Amp and preamp on same outlet?

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.
.

Jim, what did I tell you before about trying to teach a pig to sing? ;^)

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.

Hi Jim,

I can't do that with any certainty, because as I see it the specs provided in the manual are both ambiguous and inconsistent.

First, output power into the various load impedances is specified as "each channel driven." I would normally expect output power ratings to be based on both channels being driven simultaneously, but as I alluded to earlier the specified maximum input power of 6000 watts seems (given that this is not a class D amp) to be too low to be consistent with the specified output into 2 ohms of 2800 watts, if the 2800 watts (or anything close to that amount) is provided by both channels simultaneously. So perhaps "each channel driven" means "one channel driven," rather than "both channels driven."

Second, the specified maximum power consumption of 6000 watts is identical to the spec for the FPB 750Mc monoblock amp (for which specs are provided on the next page of the manual), with that amp having just slightly higher output power ratings. Same goes for the other two monoblock amps in the FPB series and their stereo counterparts. Yet the power consumption numbers for standby and idle conditions differ between the stereo amps and their monoblock counterparts by approximately a factor of two in most cases, as might be expected.

So I don't know how to reconcile all of that, and it seems that all of these numbers have to be taken with some grains of salt. And adding to the uncertainty is the point you raised earlier about inrush current, which of course is unspecified.

Best regards,
-- Al

Reading back I see that the OP Audiolover718 says his system sounds great now - that's wonderful. Glad it worked out for you. Still would be curious to know what speakers you are using if you see this.

02-23-15: Wolf_garcia
Interestingly (only to me perhaps), after switching to a moderately powered tube power amp (60 to 85 watts or so per side) I found that the lights no longer dimmed at loud passages like they did with my previous 100 watt pc high current SS amp.

I hear you Wolf_garcia. I love my Music Reference RM9 100 wpc tube amp. But here is the thing. It puts me at the 15th row of a night club's music scene which is pretty cool. The Krell however puts me in the 5th row up front. So much energy there. Now the back rows I have to admit were better in the younger days ......for checking out all the chicks. Also no lights dimming when I turn it on (20 amp circuit) - I do close my eyes when the utility bill comes in though. Still I am able to listen all day and night if I wish and not have to strip down like I had to do with the OTL 195's. Again in my younger days this could lead to good things. These days it leads to strange looks and questions.

@audiolabyrinth

Not sure why you had a problem with 20 amp and your Krell amp. As you know the Krell 600 is cruising with B&W Matrix 800 which were Dan D'Agostino's personal speakers in this amp era. Any thoughts of having to tweak the power panel (non-existent). The Apogees mentioned on this thread - Apples to Oranges. Much greater amp load, and load on the house power. I guess I can maybe understand why an Apogee owner would search for power tweaks with those speakers. Does make me wonder what kind of bad ass speakers you must own? Maybe on another thread we can discuss this.

fwiw - I sold a classe ca300 to an Apogee owner. He used it on them with those autoformers....

Happy Listening.