Show us your Head-Fi station at it's current state. No old pictures please...
Aug 7, 2013 at 10:13 PM Post #14,536 of 41,119
Vintage amps use same amp circuit that would powers the speakers. There is a resistor wired in line to reduce power output, because obviously headphones don't need 50+ watts per side. Some people say high output impedance is bad, but I let my ears be the judge, and what I am hearing is pretty stellar. Especially considering the ridiculously low price I paid for this thing.   
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I'm just wondering, do these AVR's and amps have discrete amp "circuits and stuff" for headphones or are they just using the same amp as for the speakers?

 
Aug 7, 2013 at 10:15 PM Post #14,537 of 41,119
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Laptop and a Fiio E17 feeding a vintage Pioneer SX-750 which feeds either a modded T50rp or Q701.

really nice setup - i love vintage gear!
 
Aug 7, 2013 at 10:20 PM Post #14,538 of 41,119
Silver faced Pioneers are awesome.
smile.gif

 
Aug 7, 2013 at 10:47 PM Post #14,539 of 41,119
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Vintage amps use same amp circuit that would powers the speakers. There is a resistor wired in line to reduce power output, because obviously headphones don't need 50+ watts per side. Some people say high output impedance is bad, but I let my ears be the judge, and what I am hearing is pretty stellar. Especially considering the ridiculously low price I paid for this thing.   


What resistor is typical?  150 ohm? 
 
Has anyone lowered the resistor to get even MORE output?  Not that it needs it..............none of my 5 vintage really do but ya know, makes me wonder.  
 
Aug 7, 2013 at 10:50 PM Post #14,540 of 41,119
No idea what impedance the resistor is. Lowering the resistor would gain more output power, but I already can't listen to either of my two headphones at higher than the 9 o'clock spot on the volume knob, and that is with the E17 feeding it as a DAC only.
 
All I know is that this very budget setup sounds ridiculous.
-$40 for the Pioneer SX-750
-$140 for the Fiio E17
-$240 for the Q701
-and I've got about $180 or so into the T50rp, including the headphones themselves plus the pads, cable, and modding materials
 
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What resistor is typical?  150 ohm? 
 
Has anyone lowered the resistor to get even MORE output?  Not that it needs it..............none of my 5 vintage really do but ya know, makes me wonder.  

 
Aug 8, 2013 at 2:41 AM Post #14,542 of 41,119
Very nice! I almost finished my Crack build today, gotta go in tomorrow and figure out why it blew a fuse on powerup 
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 Funny, because I definitely took my time and worked carefully (8-hours) so that I hopefully wouldn't have to do any troubleshooting... Measurements all checked out too.
 
Aug 8, 2013 at 3:08 AM Post #14,544 of 41,119
That's the thing that's puzzling me. All of the resistance measurements checked out fine, wouldn't that be affected in the event of a short or bad connection?
 
I did some Google-fu and discovered that many builders use slow-blow fuses. Mine shipped with a fast-blow 1A, 250v fuse. Might try a slow-blow and see if that was the problem. Radioshack closed a few hours ago, so it'll have to wait until tomorrow.
 
Aug 8, 2013 at 3:20 AM Post #14,546 of 41,119
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All of the resistance measurements checked out fine, wouldn't that be affected in the event of a short or bad connection?
 
I did some Google-fu and discovered that many builders use slow-blow fuses. Mine shipped with a fast-blow 1A, 250v fuse. Might try a slow-blow and see if that was the problem. Radioshack closed a few hours ago, so it'll have to wait until tomorrow.

No. If the resistors itself is damaged then it will show bad or out of spec drifted measurement ratings, double check through your work according to the manual supplied, sometimes your eyes become strained if you work on something to long and you zone out so you might've made a small mistake somewhere. Mine shipped with a fast blow 1A and has never blown. But hey could be a fuse problem and I'm smoking unicorns. 
 

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