Steep Angle Needed for a vdH Black Beauty

This vdH Black Beauty needs plenty of tilting forward. With its top level, the IMD is unacceptably high at about 12%. Lowering the arm high makes it even worse. Raising the arm on the SL1200G to the limit and slight improvements start to show. Eventually need to shim 3 pieces of cards in its front to get the numbers into the 2 to 3% range.

這個 vdH Black Beauty，調整到上緣水平時，IMD竟然高達12以上！降低一些更差，到14。SL─1200G的唱臂調到最高，稍微好一些到11左右。最後竟然前緣要墊3張名片的厚度，才到不錯的數字範圍。

AnalogMagik's Tracking Force Function

（中文在後面）
After finished writing the Part-1 of AnalogMagik review, I started to test the remaining features I haven't spent much time on. The Tracking Force function are verified on two cartridges here, Lyra Kleos (recommended VTF=1.73 according to the user manual) and DS Audio DS 002 (recommended VTF=1.7). Figure 1 is the final VTF for the Kleos after optimizing for the lowest THD using AnalogMagik. Figure 2 is for the DS 002. For the Kleos which is my main reference cartridge for the past 2+ years, even though the change is only -0.04g from the original setting, the sound has become much more refined with high-frequency extension unheard before. Similar improvements are also heard on the DS 002, but somewhat less drastic even though the change in VTF is much greater.

第一部份的評論交稿之後，開始測試 AnalogMagik其它還沒仔細研究的功能。Lyra Kleos（廠方建議針壓 1.73）最佳化後的針壓如圖一，DS Audio DS 002 （廠方建議針壓 1.7）最佳化後的針壓如圖二。調整後，兩者高頻變得細膩很多，尤其是已經用了2年多的 Kleos比起之前，「高貴感」進步幅度相當明顯。

New cartridges should all come with photos like these

The two cartridges belong to my friends. In my inspection I believe the cantilevers were both overly steep, resulting in the SRAs in the +96-degree range when the top surfaces were level. After adjustments at the factory, they came back included photos showing much more reasonable angles. For the cartridge manufacturers, providing such photos should be fairly easy, and such material will greatly help the users in correctly setting up the devices. Additionally, this makes monitoring the health of the cartridge much easier over time.

Note the angle of the coil is now only slightly away from parallel to the pole pieces. Adding tracking force and drag should put it into near perfect angle.

這是兩個針桿太陡的唱頭，原廠調整後寄回來，他們所附的照片。強烈建議所有新唱頭都應該附上這樣的照片，對用家來說會少很多調整上的麻煩。日後也容易追蹤健康狀況的變化。

注意現在線圈的角度，只偏離磁鐵的平面一點，加上針壓等外力，就應該與前後的磁鐵平行了。

"Powerful Bass" of Phono Stages?

When some people/reviewers commented certain phono stage has "powerful bass", it's better to take it with a grain of salt. Unlike pre-amps or power amps which do not have any EQ circuit in their signal paths, a phono stage has a reverse-RIAA EQ built in. And some designers will "cheat" a little by tweaking the EQ curve to achieve the desired "sound" for the device. So when we find a phono stage to have very impressive bass performance, it's likely not from the superior circuit design or strong power supply unit, just a trick of modifying the EQ. 

The three phono stages tested below are all priced at the ~8000 USD range. Using the same cartridge Lyra Kleos (without changing any parameters) to feed the test signal, I measured the high-frequency responses to be virtually identical. Whereas below 5kHz, the 2nd and 3rd devices obviously display higher output levels, ranging from a couple of dB to the extreme case of nearly 5 dB at the lowest end of the spectrum.

Incidentally, the first two are UK brands, and the 3rd one from the USA. In my experience, phono stages made by the US-based brands tend to have boosted bass responses similar to the 3rd device.

前後級擴大機沒有等化線路，而唱頭放大就必須有「反」RIAA等化。低頻很厲害的唱放，其實可能只是在等化曲線上做了些手腳，並非它的線路或電源部分有多特別。如下面3個圖的比較，用同一個唱頭不改變任何參數，得到的高頻響應幾乎完全相同。但 5kHz以下的，就開始出現明顯的差異。這3台的美金定價都在8000左右，前2台是英國牌子，第3台是美國的。

IMD numbers of the ELP laser player

What kind of IMD numbers the ELP laser player will show if running the AnalogMagik's VTA test through it? The ELP uses two ~2-micron laser "dots" to read the groove hence no SRA-related issue. IMD should be very low in theory. Initial measurements below show pretty good numbers, though not much better than a well-adjusted cartridge. I suspect the test record needs to be cleaned even further to get better measurements due to the ELP's susceptibility to dust. In any case, at least this shows AnalogMagik's IMD measurements are mostly in line with expectations.

在 ELP 黑膠雷射唱盤，用 AnalogMagik 的 VTA測試，會得到什麼結果？初始測試顯示，IMD 數值算相當不錯，但沒有比調整得好的唱頭更低。因為 ELP 對灰塵很敏感，可能要把測試唱片洗得更乾淨，才會有更好的結果。但這些數值至少顯示，AnalogMagik的 IMD 測量是有可信度的。而且，之前一直認為 ELP 的聲音雖然細節少，但失真很低，是有其道理的。

Using AnalogMagik to Tune London Reference's VTA/SRA

Most Decca-family cartridges have their styli slanted backward as in Figure 1. Naturally, one would assume the tone arm should be raised to achieve better sound. When using AnalogMagik's VTA function to test my London Reference, I found just the opposite. When the top of the cartridge was level, the IMD measured in the 8% range, and jump to ~12% if I raised the arm slightly higher. Only when I tilted back the cartridge to the extreme (as in Figure 2) did I get the best IMD numbers. The sound? Surprisingly delicate, detailed and clean with super dark background, very different from the rough-around-the-edges character that most people expect from Decca cartridges.

Decca 系列唱頭，針尖看起來多數是後仰的，我的 London Reference 也如此，如圖一，所以多數人都會把唱臂調高。但用 AnalogMagik 的 VTA 功能測 IMD， 唱頭上緣水平時 IMD竟然高達8%。再調高更不好，到 12%。反方向把唱頭調低到不能再低，後端快碰到唱片表面（如圖二），才出現不錯的數字如圖三。聽起來如何？出人意料的細膩乾淨又安靜，以前以為 Decca 系列唱頭固有的，稍微不修邊幅個性，竟然都不見了。這真是令人跌破眼鏡的結果。

Different power supply units leading to visible S/N ratio differences

Different power supply units leading to visible S/N ratio differences: Using the "Gain" optimization function in AnalogMagik, I measured the S/N numbers on iPhono 2 with its own switching-type PSU (Figure 1) and a large linear PSU by Acopian (Figure 2). The difference is about 1dB and quite consistent in various measurements.

AnalogMagik 有個原本用來找最佳放大倍率的功能，我以它測了不同電源供應給 iPhono 2 的 S/N （訊噪）比。圖一是原廠的切換式電源，圖二是 Acopian 的線性電源。測出的差別不大，約1 dB左右，但數據相當的 consistent。