My System
John Wood KT88 Amp.
Paradise Phono Stage
Sony TTS-8000 Turntable.
PMAT-1010 MK6 Tonearm.
Ortofon Cadenza Bronze
Sony X555ES Cd Player
Yamaha NS1000m Speakers
The glue almost looks like evostick contact cement, but may be a hot melt of some kind.
A couple of mine just cracked out of the glue without a problem, the rest ripped apart under the pressure.
Just as a guide for folks, ESR is talked about a lot with re-capping projects, the picture below is of a 1uf electrolytic measured using DATS v2 software.
Notice the massive difference in ESR dependent upon the frequency it sees.
PP caps do not have any where near the same level of ESR and strapping a fixed resistor in series with it will only work for a fixed frequency and is not going to give the variable level due to frequency change. This is why we change like for like with caps.
Again, I'll put this up for reference.
This first plot is of the NS-1000m bass, measured near field to avoid room effects.
I've not shown the trace, but there are no phase changes. You can see the elevated bass around 65-115Hz which gives them the punchy feel, then it falls off rapid from around 60Hz (f3 just over 50Hz), pretty much identical to the Yamaha results and also those of Troels Grevesen, when he said “the NS-1000m doesn't do much below 50Hz” he wasn't wrong, however.........
This plot from my listening spot shows the room taking effect and bass re-enforcement down to 40Hz. This explains why at a NEBO meet, in a very large room, with the speakers well away from the corners and rear wall, there seemed little bass, they would be working more like the near field response. Drop them back into my smallish listening room and they sound totally different. You can also see a suck out centered around 65Hz, there is a phase change centered here which will account for this and is probably down to room reflections/cancellations, so you win some, you loose some.
So although on paper, the bass output is pretty weak, the reality in your average size listening room is somewhat better.
To my ear, I always thought this was the case, it's nice to be able to confirm it.
Note: Measured using REW, my mic is calibrated down to 5Hz.
Last edited by Qwin; 06-01-2018 at 12:59.
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It’s not difficult to measure the L-pads and they can be replaced by two resistors (you might need more than two to get exactly the right values). If one does measure them the pots can be seen to be less than ideally matched and do not present an even impedance. Of course, once they are bypassed it doesn’t allow you to adjust them so easily.The level controls need to be in the circuit, if you bypass or remove these, you will have to alter the design accordingly to compensate. Don't ask me how, as I didn't measure the L-Pads, just leave them in circuit and you will be fine.
Last edited by YNWaN; 06-01-2018 at 16:43.
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That's correct. 'L' pads have an insertion loss. Their bypass or removal adds a couple of db or so to the output of each affected driver. Without correction, this would be output over and above what would be achieved at max 'L' pad setting. So probably resulting in a very bright, forward sound (nasty).
Last edited by walpurgis; 06-01-2018 at 16:22.