2. amps-preamps
  3. 1252450407

Need preamp recommendation

Well, the quest for the tube rolling didn't go anywhere after a quick phone call to a tube vendor who advised me that low noise tubes won't lower the background noise of the preamp. Unfortunately I need to replace my VTL TL-5.5 to something else with lower noise floor.

The new preamp must have very low noise. My amps have about 25dB of gain, and my speakers are 93dB sensitive. It can reveal small amount of idle noise too well, which was undetectable with the same speakers but with power amp of 15dB of gain. Also the new preamp must have low / no gain, or adjustable gain. My VTL has additional 20dB of gain, and it's just too loud.

Some of the preamps that piqued my interests are Aesthetix Calypso, Placette, and Sonic Euphoria. I've read some earlier models of Calypso suffered from noise issue. I'd like to hear from the owners with sensitive speakers and high gain amps if there is any noise issue.

I'd love to try the new TL-5.5 which was long announced, but I don't think it's shipping yet. Anyone from VTL reading this board?

Any other low noise preamp that I should consider? I'd like the tubes, but as tube gears have inherently higher noise floor I'll also consider solid states and passive designs. The budget is flexible, but I'd like to keep it under $3k. The new preamp will be driving Pass XA-30.5.
jylee

Showing 10 responses by jylee

jylee OP
306 posts
 
To clarify my requirement a little bit, my VTL preamp is also pretty quiet. I couldn't hear anything but slight hint of hiss with my ear pressed against the tweeter on my previous setup with my 93dB speaker and amp of 15dB of gain. On a typical system with speakers of 87dB of sensitivity and 20dB of gain from the amp, my preamp will be dead quiet as well. The problem started to appear with high gain amp of 25dB mated with sensitive speakers with 93dB of sensitivity.

The noise is present when all the components are on, regardless of the volume level. It's the background noise of the preamp. If the noise was coming from upstream, it would vary based on the position of volume knob. The noise disappears when I switch off preamp, or put it on mute, or remove preamp and connect Unidisk directly to the amp. The noise is loud enough to be bothersome at the listening seat.

Thanks for all the recommendations. Please keep them coming. I would also like to hear more about the setup the preamp was used in to keep the system sensitivity in perspective.
jylee OP
306 posts
 
My ear pressed against the tweeter was in the previous setup, while trying to compare two amps after I noticed excessive noise with the current setup. I don't normally go around and put my ear on the tweeters. :)
jylee OP
306 posts
 
I'm not sure if anyone will tolerate buzzing sound heard in the listening chair, unless he's deaf.
jylee OP
306 posts
 

I think I missed the part where you said how the Unidisc performs as a preamp. Isnt that thing pretty silent? How does it sound, anyway?

Yes, my Unidisk SC which happens to be for sale right now has a variable level output and does not need a separate preamp. Without preamp the sound is clean and airy. VTL preamp added more fleshed out midrange and dynamics, and I liked the sound with VTL more.

Tvad, if you are near California you are welcome to drop by and hear the noise in person. I don't know how else to describe this. It's random background noise, not a hiss, not a hum, but nasty sound that makes your ear fatigue after short listening. Not audible when the overall gain was 10dB lower, but audible to 8ft away now. I don't care about the noise that I can't hear in the listening seat.

I wanted to get a new set of tubes as well, but the vendor on the phone was honest to tell me that new tubes are not likely to reduce the background noise at the cost of sales for him. I might just try a new set of tubes anyways because it doesn't cost too much to try.
jylee OP
306 posts
 
No, I would consider any persistent noise heard on the listening chair when no music is playing unacceptable. Pops and clicks from the vinyl is fine, so is recorded hiss on certain albums. But if the system has inherent noise that is heard on the listening chair all the time, it is broken in my book.
jylee OP
306 posts
 
Tvad, I know you are trying to help, but have you really heard all tube preamps? The noise floor of VTL seems to be around -110dB with 1V signal. I just need additional 10dB lower. I'm not asking a miracle.
jylee OP
306 posts
 

-110dB in phenomenally low. About as good as you can get. Are you certain of this spec? How did you arrive at this figure?

From stereophile measurement sections. Take a look at the last graph about inter modulation test. Maybe I didn't interpret the graphs correctly.

I understand any equipments make some degree of hiss, and they are fine as long as they are not heard 8 ft away.
jylee OP
306 posts
 
I haven't had a pleasure to audition many tube gears, but from two that I have, VTL preamp and EAR phono stage, one produces enough noise to be heard 8ft away and the other does not. Maybe you and I have different definition of noise or hiss, or maybe your ears are more sensitive to hiss if you heard hiss from all the high end tube gears that you have listed far in the sitting distance.
jylee OP
306 posts
 
Mitch2, I'm not much of a noise freak as it may have sounded after the lengthy exchanges with Tvad. :) I just don't want my system to produce unpleasant noise all the time. I'm sure many other feel the same way about their systems as well.

The example you provided in your system is actually an encouragement. It looks like your Lamm amps provide very high gain, about 32dB. With 90dB sensitive speakers your setup reveals more background noise, if any, than mine. Although my speakers are slightly more sensitive, my amps provide less gain at 25dB than yours. If you can't hear hiss 4 ft away in your system, I probably can't hear any hiss at 8 ft away in my system. Thanks for the additional detail.
jylee OP
306 posts
 
Kensetsu, I have kept my VTL TL-5.5 and I'm trying different tubes right now. The noise level came down a little bit with RCA 12AX7, enough so that I don't hear it in the listening chair. I am also trying out an SS preamp that sounds awesome, but sounds a little too lean in my system. TL-5.5 could very well be the best remote controlled preamp under $3k.
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