[DivineCurrent]

Hey guys, I was looking around my house and stumbled across this old amplifier from the 80s that came with a tape and cd player. My parents used to use it for there home audio system, but now they just care about the TV.... and now I've recently gotten into high quality audio and stuff, so I figured why not try it out? Gave it a listen with my Shure SRH 940s, and so far it sounds awesome! Only complaint I have is sometimes there's static when you adjust the output, but considering this thing is 26 years old, not too bad. Heres a picture of the amp and the cd player:
 

 
 
 
So, does anyone here own this thing and if so is it good for high impedance headphones and speakers?

 

[brhfl]

Nak always made very high quality stuff, and their TOTL equipment was incredibly inventive and mechanically complex (such as the Dragon tape deck which physically flipped the tape, or the turntable from the same line which moved the platter around to counteract imbalances). I briefly owned that CD deck, and assuming it's in good working order, I think it can hold its own against a lot of modern devices. At the time most people weren't really straying from the demo circuitry Philips provided with the chip, Nak's CD players sounded a lot different (and a lot better) than the competition. They did some fancy tubed CD players and all as well - they seemed to want to innovate just as much with their digital offerings as their analog - and while this is obviously a simpler model, a lot of what they brought to the table trickled down. No idea how capable the inbuild headphone amp is... I remember it sounding fine when I owned the deck, but at that time only had some mid-range Koss 'phones, nothing particularly challenging. I've never used one of their amps/receivers, oddly enough.

 

[DivineCurrent]

Yeah, it does sound very good, I plugged in a pair of my AKG K240 Monitors (600 ohms) and there's literally no static sound at all coming out of it, just very clear sound. I did notice a tiny bit of static and hissing with the Shure's though, probably cause they're only 32 ohms, and this amp's output is pretty high. I'm not very learned when it comes to impedance and output voltage stuff, but I'm guessing that's why.

 

[DivineCurrent]

Sorry to double post, but I have yet another question: 
I found this: http://www.hifiengine.com/library/nakamichi/ta-2.shtml 
It says that frequency response is 20 Hz to 20 kHz, now I know that most headphones go beyond that, but will I notice a big difference when using something that responds to lower and high frequencies than this?
Also, I'm considering testing out new headphones for this, I already tried the AKG K240 Monitors, AKG K550 (I think they sound the best with the amp), Shure SRH 940s, and Senn HD 380. Any suggestions? 

 

[brhfl]

I wouldn't worry about the frequency response... 20-20k is generally considered the threshold of human hearing, and that only goes downhill as we age. I would say it's rather likely your hearing doesn't extend up to 20k anyway, and below 20... isn't much of a thing to be experiencing through headphones, at that point you're really feeling the sound if anything, not hearing it. Regardless, those extreme frequency ranges are rare anyway... it's just not worth worrying over. As far as 'phones to try on the amp, I really couldn't say, unfortunately... but I wish you luck!

 

[Twolf]

I'm not surprised to read about your impressions. Nakamichi has always put a lot of solid engineering in their devices, not just the tape decks.
Some of their power amps were based on designs from Nelson Pass himself, called Stasis. Wonderful pieces of kit.
 
As to headphone outs from amplifiers, some of them can be surprisingly good, especially with 300-600ohm headphones.
Their typical limitation is output impedance, which is often very high (up to 100 ohm or more in some cases), so they don't perform very well with low impedance headphones, for lack of damping.
In these situation tell-tale signs are a drastic drop in the bass region, lack of dynamics and screechy highs.
 
I know some of the higher end Marantz amps from the late 90's had pretty low output impedance (under 5 ohm) and they probably drive well even 32ohm headphones.

 

[DivineCurrent]

Hmm, yes i did notice not so much lack of bass with my Shures but definitely too much treble. They are 42 ohms, so that might explain why. I plugged them straight out of the Nak CD player without the amp, and they sounded a lot more controlled and better balanced highs. Also apparently the DAC in the cd player is of top notch quaity, sounds very realistic to my ears. 
Also, it does say Stasis right under the amp controls.

 

[Twolf]

Sounds like you've got yourself a couple of very nice Naka's.
Cd-players have better chances to perform well with low impedance headphones, because their headphone out is similar to a traditional amplifier circuit, typically based around an IC opamp, and their output impedances tend to be lower. Amplifiers and receivers often use resistive networks tapped right into the power amp section for the headphone out and their output impedances will be usually higher.
A lot of the headphones back in the day had had higher impedances (300-600 ohms) and less sensitivity compared to today's average headphone, which might explain some of the peculiarities of these amps.
 
 
 

 

[DivineCurrent]

My quest to understand headphone impedance is long and hard...I'm slowly starting to get it. But, there are a few things that I need clarification on.
 
First off, this TA-2A has a rated headphone output level of 117 mW according to this manual (page 28): http://www.audio-labo-vallespir.org/nakamichi/ta2.PDF
Now, after it says 117 mW, it has 40 ohms in parenthesis. Does this mean that the maximum level this amp can output for 40 ohms is 117 mW? And if so, that means that I can plug any headphone above 40 ohms into it, right? Or am I just not getting it? 

 

 

[DivineCurrent]

um, can anyone please help? 

 

[gikigill]

You can plug any headphone in it.
 
They will just sound and power differently depending on their impedance rating.
 
That is one very important piece of electronic history you have. Don,t sell it or neglect it.

 

[DivineCurrent]

  You can plug any headphone in it.
 
They will just sound and power differently depending on their impedance rating.
 
That is one very important piece of electronic history you have. Don,t sell it or neglect it.

Ah ok, thanks.
And yes, I know this is a very important piece of history, I wouldn't sell it for anything!. 

 

 

[gikigill]

Now get it serviced by someone competent as the volume pot seems to need some attention.
 
You mentioned static when changing volume and that,s the culprit.
 
Get a service done to check all resistors, capacitors and moving parts like pots, eq sliders etc etc .

 

[DivineCurrent]

  Now get it serviced by someone competent as the volume pot seems to need some attention.
 
You mentioned static when changing volume and that,s the culprit.
 
Get a service done to check all resistors, capacitors and moving parts like pots, eq sliders etc etc .

Actually, the static went away after I started using it more.

 

[DivineCurrent]

Out of curiosity, how would this amp stack up against something like the Objective 2 JDS Labs amp? I think I'm going to try one out soon, just wanted to know what I should expect. Would something this old even compare to amps that companies like Schiit makes?