad 405 in 1977, with AR 10 Pi. I remember an excellent sounding amp, but not at ease with low impedance loads. A friend of mine now uses a Crest Audio CA 6 to drive his AR 3a, designed to drive 2 ohms loads, 750 watts per channel. Ugly but effective. Unfortunately, he lives in Trento, 400 miles from Rome, so I can't hear this amp until next holidays on Italian Alps ( Dolomiti ).

Link to comment
Share on other sites

Vintage McIntosh solid-state amplifiers used output autoformers to match the load.

The MC2205 (photos attached) was a very popular model that had 1, 2 ,4, and 8 ohm taps, with the rated 200 watt output being available at any tap.

This amp dates from the late '70s, and usually sells on eBay for $1200 - $2000.

Followup models like the MC2255 and MC7270 are even more powerful, and also represent good value on the used market.

Mac continues to employ autoformer outputs in their current range of amplifiers but they're much more expensive than the used gear.

post-100370-0-24345500-1413579432_thumb.

post-100370-0-65772100-1413579442_thumb.

Link to comment
Share on other sites

My father had Quad 405 in 1977, with AR 10 Pi. I remember an excellent sounding amp, but not at ease with low impedance loads.

I was also surprised to find how nicely Quad 405/34 combo worked after rebuild. My 405 was also late mkI model with slightly better current capability than early models, but without improved 405-2 current limiting circuity. When not over driven sound stage is realistic and sound is not harsh or brittle. Quad seems to work best when source material is not too complex as this combo seems to be unable to resolve small details too well when everybody is playing fff. ARC or CJ gear can resolve more details from source material, but they are also more expensive.

Actually my point here was that when when efficiency is good or when too much volume is not needed, voltage and current swing capability is not necessarily too high. My good friend was little concerned when he did find that his triode amp with E182CC output valve had 2-3% THD at 2-3W output level. It was interesting to note that only 200-300 mW were needed to drive his Klipsch La Scala´s to full output. This will not blow 1/4A fuse.

This McIntosh gear seems Interesting... but any suggestions for less heavy duty models. My CJ Premier 7B pre amplifier shipping weight is 31,5 kg and this is too much without good rack handles.

Best Regards

Kimmo

Link to comment
Share on other sites

I find the high power Hafler amps a good match. They are reasonably priced, reliable and still serviceable if necessary. I use either a Hafler 9270 (200 wpc /4 ohms) or a Hafler 9500 (350wpc/4ohm) with 98ls speakers and have used the 9500 and an older Hafler pP505 (professional version of Hafler 500) on AR9 and AR9ls. All have given good results.

Link to comment
Share on other sites

Actually I thought that Hafler models like DH-200 or DH-220 would be nice to try. Their no frills construction and circuity is like H/K Citation 12 with 10 year upgrade with some cost cutting applied... and I like Citation 12 very much. Fet´s solved also many problems associated to current limiting, even some designers like James Bongiorno disliked them. Unfortunately Hafler´s with multi voltage primaries are not common as units with US power transformers.

Harman Kardon Citation 16A or Sumo models like 9 or Andromeda would also be nice to try. Unfortunately DC-coupled vintage solid state electronics filled with obsolete semiconductors is not too easy way to go. Citation 16 is built like tank and should have reasonable capability to drive difficult loads... but led display is ugly as sin and units with universal transformers are not too plentiful. Sumo`s were low cost amplifiers. so it might be reasonable to expect to find some cost cutting everywhere. These designs are also quite complicated compared Citation 12 or Hafler`s mentioned.

Best Regards

Kimmo

Link to comment
Share on other sites

Hi,Here in England, I power my AR3imps with a Naim 32.5 pre amp and a pair of Naim 110 power amps which have been converted into mono blocks.

These are vintage SS amps from the 80's but serviced and brought up to modern standards.

For what it is worth, in the early seventies my first hi-fi system was AR7s, a B&O amp and tuner and a thorens TD150 turntable. Purchased with a summer's holiday earnings and 21st birthday gifts.

Still have these as well as AR 2's, 4's, 6's and 12's.

All still sound good but for mr the AR3s and AR7s are the cream of the crop

John

Link to comment
Share on other sites

Interesting discussion here. I've heard good things about Emotiva amps, and Tom has espoused the new Crowns but like many of us I like to keep my vintage system vintage.

Sort of wish I had not sold my Hafler DH-220 (cheap, to a buyer in France). I used a MAC4100 receiver for a while and it seemed to do a good job even if "only" about 100wpc into 4 ohms but there's little FM reception up here in the Appalachian hills of NJ and I was never a receiver guy. The Mac will go on epay one of these days.

Lately I've been using an Adcom 555 II. It will supply 325wpc into 4 ohms and is a neutral, well-regarded amp. And it was cheap. My total cost, including purchase price, shipping and a full check-out by a professional was about $375. Yay!

John Atkinson wrote:

"I feel the GFA-555 Mk.II to be significantly more neutral as regards midrange and treble tonal quality than the Mk.I, while preserving its virtues: excellent imaging specificity, a deep, well-defined bass, and a superb sense of dynamics. Currently ranked in Class C of Stereophile's "Recommended Components" listing, the Mk.II '555 could well deserve an even higher rating."

So the latest iteration of my "All American" vintage system consists of the Adcom, a DB Systems preamp and optional tone controls, a DB Systems switch box (all made in New Hampshire), my original KLH Model Eighteen tuner (just for looks at this point), a Tivoli CD player (made in China but designed by Henry Kloss and a near-twin to the KLH tuner), modified AR-3 speakers, MicroStatic supertweeters and an assortment of other speakers for tests and comparisons. Hoping to add my AR-XA turntable (bought in 1969) as soon as I get around to restoring it.

-Kent

Link to comment
Share on other sites

Hoping to add my AR-XA turntable (bought in 1969) as soon as I get around to restoring it.

-Kent

I have original condition AR-XB and one fitted with Rega tone arm. I have discussed about this arm upgrade with some friends and consensus seems to be that original XA/XB design was clearly good in late 80´s and early 90´s... but the original tonearm with coffin head shell was outdated these days and good enough for something like Pickering XSV-625 but not for most MC`s we used.

As I use XB/Rega combo, I have some spare motors for these... but do you know does anybody sell new motors as these seems to be lubed for life ones.

Best Regards

Kimmo

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.


×
×
  • Create New...