Bozak B-310b Concert Grands
TroyD
Posts: 13,077
Circa September 1975. One owner.....
Coming to the Rancho de no Concerno in the very near future.....struck a deal to sweet to pass up.
These effers are MASSIVE. 8 tweets, 2 miss, 4. 12” woofers.... 225lbs per speaker.
Ever since Stereophile did a piece on them years ago, my interest was there. Anyway, a customer of mine has them and wants them to go to a good home....who am I to refuse?
Coming to the Rancho de no Concerno in the very near future.....struck a deal to sweet to pass up.
These effers are MASSIVE. 8 tweets, 2 miss, 4. 12” woofers.... 225lbs per speaker.
Ever since Stereophile did a piece on them years ago, my interest was there. Anyway, a customer of mine has them and wants them to go to a good home....who am I to refuse?
I plan for the future. - F1Nut
Comments
-
Can't wait to hear what you think.Rega Planar 8, Apheta 3 MC , Aria mk2 Phono
Aurender n100h, Benchmark DAC2 HGC
Arcam SR250, Parasound JC5
Revel F208, SVS SB-4000 -
What condition? Will you be trying to upgrade/refurb these?2-channel: Modwright KWI-200 Integrated, Dynaudio C1-II Signatures
Desktop rig: LSi7, Polk 110sub, Dayens Ampino amp, W4S DAC/pre, Sonos, JRiver
Gear on standby: Melody 101 tube pre, Unison Research Simply Italy Integrated
Gone to new homes: (Matt Polk's)Threshold Stasis SA12e monoblocks, Pass XA30.5 amp, Usher MD2 speakers, Dynaudio C4 platinum speakers, Modwright LS100 (voltz), Simaudio 780D DAC
erat interfectorem cesar et **** dictatorem dicere a -
There's a guy local that is selling 401b's they don't look all that special though. Yours sound awesome!Gustard X26 Pro DAC
Belles 21A Pre modded with Mundorf Supreme caps
B&K M200 Sonata monoblocks refreshed and upgraded
Polk SDA 1C's modded / 1000Va Dreadnaught
Wireworld Silver Eclipse IC's and speaker cables
Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)
There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus -
Congrats to you. I had a pair a while back and they still hold the record for me as the most miserable speakers I've yet to move. Heavy, huge, with nothing to hold onto. Hopefully you have a very big room; these monsters need lots of breathing room.
-
Always wanted to hear a pair.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Oh heck yeah! Old school!! Congratulations! Looking forward to your take on the sound and of course pictures up the whazoo!"if it's not fun, it's not worth it & remember folks, "It's All About The Music"!!
***************************** -
neat-o!
-
Always wanted to hear a pair.
And so you shall.....
So, the are n good shape it would appear.....original and unmolested.
My plan is to listen to them. I’m sure the caps need replacing....but, other than that, I intend to just listen to them.
This is a long term lust item so I’m just excited about having them....
I plan for the future. - F1Nut -
motorstereo wrote: »Congrats to you. I had a pair a while back and they still hold the record for me as the most miserable speakers I've yet to move. Heavy, huge, with nothing to hold onto. Hopefully you have a very big room; these monsters need lots of breathing room.
I got the space, hand trucks and a few employees to help moving them......so, we’ll see how she goes!
Do have to figure out how to remove the grills. It has brown cloth and I do want to replace it with linen....
I plan for the future. - F1Nut -
[/quote]
I got the space, hand trucks and a few employees to help moving them......so, we’ll see how she goes!
Do have to figure out how to remove the grills. It has brown cloth and I do want to replace it with linen....
[/quote]
A handtruck is the best way no doubt to move them. Mine had to go up and down some stairs and it was pure misery even with a strong helper. My grilles were held on by velcro and came off easily,
Here's a pic of mine from a few years ago with a pair of Mcintosh ml1c's sitting atop them making the not so small mac's look like bookshelf speakers
-
Awesome. I heard a pair of B-302's (I think..) in a stereo shop in Korea (very eclectic guy, bought a lot of vinyl from him) hooked to tube amp that he built. The sound was PURE. Not super detailed and treble was not super extended but just sounded like music....much like the sound I ascribe to AR's (but not the same, if that makes sense).........
No stairs in this project, I'm happy to say.......and really cool about the grills, I was hoping that wasn't going to be a HUGE PITA.
Anyway, I'm pretty jazzed about this......the idea of 4 12" woofers blowing (what's left of) my hair back makes my pants go crazy.I plan for the future. - F1Nut -
motorstereo wrote: »
I got the space, hand trucks and a few employees to help moving them......so, we’ll see how she goes!
Do have to figure out how to remove the grills. It has brown cloth and I do want to replace it with linen....
[/quote]
A handtruck is the best way no doubt to move them. Mine had to go up and down some stairs and it was pure misery even with a strong helper. My grilles were held on by velcro and came off easily,
Here's a pic of mine from a few years ago with a pair of Mcintosh ml1c's sitting atop them making the not so small mac's look like bookshelf speakers
[/quote]
Beautiful , just beautiful"if it's not fun, it's not worth it & remember folks, "It's All About The Music"!!
***************************** -
Okay, so the Bozaks are in the house....got them hooked up and started just listening a bit. So far struck by how smooth these are but there is no real loss of detail, if that makes sense. The treble is MUCH better than I was expecting....and they sound EFFORTLESS. THIS is going to be fun....as a wise man once said, 4 12” woofers a channel blowing your hair back is MANLY.
I plan for the future. - F1Nut -
Very cool.
Big loudspeakers do tend to do the effortless thing with considerable aplomb -- IMO and IME.
-
Very nice; and hopefully there weren't any herniated discs from moving them. Yes I thought the treble was smooth yet detailed as well. Are your tweets vertical arrays? Mine were and when I'd play them for people for the first time I'd have them stand in the sweet spot and very slowly sit down in a chair. It was like a high filter was getting switched off as you sat down and your ears became level with the tweeter arrays. My buyer smiled from ear to ear and bought mine on the spot because of that.
-
Yes, mine are the vertical arrays.....that is cool. I had three people and a hand truck so it wasn’t too bad.
So far, I gotta admit I’m impressed. I was expecting a very dated sound but it really isn’t the case.....and yes the effortlessness is something to behold. They also image much better than I expected.
TLW is less than enamored.....I plan for the future. - F1Nut -
TLW is less than enamored.....
LOL....Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Ok, so a few more hours of dedicated listening......
Musical is the best way I can describe the sound. Much like the Quads....whatever they did right or did wrong, they played music. Do no harm.
What don’t they do....3D, pinpoint imaging. Bass. Now, these got bass, don’t get me wrong....and this may well be room dependent but you gotta think with the size of these that you’d be rattling the foundation. It’s there and it seems to be pretty flat and definition is there in spades but for sheer impact (think telarc...) I’m a little underwhelmed. Treble lacks the ultimate detail and magic of the midrange. It’s not bad but it certainly isn’t the same caliber.....which considering the vintage is understandable.
So far my quibbles are few....the ability to throw such a large sound stage with adequate depth with such liquidity is worth the price of admission.I plan for the future. - F1Nut -
Could there be some attribute about their age/condition that is contributing to the bass performance you describe, or is it just how they are voiced?
-
Well, for openers....the speakers are 46 years old (and presumably the capacitors) so that's probably a good start.
Now, I was playing some bass demo tracks (Bach Toccata and Fugue in D Minor and some other faves) and the extension is definitely there......and it's clearly defined and detailed. It just doesn't have that visceral impact that you, I think, would expect from speakers of that size and with 8 12" woofers.
In terms of comparison......I'm thinking the AR9's and the AR 302's (AR 5's). The AR's have more bass impact than the big Bozaks for sure. The AR's bass has a magical tone that, AFAIK, no speaker has bested but in terms of bass resolution the Bozaks win out. At the end of the day, if I'm going to pick a speaker just for bass response, I'm going with AR. What about the Amazings you say? The Amazings have the extension and the impact in spades. Tone and definition though are not in the same league. It's not terrible by any stretch but it's a horse of a different color.
Further on up the frequency ladder......the Bozak midrange. Man. To get that level of velvety smoothness and detail.....you got to spend a LOT of money. The Quads had even better midrange smoothness and transparency but the Quads are unable to convey the sense of scale and weight that the Bozaks can. Both the Quads and the Bozaks have an uncanny ability to just be musical. Non-audiophile recordings are welcome. More than welcome. You can hear all the shortcomings...compression etc etc but they are still listenable. Surface noise on LP's float about the music so as not to be intrusive.
The treble on the Bozaks......ok, one, my HF hearing is not what it used to be so, for me, the treble on the CG's is fine. It's extension is not an issue for me. It's detail and definition is more than adequate and more than anything it is non-fatiguing. Sure, I've got speakers that have greater extension and air (Thiels)....but the Bozaks are ultimately non-fatiguing and the treble isn't a distraction.
So, what about the Amazings and where do these fit in the grand scheme for me? Well......let's start with what I love about the CG's. They are able to convey a sense of scale (large and small) and dynamics that few speakers can. The Amazings can. The big SDA's can. They sound EFFORTLESS...and I mean EFFORTLESS. They can play with ZERO sense of strain at levels that are frightening. The Amazings come close here but ask me how I know about overdriving a ribbon. In terms of sound staging.....the CG's provide all the spacial and ambient cues with sufficient detail to really convey that sense of lifelike sound that AR was famous for. The Amazings are equal here and provide a better sense of soundstage depth. SDA's, do I really need to say that nobody does sound staging like SDA?
As far as the Thiels go....the Thiels imaging, coherence and transparency is unmatched by any dynamic speaker I've heard. The bass response is first rate. In reality, the Thiel is a better speaker in that it checks all the audiophile blocks.....but, it doesn't have the sense of scale, dynamics and effortlessness that the Bozaks do...and therefore, the Bozaks aren't moving out for awhile. Maybe I'll send these home with F1Nut.....with his listening tastes, I think he is REALLY going to enjoy these at PF.I plan for the future. - F1Nut -
I have no idea what Bozak would've used for capacitors, but there could be "oilers" in there which could be of outstanding quality and should still be fine (even if they're only mediocre ones) -- i.e., don't leap to conclusions re: the XO components
-
have you tightened everything up?- Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
-
Agree. Prolly many oil caps...
16k hi frequency is good enough for me.
from audioKarma;
"My B-310B-based Concert Grands consist of 4 - B-199, 2 - 16Ohm B-209B, 8 - B-200X and N-101A Crossover (designed for the B-302).
I intended to eventually swap out all 16 200X's and replace with the Y's. But being they are very difficult to locate in pristine condition (or a price-point I can afford), as well as the issue of the Y's having an internal foam damper which desiccates over time, I have opted not to replace them. The 200X's that I have are pristine-mint condition.
The crossovers that I am using obviously does not maximize the bass/mid to full potential. The issue is the N-101A crossover network, which crosses over at 800, as opposed to 400. I have contemplated the Tobin mod, but know that his mod dealt with the Y tweeters, not the X's."
Based on that, five 5 MDF 50 VDC oil caps. You can do a few of the Tobin mods for basically
no money.
Post edited by SIHAB onSpeakers: Polk Lsim, ATC SCM19 v2, NHT SuperzeroSpeaker Cables: DH Labs, Transparent, Wireworld, Canare, Monster: Beer budget, Bose ears -
have you tightened everything up?
Darned good advice/observation.
I use good ol' audiophile fave Jennifer Warnes' Way Down Deep to check for loose screws.
PS it's also pretty good to use as a test of woofer excursion...
-
Lol...The Hunter is one of my demo discs...so, yup, everything seems to be tight and solid (these things are hefty....250lbs each) and built like a brick schitthouse.
From what I have read....the caps, of which there are three per speaker were not oil caps. That said, I’m not in a hurry to disassemble these just yet but I’m just blown away by how musical they are without sounding dated.I plan for the future. - F1Nut -
This is the crossover layout....
I plan for the future. - F1Nut -
Nice and simple
-
That 50 uF would be a mighty big oiler -- at least if it's a good one
DSC_7330 (2) by Mark Hardy, on Flickr
(a pretty good 16 uF oil-filled capacitor, for comparison)
-
-
IFAIR, over by the inductors is a tap.
If you move the tap to crossover at 800
Solder and a gun will get you there.
Wally! more bass.
Here is a thread I found on the 302s.
https://audiokarma.org/forums/index.php?threads/bozak-302a-tobin-mods-2015.654407/
does your X-over say N102-N104?Speakers: Polk Lsim, ATC SCM19 v2, NHT SuperzeroSpeaker Cables: DH Labs, Transparent, Wireworld, Canare, Monster: Beer budget, Bose ears
