• New Sponsor: ShipNerd, Ship Your Gear with Us... for less! Click Here.

Tech experts: Is Boss lying to us about amp watts?

musekatcher

Member
Messages
2,735
The question is what does it actually put out as measured by conventional means i.e. continuous, sine wave, AC RMS.
The stated output looks like hype.
Is that unethical on the part of Boss?
Well, it's certainly not illegal or unordinary.
Peak and continuous are valid terms for amplifying a transient input. But, as pointed out, they take liberties with these terms and meanings. An audience who understands power and ratings would tell you the measurements used in the industry are nonsense. Continuous power might not be the best way to compare amplifiers anyway. A lab would prove it, and if you own enough of these products, you don't need a lab report to conclude ratings aren't conclusive. Meanwhile the intended audience is content to spend more money so they have *more* advertised power than their peers. From Boss' viewpoint, the mission is accomplished with a happy customer, even if the latter is blissfully incorrect in their assumption.
 

BOBSMITH

Member
Messages
87
The power output is a frequently used and abused amplifier rating. Power output can be defined as the maximum power an amplifier can deliver before distortion impairs the sound. Usually rated in percent of total harmonic distortion. The THD percentage should be stated when the output wattage is given. We like our guitars distorted don't we?

The Federal Trade Commission in November 1974 enacted a regulation on measuring amplifier power output to address the grossly exaggerated amplifier ratings common at that time. Apparentley this is being ignored by some manufacturers...........
 

Stu Blue

Member
Messages
3,167
Don´t think they imply Energy generation out of nothing :)
We need a little more data, I hate giving "blanket" answers .

1) what else is stated together with "150W" .... RMS/Peak/Music/PMPO/EIA/EIAJ/... ???

2) watts/V.A. indication printed right beside the power cable *used* to be constant or average or maximum mains power consumption, mainly to help you select cables/extensions/even autotransformer if used overseas ... so it was realistic, and often inflated for safety reasons.

I remember 100W Plexis, which actually need about 380W (V.A. really) being suggested to be paired with 500W autotransformers ... and it was *good* advice, for safety and better performance.

But nowadays users are "Green minded" and reject perceived high consumption or inefficient stuff, so sadly the pendulum has swung fully to the other side, and often manufacturers print the "idle" consumption (I have seen verified 100/150W RMS Home Theaters and such labelled "20W" .... which is what they use if left plugged in but not played, or best case used playing average level music (or watching a movie) in an appartment living room ... usually no more than 10/15% max output power, if that much.

So for a more precise answer please link the user manual. :)
https://static.roland.com/assets/media/pdf/KATANA_e02_W.pdf Boss manual merely says "Output 50W and 100W" for the two amps. With "Power Consumption 47W and 77W"
There are no qualifications about how these figures were "measured" in the Katana owner's manual/guide.

The intention is clearly to fool the average player who knows nothing about RMS standards. Already several TGP members clearly think they are getting the same sort of power as a Mesa, Marshall or Fender valve amp rated as 100(RMS), and got cross with me for saying the two Katanas were probably only 15 and 30watts RMS.
 

musekatcher

Member
Messages
2,735
https://static.roland.com/assets/media/pdf/KATANA_e02_W.pdf Boss manual merely says "Output 50W and 100W" for the two amps. With "Power Consumption 47W and 77W"
There are no qualifications about how these figures were "measured" in the Katana owner's manual/guide.

The intention is clearly to fool the average player who knows nothing about RMS standards. Already several TGP members clearly think they are getting the same sort of power as a Mesa, Marshall or Fender valve amp rated as 100(RMS), and got cross with me for saying the two Katanas were probably only 15 and 30watts RMS.
Yea, but a watt is a watt. The discussion was over the ratings, and output being greater than the input - which isn't possible of course for a continuum, but for short bursts, its possible and measurable.

I think your folks upset at challenges to their Katanas are victims of tube vs ss:

https://www.sweetwater.com/sweetcare/articles/tube-amps-louder-than-solid-state-amps-of-same/

A watt is still a watt. However, raw amplifier continuous power isn't the main factor, or even the second most important factor in loudness. The softness of tube clipping, and a more efficient speaker-cabinet can combine to produce a 22w combo louder than a 100w combo.

So, even if there is some liberty with ratings, its less important in the end with respect to loudness.
 
Last edited:

J M Fahey

Member
Messages
2,929
Thanks Stu for posting the manual :)

Just an educated guess, but from what I read there, power ratings look fine, RMS.
Katanas are meant for live playing, it would be ludicrous if they could not match (or surpass), say, a Peavey Bandit, just to mention a classic amp known and played by everybody at least once.

They also have that 100/50/0.5 W selector ... if they were actually 15 or 30W RMS that would not make sense.
Amps are heavy too, and have what looks like "real" speakers, not toys; compred to that, SS watts are *cheap* , what´s the point of skimping on that?

So my guess is: RMS power (what´s written on the label) must certainly be accurate, or very close; wall consumption numbers are a truckload of natural, organic fertilizer.

jm2c, ymmc, caveat emptor, etc.
 

Stu Blue

Member
Messages
3,167
Thanks Stu for posting the manual :)

Just an educated guess, but from what I read there, power ratings look fine, RMS.
Katanas are meant for live playing, it would be ludicrous if they could not match (or surpass), say, a Peavey Bandit, just to mention a classic amp known and played by everybody at least once.

They also have that 100/50/0.5 W selector ... if they were actually 15 or 30W RMS that would not make sense.
Amps are heavy too, and have what looks like "real" speakers, not toys; compred to that, SS watts are *cheap* , what´s the point of skimping on that?

So my guess is: RMS power (what´s written on the label) must certainly be accurate, or very close; wall consumption numbers are a truckload of natural, organic fertilizer.

jm2c, ymmc, caveat emptor, etc.
With all due respect there are several very expensive 30wattRMS valve amps with half power and less switches and they make perfect sense to their professional users.

There are also a ton of class D SS amps with claimed outputs higher than inputs, mostly using some such phrase/excuse as "peakmusic power"/" peak output watts". So it is infinitely more likely that the Katana is class D claiming peak not RMS (constant) than that they "underrate" their input/consumption figures... the latter would be dangerous in a domestic setting leading to possible over-heated wiring and electrical fires and is illegal in Europe.

The point of "skimping on cheap SS watts" is to make more profit since 30 watt SS amps are cheaper to manufacture and if you can sell them at 100watt prices then the profit is all the greater.

The Katana is sold as an amp head so all talk of speakers is irrelevant......

EDIT BTW the are several posts on the Katana 100 threads talking of Katanas failing to keep up with Marshall 18 watts and other 20-30 watt valve amps, when placed side by side.
 
Last edited:

J M Fahey

Member
Messages
2,929
Fine with me, won´t argue just for arguing :)
As an educated guess, I added a lot of disclaimers at the end :) but like all of you, am waiting for somebody to actually measure them.

Even better: one of them landing in my shop bench, although so far I´m not sure they are available in Argentina.

Edit: yes, just checked, they arrived here, and at quite a low price ..... annoying for me because they may take a sizable slice of the market.

So I guess in a short time I´ll hear one of them side by side with one of mine ... then we´ll see.
 

Stu Blue

Member
Messages
3,167
The Federal Trade Commission in November 1974 enacted a regulation on measuring amplifier power output to address the grossly exaggerated amplifier ratings common at that time. Apparentley this is being ignored by some manufacturers...........
This is what gets my goat. Not only greedy Corporations getting away with selling 25watt amps as 100watt amps but dumb kids on the internet (including some of the MODS on TGP) defending them on a "what does it really matter" basis. Perhaps it's because I'm a "child of the '60s" (born 1945) but for ordinary people's quality of life it always seems to be "one step forward, two steps back"....
 

MKB

Silver Supporting Member
Messages
8,770
The power issue can get complicated. We are all familiar with how great tube amps sound when the output stages are starting to distort, which means if they are rated in RMS watts at say 10% THD, and you have them clipping hard, you will be effectively getting more power than that rating. Just one of the reasons that some folks claim "tube watts sound louder than solid state watts".

Another problem with solid state amps, especially digital ones, is the output voltage the amp can supply is limited, where a tube power amp's can change depending on the impedance selector setting on the output transformer. This is why a tube power amp will give you close to its rated power into any impedance tap load, but a solid state amp's power goes down considerably with increasing speaker impedance. A 100W tube power amp can supply 100W to a 4, 8, and 16 ohm load, where a solid state power amp rated at 100W into 4 ohms may only supply 50W into 8 ohms and 25W into 16 ohms. Add that to how poorly SS amps sound when clipping, and you can see why some folks have issues with SS amps.

In general you do not want any of your solid state amps to clip as the distortion can sound harsh for a variety of reasons. You especially do not want the digital class D type topologies to distort at all as usually they will shut down from the protection circuitry, as well as sound bad before they do. This is one reason that Kemper sells a 600W digital power amp; it stays absolutely clean at loud stage volumes into most speakers.

There is a youtube video where a tech connected a Behringer iNuke series power amp to a power amp tester and found it woefully missed its stated power output specs (not nearly enough power at high THD). Is it missing enough power to matter to most users? I have one and it works just fine for what it is, and sounds great.

I have seen many Marshall tube amps rated at 100W that would easily put out 120W clean into a load; my JMD:1 head will put out 130W with factory setup. But a JMD501 combo would only put out 30W due to signal attenuation before the phase inverter; lowering that attenuation woke it right up (over 50W clean with no other changes).

OTOH my Vintage Modern "100W" head will output only 80W clean. I checked with Marshall and they confirmed this was correct for that amp.

IMHO the only way you can be really sure that your amp/speaker combo will truly have enough grunt is to stick it on stage and rock out (or attempt to).
 

Stu Blue

Member
Messages
3,167
Marshalls first amp was called the JTM45 because they looked at the book spec of 5881 valves which said 22watts output went two times plus one for luck equals 45!!!!! They got a ton of phone calls in the 60s from techs saying "look I can't get this amp above 30watts and can't see anything wrong what's up with that? They also screwed the output figures for the JTM45/100 which only did 80watts. To be honest none of the three guys who tweaked the amp together from tweed Fender Bassman actually knew how to design amps... they didn't even know they had doubled the NFB by using the 16ohm tap.

That's why they got the JMP 100s to output 110-115 watts because of the past criticism. Why they again called the Vintage Modern 100watts when it was only 80watts (vintage correct for JTM45/100 4x KT66) would probably be just knowing what players would say about Marshall producing "weaker" amps.

The folk using "peak power output" to claim their 25 watt RMS amps are 100watts are in a different league altogether......
 

J M Fahey

Member
Messages
2,929
I got curious about this "new amp" showing 4 or 5 "amp modes" from Clean to High Gain to Acoustic , and the 3 effects knob, one dedicated to Reverb, other to Delay and such and the third to "all others" with a strong nagging feelingg "I have seen this before" plus some association with Roland.

Browsing my Schematic collection I found a strong DNA connection between this and 2004 Roland Cube 60D(igital) and now think this is nothing but a dumbed down Cube 60D, repackaged in a cool all black "Rocker" skin instead of the nerdy old Roland one.

Basic schematic should not have changed much, old one was MIDI programmabkle, new one is via USB, not an *esential* difference and definitely does not change sound.

FWIW Roland 60D spec´d "60W" and used an 8 ohms loaded LM3886 ,capable of honest 50W under that load (60 into 4) , modern ones should be about the same, worst (best?) case using some Class D amp instead of venerable 3886

selling 25watt amps as 100watt amps
Really? :eek:
C´mon Stu, give the guys *some* credit :) , it´s Roland/Boss after all, not GC´s "house brand of the week" ;)

Maybe the 50 is actually 40 and the 100 is 80 (like the old 60 was most probably 50) but really they would not sink that low, would they? :)
 

jay42

Member
Messages
7,088
Apropos of some of this, I've found Fender solid state amps to be honest enough for rock 'n roll. Sunn...well, old Sunn would start great then put out less and less...bad design on heat dissipation. one of the problems is competition for volume. A DR is loud as hell for some groups and drowned out by the drummer elsewhere.

Not sure about Marshall honesty.
 

Tone_Terrific

Silver Supporting Member
Messages
34,979
A DR is loud as hell for some groups and drowned out by the drummer elsewhere.
Adequate volume is always application dependent but one develops expectations that a 100W amp will be loud or a 30w will be loud enough, for me.
One tends to look at and purchase amps that are in the range of one's experience and expectations.
It is possible to make a good case for consistent power ratings being in the consumer's best interest.
 

mattball826

Senior Member
Messages
20,798
The power output is a frequently used and abused amplifier rating. Power output can be defined as the maximum power an amplifier can deliver before distortion impairs the sound. Usually rated in percent of total harmonic distortion. The THD percentage should be stated when the output wattage is given. We like our guitars distorted don't we?

The Federal Trade Commission in November 1974 enacted a regulation on measuring amplifier power output to address the grossly exaggerated amplifier ratings common at that time. Apparentley this is being ignored by some manufacturers...........
THD not really used in guitar amps. That # is ignored by most mfg's today including the high end mfgs of MI PA gear. Hi Fi standards are a different breed, though yes you do find 1000w audio packages of a small subwoofer and tv sound bar. Do any majority of people really want 1000w rms kit on their wall to watch a movie at home? no
 

J M Fahey

Member
Messages
2,929
The power output is a frequently used and abused amplifier rating. Power output can be defined as the maximum power an amplifier can deliver before distortion impairs the sound. Usually rated in percent of total harmonic distortion. The THD percentage should be stated when the output wattage is given. We like our guitars distorted don't we?
Transistor guitar amps are *often* quoted (in the fine print) at 10% distortion, which is really quite clipped; "just" visible clipping is usually about 1% or so.
Now tubes are typically 6% or so distorting, even **without** visibly clipping :eek:, just because of tube nonlinearity.
But it´s a very different sounding distortion, is perceived as warm and rich, while SS is either incredibly clean (1% or less) or buzzy nasty clipping, so just comparing "the numbers" does not provide an adequate picture.

The Federal Trade Commission in November 1974 enacted a regulation on measuring amplifier power output to address the grossly exaggerated amplifier ratings common at that time. Apparentley this is being ignored by some manufacturers...........
Oh, it´s not longer valid.
I read the new FTC (or its current incarnation) rule written under pressure from cheap Asian stuff importers (they say so in the Law text themselves) who complained about "unfair Tech requirements which would make end users pay too much :confused: " where they relaxed requirements so much that today anybody can quote any rediculous impossible "number" without consequences.

FTC server is down for maintenance so I don´t have the latest monstrosity (sorry .... "law" :cool: ) but just see what chain store lobbyist Richard Myslinski said, which of course was obeyed in the 2010 ruling:
Trade Regulation Rule Relating to Power Output Claims for Amplifiers Utilized on Home Entertainment Products #534789-00001
March 24, 2008 1:43am
Submission Number:
534789-00001
Commenter:
Richard Myslinski

State:
DC
Initiative Name:
Trade Regulation Rule Relating to Power Output Claims for Amplifiers Utilized on Home Entertainment Products

I think the FTC should let the free market reign and avoid further burdensome regulation
FWIW FTC advisor is:
Richard Myslinski is Interactive Media Manager with Americans for Prosperity, a free market advocacy group opposing proposals by U.S. President Barack Obama to reform heath care system and institute a cap and trade system to address global warming.[1]

so now you know who is "defending" consumers and who actually writes Law.
 
Last edited:

Tone_Terrific

Silver Supporting Member
Messages
34,979
I think the FTC should let the free market reign and avoid further burdensome regulation
That is scandalous.

Manufacturer's datasheets provide output in Watts @ distortion often up to 10% distortion which allows a far higher output rating but they do call it music power and indicate that it is rated over a short term of measurement.

What appears in advertised ratings could be anything.
The 'Free Market' would demand accurate and consistent ratings if better informed.
The willingness to cover up factual information is sad.
Fake news, fake facts, fake emotion, fake outrage.... real problems.
 
Messages
826
Recent solid state amps (especially class D) are also often associated with very inefficient speakers. It's now got to the ridiculous stage where many guitarists follow some personal 'logic' along the lines of 'Ah you have a 100W class D amp - no problem, my 15W tube amp will probably be louder!' :)
 




Trending Topics

Top Bottom