[brunk]

 
I don't use anything between my LCD-3s and the Cyclops and have no buzz or noise of any kind (other than the music I listen to... but that's another issue...).  Even the transformer buzz was not audible through the cans.  To me it sounds like he has a grounding issue, whether inside the amp where there shouldn't be one, or in his external wiring.  If it's the former, he should contact Klaus.  If it's the latter, he should recheck his wiring, particularly the home-made speaker tap.

Ah ok, i thought you guys that use this exact setup were using those. I guess i misread or my memory fails me from reading about it some time ago. It does sound like a grounding issue because it's buzzing without a signal going through it.

 

[henrikolsen]

 
I don't use anything between my LCD-3s and the Cyclops and have no buzz or noise of any kind (other than the music I listen to... but that's another issue...).  Even the transformer buzz was not audible through the cans.  To me it sounds like he has a grounding issue, whether inside the amp where there shouldn't be one, or in his external wiring.  If it's the former, he should contact Klaus.  If it's the latter, he should recheck his wiring, particularly the home-made speaker tap.

I would really love to hear what others are doing with that braided metal shielding around the 4 microphone wires. Could/should that be used for the grounding?
 
Gary, and others, how's your speaker tap done regarding this? Is the shield/case of the 4-pin XLR connected to anything inside the plug? And at the amp end, is any shield from wire connected to chassis of amp or similar, or just the 4 wires to each terminal? (Great terminals on that Cyclops by the way, what a grip they so easily provide)

 

[Gary in MD]

Henrik:
 
I don't know what the arrangement is inside the 4-pin XLR connector, since I've never opened it up... and don't really want to, because I'm afraid the little leprechauns in there that turn amp power into headphone sound will escape and run away....
 
There is nothing on the amp side except the 4 individual wires connected to banana lugs/spades, and I have the 4 lugs plugged into the amp's speaker out jacks... and yeah, Klaus uses very heavy-duty terminals.  In fact there's nothing light-weight about anything in the amp. 
 
You might want to take a picture of your XLR connection and post it here... there are lots of experts on this forum who will be able to help just by looking at it.  Unfortunately, I'm not one of them.

 

[henrikolsen]

  Henrik:
 
I don't know what the arrangement is inside the 4-pin XLR connector, since I've never opened it up... and don't really want to, because I'm afraid the little leprechauns in there that turn amp power into headphone sound will escape and run away....
 
There is nothing on the amp side except the 4 individual wires connected to banana lugs/spades, and I have the 4 lugs plugged into the amp's speaker out jacks... and yeah, Klaus uses very heavy-duty terminals.  In fact there's nothing light-weight about anything in the amp. 
 
You might want to take a picture of your XLR connection and post it here... there are lots of experts on this forum who will be able to help just by looking at it.  Unfortunately, I'm not one of them.

 
Here are pictures of the cable adapter.
 
   

 

[brunk]

The white wire in the connector looks like it has a cold solder joint. Try wiggling that wire around just a bit when its plugged in and see if hear any anomalies. If you do, that's a good starting point for a fix.

 

[henrikolsen]

Tried wiggling the white wire (and the rest while I was at it). No changes heard.

 

[Steve Eddy]

I would really love to hear what others are doing with that braided metal shielding around the 4 microphone wires. Could/should that be used for the grounding?

Gary, and others, how's your speaker tap done regarding this? Is the shield/case of the 4-pin XLR connected to anything inside the plug? And at the amp end, is any shield from wire connected to chassis of amp or similar, or just the 4 wires to each terminal? (Great terminals on that Cyclops by the way, what a grip they so easily provide)

The shield doesn't get used on either end. Ideally you would use an unshielded cable, but if you only have a shielded cable to work with, you just ignore the shield.

se

 

[Gary in MD]

  Tried wiggling the white wire (and the rest while I was at it). No changes heard.

Just to be clear once again, you are hearing this from the headphones only, not from the amp itself, correct?
 
If so, as I said above, the first thing I would try is connecting the cans and speaker tap to another amp and see if the noise is still there.

 

[Duckman]

Two days from the US is the quickest intnl postage I've had so far. Thanks you Fedex (and Klaus).

 

[Gary in MD]

Clearly Fedex wants to hear your review as well...

 

[henrikolsen]

  Just to be clear once again, you are hearing this from the headphones only, not from the amp itself, correct?
 
If so, as I said above, the first thing I would try is connecting the cans and speaker tap to another amp and see if the noise is still there.

It does actually also hum itself (the amp) I realise now, when putting my ear close to it. Seems kind of similar to what I hear in the headphones. 

And again, it’s the same with or without input, different volume setting and in a couple of different wall outlets. Also tried another power cord. No luck.

When you switch the amp on, it sometimes makes this boing/spring/buzzy sound, fading almost away with a few seconds, but not completely. Almost like an old cathode monitor. Left is still this humming low noise.
 
Is your Cyclops dead quiet (like when turned off) both in headphones and in itself?

 

[preproman]

  Two days from the US is the quickest intnl postage I've had so far. Thanks you Fedex (and Klaus).

 

  Clearly Fedex wants to hear your review as well...

 
 
So do we..  I just love those Klaus amps and the flexibility he gives you when making them.

 

[Gary in MD]

  It does actually also hum itself (the amp) I realise now, when putting my ear close to it. Seems kind of similar to what I hear in the headphones. 

And again, it’s the same with or without input, different volume setting and in a couple of different wall outlets. Also tried another power cord. No luck.

When you switch the amp on, it sometimes makes this boing/spring/buzzy sound, fading almost away with a few seconds, but not completely. Almost like an old cathode monitor. Left is still this humming low noise.
 
Is your Cyclops dead quiet (like when turned off) both in headphones and in itself?

It's dead quiet in the headphones.  It's quiet enough itself that I can't pick out any noise relative to all of the other background in the room, e.g., 2 computers, an external hard drive, HVAC, neighbor harvesting his field, etc.  If I put my ear within an inch of the top I think I hear a very tiny bit of noise, but it's hard to tell if it is from the box itself and I'm not turning off everything else in the house in order to isolate it.  In any case, it isn't significant in any way.

 

[zilch0md]

Speaking of dead quiet, here's my (necessary for listening without hiss) TBI Audio resistor network:
 

 
@FlySweep - What's inside your magic box?  I'll be waiting for my custom balanced cables for the HD600 for serveral days, but I'm wondering if your resistor network (that Jan built for the HD800 and which you have enjoyed with the HD600) differs significantly.  
 
Thanks!
 
Mike

 

[Chris J]

  I would really love to hear what others are doing with that braided metal shielding around the 4 microphone wires. Could/should that be used for the grounding?
 
Gary, and others, how's your speaker tap done regarding this? Is the shield/case of the 4-pin XLR connected to anything inside the plug? And at the amp end, is any shield from wire connected to chassis of amp or similar, or just the 4 wires to each terminal? (Great terminals on that Cyclops by the way, what a grip they so easily provide)

 
I would try grounding the shield at the amplifier end.
An ungrounded shield can act as an antenna and could potentially inject noise into the amplifier. This could even cause the amplifier to oscillate in extreme cases.
Assuming you have a grounding post somewhere, or the case on your amplifier is grounded and it is possible to tie a ground wire the the amplifier case.
You can try it grounded and ungrounded and see if you have a preference (if any).
 
I agree with SE, speaker cables and headphone cables don' need no stinkin' shield!