why all SS amp has high gain?

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dealaddict

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why all SS amp has high gain?
« on: 9 May 2011, 08:51 pm »
I am having a problem with too much gain in my system.  Then I am trying to find a SS amp with lower gain, and it is very hard to find.  Why all SS amp has such a high gain?  I believe it is a common problem, is there any technical difficulty to make SS amp with lower gain?

JLM

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Re: why all SS amp has high gain?
« Reply #1 on: 10 May 2011, 06:36 pm »
Lots of power is easy for solid state designs to come by, so I suppose most designers of solid state assume you'll need all the power they're providing (for inefficient speakers, large spaces, or both). 

Separate pre-amps have the same issue (too much gain).  Putting them together with typical solid state amps can really get bad (no usable range in your volume control and picking up lots of system noise).

Channel Island Audio offers 26 or 32 dB gain models and passive (no gain) pre-amps.

One solution is to add passive stepped attenuators at the power amp to step-down the volume.

roscoeiii

Re: why all SS amp has high gain?
« Reply #2 on: 10 May 2011, 07:10 pm »
Some of the FirstWatt amps have lower gain than many other SS amps. I hear you on the too much gain problem. I was happy that I could get jumpers to replace 2 of my tubes in my Atma-sphere S-30. Nicely reduced the gain. Got the preamp fine tuning I wanted and lower noise...

srb

Re: why all SS amp has high gain?
« Reply #3 on: 10 May 2011, 07:15 pm »
What preamp and amplifier do you currently have?
 
Steve

cliffy

Re: why all SS amp has high gain?
« Reply #4 on: 10 May 2011, 07:43 pm »
The Nuforce Ref 9V3SE amps that I have have lower gain (21db according to the Nuforce web site)than "typical".

All of their V3 amps have 21 db.  Their prior V2 products had 26db.  Their FAQ explains why.http://www.nuforce.com/hi/faq/faq-V3.php



Great amps by the way :)

jeffreybehr

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Re: why all SS amp has high gain?
« Reply #5 on: 10 May 2011, 09:12 pm »
deal, indeed, most audio systems have too much gain, resulting in too-low volume-control settings and too much noise.  Nelson Pass realizes this, hence eight of his 10 FirstWatt amps... http://firstwatt.com/prod.html ...have no more than 15dB of Voltage gain.  One, the F4, has ZERO gain (and actually a slight insertion loss).  Think of the F4 as a 40WPC-into-4-Ohms preamp-output buffer.   :)  I seriously considered it until I decided I needed more power for my 89dB- (and now 87dB-) sensitive speakers.

My hybrid poweramps, Monarchy SE-160s, have 24dB, which was too much for my system, so with the designer's approval I replaced the 12AT7 input tube with a 12AU7 and lowered its gain by 9dB.  I'm now able to operate my preamp, a c-j MET1, in the bottom end of its gain range occasionally instead of always in the attentuation range.

The easiest solution for too much gain is a passive attentuator at the input of the poweramp, but the better way is having some section or sections of the poweramp redesigned for much-lower gain.

DIYAudio recently issued a newsletter on system gain; I can't find an online link to it, so if you'll e-mail me at jeffreybehr(at)cox(dot)net I'll forward it to you.

dwk

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Re: why all SS amp has high gain?
« Reply #6 on: 10 May 2011, 09:19 pm »
I also am surprised at how much gain many amps have. Louder is better applies to amps, too, apparently.

If you're up for DIY, the Class-D-Audio SDS series amps ship with a pot that is part of the circuit that sets the overall amp gain. Once you have the system dialed in with appropriate levels, you swap out the pot for a fixed resistor of the appropriate value. I think you can in practice get anywhere from 15 to 32dB of gain this way.

srb

Re: why all SS amp has high gain?
« Reply #7 on: 10 May 2011, 09:40 pm »
If you're not up for DIY, you can also find amplifiers that have gain controls, one example being the Parasound Halo A21 and A23 amplifiers.
 
Steve

nickd

Re: why all SS amp has high gain?
« Reply #8 on: 10 May 2011, 09:59 pm »
I have been told that the standard gain settings were designed before digital and with the advent of low output MC pickups that gain was welcome. Speakers like Maggies and Ravel's take an amp built like an "Arc Welder" to get dynamic so vinyl owners with those designs loved the gain.

Most modern preamps (active) have gain of 12-19db. The current speaker trend is efficency above 90db. Your new DAC puts out 2.5v and will drive your amp to clipping with out any help from a preamp, and passive preamps are an aquired taste.
"Houston we have a problem" :banghead:

The industry standard for source components needs to be reduced, 1.5-2v and preamps need less gain in general (6-12 db would be fine IMHO) then we can gather in mass, stand outside of KRELL and HARMON with our torches lit and pitchforks sharpened and yell for change in amplifer gain! :lol:

James Romeyn

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Re: why all SS amp has high gain?
« Reply #9 on: 10 May 2011, 10:05 pm »
Ingeniously, Linn's current model power amps (at least the Chakra and Majik series) offer the user to select between eight different gain settings.  One might prefer this was an industry standard.

Since '99 Linn's power amps employ a pure analog monolithic chip (higher parts tolerance than discreet circuits) with bipolar transistors for current demands.  Think of it as the legendary Quad 909 (arrived '99 and still running strong).  But Linn replaced the 909's discrete circuit with pure analog monolithic chips (genius IMHO). 

Size, weight, and current draw are like digital, without digital switching noise and required LP audio filter.

     

dealaddict

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Re: why all SS amp has high gain?
« Reply #10 on: 13 May 2011, 05:54 am »
I use a McCormack and it has 30dB gain.  Then I am looking for another with lower gain, and I can't find any except the First Watt.  So, it seems some designer realized this, and design accordingly, but most don't.  If it is such a common problem, I am just surprised so few designer address this in their design.

jeffreybehr

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Re: why all SS amp has high gain?
« Reply #11 on: 13 May 2011, 05:54 pm »
deal, another solution is to have some qualified person install level controls at the input of your poweramps.  Usually it's not difficult or expensive.

Or buy a pair of Monarchy SE-160s or SE-250s and replace the 12AT7s with 12AU7s.  BTW they sound GREAT--single-triode gain stage, NO buffer or driver stages, MOSFET output stage biased Class-A to about 50 Watts, NO negative feedback whatever.  The '160 produces 160 Watts into 8 Ohms and 320 into 4 while the '250 is 250 and 500.  The 160s are $2400/pr. purchased direct while the '250s are $3000.