Full Volume Issue


I have had the strangest thing happen to me twice. With my Nu-force P8 preamp in the off position while my cd player and dac are on there is no sound. If I turn on my tv then what is on the cd player comes on at full volume. The first time I turned on the tv and this happened it scared the hell out of me. The preamp didn't have any power to it. How is this happening?
philbrady
I have noticed a similar phenomenon with my TV remote (Pioneer plasma); occasionally when I turn the TV off, it turns on my Primare pre-amp. Generally, I have noticed that most of my remotes act strangely when the batteries get weak. I cannot tell whether there is a cause and effect relationship here, or mere coincidence. And what has made diagnosing this difficult is that it is a random, non-repeatable event. You could try fresh batteries to see if it alleviates the problem.

Bob R.
Bob, thanks for responding. This happens when the tv is turned on by pushing the power button. The tv remote isn't used. Also the preamp doesn't power up at all but the volume comes through full blast. Phil Brady.
Oops, my bad. I should have read your post more closely.

Good luck; hope you can figure it out.
I think your TV is probably creating some kind of a surge when you power it up, possibly causing some circuit in the preamp to go nuts.
Is the preamp off, meaning no power to any of its circuits/components, or is it in stand-by?
You can try this, if you want - unplug the preamp from the wall, wait 5-10 minutes and turn your TV on.
I think if some kind of a circuit in the preamp is faulty, for whatever reason, anything that is hooked up on the same circuit that is capable of some power draw at turn on is going to create the same problem your tv is creating.

Call NewForce and ask explain them the problem and see what they say.

Anyway, good luck and keep us posted.
Friend

I am assuming that your TV is not connected to your preamplifier. If this is true - then you may have a rare occurance where a microprocessor inside your preamplifier is reacting to signals from your TV remote control!

The fact that the preamplifier does not power up means nothing. In the easiest terms - one of two things sounds like it's happening: 1) the CD Player is sending signal to the preamplifier to preamplify, and the TV remote triggers a microprocessor to a open circuit allowing the 2.3 volt CD Player signal to flow straight through, or 2) you have your CD Player in input #3 which allows signal bypass. If you look below at the specs for your pre you will see that the P8 has this capability. See "input 3".

Specifications:

Audio inputs: 3 sets of RCA inputs and a 3.5mm stereo input jack (for digital media player, PC sound devices). Input 3 can be custom ordered from factory with volume fixed at 0db (gain=1) for Home Theater or PC pass-through.
Audio outputs: 1 set of RCA, 1 set of Balanced XLR, and a 3.5mm stereo headphone output with cross-feeding to create a natural soundstage.
Remote input selection and volume control with memory (last selection, volume level)
Mute and Sleep functions
Digitally-controlled switched attenuator. Volume Range: +30dB to –70dB with 0.5dB steps
Dynamic Range: > 100dB

Input Impedance: 4K ohm
Output Impedance: 40 ohm
THD+N at 1kHz: < 0.01%, typically 0.003-0.005%
S/N Ratio > 85dB
Frequency Response at 20-20kHz = +0dB/-0.2dB at 20-170kHz = +0db/-3dB
Maximum output = 8V RMS
Crosstalk –130dBFS
100W SMPS with PFC (Power Factor Correction)
Dimensions: 1.75”H x 8.5”W x 16”D Weight: 6 lbs.
Power Requirements: 90-240VAC, auto select.

Now, how to fix it! Here are two ways:

1) Send your CD Player through another input.
OR
2) Make sure that you have a power-up and power-down procedure set in place where your amplifier or CD Player are not at the same time.

The reason why you get a RUSH of volume is that there is no preamplifier in circuit to regulate the signal that is being sent dirtectly to your amplifier! So, in effect what you are doing is the equivalent of plugging your CD Player directly into your amplifier with no volume control.

Some people use the first to avoid a thump during power-up on sensitive units.

Hope this helps
Studio1
The cd player is in the first output, not the number three which is theater bypass. The power isn't to the pre at all. The remote for the tv isn't used, I power the tv up by pushing the power button on the tv. I will contact NuForce. Thanks for the answers. Phil Brady.
try unplugging it from the wall, wait 10 minutes and then turn the tv on.....see what it does