set 120 amp

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drpalomo

  • Jr. Member
  • Posts: 5
set 120 amp
« on: 12 May 2021, 10:43 pm »
Very familiar with Omega and fet hybrids amps for the last 25 yrs. Now I am considering using one bridged set 120 amp for each driver in my 2 way custom speakers. The amps will be driven by a balanced signal  actively crossed by a mini dsp. So do any of you think that the bridged set 120 can be up to the job

avahifi

Re: set 120 amp
« Reply #1 on: 13 May 2021, 02:33 pm »
The basic SET 120 chassis is not designed for bridge mode operation and won't support XLR balanced inputs.  It also does not have adequate heat sinks to support very high power into low impedance loads.

This is the reason for our new M225 mono amps.  They are full differential balanced designs with XLR inputs and very high power (225W each into 8 ohms and nearly double that into 4 ohms). They will directly interface with your balanced output preamp and provide just amazing sound.

Frank

jjss49

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Re: set 120 amp
« Reply #2 on: 13 May 2021, 03:15 pm »
omegas are very high efficiency speakers, i would think one set120 would be plenty

depends on volume level desired and room size of course

avahifi

Re: set 120 amp
« Reply #3 on: 13 May 2021, 03:52 pm »
Agreed.  With the 93dB efficient Omega speakers our SET 120 basic stereo amplifier amplifier is way more power then you actually need.

What is not generally understood is that change in efficiency of 3d between two speaker designs changes the power needs up or down by half or double power.

So assume you are starting with a big inefficient tower speaker rated at 83dB sensitivity and you have a 400W per channel amp driving them.

If you increased the sensitivity by 3dB to 86dB, then 200W per channel would do just as well.  Increase the sensitivity another 3dB to 89dB and now all you need is 100W per channel. Go up another 3dB to 92dB and you power requirement drops to 50W per channel.  So with your 93dB efficient speaker, all you need is 30W per channel and the SET 120 produces double that.  Another way of looking at is is that the SET 120 amp into your 93dB efficient speaker will go as loud as over 400W into that 83dB efficient speaker.

Power ratings are a V squared function so are a very unintuniteve way of looking at amplifier specifications.  This make it hard for non-electrical engineers to understand.

So trust us who have this somewhat figured out when it comes to answering the question as to how much power you should buy to run your speakers.

Frank


sonomahifi

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  • Posts: 1
Re: set 120 amp
« Reply #4 on: 13 May 2021, 07:41 pm »
I've had a new SET-120 for a month now, driving 93db efficient 12ohm Spatial M4Triode Masters. So I wanted to second Frank's comment on power needs.

I'm new to this circle, so a brief introduction. In 1966 I began this hobby with a Dynaco Stereo 70/Pas 3x with AR4x speakers and AR turntable. Since then I've put together many systems, all which I'd categorize as no more than "budget audiophile."

I've used the AVA SET-120 with two preamps.

First, combined with Spatial M4TM speakers and a cheap passive preamp, the SET-120 is capable of thunderous and clear reproduction (at levels 95db+ at 10 feet away) that would soon lead to hearing loss. And at that high sound level, the potentiometer of the pre is at about 12 o'clock.

Second, the Spatial M4TM speakers/ SET-120 combination using my 18-year-old 12sn7 Mapletree preamp with 20db of gain. The sound is balanced across the spectrum, soundstage has good depth and is much wider and higher than the speakers, and on the romantic side of neutral (mostly due to the tube pre, comparing the result to the passive pre that I mentioned above). With the Mapletree preamp I can't get beyond about 10 o'clock on the potentiometer. I suspect, at the levels I normally listen, below 85db, the SET-120 runs exclusively in class A.

BTW, a couple of posters on the Spatial Audio circle had reported very favorably on their results with Spatial M3s and M4s driven by SET-120, which led me to AVA. It was good advice.

Thanks to Frank for a great amp at a bargain price!

Tom Mitchell

Nick B

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  • Posts: 894
Re: set 120 amp
« Reply #5 on: 14 May 2021, 06:22 am »
My SET 120 easily drives my Fritz Carreras…. 87 dB

Birdbrain

  • Jr. Member
  • Posts: 71
Re: set 120 amp
« Reply #6 on: 14 May 2021, 01:58 pm »
I've had a new SET-120 for a month now, driving 93db efficient 12ohm Spatial M4Triode Masters. So I wanted to second Frank's comment on power needs.

I'm new to this circle, so a brief introduction. In 1966 I began this hobby with a Dynaco Stereo 70/Pas 3x with AR4x speakers and AR turntable. Since then I've put together many systems, all which I'd categorize as no more than "budget audiophile."

I've used the AVA SET-120 with two preamps.

First, combined with Spatial M4TM speakers and a cheap passive preamp, the SET-120 is capable of thunderous and clear reproduction (at levels 95db+ at 10 feet away) that would soon lead to hearing loss. And at that high sound level, the potentiometer of the pre is at about 12 o'clock.

Second, the Spatial M4TM speakers/ SET-120 combination using my 18-year-old 12sn7 Mapletree preamp with 20db of gain. The sound is balanced across the spectrum, soundstage has good depth and is much wider and higher than the speakers, and on the romantic side of neutral (mostly due to the tube pre, comparing the result to the passive pre that I mentioned above). With the Mapletree preamp I can't get beyond about 10 o'clock on the potentiometer. I suspect, at the levels I normally listen, below 85db, the SET-120 runs exclusively in class A.

BTW, a couple of posters on the Spatial Audio circle had reported very favorably on their results with Spatial M3s and M4s driven by SET-120, which led me to AVA. It was good advice.

Thanks to Frank for a great amp at a bargain price!

Tom Mitchell
I've been running my M3 Triode Masters with an SET 120/T10 SLR combo for just over two years. I feel set for life. The GAS is gone.

Nocturne79

Re: set 120 amp
« Reply #7 on: 14 May 2021, 06:08 pm »
Hello I am using a set 120 amp with my omega HO alinco towers and also my HO rs5 monitors and I have no issue with power.  The music is full sounding and never once have i felt wanting more power.  If anything I have to turn my preamp levels down to have more volume control.

Hope this helps, this is an amazing amp and I love it, so much that I bought a set control amp for my desktop and have never looked back.