Amp and preamp on same outlet?

I would like share some info in regards to the Krell references made on this thread.
I also believe the info would be of interest to the OP Audiolover.

If I can ask Audiolabyrinth a couple questions first.

@Audiolabyrinth

Am I reading your posts here right that you are using a 30 amp circuit breaker, but not 30 amp rated line or a 30 amp outlet; and therefore a 30 amp terminated male end on your Krell power cord ?

Has your 20 amp line been checked ?

So I have a friend considering a Krell amp. He has a shared 15 amp line for his present set up. To offer him more insight I reached out to Patrick at Krell about a dedicated 15, 20 and even 30 amp service (in a second email) - this due to what I read in this thread.
I would like to share this info from Patrick.

Patrick's answer.

The answer to this is somewhat dependent on the speakers being used, as well as the length of the speaker cables. We recommend 20 amp service because with rare exception it almost always works best in terms of the amplifier always having continuous current available to be able to instantly respond to whatever type of listening style a customer may have.

The above now said, in some homes installing a 20 amp line is either not possible, and or its install cost can be prohibitive, depending on the age of the house. I know for a fact that there are many customers out there who are successfully running systems with large Krell amplifiers using a 15 amp line. Would there be a dramatic sonic difference between using a 15 amp line and a 20 amp line? Maybe and maybe not. A good stiff 15 amp line verses a weak 20 amp line, in my opinion you would probably not hear the difference between these two.

As the expression goes, “the proof is in the end result”. If when using a 15 amp line, the amp sounds open and fast and detailed with good bass and sound staging, and it does not pull the 15 amp line breaker down during loud playback or loud musical transients, he should be good to go as is. However if he is tripping the 15 amp AC line breaker occasionally during playback, he should go up to a 20 amp line if possible.

The Key words that stood out to me in the above.

Speakers used
Length of Speaker Cables
The proof is the end result (the amp sounds open and fast and detailed with good bass and sound staging)
A good stiff 15 amp line versus a weak 20 amp line.

And from some of the discussions on this thread about 30 amp service I asked.

Whats the deal with 30 amp service. Is it ever needed or warranted.
FWIW I take his response as normal for someone representing a company that makes high power amplifiers.

Patrick's response

As they say, “the more the better” and giving a powerful amp like the FPB-600/600c/700cx a dedicated 30 amp line will make a serious difference from a performance perspective that would be obvious straight across the audio frequency spectrum. Under these circumstances however you would need to re-terminate the male end of the amps AC cord with a 30 amp twist lock type male connector. Is this really needed? Not really. But you asked . . .

I interpret Patrick's comments that for 30 amp service, a 30 amp breaker, 30 amp line, 30 amp outlet and a 30 amp male connector is required to go this route.

Happy Listening.

Listen everyone, I have a dedicated line rated above 30 amps!, their is no issues,I have said numerous times, I have a 10/3 romex, meaning 10 awg 3 conductor dedicated line, it is the same as the captive cord on my krell 700cx, seems no one is listening to me more like it!

thankyou ct0517, it is patrick bresnahan that asked the technician's and R&D design team about the 30 amp breaker, this was NOT my idea at all, it was numerous other big krell amp owner's and krell that made this sugestion to me,however, Patrick is correct about the male wall plug, I have no issues at all, but I also said, I will be getting a high performance male wall plug for sound, Not any thing else, if I decide I really want one, currently, I do not, cheers.

Jea48, also, this captive cord is a 10/3 copper power cord,when I get the money, I will be changeing the wall plug to a furutech or oyaide for performance, It seems I really don't need it, but I can always return it if something like this wrecks my sound, I am a skeptic by nature, so we will see Jim, cheers.

Listen everyone, I have a dedicated line rated above 30 amps!, their is no issues,I have said numerous times, I have a 10/3 romex, meaning 10 awg 3 conductor dedicated line, it is the same as the captive cord on my krell 700cx, seems no one is listening to me more like it!
03-05-15: Audiolabyrinth

Audiolabyrinth,

Yes from day one you said the branch circuit wiring you have is #10 awg. And yes that is the minimum size needed for a 30 amp branch circuit. If you were not using a 125V 20 amp rated receptacle your branch circuit would be code compliant. So for me in your instance the problem is the 20 amp rated receptacle. Whether you like it or not because of the 125V 20 amp rated receptacle, you are insisting on using, in the eyes of NEC code the NEMA 125V 20 amp receptacle dictates the branch circuit shall be 125V 20 amp regardless whether you used #10 awg wire or larger. Therefore per NEC Code the breaker must be a 20 amp breaker.

My concern with your posts to this thread and others is when you say Krell tells customers to change out a 20 amp breaker, that is protecting a branch circuit that meets NEC code which likely may have #12 awg wire with a 15 amp duplex receptacle or a 20 amp receptacle connected to the branch wiring, to a 30 amp breaker.

As for the captive power cord, my bad for being lazy and not reading through the owner manual of the Link I provided for the Krell amp above. In your particular case because at least your branch circuit wiring is #10, 30 amp rated wire, and the power cord for the Krell amp is captive that eliminates you/others from using a DIY or other non UL and or CSA Listed power cord. Why do you thing Krell chose not to use a 20 amp IEC inlet connector on the back of the Amp?

At $14,000 list price for the Krell 700cx amp, Krell did the consumer an injustice, imo, by installing the 125V amperage?? type plug on the end of the 10/3 power cord. Amperage??, I could not find in any searches whether the plug is a 15 amp or 20 amp NEMA rated plug. By their specs for the amp they say it should be connected to a 20 amp circuit minimum. That would suggest the plug is a NEMA 5-20P 125V 20 amp plug. What plug did Krell install on the end of the cord?

15 amp plug?

20 amp plug?

Also I could not find if the Krell 700cx amp is safety tested, Listed, by any recognized independent testing laboratory like UL or CSA. Do you know if the amp is Listed?

Bottom line, imo, Krell chose to use the captive 10/3 cord to stop a user from using an aftermarket power cord there by prevent the possibility of electrical fire due to the power demand the amp can place on the power cord if the amp is driven hard. And , imo, a 20 amp IEC inlet connector would never be able to handle the varying load current placed on the connector if a user was driving the amp hard.

See page 22 of owner manual.

Output both channels driven,
8 ohm 700 watts
4 ohms 1400 watts
2 ohms 2800 watts

8 ohms, 700W / 115Vac = 6 amps plus.
4 ohms, 1400W / 115Vac = 12.8 amps plus.
2 ohms, 2800 watts / 115Vac = 24.35 amps plus.

AC mains power consumption,

6,000 watts max. @ 115V

Not sure why FLA was not given.

If Al is still following this thread he can do a better job of translating the info from page 22 of the owner manual than me.

The plug Krell chose to use? Imo, it was chosen because the standard receptacle configuration in the USA and Canada is the NEMA 5-15R receptacle. And just guessing, imo, they used this number

4 ohms 1400 watts

from their specs to justify the reason they choose the plug and not a 30 amp rated plug.
.