Bozak LS-250. Any information?

[JKent]

I just got a pair of Bozak LS-250s and there is very little info on these on the 'net. I haven't looked inside yet or even listened critically but they are pretty substantial, about the size of the AR-2 (ish). Drivers are B199 BC woofer (12"), B450 C midrange, B200 Z tweeter according to information I found. The 12" woofer has a pleated surround--no foam. The only negative so far is the finish: fake walnut vinyl. Oh well.

I'll be back with some photos but does anyone have these? What can you tell me?

-Kent

[JKent]

So I listened and they sound good. Not AR-3a good but good. The tweeters aren't Bozak, they're Vifa DT25G. Dimensions are 23h x 14.5w x 11.5d. According to some sales lit I saw,  the LS-250 had a level control for the tweeter but mine do not.

Don't know how to characterize the design. Not ported but the woofers have no gaskets, so not exactly sealed and there is no stuffing--the cabinets are lined with 1" thick padding. The sales lit called it an "infinite baffle" design but I thought that was for drivers in MUCH bigger boxes (then again, that same lit stated "Exposed surfaces are clad in walnut-grained vinyl of such quality that it is scarcely distinguishable from actual wood"  If you believe that, I have a bridge for sale or a Nigerian prince to introduce you to). According to Wikipedia "Rudy Bozak never offered an acoustic suspension speaker system; he stated that the full transient response and clean bass for which his woofers were famous could not be obtained with the heavier, reinforced woofer cones necessary for acoustic suspension. Bozak began offering smaller speaker systems to answer consumer demand, but none were noted for exceptional performance until the LS-200 and LS-200A of the late 1970s."

So I guess the LS-250 is part of that series and therefore have "exceptional performance." This pair appears to be from 1982. The 12" woofers are apparently essentially the same as those used in the Concert Grand, the refrigerator-size speakers introduced in 1951!

[JammonLS]

Hey.....I know it's been awhile, LOL!

I have these same ones only the tweeter control is available on mine.....only difference I see from your pics! These, when placed well are really nice for Listening to what I listen to........which is Blues mainly and they shine with a good EQ because of my room dimensions aren't ideal.

If you still have these I would like to know what you think of them if you have done anything such as placements or ? I have mine, currently, connected to a Denon PMA-550 and they have excellent Bass, mids and highs for my tastes. Better than my old BA T-960's.

BTW: I run my amp with NO Tone controls (tone defeat) and my EQ at just barely above the "0" (midway) points and get the best out of these. I have heard the older "B series" but never owned any so I have no idea what to compare these to when it comes to Bozak history. I'm happy with these and because I'm not into anything more than 4 speaker amps......these and my BA's are mostly all I need for music.

Let me know if I can answer any specific questions.

Edited July 8, 2019 by JammonLS
I'll post pics later......

[Bozak Mike]

Bozak Listener Series 

specs

30 cm woofer Bozak

Mid and tweeter- Audax

Freq response- 28-20,000 +\-3

Sensitively 92db (1v/1mt)

Impedence 8 ohm

weight 20kg

i just broke mine out for an upcoming party. Driving them with Hafler dh200 amp

and hafler 101 pre amp

These are going back into service. They sound amazing compared to all the micro speakers.

so warm and really come alive if you push them.

i picked mine up in 1980 right at the dock at the Bozak factory 587 Connecticut Ave Norwalk CT.

my brothers girlfriend best friend worked there and got me a great discount.

these are very nice vintage speakers.

mine have 9/79 and 2/80 date codes.

i had an issue with the tweeters in the late 80s or 90s and brought them to Glastonbury ct to the factory for repair. They were really great and replaced drivers and tested everything.

i believe this was actually the NEAR factory after Bozak sold to them.

these sound great- no sub needed like the small speakers nowadays.

after firing them up and cranking Steely Dan- i now realized how kind my parents were back then. Im shaking the pictures on the walls here!

 

 

 

[JammonLS]

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Posted July 11

 

"these are very nice vintage speakers.

mine have 9/79 and 2/80 date codes.

i had an issue with the tweeters in the late 80s or 90s and brought them to Glastonbury ct to the factory for repair. They were really great and replaced drivers and tested everything.

i believe this was actually the NEAR factory after Bozak sold to them.

these sound great- no sub needed like the small speakers nowadays.

after firing them up and cranking Steely Dan- i now realized how kind my parents were back then. Im shaking the pictures on the walls here!"

 

 

Do you have yours off the floor or on flat? I find they are less Bassy off the floor about !0" or more and are more precise. They DO have a heavy side to them when pushed and I really like the more precise Bass over the boomy stuff. I did replace my tweeters with some silk domes that are more efficient than the originals and all of the specs in the crossover are within original. Whoever had these before really took care of them. I thought about selling them at one point.......then after  I fired up the old Victrola, it wasn't even considered an option. They aren't the best sounding I've owned, but they are a pair of work horses that will hold thier own with anything in the price ranges today, IMHO. The only floorstanders this size that I would even consider replacing these would be my former  Heresey's.

[Paul Tomassetti]

I worked for Westchester Stereo in Westport Ct. in the late 70`s and we sold Bozak speakers. The owner of the company was friends with Mr. Bozak. I recently revived my interest in stereo gear and am looking to recreate my favorite system of components from that era. First on the list would be a pair of Bozak LS 250 speakers. The LS 200 and 250`s were known for their neutral or flat sound. Not boomy or brassy but right in that sweet spot. We loved them. I`m looking for a pair along with an Onkyo tx 4500 receiver and a nice turntable. 

[Garfield]

LS-250 and LS-250s is crossover with low norm and bright on high end . woofer is not the same either .  Both are great. I have a pair of mint 1979 LS-250-s all original drivers sweet music to my ears .  This guy was way ahead of his time!!!! Google Tom Bozak  WOW !!! 

Edited October 22, 2021 by Garfield
Wrong model

[Garfield]

LS250 vs LS 250A    Woofer and crossover with low  normal and bright in rear both are awesome speakers.  Goggle Tom Bozak 

[Garfield]

Bozak speaker Ls 250a are the best speakers I have owed and lol I have owed a lot of speakers in my time they reminded me of old JBLs from the 1970 s so impressed I had to post this. If you can find theses TANKS you should buy them   WOW BLOWN AWAY don’t let size fool you !!! Anything Tom Bozak built or designed will blow you away. He was ahead of his time in design 

[mergman]

I know this is an old thread but I am looking at a pair of Bozak LS-250a. What info can I get from the code and serial # on the back label. Guy that has them says he thinks one tweeter isn't working. Wants $100.

 

Code: 80 5

Ser#'s: EE 56961 and 56960

[Garfield]

Get them if cabinets look good 👍 tweeters are weak spot anyway I upgraded mine with soft dome B&W the woofer has lambs wool spun into them perfect music reproduction Maybe try some Stevie Ray Vaughan with them midrange driver is aluminum with some kind of Coating over the aluminum

[JKent]

1 hour ago, mergman said:

he thinks one tweeter isn't working

If you're lucky it's just the tweeter pot. I had the 250. The 250A is different. The 250 had Vifa 25G 6 ohm tweeters. BozekMike (above) says the 250 has Audax tweets. 

[mergman]

What is the difference in the tweeters?

 

[Garfield]

J Kent is right try to clean pot first or ohm out the tweeter 

[JKent]

On 1/28/2018 at 3:09 PM, JKent said:

Vifa DT25G

On 7/11/2019 at 11:17 AM, Bozak Mike said:

Mid and tweeter- Audax

18 hours ago, mergman said:

What is the difference in the tweeters?

I don't know. I'm no Bozak expert and don't know which Audax was used but here are some thoughts:

• First check the tweeter to see if it's OK. As Garfield wrote, use an ohmmeter. You can also hook the tweeter up directly to a music source at low volume.
• The Vifa DT25G is no longer made. I see one on ebay for $55 + $25 s/h but I wouldn't spend $80 for a used tweeter for that speaker. I believe the Vifa line somehow morphed into Peerless byTymphany. I'd check the dimensions of the original and look for a matching Tymphany. This one is 6 ohms and may work. Get a pair and sell the Vifa https://www.parts-express.com/Peerless-D27TG-35-06-1-Silk-Dome-Tweeter-264-1022
• If the ones you are buying are the "A" version, those had an Audax tweeter but Bozak Mike did not give the model number. The Audax TW025A0 1" Textile Dome Tweeter was/is very popular and "may" be a good choice. It come in 4 ohm and 8 ohm. 

I suspect that either the Tymphany or the Audax would work fine IF they fit the hole. Both are silk dome. The 250A is an 8 ohm system and I think either the 6 ohm or 8 ohm tweeter would be fine. And there's a volume pot for the tweeter (on the A) so you can make fine adjustments.

Hope this is helpful.

Kent

 

[mergman]

Thanks everyone for your input, picked them up for $100. They sounded good and the cabinets were in good shape for a 40 yo speaker. Haven't tried to Ohm out the tweeter yet. Fingers crossed.

[mergman]

 Turns out  both tweeters were fried. No big deal since I found a pair of GRS 1TD1-8 1" Dome Tweeters for $10 each at Parts Express. They were an exact fit. Should have in couple days. Speakers sounded pretty decent wo the tweeters so can’t wait. Was told these had issues with the tweeters burning up, not sure why. Reason for the post is the crossovers, whether or not to rebuild them also. I pulled out a woofer to take a peak and this is what I found. It looks really clean. I have never seen a crossover like this. If anyone would want to give me an opinion I would appreciate it. Cabinets were decent also. The tweeter circuit is on the right. Y/W.

 

Edited February 2, 2022 by mergman
Added content.

[JKent]

You can see from left to right the connections for woofer, mid and tweet. The caps are probably OK but why not go with new? The woofer cap is 100uF electrolytic. Replace with a new bipolar 'lytic of 50V or more. The mid has a 4.7 and a 15uF. I'd use film but they will be bigger. If you get mylar film caps from Erse they will be smaller than the Dayton polys from PE. http://erseaudio.com  The thing is, the Erse electrolytics aren't great so great. PE or Madisound has 100uF 'lytics.

Your tweeter has a yellow cap I assume is mylar. Looks like 5.0/5% which I assume is 5uF but check all the writing on there. It "should" still be good but if those speakers are burning up tweeters I think I'd replace it just to be on the safe side. 4.7uF is OK if you can't get 5.o.

Others with more expertise in xo work may offer other opinions.

[mergman]

I took all of the drivers out of the cabinet, cleaned them up, vacuumed the dust off the crossovers, Deoxted the level switch (which seems to be working) used some 3/8 x1/4 closed cell neoprene weather strip to seal the drivers in the cabinet. Didn't do anything to the crossovers. They sound pretty darn good, nice base and sparkling highs. Just may have to hold on to these for awhile. Nora Jones sounded fantastic.

 

[imnokid]

I just hooked up my Bozak LS 250s that I had bought new in the early 80s. One of my cats clawed through the foam on one of my McIntosh AR16 powered speakers. The Bozaks STILL sound great. My wife(who is a singer) said she thinks that they sound better than the McIntosh. I just placed them on top of the Mac cabinets and the sound comes right at you. GREAT sound.