Are NuPrime/Nuforce Power Amps Direct Coupled Amps?

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Beano

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Are NuPrime/Nuforce Power Amps Direct Coupled Amps?
« on: 23 Feb 2015, 08:42 am »
Hi,
 
I have a Pair of Ref9SEv3 amps. I am thinking of trying a friend's tube preamp but the preamp manual states that it should not be paired with direct couple amplifiers or there may be a chance the speakers will be damaged. I have another friend with Ref18 amps who is also thinking of trying out the preamp. We are not technically inclined and have no clue whether our nuforce amps are direct coupled or not....or even what direct coupled means.  Appreciate any clarification on whether Nuforce/nuprime amps are direct coupled or not. Thanks in advance

Srajan Ebaen

  • Industry Participant
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Re: Are NuPrime/Nuforce Power Amps Direct Coupled Amps?
« Reply #1 on: 23 Feb 2015, 10:27 am »
I can't tell you about the amps but direct-coupling means no signal-path capacitors. Depending on the presence of DC servos or other schemes, DC components at the input can be passed on to the output. Tube preamps can be guilty of that. If they output a small amount of DC and the subsequent amps pass that to the speakers... you could have unhappy tweeters  :nono:

gammajo

Re: Are NuPrime/Nuforce Power Amps Direct Coupled Amps?
« Reply #2 on: 23 Feb 2015, 04:30 pm »
All I can say is that I have used an Ayon CD5s tubed preamp with both V3s and now Ref 20 with no problem, but YMMV. I would wait until hearing from Nuforce or Nuprime on the question

rustydoglim

Re: Are NuPrime/Nuforce Power Amps Direct Coupled Amps?
« Reply #3 on: 23 Feb 2015, 05:47 pm »
Thanks Srajan. Beano, you should ask your preamp manufacturer, not NuPrime.

JoshK

Re: Are NuPrime/Nuforce Power Amps Direct Coupled Amps?
« Reply #4 on: 23 Feb 2015, 07:18 pm »
Most tube preamps have a cap on the output (AC coulped) to protect against DC offset.  What kind of tube preamp is this?  DC coupled?

I think even AC coupled tube preamps can provide very small amounts of DC offset, couple mVs.   This is typically fine for tube gear. 


Beano

  • Jr. Member
  • Posts: 37
Re: Are NuPrime/Nuforce Power Amps Direct Coupled Amps?
« Reply #5 on: 24 Feb 2015, 04:11 am »
Thanks all for your reply. I found out that the preamp design doesn't have output caps....supposedly to enable a "purer" signal.  I don't think I'll risk my amps and speakers on it... :nono:

Ike Carumba

Re: Are NuPrime/Nuforce Power Amps Direct Coupled Amps?
« Reply #6 on: 26 Mar 2015, 11:27 pm »
I would like to know if my NuForce REF9V3se amps are direct coupled or AC coupled. If they are AC what are the values of the coupling capacitors ?

My DEQX processors are being upgraded right now and the ( authorized DEQX ) tech asked me to find out.

Before he's done the tech will track down and replace the faulty component but he wants to know if the NuForce amps are input capacitor-protected in case the fault should recur.

rustydoglim

Re: Are NuPrime/Nuforce Power Amps Direct Coupled Amps?
« Reply #7 on: 27 Mar 2015, 05:16 am »
There is a capacitor on Ref9V3SE, so its AC coupled.
The value of the capacitor 1µF 250V (WIMA FKP4).