Outlaw Model 7125 Power Amplifier Preview

[AcuDefTechGuy]

Never doubted your numbers, but it was very early in the morning, like before 7 I think.

I bet if put on the HTM bench this thing will measure >170W 8 ohm and >300W 4 ohm 2 channel driven, very impressive for a 125W amp to have such a large transformer. If they were to comply with the NEC (CEC in Canada), and follow the 125% rule, it will need a 20A outlet. For a mere $999 I should have bought one of those instead of the MM8003 (600VAX2), even after paying for shipping I would have still come out ahead in terms of watts and money. Now I have to convince myself that the Marantz looks better.

Image - it's everything.

 

[RichB]

Now I have to convince myself that the Marantz looks better.

That may take some doing.

If my Sunfire Cinema Grand 200 watt amp every dies, this will be the replacement.

- Rich

 

[PENG]

That may take some doing.

If my Sunfire Cinema Grand 200 watt amp every dies, this will be the replacement.

- Rich

Agree, I just can't over this, $999 for 875 conservatively rated watts, very tough to beat indeed. For those who value weight unconditionally, $19.6 per lb is pretty good too, you can easily pay that much for steak in a restaurant.

 

[fuzz092888]

I love Outlaw amps and I don't think their value can be beat in the majority of cases. ATI makes such solid and reliable amps it's crazy. After having had the Outlaw 755, I wouldn't hesitate to go back to Outlaw and Steve's review just further confirms that ATI and Outlaw make a tremendous product.

 

[Steve81]

Update:

Having spent a bit more time with the 7125, I have noticed a bit of mechanical hum from the transformer. It's not really an issue at my listening position as its mostly masked by other noise from the cabinet (fan noise, DVR), and a total non-factor when figuring in HVAC noise and actual program material, but it is there and I know it drives some of you guys nuts. I did contact Outlaw regarding the issue, and they have offered to service it under warranty (they're actually quite responsive via their support site), but its not really worth the trouble in my estimation.

 

[RichB]

^^
I had this problem on my ATI3005 but not on my Outlaw 7500.
I concluded that it might be environmental since ATI tested this 3005 at their site and said there was some hum but it was very soft.
I cannot know if they had the same hum level as I but in my environment with a wood floor, open credenza, and plaster wall in back, it beamed at me.
It was not something that I could not live with.

I ended up getting a Parasound A51 (with some connections) for only a few hundred dollars more.
Parasound encases their transformers in epoxy and it seems to work well, I have no hum.

My Outlaw 7500 developed a bad speaker hum in the left surround channel.
I send it in for repair to ATI (via Outlaw) and they replace the transformers, caps, power switch, some resistors for $125.
That is fanstastic service. For fun, I am going do some comparissions of the 7500 and A51 next week with a friend who is an Outlaw fan.

With ATI/Outlaw transformer hum seems to be a secondary concern and a trade off to maintain excellent value and performance.
Some people have more than others and it bothers some more than others.
Scanning the inter-web, I have not found anyone who had it "Fixed".

- Rich

 

[sharkman]

My 7125 has never been anything but dead silent. The power grid can be a contributor, or homes with appliances on the same circuit, it's good to have your electronics on separate circuits.

 

[AcuDefTechGuy]

All 4 of my ATI are dead silent as well - no hum or hiss.

As far as these power-related noises, would a power conditioner like Panamax help?

 

[Steve81]

Morning gents,

FWIW, the 7125 is on a Tripp Lite HT10DBS surge protector which claims to perform some power filtration as well. I also tried putting the amplifier on its own dedicated circuit, which didn't impact the transformer hum.

However, to put things into perspective, the hum is largely masked by one of these:
Amazon.com: AC Infinity AI-CFS120BA Single 120 Quiet Cabinet Fan Kit, for Home Theater AV Amplifier Media Cooling, Black: Home Improvement

Breaking out Omnimic's SPL meter which also shows spectral content, there wasn't any significant difference that I could tell in having the amplifier on or off (with the fan on) from a distance of about 1 meter.

 

[PENG]

All 4 of my ATI are dead silent as well - no hum or hiss.

As far as these power-related noises, would a power conditioner like Panamax help?

Sorry I know you heard me saying this before but have to repeat for those who haven't. All transformers hum to an extent. Of course you can make them inaudible to most human but the manufacturing cost would then likely be too high for products in the price range we are dealing with. Many are already very quiet, close to or completely "dead silent" depending on one's sensitivity to the power frequency harmonics, while many are noisier for sure. A few years ago while in a large store I had the opportunity to put my ears close to a few AVR and amps including products of Anthem, Denon, Yamaha, Onkyo, NAD etc., and found Denon had the almost dead silent transformers. That seemed to hold true today as the only Denon I owned that I could barely hear the transformer with ear touching the unit, is the 4308 (may be it's just mine), the rest including even the entry models are "close to" silent.

 

[RichB]

Morning gents,

FWIW, the 7125 is on a Tripp Lite HT10DBS surge protector which claims to perform some power filtration as well. I also tried putting the amplifier on its own dedicated circuit, which didn't impact the transformer hum.

However, to put things into perspective, the hum is largely masked by one of these:
Amazon.com: AC Infinity AI-CFS120BA Single 120 Quiet Cabinet Fan Kit, for Home Theater AV Amplifier Media Cooling, Black: Home Improvement

Breaking out Omnimic's SPL meter which also shows spectral content, there wasn't any significant difference that I could tell in having the amplifier on or off (with the fan on) from a distance of about 1 meter.

I no longer plug my amps into the Panamax M5300 because it degrades its performance.
The Panamax also has some transormwer hum.
You may want to try plugging the amp directly into the wall to see if it changes the tramsormwer hum and it may improve the clarity and dynamics.
Even if they say they do not, I believe these lower end power conditioners degrade amplifier performance.

Regenerators ($3K range) are different animals. ATI tech support told me that they have used these 3K devices at trade shows and they were a great improvement.

- Rich

 

[Steve81]

You may want to try plugging the amp directly into the wall to see if it changes the tramsormwer hum and it may improve the clarity and dynamics.

Just to clarify, when I popped the 7125 on a dedicated circuit, it was sans the Tripp Lite.

 

[Irvrobinson]

The Panamax also has some transformer hum.

Hmmm... I'm thinking you might have some significant DC offset on your home power.

 

[RichB]

Hmmm... I'm thinking you might have some significant DC offset on your home power.

Can that be measured?
Does this thing help:

http://shop.emotiva.com/collections/accessories/products/cmx2

For the record, there is no hum coming from my Outlaw 7500 nor Parasound A51.



- Rich

 

[moves]

That's 228.57 kVA and 20,000 uf per channel if your numbers are right. Compared to the XPA-5's 240 kVA and 12,000 uf per channel, the Outlaw has more believable rated output of 125W vs the Emo's 200W.

Sorry what does the Kva and uf mean? Does this mean that a 200W amp MAY not be as powerful as a 125W amp?

 

[Irvrobinson]

Can that be measured?
Does this thing help:

CMX-2 | Emotiva Audio | High-end audio components for audiophiles and videophiles, spanning 2-channel music systems, as well as 5.1 and 7.1 home theaters. Products include multichannel amplifiers, stereo amplifiers, and monoblock amplifiers, as well

For the record, there is no hum coming from my Outlaw 7500 nor Parasound A51.



- Rich

Measuring the DC offset takes an oscilloscope. Good catch on that Emotiva product! I never noticed it. Yes, that looks like exactly the device to solve the problem, if indeed my guess is correct. The price is right, and it's rated for 15amps of current, enough for most amps, though not the ATI AT3005, obviously.

 

[RichB]

Measuring the DC offset takes an oscilloscope. Good catch on that Emotiva product! I never noticed it. Yes, that looks like exactly the device to solve the problem, if indeed my guess is correct. The price is right, and it's rated for 15amps of current, enough for most amps, though not the ATI AT3005, obviously.

It says 15 amps but the plugs are for 20 amps. Maybe they were just hanging around.
How would such a product work?
I am curous because I am skeptical of such product claims.

- Rich

 

[Adam]

The guts of that Emotiva product look a lot like the Belkin and Acoustic Research power conditioners that I've taken apart. I can't recall if they claim to eliminate DC offset, though.

Emotiva

Belkin

 

[Irvrobinson]

Sorry what does the Kva and uf mean? Does this mean that a 200W amp MAY not be as powerful as a 125W amp?

KVA is an abbreviation for kilovolt amperes, which is a measure of the apparent power in an alternating current electrical circuit. uF is an abbreviation for micro-farads, which is a measure of capacitance. Without knowing the rail voltage that the amps operate at, it is difficult to calculate specifics, but what PENG is talking about is the capacity of the transformer to provide a certain amount of power, and the power supply capacitors to handle a certain level of DC ripple filtering. Many of these multichannel amps will only give you the rated power when two channels are driven, especially into four ohm loads, and as you drive more of the channels the delivered watts per channel (watts are the unit of usable electrical power) may fall off.

The Emotiva is rated to deliver 300W per channel, all five channels driven, yet it only has a 1200KVA rated transformer. PENG's observation is that 1200KVA looks a bit underrated for that power level, yet in Emotiva's published test results it does indeed seem to produce 300W/ch at four ohms, though they are a bit fuzzy about whether or not all five channels are driven simultaneously.

 

[Irvrobinson]

It says 15 amps but the plugs are for 20 amps. Maybe they were just hanging around.
How would such a product work?
I am curous because I am skeptical of such product claims.

- Rich

Think of it as a high current high-pass filter.