input sensitivity

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Jos

input sensitivity
« on: 22 Jan 2013, 08:29 pm »
Can anyone tell me what the input sensitivity of the 541 is?

I'd like to know because I play with a turntable and rhe output of my phono pre is 0.7V.

Thanx,
Jos

Jos

Re: input sensitivity
« Reply #1 on: 22 Jan 2013, 08:35 pm »
oeps, the 451.

Jos

Jason T

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Re: input sensitivity
« Reply #2 on: 23 Jan 2013, 12:03 am »
50k ohms @ 2.0 volts maximum?

I've run it as high as 2 volts using a preamp but it's not a good idea. most cd players put out much less! (400-1200 milivolts on average) from what I've measured.


Jos

Re: input sensitivity
« Reply #3 on: 23 Jan 2013, 09:27 am »
Ok Jason,

But I'd like to know what the number for the input efficiency is, so that I can determine whether I can drive it with my phono pre.

Jos

Jason T

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Re: input sensitivity
« Reply #4 on: 23 Jan 2013, 03:26 pm »
Ok Jason,

But I'd like to know what the number for the input efficiency is, so that I can determine whether I can drive it with my phono pre.

Jos
Jos I'm not quite sure what your asking for.

your phono pre's .7v (700 milivolts) should work fine.
my Mccormack phono pre has about the same output voltage.

Jos

Re: input sensitivity
« Reply #5 on: 23 Jan 2013, 04:37 pm »
Ok, thanks Jason. Then it should work fine with mine.

Input sensitivity is a number that's normally stated in the list of specifications. If it were, for example, 1.5 Volt, I wouldn't be able to drive the Virtue properly with my pre, since it, the Virtue, would need an input of 1.5V to be able to reach its full power.

Jos


cheap-Jack

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Re: input sensitivity
« Reply #6 on: 23 Jan 2013, 05:32 pm »
Hi,

Input sensitivity is a number that's normally stated in the list of specifications. If it were, for example, 1.5 Volt, I wouldn't be able to drive the Virtue properly with my pre, since it, the Virtue, would need an input of 1.5V to be able to reach its full power.Jos

Mmm... My question is: do we really NEED to drive the power amp to "its full power" ??? :scratch:

The fact is, with my ears-on experience, we really don't NEED.  Don't go by the specs which is only an industrial standard for manufacturing any phono-preamps for selling in the marketplace.

My phono-preamp is a 50-year-young Dynaco PAS-2 phono-preamp. I super-rebuilt it by chopping off the entire 2-stage tone-control linestage & replaced in with passive linestage. So this PAS-2- phono-preamp is virtually a 2-stage RIAA phonostage which I further reduced its factory-set gain by taking off its interstage
positive feedback resistor. With this rebuilt, I dare say such Dynaco modification is the one & only
on this planet so far. Yet it sounds superb driving both my Dynaco ST-70 power amp (1.3V I/P sensitivity) & my DC SS power amp (2V I/P sensitivity). With ample volume (not full rated power of course) driven direct
by this reduced gain 2-stage RIAA phono-preamp !!!

In return for the power amp's fully rated power, I get fast, pure, see-thru transparent & musical sound with setting 11-12 o'clock volume setting for my Blu-ray audio & DVD-audo player, & 1-2 o'clock volume setting for vinyls.

Don't bank on the specs alone, which are set for the component manufacturing, not for home use, my friend.

c-J

Jason T

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Re: input sensitivity
« Reply #7 on: 23 Jan 2013, 05:41 pm »
you can reach full power without the full 2 volts of input power, in fact you can usually reach it with about 60-75% of that.

Jack when your limited to either 50 or 90watts then in many cases yes full power would be required by many.
not to mention its like a new muscle car. "Punch it, let's see what this baby can do"  :P

cheap-Jack

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Re: input sensitivity
« Reply #8 on: 23 Jan 2013, 06:01 pm »
Hi.
you can reach full power without the full 2 volts of input power, in fact you can usually reach it with about 60-75% of that.

Jack when your limited to either 50 or 90watts then in many cases yes full power would be required by many.
not to mention its like a new muscle car. "Punch it, let's see what this baby can do"  :P

Not everybody wants to bring a rock concert back home, bud!

c-J

Jason T

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Re: input sensitivity
« Reply #9 on: 23 Jan 2013, 06:11 pm »
Hi.
Not everybody wants to bring a rock concert back home, bud!

c-J

WWHHAATTT????    :duh:

your totally right. most of my listening is done at around 3-10 watts but when that certain track comes on...!!! everyone shut up cuz I'ma crankin it up!  :icon_twisted:
there's something about "Money for nothing" that drives me to blow up drivers during that initial 90 seconds of the song.
yes I have spare woofers and tweeters lying around lol

Jos

Re: input sensitivity
« Reply #10 on: 24 Jan 2013, 04:18 pm »
Hi guys,

I play with a 5 Watt tube amp. For me it's not about the power but about the dynamics. If your input is too low relative to the i.s. of the amp, you can crank up the volume whatever you like, but the music won't come to life.

At least, that's my experience.

Jos

Jason T

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Re: input sensitivity
« Reply #11 on: 28 Jan 2013, 02:43 am »
Hi guys,

I play with a 5 Watt tube amp. For me it's not about the power but about the dynamics. If your input is too low relative to the i.s. of the amp, you can crank up the volume whatever you like, but the music won't come to life.

At least, that's my experience.

Jos

solid state stuff seems to be a little less picky than tube gear when it comes to input sensitivity but you are correct.
to low of an input signal can kill the amplifiers all around attitude and dynamics but our amps use a passive preamp section which actually adjusts the original input signal up and down so that scenario doesn't apply.
when someone uses a preamp with our amps we suggest turning the volume knob up all the way. it's passive and doesn't matter you will only get as much volume as your input signal will allow you, the amplifier is always at "full power"

TQdB

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Re: input sensitivity
« Reply #12 on: 6 Feb 2013, 08:55 am »
Quote
there's something about "Money for nothing" that drives me to blow up drivers

That entire album is Amazing, songs are great - , it won a couple of Grammys actually, and for its time it's a really clean DDD release. Scary thing is (speaking of an early CD circa 1985) that it's like 15dB or more down from peak. Other releases might have had that changed, but for mine I eventually ended up ripping it as Wav in EAC and boosting the amplitude on each song considerably to 2dB off peak using CoolEditPro ... then slow-burned that to a 100 year metal azo.

Now that one will rattle the windows :green:

If people haven't heard this album all the way through, they should go do that immediately. M.F.N. is the only 'rock' song on it, it's clean, brilliantly done, the soundstage is huge, it's both well-defined and varies, it envelopes you, and on M.F.N is actually revolves. LOVES good amps and speakers, very rewarding.

Now I gotta go find it, haven't heard it in a while...

Randy

Re: input sensitivity
« Reply #13 on: 6 Feb 2013, 07:07 pm »
That entire album is Amazing, songs are great - , it won a couple of Grammys actually, and for its time it's a really clean DDD release. Scary thing is (speaking of an early CD circa 1985) that it's like 15dB or more down from peak. Other releases might have had that changed, but for mine I eventually ended up ripping it as Wav in EAC and boosting the amplitude on each song considerably to 2dB off peak using CoolEditPro ... then slow-burned that to a 100 year metal azo.

Now that one will rattle the windows :green:

If people haven't heard this album all the way through, they should go do that immediately. M.F.N. is the only 'rock' song on it, it's clean, brilliantly done, the soundstage is huge, it's both well-defined and varies, it envelopes you, and on M.F.N is actually revolves. LOVES good amps and speakers, very rewarding.

Now I gotta go find it, haven't heard it in a while...

I bought a SACD of the album when I was in London six or seven years ago. I had the red book issue, but the SACD was a huge upgrade in SQ.  It's the only "rock" CD I listen to. The rest of the time I am strictly a classical fan.

Jos

Re: input sensitivity
« Reply #14 on: 5 Mar 2013, 08:37 pm »
jason,

As I was looking back on my older posts  i saw that I had been reading your reply to my question with my head up my a.. You mentioned 2V as the maximum and I hadn't seen it.

Thanks for your reply!

Jos