2. amps-preamps
  3. 131822-10803

Low output gain amplifier for ZU 101db Efficient speakers

I am thrilled with my new Rogue RP-5 preamp. However, like I mentioned before, the tube Hiss is really loud (I can hear back of room). It’s a smooth, non noisy hiss. I chatted with Rogue and they are sending replacement tubes but guess it’s due to my Nuforce STA200 amp with output gain of 34db. I was told that was quite high for having such efficient speakers. Rogue told me they test their equipment on high efficiency Klipsch speakers and the RP5 is quiet.

Anyway, I have attenuators coming today to help until I now find a power amp. I would love to have an Atma-Spere amp, however, they are too pricey for my budget (even used). Maybe a used Firstwatt f3 or these Quicksilver monoblock amps that are made for high efficient speakers http://quicksilveraudio.com/products/horn-mono/

The lower priced Decware amps look nice, plus they have gain settings.

For those who own high efficiency speakers with a tube pre, any other options? I really hate to switch out the RP-5 because it has all the functions available on the remote and it sounds great.


aberyclark
aberyclark OP
594 posts
 
I've got both Decware and Quicksilver Horn Monos. The Quicksilvers are really dead quiet amps and they sound superb. They'd be a great match in your setup.


Which do you prefer and what are the sound charactoristics of each?
stereo5's avatar
stereo5
2,766 posts
 
Sorry to hear that about your preamp.  Mine is dead quiet and although my speakers are only 93.5DB efficient, with the gain cranked up to max on my RP-5 and connected to a Conrad-Johnson 250wpc amp, it is dead quiet.  I can't hear anything from the speakers even with my ear right against the grills.  The JJ tubes supplied with your preamp should be dead quiet as that is one of the reasons Rogue uses them.
georgehifi's avatar
georgehifi
4,966 posts
 
aberyclark
 Low output gain amplifier for ZU 101db Efficient speakers

With speakers that are over 98dB there's really no advantage in having a preamp with gain, as you've found it's a diadvatage, you'll find many now are starting to go for passive preamps as per this Nelson Pass quote:

We’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more.

Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up.

Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control.

What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.

And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp.


You could always trial a Schiit Freya preamp it has virtually no gain (unity gain) itself, in all of it’s modes tube, solid state, or passive output, got remote 3 inputs and balanced or rca, and sounds from reports very very good.

Cheers George
kosst_amojan
2,095 posts
 
What you want is a Nelson Pass First Watt J2, F7, or F4. Just read the reviews. 
aberyclark OP
594 posts
 
Yes, the First watts have got my attention. Plus, they supply a great low end wheras the pre can add smoothness to highs and mids. The RP-5 did sound great ontop of all the freaking hiss. I took an iphone video of me muting and unmuting the preamp. Ill post it later
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