The *NOT BORING!* Hi-Fi faff chat and sales

I'd continuity test the lead...sounds like its got a short to earth at the IEC plug end or there is crush damage to the cable.

Not the lead, tried the lead supplied and two of my own, they all blow the fuse with the earth wire connected but power my av amp perfectly.

It’s an issue with the pre, but I don’t know why, it makes no sense...

Most US & Japanese gear does not have an earth -2 pin (medical gear is different hence they have 3 pin). Looking at those images the earth pin top is free which makes sense. They rely on earth through the negative (blue) (from memory) hence by connecting an earth short circuit.
UK we require "earth grounding" (green & yellow, US/Japan do not.

I remember Vickers Hifi from my old job, they were not nice to deal with.

Saying you shouldnt have opened the plug is not the most helpful.

From what I can see of pictures on the net and of yours, I cant see that the ground pin is actually connected to anything, just left bare. Where I worked, all the pre-amps were the two pin version as they double insulated.

Indeed! That comment mightily pi55ed me off!!




OK, so in your eyes do you think that the pre is safe to use then?

They said they ran it in their demo room with the lead they sent me (no earth connected) and it runs fine here with it not connected...

I really want to try it out, was just worried.

If I return it am I making myself out to be an eejit because of the "earth through neutral" issue?!

The unit is mint and looks totally unmollested (looks lovely inside!)


EDIT: if the top pin is not connected to anything, why does connecting the earth wire blow the internal fuse? That's the bit I don't understand....

Out of curiosity I did a continuity test on my meter... top pin to bottom left pin beeps as does top pin to bottom right pin.... that would imply the top pin IS connected to something, somewhere, somehow....

I'm neither an electrician nor an expert in electronics, however I have used a fair number of appliances without an earth connection in the plug, sometimes having an earth wire taped over and not wired into a plug terminal as you describe. However I'm happy to admit that would be a bodge and ideally I'd prefer correct lead/plug to be available. For a specialist hifi supplier to hand kit over in such a condition, whilst perhaps safe, smacks of shoddiness to me.

Always annoying when something you're looking forward to comes with an unexpected defect, but I'd probably run it without the earth and vent m spleen at the shop....

There should be a label with manufacturer and power rating details somewhere on the amp, if it is 'Class 2' (double insulated and not requiring an earth connection) it should have this mark on it.

Matt

Slept on it (not physically) and I'm not happy about this so it's going back... decision made

Found a KRC-3 instead (with the earth wire connected ) so we'll see how that works out instead!

Got a fantastic response from Krell, great that they even bothered to reply, that gets a big thumbs up from me:

Hi Mike,
Funny what you can still learn about an older product today. I am told that the AC receptacle is a PC mount version (I knew this part) and that one of the pins that connects this receptacle to the main circuit board act as the earth connection. This is connected to the chassis through the PC board and one of the standoffs (connecting hardware) that connects the circuit board to the bottom chassis (I did not know this part). The vacant lug on the back of the AC receptacle is a redundant earth connection. The KSL (as well as all of our other products) is a Class I apparatus and requires the earth ground connection from the power cord, which then goes through the PC mounted pin via the AC receptacle. Meaning that the AC receptacle does not require an additional connection to the vacant lug on the back of the AC receptacle. We are at a loss to explain why the fuse blows when a wire is connected to this redundant lug on the AC receptacle.

As I was about to send this response, I saw your other email stating that you returned the KSL and got a KRC3 instead. Ultimately you will like the sound of the KRC3 much more than the KSL, plus it has IR capability. Good luck.
Regards, Patrick

So it was faulty after all!

However, everything happens for a reason, and the new preamp has remote too... win-win!