Evolution 302e Review

[joeinid]

Originally Posted by bodiezaffa

I have the amp plugged into a Pure Power 1050.
Do you think it needs a dedicated 20amp outlet or maybe the PP1050 isnt enough to handle that plus the other audio and computer components

In my experience, neither a PS Audio PPP nor a PurePower 2000 will remove DC. I still needed something like the Humbuster III or the 948 conditioner.

Have you tried straight into the wall outlet?

[bodiezaffa]

Originally Posted by New guy

Is the hum from the speakers or from the transformer? I run my 403E straight to the 20A wall outlet and it's silent.

Are you using RCA or XLR? If you are using RCA inputs, be sure to short pin 2 to ground pin of XLR otherwise, the negative input of XLR will be floating. This will cause hum.

Richard

The hum is from the transformer. I'm using xlr from nad dac to amp. Nad does have option to reverse pin. Ill try that tomorrow.

[bodiezaffa]

Originally Posted by joeinid

In my experience, neither a PS Audio PPP nor a PurePower 2000 will remove DC. I still needed something like the Humbuster III or the 948 conditioner.

Have you tried straight into the wall outlet?

Not yet but ill try that tomorrow and see if the hum is still there

[New guy]

Originally Posted by bodiezaffa

The hum is from the transformer. I'm using xlr from nad dac to amp. Nad does have option to reverse pin. Ill try that tomorrow.

Mark,

If the hum is from the transformer then switch XLR polarity won't help. I had a sub that hum only certain times of the evening and I tracked it down to a heating pad in the house. The heating pad uses an SCR and it really distorts the AC waveform. Light dimmers, electrical heaters and some electrical appliances can cause AC distortion.

My dad had a Krell monoblock that would hum around lunch and dinner time on some days. It was caused by the electric oven.

[bodiezaffa]

Just to give a shout out to Krell and Peter Mackay VP of International sales.
I sent him an email last night which he returned with 6hrs.

Now thats what I call dedication to your company brand.

Here is his reply.

Hello Mark,

Thank you for purchasing an EV-302e.

Hum noise within a system may be caused by a number of things. Your answers to the following questions will help us determine what may be causing the described “low but audible hum.”

1. Are you plugging the EV-302e into a line conditioner or directly into the wall AC plug?
2. Are you using the stock AC cord or an aftermarket AC cord?
3. Are you using balanced (XLR) or single ended (RCA) cable connections?
4. If using single ended (RCA) cable connections are the shorting pins installed into the XLR inputs?
5. What preamplifier is being used in the system and is it connected to a line conditioner?
6. Is the audible hum heard at the amplifier or from the loudspeaker?
7. Has the polarity and ground of the AC wall plug been checked?
8. Are you using a turntable in your system with an external phono stage?
9. Is the low audible hum constant or variable with gain change and is it present on all preamplifier inputs?

We appreciate your support of Krell Industries and your time required to answer the above questions.

Best regards,
Peter



Peter J. Mackay
Vice President, International Sales and Marketing
Krell Industries, L.L.C.
pmackay@krellonline.com
Tel: 1-203-298-4012 Fax: 1-203-891-2028

[bodiezaffa]

And a shout out to Joe(Joeinid) and New Guy for continuing to offer advice and experience. Thanks very much, fellas.

Going with a dedicated 20amp outlet being installed on Friday. I think thats the culprit.

[bodiezaffa]

Found the problem although it has raised more questions...
The hum was coming from the PurePower 1050 the amp was plugged in to.
When i went straight to the wall, the hum was gone.

[New guy]

Originally Posted by bodiezaffa

Found the problem although it has raised more questions...
The hum was coming from the PurePower 1050 the amp was plugged in to.
When i went straight to the wall, the hum was gone.

So the hum is coming from the 1050 and not the Krell?

[joeinid]

Originally Posted by bodiezaffa

And a shout out to Joe(Joeinid) and New Guy for continuing to offer advice and experience. Thanks very much, fellas.

Going with a dedicated 20amp outlet being installed on Friday. I think that's the culprit.

Hi Mark,

We've all been through it at some point. So glad you isolated the problem. Dedicated outlets are mandatory at this level and going bigger (as in power conditioner) is usually better. Big thumbs up to Krell for the prompt reply and Damien Janzen took care of me with the upgrade of my PurePower 2000 last year. Awesome service.

You might want to consider using the PP 1050 for everything but the amp.

[thezaks]

Krell recommends straight to the wall and no power conditioners anyway. My S-1500 is hooked up that way and works great. The first amp I've had in many years that did not go through a power conditioner...

Dave