Home audio integrated amp question.

[brokenwallet]

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[amb]

Quote:

Originally Posted by brokenwallet How good are the average integrated amps from the early 80's (silver metal casing) for headphone amplification? Let's say compared to an average cMoy?

If you're talking about using the headphone jack on these, they are typically just taken from the power amp output with a series resistor added to drop the voltage and current. Depending on the headphones you use, a cmoy may or may not be "better". A more deluxe headphone amp would certainly be better.

Quote:

And the other thing was, like i said earlier, WTH is a Super A?

Class A amps are biased heavily such that the output transistors are always "on" and never switch off, providing better linearity and avoiding crossover distortion. However they run hot and draw a lot of power. Class B is the other polar extreme, the output transistors are normally off, and only turns on in the presence of signal. It runs cool when idle but has problems with switching/crossover distortion. Class AB introduces a small, fixed amount of DC bias to allow the output transistors on the positive half and negative half to have an overlapping turn-on region, suppressing crossover distortion but still have relatively cool idle. "Super A" is a variation where the biasing of the output stage is dynamically varied based on the audio signal, in an attempt to achieve the benefits of Class A without the heat and consumption. Other manufacturers used different names for essentially the same technique, like "New Class A", "Non-switching", or "Dynamic Class A" or somesuch. This scheme works ok, but introduces issues of its own.

-Ti

 

[mkmelt]

[How good are the average integrated amps from the early 80's (silver metal casing) for headphone amplification? Let's say compared to an average cMoy?]

Older integrated amplifiers and receivers, from the 70s and early 80s can perform very well as headphone amplifiers. Although not compact in size, you get the benefit of multiple high level inputs, tone and balance controls and a phono stage preamplifier (for use if you ever plan to listen to vinyl). None of the dedicated headphone amplifiers will offer these refinements.

I personally like the Marantz amplifiers and receivers from the 70s, but other older equipment has been shown to work well too when used with many of today's headphones.

To buy a new dedicated headphone amplifier that would perform as well as or better than a quality vintage amplifier or receiver, you would have to spend more than $200 for the amplifier, or for a DIY amplifier, for the parts. One of the most important, and also most expensive, part of an amplifier is the power supply. The better quality older receivers and integrated amplifiers had very robust power supplies. Today, the cost to replicate these power supplies would be several hundred dollars. A vintage amplifier that today costs around $75~$100 used in good condition can be a good value, especially considering all of the features included for the price, at around 1/3 the cost of buying a dedicated headphone amplifier.

The headphones you've listed are not very demanding in terms of power or impedance, so go ahead and enjoy them with your JVC amplifier, they should work fine.

On an absolute basis, the background noise level of the JVC amplifier may not be as low as with a dedicated headphone amplifier, but in actual use you may not be able to hear whatever transistor noise there is at any volume level you would ever use.

If you ever upgrade your source, i.e., to a quality vinyl playback setup or to a DVD-A/SACD/universal disk player, and upgrade your headphones, then it might make sense to purchase a dedicated headphone amplifier. Otherwise, you are way ahead using the amplifier you have as long as it continues to work properly. If you have any noisy controls on the JVC, you can use contact cleaner spray (available from Radio Shack and also other sources) on the inside of each rotary control or switch. That will usually solve the problem.

Regarding the Onkyo T-4 tuner, here is a quote from another forum:

"Got one of these for $104 with freight off the 'Bay. Very good sensitivety and seperation. One of the best tuners I ever had."

Try hooking up an antenna, or even just attaching a short length of wire about 5 ft, in length, and the Onkyo tuner should surprise you with the quality of the reception.

 

[brokenwallet]

Thankyou for the informative replies! I really appreciate it.

I have tried the stock fm ribbon antenna, but i live in the suburbs and signal lock is a problem for the stations i listen to. That's why i'm thinking an outdoor or powered indoor will be necessary for a good fm experience.

I haven't spent any time to test decent speakers or let alone headphones with the jvc amp. The current speakers are old sony 6-1/2" 2way monitors. AFAIK the sound from cd is clean, but there's noticable dips in the freq range (inadequate speakers). I need to get a 1/4" adapter and see how the koss sound with it.

Again, thank you both for the great replies.

-broken

 

[brokenwallet]

Just a small follow up.

I've listened carefully to cd's amped with the jvc and unamped. The sound is definitely better amped. The tones of voices and trumpets are not as harsh and the bass have more presence. I can readily hear bass strings, which is lacking on my straight cd - headphone setup. On higher volumes my ears aren't as strained as listening to the cd's straight off of the sony pcdp. Although what's more revealing to me is that my poorly recorded cd's sound just as poor either way, lol.

I've also tested my pc setup, it's not a great setup but again it's better amped. There's a definite white noise, but not noticable when the music is loud enough.

Overall i like the jvc amped koss sound, but i think i will get a decent small headphone amp sometime in the future, for electric consumption savings if nothing else.