2. amps-preamps
  3. 123296-8622

Will Changing my 100 Watt Tube Amp to a 200 Watt SS Amp Solve My Problem?

Hello All,  I have a 100 watt Audio Research VT100 mk II amp, with an Audio Research LS-25 preamp.  My speakers are relatively low in sensitivity, and I find that I must turn the volume up to 3 o'clock on the preamp to get enough volume for a loud listening experience.  When I do that, I am introducing more background noise.

I would like to achieve a quieter noise floor.  I am also curious about the limits of the 100 wpc amp with the Mira Monitors.  Would an older Krell 200 watt class A amp "control" the speakers better?  If so, what are the benefits of this?  There are a few amps on this site that caught my eye, all about the same value as my amp, so I can potentially make a move with very little cost.  Is this a good idea? How much wattage increase is necessary to get a significant enough difference?  Would a jump to 150 watt solid state be sufficient?


here are the 3 amps that caught my eye:

Ayre: https://www.audiogon.com/listings/solid-state-ayre-acoustics-v-5xe-amplifier-2016-02-05-amplifiers-h...

Krell: https://www.audiogon.com/listings/solid-state-krell-ksa-250-2016-02-14-amplifiers-91754-monterey-par...

BAT:
https://www.audiogon.com/listings/solid-state-balanced-audio-technology-bat-vk-250se-bat-pak-2channe...



You can see my complete system here if you want to know more about the other components:  https://systems.audiogon.com/systems/5421



Thanks!
Mark
marktomaras
atmasphere's avatar
atmasphere
11,841 posts
 
This is not a power amplifier issue!

This is a noise problem in the preamp. Ahendler got it right.
almarg's avatar
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almarg
9,670 posts
 
Ahendler got it right.
Not sure about that, Ralph.  His statement that:
You need either a preamp with more voltage output or a power amp with higher input sensitivity.
... does not appear to be consistent with what I said in my post above, and I therefore disagree.

Best regards,
-- Al

atmasphere's avatar
atmasphere
11,841 posts
 
Al, when you turn up the volume and that results in noise, that is a preamplifier problem. Its true that the amp might have a certain low sensitivity requiring a higher volume setting, but even if the amp was more sensitive, you would still get the same noise even though you didn't turn up the volume as far on the preamp.


almarg's avatar
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almarg
9,670 posts
 
Hi Ralph,

Those were exactly my points! Although if I am recalling Mark’s previous thread(s) about the noise issue correctly, the noise performance of the phono stage is also suspect, as well as the performance of the preamplifier.

Best regards,
-- Al

marktomaras OP
544 posts
 
After tinkering with the placement of the phonostage and the gain settings, I am suspecting the preamp is the culprit.

Am I wrong in feeling funny about 3 o'clock on the volume to get a rockin' experience? Seems like the high dial position is pushing the ability of the preamp too far.  One would think that my pre and power amp should be a good match though. They are both from the same era, same company, and same price point.

as it is, the sound is excellent, I am just complaint about the noise floor, which could be reduced.

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