Review: Portable amp roundup! 56 portable amps reviewed and compared - FINAL update 12-20-10 added RSA SR-71B
May 8, 2008 at 7:13 PM Post #1,921 of 3,234
As a beginner, I am not very happy with this compilation as it provides too much info. A poor beginner in this hobby can get overwhelmed. How I wish that"product A is slightly different than product B, and they are both outdone by product C to thrice the price"
Anyhow, I guess based on what I have read here, going for a Meier 2Move or an Ibasso D1/D2 or a Tomahawk, one does not go very wrong.
I do appreciate someone taking the time and effort to create a thread like this. Thanks :)
 
May 9, 2008 at 12:10 PM Post #1,923 of 3,234
Quote:

Originally Posted by Geir /img/forum/go_quote.gif
As a beginner, I am not very happy with this compilation as it provides too much info. A poor beginner in this hobby can get overwhelmed. How I wish that"product A is slightly different than product B, and they are both outdone by product C to thrice the price"
Anyhow, I guess based on what I have read here, going for a Meier 2Move or an Ibasso D1/D2 or a Tomahawk, one does not go very wrong.
I do appreciate someone taking the time and effort to create a thread like this. Thanks :)



You're absolutely correct: I own the 2Move and the Tomahawk and have heard the iBasso D2 thanks to Mrarroyo and can tell you for the money, any of these three would be a wise purchase. Check the F/S forums and buy used or go for new. Any one of the three will serve you well.
 
May 11, 2008 at 1:24 PM Post #1,924 of 3,234
...Listening was done with the levels matched to within 1db using a RS SPL meter said:
Level-matching ¡¡¡ 1 db !!!, please Skylab more technical seriousness. Ideally, playback level is 0.1 or max. 0.2 db. Level-matching is crucial. Slight level differences between products can lead to the wrong conclusion. The ear's sensitivity to bass and treble increases disproportionately with volume. It is to say, we hear more bass and treble when the music is loud. If amp A is played louder than amp B, amp A may sound brighter, more detailed, more forward, more dynamic, and have more bass. If amp A has a soft treble, lacks detail and has a lean bass balance. if the level is not exact, these differences we will not be able to detect them.
 
May 11, 2008 at 1:48 PM Post #1,925 of 3,234
Jaume:

A couple comments:

1. It's impossible to guarantee matched levels using an SPL meter to be more accurate than 1db. In fact, they may be - I use pink noise to get the SPL meter level to exactly 80db. So they are matched to a tighter tolerance than 1db *if* you believe the meter has that level of accuracy. I'm not sure it does, so I take a more conservative approach in making my claim. In any case, to get a more guaranteed accurate level match would require using a volt meter and a very tricky measurement technique, which I have no interest in.

2. In general, I believe 1db is plenty accurate enough. Volume deviations lower than that will not have any effect on long-term listening tests. I am very aware that changes in volume impact our perception on sound, which is why I match levels. But I do not think changes lower than 1db are relevant.

3. As far as I know, most of the other people who regularly review amps on this site do not make any attempt to match levels.

4. If 1db is not a close enough level match for you, you are under no obligation to use my review. However, I believe I have matched levels as closely as is reasonably practical.
 
May 11, 2008 at 1:57 PM Post #1,926 of 3,234
Jaume;4197835 said:
Quote:

Originally Posted by ...Listening was done with the levels matched to within 1db using a RS SPL meter, so that the listening volume level was identical with each amp....QUOTE

Level-matching ¡¡¡ 1 db !!!, please Skylab more technical seriousness. Ideally, playback level is 0.1 or max. 0.2 db. Level-matching is crucial. Slight level differences between products can lead to the wrong conclusion. The ear's sensitivity to bass and treble increases disproportionately with volume. It is to say, we hear more bass and treble when the music is loud. If amp A is played louder than amp B, amp A may sound brighter, more detailed, more forward, more dynamic, and have more bass. If amp A has a soft treble, lacks detail and has a lean bass balance. if the level is not exact, these differences we will not be able to detect them.



As another voice of defense, the fact that he level matches at all is commendable, and above and beyond what most do. If everyone level matched to that extent, reviews here in general would be a lot more credible.
 
May 11, 2008 at 1:59 PM Post #1,927 of 3,234
Thanks Monolith. I'm sure that people who have never actually done it do not realize what a PITA it is to match levels. But for me, it is a critical part of the amp review process. It's impossible to nail down the differences otherwise.
 
May 11, 2008 at 2:31 PM Post #1,928 of 3,234
I do use a dB meter to match when I review. I find that using my ears gets me almost as close as the meter does.
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But it really does not matter what each person does or does not, there will be some who do not want to believe and attack. Sometimes because they do not have anything to say.
rolleyes.gif
 
May 11, 2008 at 2:37 PM Post #1,929 of 3,234
Quote:

Originally Posted by mrarroyo /img/forum/go_quote.gif
I do use a dB meter to match when I review. I find that using my ears gets me almost as close as the meter does.
eek.gif


But it really does not matter what each person does or does not, there will be some who do not want to believe and attack. Sometimes because they do not have anything to say.
rolleyes.gif



Excellent, and I agree with you, Miguel
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May 11, 2008 at 3:20 PM Post #1,930 of 3,234
I use a cheap SPL meter also to level match, and mostly to confirm to myself that I'm not listening too loud.

I find reviews or comparisons between items that aren't level matched are highly unreliable, because in my experience even a relatively small increase of 2-3 dB drastically changes the sound.
I always wonder when people compare gear if they aren't just hearing the difference in volume, and not actual sound quality, especially when there are those mythical "night and day differences".
smily_headphones1.gif

For this reason alone, I wish I had a stepped attenuator on my amp instead, but oh well.

Since Skylab is doing fairly accurate level matching when reviewing, I don't see what the big deal is.
 
May 11, 2008 at 6:36 PM Post #1,931 of 3,234
Off with his head!!! Let it be known throughout all the Head-Fi Kingdom that Skylab doesnt keep matching below 0.0001db!
smily_headphones1.gif


Jude call the gaurds!

Personally i think he reviews well, and pretty neutral for a ((((BASSHEAD))))
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May 11, 2008 at 10:38 PM Post #1,932 of 3,234
Quote:

Originally Posted by tk3 /img/forum/go_quote.gif
Since Skylab is doing fairly accurate level matching when reviewing, I don't see what the big deal is.


Quote:

Originally Posted by Drag0n /img/forum/go_quote.gif
Personally i think he reviews well, and pretty neutral for a ((((BASSHEAD))))
smily_headphones1.gif



Have to agree. The variety of reviewers all do a very good job and approach it as professionally as possible given what time they have and the ability of the SPL meters to level match.

Keep up the good (very good IMHO) work, portable amp reviewers.
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May 11, 2008 at 10:52 PM Post #1,933 of 3,234
May 11, 2008 at 11:28 PM Post #1,934 of 3,234
I looked up my specs, and my meter is only a +/- 2db at 114 db spl. So I could repeat the test producing a consistent 114db noise each time and get anything between 112-116 on the readout.

I don't know if it is better or the same at 80db, but that means it "could" read 80 when it is as low as 78 or as high as 82db.

However, If I have two amps reading 80, but they are really 4db apart, I KNOW I CAN hear the difference, and typically I can hear a 1-2db difference. So, my ears tell me if works better than the specs say it does.

Battery.........................................9-volt Alkaline
Microphone.........................Electret Condenser
Range......................................50 dB to 126 dB
Accuracy............................± 2 dB at 114 dB SPL
Reference...................0 dB = 0.0002 Micro Bar
Weighting......................................... ....A and C
Display Response......................Fast and Slow
Signal Output:
Voltage...................1 Volt Peak-Peak Min.
(Open Circuit, Full Scale at 1 kHz)
Impedance..............10 Kilohms Min. Load
Distortion..............Less than 2% at 1 kHz.
0.5 V p-p Output
(Input: Mic Out, Output: 10 Kohm)
 
May 11, 2008 at 11:32 PM Post #1,935 of 3,234
From what I have read, the analog RS SPL meter is more accurate than the digital one. But heck, ANY attempt to level match is better than no attemp
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