As far as I can tell this was Dyna's first speaker product offering. (From the now defunct manufacturer of various Dynaco tube and solid state amps/preamps,
a la, Stereo 70, and MK III tube types and the really nice Stereo 200 (325 watt/ch. at 4 ohms both channels driven continuously on sine wave). Dyna was not
apparently deeply commited to the concept of making speaker systems. They contracted to have sealed boxes made and simply bought cheap Danish drivers from
Bang & Olufsen in Denmark. (Dyna had previously been marketing B&O tone arms
and phono cartridges for 15 or 20 years before the 1970 entry of this speaker product.

As small box systems go this was not a particularly spectacular sounding example. The extreme low end was certainly not the reason to own these (around
55 HZ at -3db even when placed well in the corners of a room. The extreme top
end was respectable up to around 12,500 HZ at -3 db. (according to independent
measurment with HP 1/3 octave pink noise gen., and Bruel & Kjaer sound pressure level meter. The whole thing really was somewhat better than average in imaging and really smooth peak free performance accross the entire range, with a slight hole around 120-150 HZ so typical of almost all acoustic suspension systems
due to the diagonal internal dimension of the box. You will see this characteristic dip in response on 95% of all acoustic suspension boxes with the larger box acoustic suspension types in the 100-125 HZ range and the smaller
boxes dipping in the 120-160 HZ region.

For those of you that like to fiddle with equalizers, don't try try to buy a typical 10 band (octave bandpass type) 'cheapie' equalizer to correct this on these types of systems. I have never seen this dip to be measurably wider than 1/3 octave and it is usually around 1/5-1/4 octave wide. (cavity resonances of regular rectangular boxes of the ratios typically found are pretty much all like this). A pricey 1/3 octave equalizer will just barely get rid of this without mucking up adjacent bands that are already perfect. A one octave bandpass equalizer will genereally make things much worse in this range even if you do have the equipment and knowledge to set it properly. This frequency range is crucial due to so much information being present in lower voice and piano registers.

It was just such a dip or 'trough' as this (typically 6-7 db deep) that gave AR speakers of the late 50's and through the 60's their characteristic sound signature. 'Nay sayers' would poo-poo the AR's by holding their hands in a rectangular shape up around their mouths and say 'This is the way an AR speaker sounds'.

Well in reality all little box systems have this problem in this frequency range
and it has nothing to do with the drivers. It is the cavity resonance of the
closed box causing this. Once I actually had a related but opposite problem in the same frequency range while making response curve measurements on much, much larger systems in the old sound room at Audio Center/Houston except of course with a peak in response. of around 6-7 db. I really couldn't understand why I was getting this on speakers that had never measured this way before until it
dawned on me that the heavy duty cardboard boxes from the AR-3's just unpacked
earlier were still sitting just next to the other larger speaker being measured and were of course an 'open' cavity of almost the same size as an AR-3 resonating at 120 HZ and peaking since it was an open box. Moving the boxes out of the measurement room eliminated the measured peak.

Back to the Dyna A70. There appears to be very little listener 'fatigue' with these otherwise unremarkable speakers. They haven't been made in at least 20 years, but if you happen to spot a pair in a garage sale and they are still intact, buy em cheap and you probably won't be sorry.

I bought a pair of these for my father in 1970 when I persuaded him to ditch his "console" stereo system. He still has them, and I listen to them occasionally through his late 70s Yamaha 35 wpch receiver. They are not a sealed-box system. There's slot on the lower front panel that is blocked by a gauze-like mesh. The design was called "aperiodic." Supposedly, each speaker had this slot hand-stuffed for minimum "back EMF" or something like that. J. Gordon Holt , the sage of Stereophile, went nuts over them in his magazine at the time, claiming bass performance down to 35Hz. I think the previous reviewer's lower limt of 50 - 60 is more like it. These speakers have a nice, "natural" sound. The top end rolls off gently in the last octave (there's a multiple-position rotary switch on the back that adjusts tweeter level) and is not extended by today's standards. However, it has no apparent peaks. Unlike its "acoustic suspension" contemporaries from Acoustic Research and KLH, the A-25 does not have a mid-bass emphasis that adds a testosterone shot to every male voice; but J. Gordon Holt's opinion notwithstanding, it does not have the lower-bass power of an AR-3 or a KLH 6. A good garage-sale buy if you can find them or their larger siblings, the A-50 (each using 2 8" midwoofers in a two-chamber internally-vented cabinet). For my money, a much better speaker than the similarly-priced AR-4x or KLH-17.

Here's one of my favorites. But what is it? Or rather what can it be? I have three pair, and they're nearly all different. As stated, this was an outsourced manufacturing arrangement for Dynaco, but I feel more enamored of them than perhaps some others. But I digress.
As for the differences, one of my pair are vinyl--my first foray into A-25's, a cheap pair up on eBay to try them out. Nobody wants vinyl, so I got a deal ($87). They have three-position tweeter level control switches on the back instead of the five-position switches on the wood guys. I liked them, although they sound louder than the wood versions (more sensitive?), as I later would learn. But I was hooked--see, my sister has had a pair I recommended she buy back in the day that are in storage somewhere in Minnesota that she's too lazy to retrieve, so I had to go buy some to reacquaint myself with them. I always remembered them as being special for their size.

So, I figured--wood next. These also came from eBay, looked real nice, and were mirror-imaged to boot--I'd heard that you could find them that way occasionally--but bidding got intense so I paid more than I expected to ($157.50). Ouch! What helps, though, is that they're small enough to ship in one box. They looked similar, but I started to notice that nothing is the same on these things. A few stripped speaker mounting holes, however, but otherwise working well. In fact, contrary to stories I've heard about A-10's, I've never seen a blown A-25. BTW, cyanoacrylate gap-filling glue and hard wooden toothpicks fix a stripped mounting hole perfectly (a little guitar luthier's trick). These were more like it--the real thing. I started to get used to the sound and found myself benchmarking amps that I was rebuilding using them. I could hear subtle variations as I adjusted circuit values in a sort of microcosm of the sound of the amp under test that would later be amplified on larger speakers. The A-25's were an easily referenced constant, much like studio monitor speakers are used for--you can remember how they sound in your head, even when you're not listening to them.

Then things got a little out of hand--I read a review of vintage speakers in Vacuum Tube Valley and the A-25's were recommended, then saw yet another pair on eBay and started bidding. What the Hell, I could do a lot worse than corner the market on A-25's, I thought. These came in at $135.03 the pair--a little better, but when I got them, I saw yet another variation--one had its tweeter mounted in the middle, with the woofer at the top and the slot at the bottom (in its standard position). All the others have the tweeter at the top (either at the left or the right side of the front panel), the woofer in the middle and the slot at the bottom. But try as I could, I couldn't hear that much difference in how it sounded, as compared to the other one (or three, depending). I figured--center channel! So I tried that for a while, running it off an L-Pad on the center-channel output of my SCA-35, which was amusing and interesting, but not all that compelling. A prototype? A drunken Danish? Who knows?

In all, I have to say that for their age, and all the manufacturing vvariations I've seen, they hold pretty close to a dependable sonic signature, so QC must have been decent, if not completely rigid. Serial numbers seem to have no bearing--I have close numbers that look completely different in terms of finish,
application of the front panel adhesive, etc. Not unlike Fender Stratocasters, by the way, where parts were serialized and then sat in a pile until used.

But for what I love about them--the pure boogie factor they provide with tube amplifiers of their era, and their easily driven nature--for the price, they have no equal. I'm completely surprised that their design hasn't been resurrected by somebody by now (tried the Dynaco/Panor website in the last year?--Bye!). Their claim to fame, by the way, for those of you that haven't been around that long, was square-wave response of a pulsed waveform--reportedly the best Stereo Review Magazine had ever tested at the time. How that equates to what I love about their inimitable sound is unknown, but for the buck, if you see any, take a chance. If you don't like them, email me--I can find room for another pair somewhere. (My vinyl pair are fronts on a Dolby Surround system--pre-Pro-Logic--and doing great.)

Be a tissue and organ donor and support a National Organ Draft. Thanks.

Musicality, brilliant highs, smooth bass

Bass is not tight

This is a review of the Dynaco A-25 Classic.

I purchased these believing them to be a slight upgrade to
the classic A-25s. They are not identically sounding, however.

Contrary, to the first review on this product, they are not acoustic suspension, since they have a vent at the bottom of the enclosure. The design is refered to sometimes as 'constant impedance' since the designer tries to make the impedance vs frequency response of the speaker as constant as possible. The KLH - 33s come the closest to achieving this goal.

The vent is much smaller in this version than on the original.


I can't, however, comment as to whether they exhibit this dip in the 110-125 range.

The enclosure that I purchased is Walnut veneer, although the wood didn't smell like walnut and the stria was a bit too dense and contrasting for walnut. The fit and finish was excellent.

The manufacturer claims that the speakers were manufactured in the US, but one of the speakers had a 'Made in China' sticker on it. At this price point, I'd have to say that the speakers were made elsewhere.

The speakers are not the original. The tweeter, in particular, is an aluminum dome rather than the soft dome of the original

I auditioned the speakers with a wide range of cabling and tube equipment. Hence, the sound reflected this tube bias. Overall, the sound was much better than the original, the bass was extended down to about 40Hz and the treble to above 14kHz. The bass was not as tight as I would like, but I was listening to them on tube equipment. The fact that it is there is an improvement over the original.

The boxes have the squared edges and are not flush to the surface of the speaker, causing some fall-off after 60 deg off axis.

Overall, these speakers are very musical; they reproduce violin, cello, and viola sounds incredibly well. (The jury's still out on the bass viola.) They are a quantum leap above the old A-25s.

I'm recommending them in my $20 challenge, i.e., you can put together a system for $20 that can compete sonically with a $10000 system. (I've listed $20 1950s 12AX7/EL-84s amps that I've upgrade that sound better than $2000 amps).

These speakers are fairly efficient and can be used with any amp over about 12 watts (tube) and 20 watts (trans). I would highly recommend them as the back speakers in a home theater system, but they should serve you well in a budget system.

The orignal price of these speakers was $55.00 ea discounted. Adjusted for inflation, that would be about $178 ea. At $199 for two, they are lower than the original price!!!

Similar Products Used:

Dynaco A-25, AR-2As, KLH-33s

Definition,especially in the bass. No bass "boom" at all.

Low-frequency extension.

This review applies to the ORIGINAL A-25, which has a 10" woofer and 1.5" tweeter. I hear there is a reissue which is different by the "new" Dynaco, the ones that copied the Van Alstine Super PAS. Don't know anything about the new version. My 29-yr-old A25s still sound better than most of what I happen to hear, even though they are not my main system anymore..

Price, Construction

Bass response

These speakers are fantastic! My stepmother bought them new in the mid-70s, but has now moved up to a DBX system (I doubt if it's actually a move up), and I recieved these for only the effort it took to get them home!

These speakers are sturdy! I don't recommend trying this, but I accidentaly dropped one while transporting the pair, and other than a slightly dinged corner, the speaker is fine! Solid wood construction makes for a very rugged (but heavy) design.

These speakers are fantastic, with very crisp and clear response. Before this I had been using a pair of Empire Cavalier Model 2000s, which absoultely blow these away in terms of bass response, but compared to these sound incredibly dark. I also formerly owned a pair of KLH Model 32s, and the Dynaco speakers absolutely put those to shame.

I have these connected to a pair of Bogen DB20DF tube amps, and the sound is fantastic! Warm and smooth, even at higher volumes, without becoming harsh in the high mids. The high-frequency response is adjustable (I have 2 settings below, a normal setting, and 2 above), but I have never found the need to move the controls away from normal. This is in contrast to the Empire speakers, where I had to boost the HF response to get them to sound remotely near bright.

I would recommend these speakers to anyone looking for a good low-priced set for casual listening. The listening fatigue is very low, but they're best suited to lower powered amps, perhaps in a bedroom or study. They seem to go on eBay for between $100-150, which is a fantastic deal considering what an equivalent pair of new speakers would cost!

Overall, I was exceptionally pleased with these speakers. I have also owned a Dynaco SCA-80Q amp, and after extensive use of that and these speakers, I would recommend Dynaco products to anyone looking for a good bargain in older technology.

Similar Products Used:

Empire Cavalier Model 2000s, KLH Model 32s

BEST BOOKSHELF SPEAKER I'VE HAD

DESIGN MAKES IT HARD TO PLACE

I DO NOT HAVE A-25... BUT XL-20 HAVE HAD THEM SINCE 1974
STILL HAVE THEM TODAY AND USE THEM EVERY DAY. THEY HAVE AN 8" WOOFER AND A 2" TWEETER... THEY MUST BE PLACED ON STANDS APPX. 30" OR AS I HAVE THEM ON A WALL FACING THE LISTENING AREA... WILL HOLD UP TO 150 WATTS.... BUY THE WAY THE A-25 ARE LISTED FOR $758.00 A PAIR IN STEREO REVIEWS 1996 PRODUCT GUIDE........

Similar Products Used:

ELECTROVOICE

POWERFUL AND CLEAR

NONE I CAN THINK OF

THESE SPEAKERS FOR ANY MONEY ARE A STEAL. I'VE BEEN LISTENING TO SPEAKERS THAT COST $1000-$2000 AND I HAVE TO BE HONEST THE DYNACOS SOUND GREAT COMPARED TO THEM. I'M AMAZED WITH THE DETAIL. I OWN THE A25XL'S THAT HANDLE 30-100 WATTS I HAVE THEM HOOKED UP TO A MARANTZ SR5000 RECEIVER. MARANTZ MAKES A VERY NICE EVEN PRODUCT WITH MIT CABLES HOOKED UP TO THE SPEAKERS. IT DOESN'T TAKE MUCH MONEY TO GET A GREAT SOUND. REMEMBER IT'S NOT ALL IN THE SPEAKER!

Similar Products Used:

DYNAUDIO SPEAKERS