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
 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
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.
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?
Well, I did some more testing. I have a defective pre-amp. I had time to kill. I went and purchased some new JJ 12au7's and the loud Hiss is still audible from back of room. Another audiophile from another forum told me that, even with my amp's gain and speakers, the hiss should not be that loud. Plus, I tried headphones, the hiss is loud WITH buzzing. Again, I'm not expecting SS quiet, especially with my speakers. I plugged in my class D ceiling speaker amp (along with  ceiling speakers)---hiss is loud as can be. Same with my older B&K amp and different speakers. Plus, I did all the usual (cables, outlets, power conditioner, power cord, etc).

So I am boxing the amp and sending off to Rogue today. Hopefully, I can get back in the next week. This was my 50th Birthday gift from my wife  I'm taking a couple of days off late next week and I hope I get the unit returned by then. Very disappointed :(
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. 
I own a pair of Zu Omen def with a Line Magnetic 219ia. This is an expensive amplifier, but even the cheaper ones (518 and 508) are excellent.
Another good option is a relatively new amplifier from Hong Kong - KingKo Audio. The designer is a friend of mine (he was previously selling Rogue Audio, Line Magnetic and Zu, so he decided to create his product based on his own ideas and also the best from each brand he was selling).
His amplifier is small and perfect for high efficiency speakers. Top quality parts, extra care with the transformer and even a very high quality headphones tap. Also very affordable valves and gorgeous meters. 
Can work as integrated or power amp. 
The sales are exceeding his previous expectations and there is a very good review on the audio website DAGOGO. 
Here are the links:
http://kingkoaudio.com/en/pages/KINGKO-AUDIO.html

https://www.dagogo.com/kingko-audio-ka-101-integrated-amplifier-review/

Note: although friend of the owner of this brand, I have no interest or profits from his sales. I'm just giving a very personal and honest suggestion. 

A Solid State option is the Benchmark AHB2. Most quiet amp on the planet. Don't know how it sounds, however...