Speaker amps for headphones
Dec 21, 2013 at 7:59 PM Post #2,026 of 3,873
  @potterma perhaps you are onto something here in regards to the mechanical connection of the resistors. The losses we are experiencing may in fact be due to the leads of the resistors themselves. I may have a possible solution for that. Can you or someone else using the resistor network snip off the leads close as possible to resistor and solder on a 20awg solid core fly lead and see if listening impressions improve? Most resistor leads are quite thin and we may be running into a limiting/loss effect due to that. I would do it myself, but I only have the HE-adapter box and I really don't feel like hacking it up right now lol.
popcorn.gif
 

 
The signal runs through wire and pcb traces inside the amp. For those with stock wiring, it also goes through a mini-coax terminal at the cup which isn't even a bonded connection. An inch of resistor lead isn't going to make a difference.
 
 
  Not just "effectively a pencil lead".  EXACTLY a pencil lead...

 
Here you go... http://www.troelsgravesen.dk/graphite.htm
 
Dec 22, 2013 at 12:10 AM Post #2,027 of 3,873

   
The signal runs through wire and pcb traces inside the amp. For those with stock wiring, it also goes through a mini-coax terminal at the cup which isn't even a bonded connection. An inch of resistor lead isn't going to make a difference.
 
 
 
Here you go... http://www.troelsgravesen.dk/graphite.htm

Yup! 
 
 
Quote:
  Artistic masterpiece you say ...
 

 
Yes that is a Faber Castell pencil lead 
tongue_smile.gif

 
Dec 22, 2013 at 11:03 AM Post #2,028 of 3,873
Now that is interesting . I have read of this happening but the truth is I never thought is was true. Please tell me what kind of wire and it must have been a long run , how far.?


I think it was a 12 foot pair.
It was a flat braided cable, I don't remember seeing a brand name on the cable.
I also used the cable with a Yamaha CR-2020 receiver for many years without any trouble.
 
Dec 22, 2013 at 11:10 AM Post #2,029 of 3,873
There you go. I figured it had to be a coax type wire as the one wire is surrounded by the other.
Here is some almost no electricians understand why but we do.
When mega the wiring I install in large services when do e testing I gnd to each other the wires.
The wire is a large capacitor that I am charging with 1 kilo volt. When I first turn on the mega
It's appears shorted but the. Goes up and levels off at a few 100 kilo ohms.
Now if you want to mess with your men leaving it alone it will give one hell of shock
To the poor guy thinking there is no power there. This whe true to service buss as well

Lol. You should see there faces when they see the discharge spark.
 
Dec 23, 2013 at 6:40 AM Post #2,031 of 3,873
Rob before my comment gets misconstrued , what I meant was a coax like cable. Meaning as with coax the center conductor is surrounded by the gnd , usually in a mesh. As such the flat braided cable he was refereeing to is similar in design , not being like most speaker cables as in two wires twisted or next to each other. This design can yield a higher than normal speaker wire capacitance , as such affect the output Of the amp. Hope this helps .

Cris j. thanks for the reply.

Al. D
 
Dec 23, 2013 at 7:42 AM Post #2,032 of 3,873
Rob before my comment gets misconstrued , what I meant was a coax like cable. Meaning as with coax the center conductor is surrounded by the gnd , usually in a mesh. As such the flat braided cable he was refereeing to is similar in design , not being like most speaker cables as in two wires twisted or next to each other. This design can yield a higher than normal speaker wire capacitance , as such affect the output Of the amp. Hope this helps .

Cris j. thanks for the reply.

Al. D


I'm sure I still have this cable buried somewhere in the basement.
I'll see if I can find it tonight.
Who knows, maybe it even has a brand name on it?!
 
Dec 23, 2013 at 10:56 AM Post #2,033 of 3,873
Rob before my comment gets misconstrued , what I meant was a coax like cable. Meaning as with coax the center conductor is surrounded by the gnd , usually in a mesh. As such the flat braided cable he was refereeing to is similar in design , not being like most speaker cables as in two wires twisted or next to each other. This design can yield a higher than normal speaker wire capacitance , as such affect the output Of the amp. Hope this helps .

Cris j. thanks for the reply.

Al. D

Oh, sorry Al, I misunderstood.
 
Dec 23, 2013 at 1:24 PM Post #2,035 of 3,873
I think it was a 12 foot pair.
It was a flat braided cable, I don't remember seeing a brand name on the cable.
I also used the cable with a Yamaha CR-2020 receiver for many years without any trouble.

Well, 12 foot is not very long. It seems that with the capacitance of the cable in addition to the capacitance of the passive crossover was too much for the amp to handle.  Makes me wonder if that amp is more prone to some ringing on music transits as well.  I have always used large gauge plain clear jacket speaker wire to the passive speakers.
 
Dec 23, 2013 at 7:55 PM Post #2,036 of 3,873
Yea but the fancy fat ones from MIT just look so much better lol. But i agree .

Al. D
 
Dec 24, 2013 at 3:03 AM Post #2,037 of 3,873
Subbed.
 
Dec 24, 2013 at 5:05 AM Post #2,038 of 3,873
Hello,
 
I experienced noise with my HD800 and my Threshold and MCIntosh. I use the HE adapter. I don't have noise with HE60, K1000 and HE6. 
It seems a bad impedance ? What shoud I buy ?
 
Dec 24, 2013 at 6:30 AM Post #2,039 of 3,873
Hello. Sounds like you need more attenuation with headphones that have a Better effitioncy . May I ask what is a HE adaptor?

Al
 
Dec 24, 2013 at 10:16 AM Post #2,040 of 3,873
  Hello,
 
I experienced noise with my HD800 and my Threshold and MCIntosh. I use the HE adapter. I don't have noise with HE60, K1000 and HE6. 
It seems a bad impedance ? What shoud I buy ?

As Al suggests, you probably need more attenuation for the HD 800's.  You probably want a separate box for the HD 800 since enough attenuation for the  HD 800 will likely result in too much attenuation for the HE-6.
 
Read back in this thread and keep an eye out for RobRob's post.  He posted a spreadsheet and circuit diagrams for various resistor networks.  The "Preferred Network" should suffice.
 
@ALRAINBOW The HE adapter is the HiFiMan speaker amp adapter box.
 

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