[VinylStar]

Got this bad boy of out my dad's garage. It's about 20 years old, probably cost about 1500 dollars in today's money. 
 
Heres a pic:
http://www.flickr.com/photos/canadagaragesale/5671650738/
 
I recently bought a pair of HD 650's and am enjoying them immensely. I'm just curious if it would actually be beneficial to run them through this amp, it being 20-25 years old. I'm not sure if im hearing things, but the track seems clearer when the headphones run straight off my Mac book pro. The bass is definitely bigger on the amp though, that was what i expected. Also when i plug in the headphones without music playing, there is a faint hissing/static noise, is there any way to reduce this?
 
Cheers

 

[classakg]

Generally old receivers are pretty good headphone amps. 
 
Do the hp's work fine when plugged to another source? (no hiss?)
 
Try cleaning the headphone jack on your receiver (some contact cleaner helps)

 

[VinylStar]

Yeah when the headphones are plugged straight into my computer there is no hiss at all, or at least about 90% reduced. I'm also curious as to whether adding the equaliser into my setup will do anything? will it reduce or increase the quality if its just plugged in and no setttings are changed?

 

[VinylStar]

bump - Another thing, i have a pretty low quality cable connecting my laptop to the amplifier, will this be degrading the sound quality and maybe causing the output of the amp to be a bit less clear than it could be?

 

[scottiebabie]

welll i drive my HD650 with a vintage pioneer sa7500 integrated & it sounds fab. no complaints cept a diy recable in the near future. so it wouldnt surprise me if your 650 should sound great of the yami.
 
that said, not all stereo hifi amps sound good off the headphone & vice versa. & for sure a better IC would be beneficial - at the very least, it cant hurt. LOL
 
O & i dont hear any hissing off my amps & certainly not with the 650. not sure why that is with your yami.

 

[priest]

Quote:

bump - Another thing, i have a pretty low quality cable connecting my laptop to the amplifier, will this be degrading the sound quality and maybe causing the output of the amp to be a bit less clear than it could be?

How exactly are you connecting them?
 
 

 

[RexAeterna]

get an external soundcard. what you doing is amplifying your soundcard's signal with the amp plugged in. an external usb soundcard or Dac will clean up the signal.

 

[VinylStar]

Quote:

Quote:

How exactly are you connecting them?
 
 

 
 

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Im connecting my laptop to the amp using a normal small headphone jack to RCA cable. I spoke to someone at JB HIFI and he said it was the power supply. i dont really know if they know what they are talking about. 
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[priest]

Quote:

Im connecting my laptop to the amp using a normal small headphone jack to RCA cable. I spoke to someone at JB HIFI and he said it was the power supply. i dont really know if they know what they are talking about. 
​

 

 
I can't tell you why, but I am not surprised that this is less than perfect. I think to get the most out of the external amplification, you would have to feed it a nice signal from an external DAC. Might get rid of the hiss to. Which RCA jacks are you connecting the laptop to btw?

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[VinylStar]

Quote:

Quote:
 
I can't tell you why, but I am not surprised that this is less than perfect. I think to get the most out of the external amplification, you would have to feed it a nice signal from an external DAC. Might get rid of the hiss to. Which RCA jacks are you connecting the laptop to btw?

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Im connecting them into the AUX section of the amp. i went through all three and this one has the least amount of distortion. i have an external sound card at home, so i might grab that and connect them up and see if that makes a difference. the RCA cable is only about 20 bucks so i might just buy a new one as well. 

 

[RexAeterna]

your rca jacks are fine. it's the macbook that's the issue with the hissing. aux probably gave you the less hissing cause it's a ceramic input compared to the actual phono inputs of your amp which are magnetic inputs with very high impedance for turn tables and even some tape decks.that's why you notice if you hook a computer or cd player to the phono inputs you get crazy distortion even when volume is at 0. aux is just another name for a ceramic input. the tape inputs has a different impedance input and different SNR. usually aux has the highest SNR(like 87-93db) which is another reason for it being more quiet. i also would suggest give it a good cleaning by deoxiting the switches and pots. do it inside and out to fully give it a good lubication. also over the years of sitting doing nothing the bias can be out of whack.

 

[VinylStar]

 
Quote:

your rca jacks are fine. it's the macbook that's the issue with the hissing. aux probably gave you the less hissing cause it's a ceramic input compared to the actual phono inputs of your amp which are magnetic inputs with very high impedance for turn tables and even some tape decks.that's why you notice if you hook a computer or cd player to the phono inputs you get crazy distortion even when volume is at 0. aux is just another name for a ceramic input. the tape inputs has a different impedance input and different SNR. usually aux has the highest SNR(like 87-93db) which is another reason for it being more quiet. i also would suggest give it a good cleaning by deoxiting the switches and pots. do it inside and out to fully give it a good lubication. also over the years of sitting doing nothing the bias can be out of whack.

i dont get any hissing when i plug my headphones directly into my mac book though, could it still be my computer? how do i clean inside the RCA jacks and what do i use as the cleaning agent. would a DAC help clean up the signal?
 
 

 

[RexAeterna]

you just give the jacks quick spray of lubrication and wipe it off. for the tuning knobs and volume you take the knobs off and give them a quick burst inside and spin it back and forth about 40 times to have the lub fully settle in there deep. another best way is take top cover off and spray the pots from the inside also. i mean if you can't get hold of deoxit then stuff at radioshack work just well if you want to pick something up nearby locally. radioshack uses same colors on each bottle and marked simuliar so need to read the descriptions. one mentioning removing oxidation and so forth one to look for if you do plan on going to radioshack instead. you can find more going to the vintage receiver thread in the headphone amp section(full size) cause you possibly might need to check the bias as well. if the bias is too much out of whack can cause distortion in each channel.

i point it to te macbook cause it's the source and it might seem it not hissing on it's own jack but as soon you hook the amp up to it your amplifying the signal even more from the source and it's amplifying everything from inside your macbook so an external DAC can help clean up the signal and add better clarity to what you hear. try your soundcard you mention and see how that goes. if amp turns out great working order with bias good and dc offset then all you could point it towards is of course the amp itself. try other sources to it as well like tv,cd player ect and see how the amp sounds.

 

[VinylStar]

Would any specific lubrication be necessary? i will have to wait a few weeks to get my soundcard as it is at home, but tonight i will go back and compare the noise it makes when connected to other sources, i.e. my iphone and a CD player if i can find one. how do i check the bias? i googled it and it looks complicated. thanks for your good responses, they are helping me understand my amp.
 

 

[yashu]

Nice receiver!
 
You lucked out, truly. Yamaha's older "natural sound" stuff was great.
 
I use the headphone jack on my NAD c160 premap sometimes, and it's not bad. I took it apart and saw that NAD did try to do it right. I have another receiver that kept it's own amp stage for the jack, unlike the NAD, and it sounded, less than great. Sometimes an amp will have a resistor to take it down to headphone levels, and this CAN sound good (because you can do it externally if you know what you are doing, hooking straight to an amp with some minor parts so you don't blow your phones up)
 
Really it is hit or miss. Yamaha's vintage, Pioneer's, and Sansui's are good and if you can find vintage Onkyo, get it, it's great.