I start this thread because I want to make sure I'm giving my First Watt J2 a fair chance to compete with a few other amps. Cause so far, it's not sounding good to me...
This has nothing to do with measurements -- only a listening evaluation where I keep the source and the speakers constant. The variable is power amps.
Speakers: Tannoy V12
Source: iphone 5s
All amplifiers have been warmed up for 2 hours. The switch from amp-to-amp takes about 30 sec, thanks to phenix connectors.
Let's say I have 5 amplifiers and I want to figure out which ones sound best to my ears.
Is it fair to evaluate good amplifiers from an iphone 5s, as the source of music material?
This has nothing to do with measurements -- only a listening evaluation where I keep the source and the speakers constant. The variable is power amps.
Speakers: Tannoy V12
Source: iphone 5s
All amplifiers have been warmed up for 2 hours. The switch from amp-to-amp takes about 30 sec, thanks to phenix connectors.
Let's say I have 5 amplifiers and I want to figure out which ones sound best to my ears.
Is it fair to evaluate good amplifiers from an iphone 5s, as the source of music material?
True. But I figured the V12 is a good all-arounder, and I thought that Nelson Pass voiced his amps on the Tannoys as well...
The V12 roll off below 100hz. But in this case I am not evaluating for deep bass response -- there's subs for that! Just general sound signature.
Should I try a different speaker in the rotation? What do you recommend?
Because your prejudice, you already think the J2 sounds bad...but you can get some data, even if it’s not prefect...come up with a short test playlist listen to the complete playlist at a set volume with a spl meter on your phone with each amp, rank them. Then connect one channel of 2 different amps, redo step one till all amps have been tested against the top ranking amp and rerank. This has MANY holes, synergy with speakers, different amounts of gain and impedance, subjective, etc...but it may help.
I used to have a set of crap speakers that I used to test receivers because they matched the receiver, they sounded like crap with a crap receiver and sounded pretty almost amazing when hook up to a nak ta3a. This is even more subjective but I like magic, fairy dust and daybreak rituals.
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The J2 does not sound bad, it's just not sounding good to me so far. SO... I wanted to verify the methodology. Alternatively, I would like to try and reproduce what setup I need to make the J2 sound it's best. Suggestions?
I don't think I have any prejudice, I really don't care which ten amps to sell. All I know is that I don't need more that two 🙂
I don't think I have any prejudice, I really don't care which ten amps to sell. All I know is that I don't need more that two 🙂
What is the input impedance on the different amplifiers?
If it is below say, 50-100kohm, I would not expect your iPhone to be able to drive the input properly, and the sound quality would suffer.
Can you get a preamplifier or at least a buffer in between?
/The Priest
If it is below say, 50-100kohm, I would not expect your iPhone to be able to drive the input properly, and the sound quality would suffer.
Can you get a preamplifier or at least a buffer in between?
/The Priest
Good point as well.
Says here the J2 input imp is 100K.
FIRST WATT PRODUCTS
But I thought of something. Maybe it needs to be driven by balanced signal for best sound??? I'll try that.
With what type of speakers should the J2 shine its best?
Says here the J2 input imp is 100K.
FIRST WATT PRODUCTS
But I thought of something. Maybe it needs to be driven by balanced signal for best sound??? I'll try that.
With what type of speakers should the J2 shine its best?
Your brain is very good at filling in the blanks based on your expectations. Read about expectation bias and double blind testing. There is a lot of information out there.
Sighted listening tests are completely meaningless.
If that is how you will use the amplifier, then yes it is fair for your purposes.
If you will use a different source or speakers or room for normal listening, then not fair.
Did you use diyAudio sourced boards and parts, properly biased? If not, it is possible
that the amplifier is not functioning as intended.
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Genuine First Watt J2
>>Sighted listening tests are completely meaningless.
Need a helper then... So far I have been the only one running this experiment. Anyone here in Chicago?
>>Sighted listening tests are completely meaningless.
Need a helper then... So far I have been the only one running this experiment. Anyone here in Chicago?
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I would suggest trying the J2 with a speaker that has a more benign impedance curve. The J2 likes it around 8 ohms but odd order harmonics increase a bit into 4 ohms. But, I don’t know the harmonic signature into higher impedance. I think your Tannoy has a 50 ohm impedance spike around 2000 Hz and it may be outside the J2’s happy place.
Just guessing though. I have a non- diy J2 that I’m researching speakers for. Can anyone enlighten me on this amps harmonic characteristics into, say, 16 ohms?
Scott
Just guessing though. I have a non- diy J2 that I’m researching speakers for. Can anyone enlighten me on this amps harmonic characteristics into, say, 16 ohms?
Scott
Why not?
iPhone is made for 32 Ohms. This may be a mild strain, but anything over 320 Ohms should be easy as sin.
Otherwise: YES YES YES get someone else to switch wires behind your back.
And EXACTLY equalize sound level.
Or just do as you have. Make casual decisions without much evidence. That's how most things really work anyway.
What recordings are you using?
If you have a good amp and play bad recordings, a good amp will show you they are worse than you previously thought, then you may think that the amp is to blame when in reality it is the exact opposite.
If you have a good amp and play bad recordings, a good amp will show you they are worse than you previously thought, then you may think that the amp is to blame when in reality it is the exact opposite.
OK, ok. Gonna have to bring my wife down again. She's gonna roll her eyes, again. If anyone does not give a sht -- it's her. Perfect subject. Just for a reference point.
I was thinking this, though. For an experiment... to NOT level match. Instead, to turn the level down to zero, after each play. Then to let the listener bring up the volume level to their own liking. To then note the db level for each amp that the subject adjusted.
We will have a list of average listening levels for each amplifier. Why is this useful? I don't know yet.
My speakers: www.fullcompass.com/common/files/8777-TechnicalData.pdf
Nominal 8ohm but 50ohm@2khz (like Scott pointed out)
>>What recordings are you using?
I use a variety of recordings. Acoustic Jazz of various quality, vocals, electronic, etc. A variety of stuff, but mainly what I like to listen to -- not the designated audiophile tracks.
I have the factory J2. Should I check the bias on it? Instructions available?
I was thinking this, though. For an experiment... to NOT level match. Instead, to turn the level down to zero, after each play. Then to let the listener bring up the volume level to their own liking. To then note the db level for each amp that the subject adjusted.
We will have a list of average listening levels for each amplifier. Why is this useful? I don't know yet.
My speakers: www.fullcompass.com/common/files/8777-TechnicalData.pdf
Nominal 8ohm but 50ohm@2khz (like Scott pointed out)
>>What recordings are you using?
I use a variety of recordings. Acoustic Jazz of various quality, vocals, electronic, etc. A variety of stuff, but mainly what I like to listen to -- not the designated audiophile tracks.
I have the factory J2. Should I check the bias on it? Instructions available?
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Most of the time I don't even know why something sounds exceptionally good to me. It is a learning curve. There are many experienced people who try to correlate measurement to listening experience. But still in Jan Didden Interview even Papa with all the measurement gadgets and 50+ years experience said, "The only magic involved takes place in the neural networks between our ears. What happens there is still poorly understood and varies between individuals."
So how do we define fair? You can listen to your setup and compare stuff, but your impression is unique to you, could be applicable to many others but never to all. I don't think those with extreme hearing ability such as Matt Murdock or the deaf will agree with you. Also men and women generally have different impression. Can't please them all. Just my
.
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I can judge if anything is wrong/bad in few minutes
when something is good, I need at least a week of relaxed listening, to judge how good is
when something is good, I need at least a week of relaxed listening, to judge how good is