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Gain challenge with Lyra Delos

I recently upgraded to the Lyra Delos. It bests my previous cartridge, the dynavector 10x5 by a long shot. But praises aside, I am having trouble driving this cartridge with my electronics, and something seems like it may be wrong.

I am going from lyra Delos, to audio research ph3se (54dB gain) to audio research LS25 via single ended cable (12dB gain) to Audio Research VT100 mkII amplifier, to Rockport Mira Monitors (87dB sensativity).

In order to get loud-ish sound in my small to medium sized room, I need to set my volume knob on the ARC LS25 to 3 o'clock or all the way to maximum. Once the level is this high, noise from the preamp is quite an issue, not to mention, there is nowhere to go from maximum. It is a bit surprising to me that with 54dB out of the phono pre, and 12 dB more from the preamp, that this situation would present itself. Is there something wrong?

I am considering switching the ARC PH3SE for a BAT VK-P5, which would get me one extra dB from the phono pre and 6 extra dB from the ARC preamp when using the balanced input over the single ended. I am thinking a 7dB jump would solve my problem.

Do you agree? Also, do you think there is something wrong in my cartridge or system, or this low output with this collection of gear seems right?

Thank you!
- Mark
marktomaras
11 responses Add your response
marktomaras OP
544 posts
 
Thank you all. Very good responses and suggestions. I think many of you are correct. Gain of 54dB is probably fine for the Delos, with the rest of the system cooperating. In my case, I have tube amps and speakers that are not very sensitive, so I need that extra gain from the phono pre.

I changed the phono pre from ARC PH3SE to Whest .30R which I set to 60dB of gain, plus the extra 6dB i tap into by running balanced to my ARC LS25 - problem solved!

I tried a few different loads, and I am at 200 now, which sounds pretty good.

Now I have an excellent ARC PH3SE to sell! Anyone interested?
actusreus
733 posts
 
I use my Delos with 58 dB of gain with sufficient volume; in the past it worked fine with 54 dB as well. I find 63 dB makes the sound shrill and overall unpleasant so I would not recommend going over 60 dB on the pre, but...

I think the issue is with your speakers that have a rather low sensitivity, and possibly low or not flat impedance for the tubes to drive them well. When I switched from my 91 dB/8 ohm flat monitors, to 86 dB/6 ohm speakers, I also had to crank up the volume on my line tube preamp quite a bit to get sufficient volume even though I drove them with a pair of 180 WPC tube monoblocks. So in your case, perhaps more gain would work, but I'd recommend trying to fix the problem with a better match for your amps rather than more gain as 0.6 mV cart should not need more than 54-58 dB in most systems for best performance.
rsfphil
139 posts
 
Try running the LS25 balanced. You will get an extra 6db of gain which will give you a total of 72db (18db + 54db). That should help.
manitunc
795 posts
 
I use the 60 db gain on my Manley Steelhead with 100 ohm loading. Are you still running at 47kohm?
tom_hankins
928 posts
 
I used 66db of gain on my BAT phono when using my Delos, to run my preamp (BAT REX) with volume around 12 oclock.
norfolkbarry
5 posts
 
I think that 54db of gain should be sufficient, so I would be concerned that your acoustic research ph3se may not really be making that much gain. AR claims it is compatible with MC cartridges having only 0.25mv output. Are all the tubes in good shape? I am only using 60db of gain via an Ayre P5xe with a Lyra Helikon (0.5mv) to get volumes similar to my digital sources. If all checks out, you may indeed need an SUT to drive it. That would also obviate the need to adjust the impedence, which at 47k ohm on the AR is not usually what most people find best for a Lyra cartridge. You can get a good intro to SUTs at the bobsdevices.com website. He will also answer questions for you.
stereo5's avatar
stereo5
6,247 posts
 
You need to insert an SUT in between the turntable and phono pre.
racamuti's avatar
racamuti
362 posts
 
Step-up transformer should do the trick.
jperry
2,429 posts
 
I think you need a phono preamp with more gain. At least 60 db
stevecham
3,340 posts
 
I use a Delos feeding a Manley Chinook (60 dB of gain) and have no volume/loudness issues. Eleven o'clock on my preamp volume is plenty loud. Hope this helps.
swampwalker's avatar
swampwalker
5,138 posts
 
You went from a 2.5 mV HO MC cart to a 0.6 mV output low/med output MC cart. According to the KAB gain calculator, your new cart needs 13 dB more gain than the old, so I don't think that the BAT is going to solve the problem. The hiss you are hearing is probably a combination of overload and tube noise from goosing the volume up so high, which, IMO is likely the result of trying to drive low efficiency monitors (published spec I find is actually 85 dB w a nominal impedance of 6 ohms) w tubes. In most cases tube amps will make less power into a lower impedance load. W/O seeing the impedance curve of the speaker, or knowing your room size, it's hard to be more specific.
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