I’ve used the loop outputs for lots of things, testing other speakers off another amp, running A/B comparisons and such.
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Niles SI-275 Amplifier Review
- Thread starter amirm
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I’ve used the loop outputs for lots of things, testing other speakers off another amp, running A/B comparisons and such.
OP
- Thread Starter
- #22
A-weighting is a filter that rolls off some of the noise in the spectrum. It makes SNR measurements better and hence the reason manufacturers like ot use it.
Niles amp heads-up for Aussies. 12 channels. Pairs can be bridged for 6 channels. $AU310 incl. shipping.
https://www.ebay.com.au/itm/Niles-A...rentrq:e61b55ce1700ad31c40a9148ffd3c800|iid:1
https://www.ebay.com.au/itm/Niles-A...rentrq:e61b55ce1700ad31c40a9148ffd3c800|iid:1
engineeringDynamo
Member
You can bridge the si-2125, which is a little harder to find.
The si-2125 is bigger, but more powerful.
Like the si-275, it is a bargain used.
Oddly the published specifications for the 2125 show it has a lower power consumption than the SI-275.
engineeringDynamo
Member
You are right.
I just looked at the back on my 2 amps:
Niles SI-275 reads 600W
Niles SI-2125 reads 420W
From the manual of the SI-2125
Design Principle - linear voltage/current amplification.
Continuous Average Power Output
125 watts per channel rMS at 8 ohms, both channels driven
175 watts per channel rMS at 4 ohms, both channels driven
350 watts bridged channel rMS at 8 ohms.
From the manual of the SI-275
Design Principle - Linear voltage/current amplification.
Continuous Average Power Output
75 watts per channel RMS at 8 ohms.
100 watts per channel RMS at 4 ohms.
What’s your impression comparing between these two amps?
engineeringDynamo
Member
I know this is subjective, and this is an objective forum, but here is my answer:
I have 2 of each, so I have recently biamped a pair of Monata SPX with both.
The SI-275 and SI-2125 sound very similar.
The SI-2125 has a little more gain.
I think the SI-2125 sounds better (bass and treble), but this might not be real.
Biamped, they both can get as loud as I would ever want.
I also have 2 Behringer A800.
I am biamped with these now.
They sound sharper than the Niles, with a little sibalance.
I am pretty sure this is not in my head.
I tried one A800 in another system. It is harsher than the Akitika that I usually use in that system.
Maybe the A800 could be used to brighten up speakers that are too laid back?
Thanks. I had the opportunity, after talking to my neighbor about loud noise, to test the limits of my tolerance. Listening to Pink Floyd's Money at -5.0dB at the preamp with Linn Katan monitors as my mains. They're spec'd to be 85dB 1w/1m and an 8 ohm nominal load. The Niles SI-275 never allowed the Katans to become strident or compressed, even with peaks exceeding 105dB! That was far louder than I'm comfortable listening 99% of the time. The Katan's are run with high pass filter set at 80Hz with a PSB SubSonic i 8" ported subwoofer filling the bottom end. This is a very satisfying setup and I don't feel that I'm lacking for needs in power.
A few months back I bought two Speakercraft BB-2125 commercial amps, same target market.
Here's a snap shot of the inside I found on google.
I had considered it was possible Speakercraft, Sonance and Niles shared the same OEM, but if they do the quality may vary greatly. One of the amplifiers was DOA and the other made a lot of noise, both the amp itself as well as line noise at the speakers. Generally unacceptable performance for any level of HiFi. I've not tried a Sonance yet, but the exterior quality on units I've seen seems in between that of the Niles and Speakercraft with Niles being superior to both in fit and finish. The Speakercraft quality was alarmingly poor. The front panel flexed from the top of the chassis on both units. I could have easily stashed my junk mail in through the gap of the front panel and the chassis while I was prying.
Here's a snap shot of the inside I found on google.
I had considered it was possible Speakercraft, Sonance and Niles shared the same OEM, but if they do the quality may vary greatly. One of the amplifiers was DOA and the other made a lot of noise, both the amp itself as well as line noise at the speakers. Generally unacceptable performance for any level of HiFi. I've not tried a Sonance yet, but the exterior quality on units I've seen seems in between that of the Niles and Speakercraft with Niles being superior to both in fit and finish. The Speakercraft quality was alarmingly poor. The front panel flexed from the top of the chassis on both units. I could have easily stashed my junk mail in through the gap of the front panel and the chassis while I was prying.
jsrtheta
Addicted to Fun and Learning
A few months back I bought two Speakercraft BB-2125 commercial amps, same target market.
Here's a snap shot of the inside I found on google.
I had considered it was possible Speakercraft, Sonance and Niles shared the same OEM, but if they do the quality may vary greatly. One of the amplifiers was DOA and the other made a lot of noise, both the amp itself as well as line noise at the speakers. Generally unacceptable performance for any level of HiFi. I've not tried a Sonance yet, but the exterior quality on units I've seen seems in between that of the Niles and Speakercraft with Niles being superior to both in fit and finish. The Speakercraft quality was alarmingly poor. The front panel flexed from the top of the chassis on both units. I could have easily stashed my junk mail in through the gap of the front panel and the chassis while I was prying.
I have no reason to believe these companies share an OEM. Anecdotally (I know, I know), I read on an online forum a post from a guy who had bought a Speakercraft amp that lasted about a week before it died, and then had it replaced about five times before giving up. Just a horror story.
Never had a Niles, but I've bought two used Sonance amplifiers, and found them to be unkillable. Each performs flawlessly to this day, despite being around 15-20 years old. Though they are meant to be back-ups, I'm using one in my main system. Outstanding.
I bought three of these. Two observations/questions.
1. Two of the amps have the Niles SI-275 on the faceplate in larger font than one of them. Were there different runs?
2. One of the amp's green power light is much dimmer than the other two which glow bright green. Nothing to worry about or could be a sign of weakening power source or early sign of failure?
1. Two of the amps have the Niles SI-275 on the faceplate in larger font than one of them. Were there different runs?
2. One of the amp's green power light is much dimmer than the other two which glow bright green. Nothing to worry about or could be a sign of weakening power source or early sign of failure?
I have two of them, with different fonts as well. The model was in production for several years. They seemed to source different OEM parts over the span of production, but they appear to be the same configuration inside.
This could just be as simple as changing the LED OEM, which I'm guessing is the more likely scenario than some power supply failure. An LED requires so very little power that I wouldn't put any weight on the performance of the unit as a whole based on the dimness of the LED power indicator.
Much appreciated! I got that one for $100 delivered so would rather not return it if it is OK. One other quick question. Would you say that all the channels are mix and match? Do the fronts need to be on one amp or can I have L and R on different amps. Is power, power? Boy I sure like the way these amps sound.
I'm not 100% certain I understand the question. One thing to take note of is the potentiometers on each unit. Depending on what they were used for before the gain might be adjusted to unequal levels. I usually just set the gain to max on each channel. Each amplifier should sound identical assuming they've been setup the same way. Only thing I can think of would be to NOT recommend using one Niles SI-275 to bi-amp one speaker. Generally I would use one amp per stereo pair of speakers. There could be benefits to using one stereo amplifier to power a left front and left rear speaker as the power demands on a shared power supply would likely be reduced, but in real world applications I don't know that you'd notice any difference. It would have been interesting to see measurements for this amp with only one channel driven to see if it varied much from both channels driven. That would have shed some light on if the total power output of this amplifier is bottlenecked by the power supply.
You make a good point on dialing each channel to the highest level because one of the channels was turned down and I thought I had a faulty amp. So what I did was used only one channel on that amp for one of the fronts and then I plugged the other front into another of the amps. Before I sent the app back by realized that the Left channel wasn't turned all the way up but I didn't change anything. I still have a front channel running on two different amps. Sounds great though. Just didn't know if there was any advantage or disadvantage in that configuration and if power was mix and match which I believe it is. Don't know if individual apps have different tonality characteristics is the only other thing I could think of...
KxDx
Senior Member
I bought one of these for $100 + shipping to power the PSB Stratus Goldi's I just bought. Those speakers were making my receiver quite hot (they'd probably make a cheap Chi-fi amp catch fire). The Niles is a beast. I had my speakers up to house-shaking levels and the thing didn't even get warm.
I'm flabbergasted at this amp's value. Slap an "audiophile" brand name on the front plate and they'd be going for $500 used.
I'm flabbergasted at this amp's value. Slap an "audiophile" brand name on the front plate and they'd be going for $500 used.
Amen!
Got lucky the other day, and scored a Niles SI-2125 for $120! It's (along with an SMSL Sanskrit Mk II) replacing a Yamaha AVR and wow what a difference. The hiss I got from the Yamaha is now gone, and everything just sounds much more clear. These Niles amps are bargains for what they can do - cheap, clean power.
I just upgraded mine to 1 m 14 gauge power cables.
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