What Amplifier Specifications Do You Feel Is Beneficial?

[TrevorOfDoom]

in amps, a graph detailing the frequency response with all knobs at noon, and showing where all knobs must be for "frequency flat" response.
If a HPF is built into the amp, then specify at what frequency and slope.
All EQ knobs should be marked with their hinge frequency (and maybe Q. maybe not)

In cabs, we need a standard testing frequency to determine power handling and frequency response.
For guitar cabs, maybe 1kHz.
For bass, try 200Hz.
And ideally, a graph detailing the frequency response of the cab.

 

[Mugre]

Which frequencies each EQ knob adjusts & to what degree.

Nothing wrong with knowing +/- 12 db at 80 hz shelving or peak and dip at 2k and another shelving at 6k. Even if you add the Q to the mid bumper/cutter, it'll mean nothing to most people and it tells you nothing with how they interact until you do what most people should do anyway which is:

all eq knobs all the way up. It may be the same plot as at 0 db or not; it doesn't matter; the idea is to generate the most "cut" possible. Now take the lowest eq knob and pull it all the way out, max cut and listen to what happens/disappears on the music/instrument. Put it back and to the same to what ever mid knobs you may have. LISTEN to what happens when you pull all those mids out. Of course do the same thing with any hi-freq bands. Now reverse the process, max cut everything and put them up to full one at a time. In this process you're tuning your ear to what's actually happening to this sound with this eq and these speakers. I do this almost everytime I sit in front of a new amp or desk. I started when I was mixing in clubs 30 years ago and the only way to "tune" the PA was to find the feedback and notch it out with a 15 or 31 band EQ so we had to train our ears to intuitively know about where on the eq any given squeal or squawk could be found or what the frequency was to add or cut a little "smack" to the skins of a floor tom or a little "shimmer" to an acoustic guitar. Until you you have the experience to connect 320 hz to a certain sound characteristic, listing the center frequency of the tone knobs is just window dressing.

 

[superheavyfunk]

"And set things to where we think will be an approximation of the sound we get on another amp..."

Are you saying you're trying to achieve the same sound on 2 completely different amps? Plus, when going out to try other amps, won't you end up fiddling with all the knobs to find the sound that's most pleasing?

Are you saying that you weren't ever confused with amps and how all the knobs worked differently from manufacturer to manufacturer before you learned all the ins and outs of how tone stacks worked? That you didn't start by just putting all the knobs at noon and go from there?

For me personally, a scope of what the amp's "EQ at noon" would be nice. I like visuals.

in amps, a graph detailing the frequency response with all knobs at noon, and showing where all knobs must be for "frequency flat" response.

Obviously, I'm not the only one who thinks this is an important, or at least a relevant piece of information. I'll bet that if this thread had a poll, this request would be at or near the top

 

[_Some Dude]

From how high you can drop it onto concrete and how many ounces of beer before failure.

Seriously, something like the falling on concrete spec would really help give an idea how well put together something is.

Someone will read it, then film themselves dropping it on concrete and post it on YouTube, probably with a comment that Mesa refused to warranty the product because it was obviously dropped and still had concrete dust on it. If it's at all damaged that video will be used against the manufacturer for years.

Rather than list a drop spec I think the reliability is indicated in the 5 year warranty and decades of satisfied customers.

THD

If there's one spec I don't give a sh*t about it's THD. I'm never going to be in a position where I'm going to be comparing two bass amp spec sheets and making a decision based on which amp produces X watts at 0.1% THD.

On that note, I only loosely care about wattage, and that's primarily to judge what class of amp I'm looking at. If it's ~800w then I know that I should be comparing it to other ~800w amps. The exact number is inconsequential.

The specs that do matter to me are the specs/descriptions that help me better utilize the features on the amp or avoid damaging equipment. Frequency centres and sweeps, behaviour of tone controls (voice, bright, deep, etc. How to hook up multiple cabs, etc.

I think Mesa does a really good job in this regard by plain english descriptions of functionality, then reinforcing it with actual data when applicable. One addition I'd find useful is better visual references, and in that regard I really liked this Strategy/Prodigy review produced by Bass Gear Magazine;

I really liked this Strategy/Prodigy review produced by Bass Gear Magazine;

Bass Gear Winter 2014


The visual references give me better understanding of what's going on than can be articulated via text, and comparisons give context. Using the voicing control as an example, the image created in my mind using the text in the manual didn't match the curves that were produced in that graph.

As someone already mentioned, it might be worth having this level of detail and maybe some commentary on design philosophy located on the website rather than in the manual.


Edit - Fixed link

 

[TrevorOfDoom]

Why the focus on "flat", when most of the most coveted amps are anything but flat? If you knew that an amp wasn't ruler flat, wold that disqualify it from consideration? Most players just simply don't choose flat what presented with such options in a blind listening test.

It's not that I care about playing thru the amp at a 'flat' setting. Its because I need a point of reference. It's confusing to people who aren't technically inclined, when we go out looking at amps and set things to where we think will be an approximation of the sound we get on another amp, only to discover that the amp "sounds like crap" because we are almost all under the (false) impression that all knobs at noon is supposed to be the "flat" position.

So yeah, something that allows me to know where that setting is in any particular amp would give me an excellent starting point to discover what it can do and how I can work with it. Does that make sense?

I like frequency flat. It lets my Pbass sound like a Pbass and my Brubaker sound like a Brubaker. I like the sound of high quality DI's (the Rupert Neve DI being my favourite). If i need a bit more or less of a thing, I like knowing where that is and how to get it.
If I had known where "flat" was on the Orange TerrorBass, I might not have bought it. (It was with treble and bass at 0, and mids maxed) If i ever needed more mids, I was screwed. If I needed less bass, I was screwed.
I read the manuals to every amp I buy, rent, or backline, so I know what I'm getting into.
And yeah, I like the sound of Ampegs and Oranges and HiWatts and Ashdowns, but I always wanna know what I'm working with and how to make it do what I want.
Having a reference to "flat" helps make that happen.

 

[quickfix]

Class of the power amp section. I look there first on any spec sheet or advertising pamphlet. No point in looking any further if it's not the Class I'm looking for.

 

[HolmeBass]

Nothing is going to be perfectly linear when performing the anti-log function of the adjustment in hardware, but it's almost always within 10%.

On highpass filters I do provide a detailed discussion and info, because I usually use either a 2 pole (12dB/octave) or 4 pole (24dB/octave) depending on the application.

Q and slope are two independent parameters. For active mid eq, slopes typically resolve to 6dB/octave on each side of the bandpass, the Q does vary with boost/cut. At very small amounts of boost & cut it may be as low as 1 and at high boost/cut amounts might increase to say 4 or so. This gives the impression that the slop is greater though the definition of the slope is what the filter response resolves to. It's useful for the Q to increase with more boost/cut, this way when you are making deeper adjustments they become more precise and less intrusive (in %) on the surrounding frequencies.

The shelving filters are ~6dB/octave and with a Q of a little less than 1.

Good question... hope this helps.

It sure does, I wouldn't mind seeing info like this for every amp I consider buying, at least in the manual. Thanks @agedhorse! And thanks for all of these killer bass amps, too.

 

[Lo-E]

I like to know weight, Wattage ratings at the workable impedance loads and what the EQ frequency points are. Past that, the only thing I'm really looking at is how intuitive the control layout is.

Even Wattage ratings are really just a ballpark comparison from amp to amp so I read them with a big grain of salt. My needs are pretty simple....

Oops.... I'm a chowderhead. I forgot another spec that is, actually, pretty important to me: Input impedance.
That's a very useful thing to know.
Someone else mentioned listing the supported connectors and I agree that's pretty useful. Knowing if the DI is pre or post is also helpful.

Maybe my needs aren't as simple as I thought!

 

[HolmeBass]

Oops.... I'm a chowderhead. I forgot another spec that is, actually, pretty important to me: Input impedance.
That's a very useful thing to know.
Someone else mentioned listing the supported connectors and I agree that's pretty useful. Knowing if the DI is pre or post is also helpful.

Maybe my needs aren't as simple as I thought!

If only every bass manufacturer listed the output impedance of the instrument with its stock pickups, all knobs up full, or some such way that we could start to grapple with impedance matching our basses to our rigs.

I guess if the input impedance is really high it will work with hi as well as low Z output impedance basses?

 

[MojoPenguin]

What I personally like are close to what Fender have on the Rumble amps. But better done.
A couple of switches and button to get an instant EQ curve and the ability to "block" some good settings I have on my amp as I keep forgetting those.

 

[Bubble]

Are music amps supposed to be flat ? I thought they had tonal personalities, recognized by brand name. In that case a basic RMS, bandwidth endpoints possibly with -3db reference, equalizer depth in +- db (relative), all functions named and detailed in another section.
I don't know if true or not but if music amps are designed with tonal personality, then revealing detailed specs may reveal trade secrets to attain that sound some brands prefer to keep.

Forgot output impedance, input impedance and sensitivity, max line input voltage in RMS.

 

[TrevorOfDoom]

No lie, because of this thread I just read the owners manual for the Mesa Subway D800+.
Very well done, @agedhorse !
Of course, the only thing that you didn't have on there that I'd want to see is a reference to "frequency flat" vs. all knobs at noon.
But honestly, because of the thorough nature of the manual, I'm considering a couple Mesa products now, for backup. Nicely done!

 

[SirMjac28]

The meltdown point or how long a amp can operate at max volume before going into distress.

 

[Rip Van Dan]

So I'm sitting at my desk pondering some thoughts for an update of specifications provided, and while there are a ton of possible specs. to include I think many of them are virtually meaningless to the overwhelming majority of players. Of course there are some important ones as well.

Now's your opportunity to state your opinions as to what an "ideal" amplifier spec. sheet should contain. As ideas come up, I may wish to discuss them to be sure we are on the same page.

The one thing I am not going to accept are disrespectful posts however, and this is not (yet another) class D amp debate as the class of amp does not matter for this discussion.

Specs I look for are RMS-watts; peak-watts (so I know what the headroom is); minimum ohms load; THD rating (so I know what kind of clarity of sound I can expect); Frequency Response at +/-3db; and S/N ratio if available, although the gain will have a big influence on that (55db was considered hi-fidelity in the age of vinyl). S/N ratio is probably not such a big deal anymore especially if you are striving for an overdriven sound. Still, I like to know what it will do "clean". Also, like one of the first responses said, a frequency response curve with controls set flat would be nice so you know where you are actually starting from.

When explaining EQ controls, it's helpful to know if they are shelving controls (bass and treble almost always are) or semi-parametric controls. On semi-parametric controls that do NOT have an adjustable sweep, really need to know where they are centered. Also, if there is a specific way to get "the best sound" out of the amp using the gain control, would like that explained. For example, Eden used to go into detail on how to get the best sound out of their amps. Even with that you'd find people asking on the Eden forum how to set it up. Now that Marshall owns Eden, they have super simplified the owners manual so they could include 7 languages in the one manual. Take a look at any of the new Eden manuals for a good example of what not to do.

 

[Rip Van Dan]

Are music amps supposed to be flat ? I thought they had tonal personalities, recognized by brand name. In that case a basic RMS, bandwidth endpoints possibly with -3db reference, equalizer depth in +- db (relative), all functions named and detailed in another section.
I don't know if true or not but if music amps are designed with tonal personality, then revealing detailed specs may reveal trade secrets to attain that sound some brands prefer to keep.

Forgot output impedance, input impedance and sensitivity, max line input voltage in RMS.

I doubt if tonal personality is a trade secret. It's too easy to measure the frequencies to expect it to be secret. "There's a app for that!"

 

[wmhill]

For me I really want to see-
* wattages at perspective ohms (@8 @ 4 etc....) preferably continuous VS peak
*weight
* physical dimensions
* EQ centering per control (lows- 60, mids 250 etc)

 

[RonEW]

Honest RMS watts @ 8-4-2, peak w, THD, you guys proved you don't need dozens of knobs and sliders, loving my D800, thanks.

 

[Hoyt]

Honest THD specs. Headroom means a lot to me.

This. I get tired of getting excited about a new amp offering only to find out that "500 watts" is closer to 300 on a good day.

I'm not too picky about the rest of it. I can usually get a sound I like out of most amps and have come to the conclusion that most models will require me to buy some sort of outboard preamp like the Grace Design FeliX to get me where I want to be.

 

[Hoyt]

This is kind of where the pondering started, there are additional specs that might be important but there is also the potential to get so buried in the specs that they become meaningless (or worse, confusing) to those seeking information.

Personally, I'd place the important specs at the top of the sheet so interested parties can see it before their eyes glaze over, lol...

 

[4stringsjack]

What a great thread! People have already said everything I’d want (and THEN some!) so I’ll just pick out a few specs that are important to me-

Specs I want when shopping for a new amp:

• Watts
• Dimensions (L x W x H)
• Weight
• Inputs and outputs
• Features (tone controls, mute, tuner out, effects loop, DI, built in compressor, etc.)

Specs I want when using (or learning to use) the amp:

• Tone control frequency centers
• I’d also love to have the “flat” setting, as others have said, because I personally like to use that as a starting point or at least as a mental reference point. [I enjoy the heck out of my Streamliner 900. I've been gigging it for years and it never fails to kick butt. I've read somewhere here on TB what the flat settings supposedly are. I don't play it set to flat, but knowing where flat is (again, supposedly) helps orient me and makes me feel like I understand the EQ section better, and perhaps use it more effectively. I don't care at all if "all knobs set to noon" is flat; I'd just like to know where it is.]
• If the tone controls interact heavily with one another (like the old Fender tone stack), I'd like at least an overview description of that interaction.
• If it has a tube preamp, I’d also like a list of what tube types are compatible and can be swapped in without amp and/or tube damage (e.g., whether various flavors of 12A_7 tubes can be used)
• Environmental limits (max/min storage temperature and max/min operation temperature, for example)

And, of course, I want the maximum loudness of the amp expressed as a percentage of SVTs. “Amp can play up to 0.87 SVTs through a sealed 8x10 cabinet”.

Also, include drop testing videos shot with a high speed camera in the digital version of the owner’s manual.

(Just as an aside, in one of my roles as a product design engineer I used to conduct and film drop tests to a very specific regimen: drop height and product orientation when dropped. The bigger and heavier the product, the more fun the high speed videos were to watch. It’s amazing to see how rubbery steel structural members would become on impact.)