Revox Agora B Interesting find in the used market.


I was browsing the fakebook marketplace locally and came across a chap selling his Revox Agora B active speaker system. I never heard of Revox / Studer speakers before they interested me for the looks at first as I’m into vintage gear as well.

I read up on these speakers and it was a wow moment, these larger stand mount size speakers have so much tech in them for the mid 80’s (1985 vintage). Each speaker has 3 X 100 class A/B amps in them. the two bass drivers in each are asymmetrically aligned and use feedback (i.e.servo control), the bass drivers one facing front one on top firing down into the cabinet with ports on the top and front baffle. The tweeters are titanium and open to radiate to the front, top, sides and back (180deg) like an open baffle, the midrange driver carries almost the whole pianos range.

So, I bought them, after a 30 min listen. I was shocked at how detailed and fast these speakers were. They separate instruments like no other speaker I’ve ever heard, including my Spendor D9.2’s in my main listing room. supper interesting and rare I’ll be setting these up in my office computer space. little over kill maybe. but an interesting find for a vintage speaker. these have been fully restored, recapped etc, yes, all 6 amps were done. no not going to replace the main speakers but such an interesting design i had to buy them, I paid $1000 USD basically maybe the best deal in vintage audio I’ve had in a while.

Revox Agora B on thevintageknob.org

Anyone else had Revox / Studer Speakers?

 

 

128x128glennewdick

Found a shop that will repair my AGORA B.  They estimate $600 - $800 to repair the speaker.

Is the speaker worth investing that much into a repair?

Thanks! 

 

Yes!!! you will be surprised how good these are for the money invested. 

Welcome to active.  May not be for everyone, but for fans of it, it’s the real deal.  I’ll never leave it for my reference.  ATC 50A.  Good on you.  Enjoy.

Found a shop that will repair my AGORA B.  They estimate $600 - $800 to repair the speaker.

Is the speaker worth investing that much into a repair?

Thanks! 

OP:

 

My point was just that they were pretty good, and that was 40 years ago.  It's a shame active speakers haven't been more widely accepted in high end mainstream.

We may use DSP and Class D amplifiers now but 40 years ago we knew everything we know now about delay and phase matching and how to make great active filters.  While DSP can create virtual filters in the sense that we are no longer buying op amps, caps and resistors to create our filters, everything we needed to know about using active filters to build speakers was already there.

 

Best,

 

Erik

Erik,

I don't think this is a active vs passive thing as such. These Speakers are rather rare and special in what they Revox/Studer were trying to do back in the mid 80's. They were trying some interesting tech and configurations. not your typical mid 80's active/or not speaker that's for sure. 

after the spark did it still work, or did you unplug it and not try it again? reason i ask is that’s what happened to mine and it was the power socket solder joints, but that said it also could be a component like a capacitor, transistor etc. they are not hard to work on.

In my time with mine i can’t find much to complain about them. when running correctly and after a recap these speakers sound really good, if I was honest I prefer them to my McIntosh MC275Mk6 and Spendor D9.2’s ( $20,000+)combo. I find them to be musical, engaging, dynamic, excellent sound staging and some of the best bass (detailed, fast and deep) I’ve heard. If I was critical the ultimate detail level is slightly lower them the Spendor’s and they are a little light in the lower midrange area. really minor stuff considering you can buy these for a grand and for that kind of money they are steel. still cannot believe the bass these put out.

one note in my research i found that Studer/Revox used the same drivers in many other of their hi end studio monitors,  like the Studer A723 uses the same midrange driver and the sell for upwards of $8000 on the used market. the agors's seem to run under the radar. So work repairing for sure. 

Thanks Glennewdick!  The first time I plugged the speaker in and turned it on, there was a spark I could see in the thru the rear grill of the speaker cabinet.

David_sd:

I had mine repaired/recapped they are not difficult to work on and all the parts are available or have replacements. the amps come out easily and the diagrams are readily available, i have a set for the Mk1 if you need them i can scan them.

My thinking is most don't know what they are and hesitate, but in reality they are just amps and drivers nothing out of the ordinary or unobtainium as they say. also parts are still available from Studer i'm told. I also have the complete parts list. 

I'd keep looking for reputable tech close by and take them to them and get them updated and repaired very worth while.  if your going to have one looked at may as well get them to recap both of them while they are in there. 

May i ask when you say one doesn't work what exactly is not working? could be something simple like a fuse, switch. one of the power connection on one of mine was loose and had a bad solder joint. 

A buddy of mine gave me a pair of Studor Revox AGORA B speakers. One of them doesn’t work. The other sounds fantastic.

 

I live in Nashville, TN and can’t find anyone who will work on these speakers.

Anyone here know of someone who would attempt to resurrect this non-working Studor Revox AGORA B?

 

 

an interesting review i found online. I have the MK1 and the link to the manuals. 

REVOX AGORA B OPERATING AND SERVICE INSTRUCTIONS Pdf Download | ManualsLib

 

machalik

Registered User


🎧 15 years

Okay, let’s go for a little review of both of them, I mean Mk I and Mk II.

I’ll start with the Mk I since I’ve owned these for nearly two years by now.
These are real beasts. Small and old, yet SO much performing and amazing. In a way, I’ve never heard a speaker like this. Of course there are better, but the size/performance/price ratio is unbelievable. I am never going to sell them. One day, when I buy much bigger and better boxes, I will still keep these for bedroom or something.
They sound so open. So big. So fluid. So powerful in bass, even if they are missing a real bass driver. Having stood them on a pair of small stands the sound has lifted up from the floor and now they nearly sound like big speakers. After two years with no improvements in the hifi set, I am still being amazed. Still in love with them, I’d say.

But they lie.
Since I’ve bought the Mk II, I am experiencing a much more precise sound. Now I really understand what all the people were telling to me about the lack of detail, treble inadequacy, bass inaccuracy etc. Mk II are better. Technically. There’s no doubt. In every aspect they sound more precise, better defined, the bass is more contoured, the details spring out, the voices sound like real and so forth. People who like classical music made their opinions after five minutes of listening and they were absolutely right.

Well, whatever.
I don’t care.

To me, after switching to Mk II the sound dimished. It gained all that accuracy and everything, but somehow it also went smaller, regardless on the stands. The bass doesn’t go so deep anymore and loses its punchiness in exhange for being well-defined. The midrange doesn’t sound that liquid and seamless since then. I can now hear all the tiny things in the treble area but who cares. There’s less life, less joy, less reality in the music for me. Now the speakers make no lies. They sound exactly like small boxes, just as they really are. They do not hide anything, nor do they make you feel like "wooow, now what’s this!" anymore.

Definitely, the Mk I is my cup of tea. The Mk II is more like a monitor kind of a speaker, with all it’s pros and cons. In many respects they remind me of the Studer A723 studio monitors which I also happened to have at home for some time. They actually use the same tweeter and midrange speakers.

Now, of course I was little exaggerating. Any of these two are neither the best or bad speakers. Compared to any modern competition within reasonable price margins they still kick ass. The built-in amps are a big plus; one doesn’t need to seek an amplifier and spend another fortune for it. The sound color is very normal, neutral and pleasant, there’s no harshness or synthetic impurity in it, they are not directional and the sweet-spot is huge, the sound is compact and seamless and everything. I have heard some definitely better speakers, such as Quadral Titan or B&W Matrix 800 or Dynaudio Consequence, but these cost different money and need strong amps that cost just as much also.

So, here’s my summary:
Anyone who’s looking for an accurate, detailed and monitor-like sound, should go for the Mk II.
But people who value features like rather huge sound mass with a lot of clarity and liquidity to it might find the Mk I better.

Does this do?
Sorry for being so wordy.

 

Revox / Studer is Swiss. actually, the drivers are all stamped Studer.

totem395; yes, I'm in Victoria BC just north of Seattle. got them from a nice gent named Paul. 

 

lalitk: my office / bedroom area is just an offshoot if my loft that's a large L shaped, so these will be fed from my computer-DAC. I'll use them for music when working in the office and movies when watching in bed, ok maybe some gaming too. 

I'm actually rather shocked at what these can do specially for the age. they do dynamics like horns, detail like a modern hi end speaker and separate instruments like some of the best out there. They are a little lean in the mid bass area though and the top end is not quite as detailed as my Spendors. They do some interesting things with soundstage and depth that's quite impressive for the era or even modern speakers. Very detailed bass with superb instrument separation Very much a studio monitor sound. Supper rare from what I can find.  

I'll be playing with them to see what they can do with the various settings they have. they came with a book with set up instructions for various insulations and a full maintenance manual with diagrams etc. wish modern stuff came with that level of information detail. I'm still shaking my head that there is 600w of power hidden in these relatively small cabs. 16" x 16" x 28" but heavy 70lb each. 

Everything i read puts these as marketed to the audiophile and studios. 

Power bandwidth : 4Hz...42Khz (DIN 45500)
Frequency response : 30Hz...21Khz (-3dB)
THD : 0,5% max. (max., 86dP SPL)
1% (max., 96dB SPL)
SPL : 110dB (at 2m, in a 100m3 room with 0,4s reverb)
Drivers : 2x 20cm bass (2x 1,25T / 2x 612µWb)
1x 12cm mid (1,2T / 392µWb)
1x 1,9cm high (1,9T / 349µWb)
Crossover : 200Hz (14 or 17dB/octave)
3,7Khz (17 or 24dB/octave)
PC : 2W in sleep mode
200W max
Dimensions : 42 x 72,5 x 42cm
Weight : 31kg.
Inputs : 0,775V / 47kOhm (preamp in)
4V / 1,2kOhm (power amp in)
Bass control : 0 / -2 / -4 / -6dB at 45Hz
Treble control : +2 / 0 - / -2 / -4dB at 10Khz
Automatic power on : 1mV (pre amp inputs)
6mV (power amp inputs)
Automatic power off : 4 minutes (±1 minute)

 

 

@glennewdick 

Noticed a pair for sale just the other day local to me at what seemed a reasonable price and knew they'd be gone quickly. 

Are you located on the West Coast with a northern latitude?

 

 

WOW! What a great find and Congratulations. Just curious, how big is your office and what are you using for source? I wish I’d another room for a Shindo Labs Pre / amp & Field Coil Speaker system, maybe someday I get lucky :-)