[pixelsphotopro]

Quote:

 
You are correct until Volt.
V=26.8 at the beginning, how much current can run through resister? I=V/R=0.057ampere. So your headphone port has maximum 0.057 ampere, if you drive a 600ohm headphone, you get P=RI^2=1.94w. that's pretty high power.
 
@Pixelsphotopro, you can replace the resistor yourself like many people did. You can also build a resistor box that can link your cans to speaker post of receiver directly. Your HK pm655 can drive most phones.
 
Edit: Check PhoenixG's post below!

My headphone are the JVC HA-RX700 64 ohm and I have to go up to 1:00pm on the volume knob to get good sound

 

[verde57]

Can someone tell me what resistor values should I have in my receiver for orthos like HE-400?
they are 32ohms, but they draw high current.
The brands own  head amps goes around 5w into 50ohms.

 

[PhoenixG]

I wouldn't change it. Optimal resistor value is to be the same as your HP's, but 50 and 32 are plenty close.

 

[verde57]

32ohms is the impedance of the headphones, or 35ohms.
the amp has resistors around 220ohms, 1W.
 

 

[PhoenixG]

Ok, if you have an idea of how much current/power you want your HP's to have, I'll run the numbers. Send me a PM maybe, IDK if people want to be reading everything. 

 

[verde57]

Hifiman  HE-400 rec. power must be between 1W-2W.  35ohms
 

 

[Meewoo]

My headphone are the JVC HA-RX700 64 ohm and I have to go up to 1:00pm on the volume knob to get good sound

My HK665 has 500ohm resistor at headphone port, it can drive AKG Q701, K340 etc without sweat. I never turn volume pot over 12 o' clock. Check your amp with speakers, I think your amp has problem or you select wrong input source.

 

[LugBug1]

I can never get passed 8' oclock on my amps with my computer on full volume... Cd player the same. I must be a Wuss 

 

[MattTCG]

I got the Marantz 2270 completely cleaned up today. Deoxit on all the pots and switches. Replaced the power cord that had been severed. And now, time to give it a listen. 

 

[LugBug1]

May the force be with you ^ 

 

[MattTCG]

I was told by a trusted source to plug it and if all seems well to let it just sit for about 24 hours to burn in the caps, solder joints ect. ??

 

[LugBug1]

If it hasn't been used in a very long time then yes. That would be the sensible thing to do. 
 
Are you sensible? 

 

[MattTCG]

^^ Yes, well sometimes. 

 

[LugBug1]

Have you plugged her in yet? Are there lights? Pretty ones? 

 

[MrQ]

Quote:

Ok last one.. No seriously 

 
Had to try a Sansui and this was too much of a bargain to pass up. Perfect condition apart from a little nick off the corner of the vinyl. Insides are spotless as well. 
 
Its the AU 505 low powered early 70's integrated. Ideal headphone amp with a lovely balanced, detailed sound with a hint of warmth.
 
 
Thats me done for my main listening station. I've got my Marantz for my bedside and a spare Technics in case anything blows up. Those 3 amps in the pic cost me appox £200 in total. Thats £100 less than my last headphone amp... None of these amps are end-gamers I know, but I'm more than happy for what I've spent. I bought a couple of duds along the way as well, but this vintage hobby is all about learning as you go. And of course being at the right place at the right time...  
 

 
 

 
Good luck with stopping right there. Seriously, I want to believe it's possible, for my own sake. In the UK it's a lot easier because we don't get the bargains and the opportunities that come stateside.
 
Being in the right place at the right time can been very costly this side of the pond. When I bought my SX1980 from a UK seller, I knew the chances of a '1980 coming up again for sale were slimmer than being the father of the next royal baby. Now two years later I shipped it to the US for a full recap and restoration (don't ask what the shipping is for 78lbs) . I'm hoping it will be part of my 'end-game' rig. 
 
Just because I already own a Marantz 2385 and a Sansui AU-D907, which will have to be restored (in the US), I can stop any time I want to.