<style>@font-face { font-family: "新細明體"; }@font-face { font-family: "Cambria"; }@font-face { font-family: "儷宋 Pro"; }@font-face { font-family: "Apple Symbols"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 10pt; font-size: 12pt; font-family: "Times New Roman"; }a:link, span.MsoHyperlink { color: blue; text-decoration: underline; }a:visited, span.MsoHyperlinkFollowed { color: purple; text-decoration: underline; }span.javascript { }div.Section1 { page: Section1; }</style> [FONT=新細明體]突然想到一些問題...[/FONT] [FONT=新細明體]大家在使用[/FONT][FONT=新細明體]head的時候[/FONT][FONT=新細明體]，[/FONT][FONT=新細明體]為了音量縮減[/FONT][FONT=新細明體]，[/FONT][FONT=新細明體]一般常用的方法[/FONT][FONT=新細明體]！[/FONT] [FONT=新細明體]一[/FONT][FONT=新細明體]：[/FONT][FONT=新細明體]使用衰減器[/FONT] [FONT=新細明體]二[/FONT][FONT=新細明體]：[/FONT][FONT=新細明體]拔後級管並調偏壓（減瓦數）[/FONT] [FONT=新細明體]三[/FONT][FONT=新細明體]：[/FONT][FONT=新細明體]head輸出[/FONT][FONT=新細明體]，[/FONT][FONT=新細明體]接不同組抗值的cab[/FONT][FONT=新細明體]（[/FONT][FONT=新細明體]這我沒試過[/FONT][FONT=新細明體]）[/FONT] [FONT=新細明體]先[/FONT][FONT=新細明體]不討論音色是否會吃痛嚴重性[/FONT][FONT=新細明體]！[/FONT] [FONT=新細明體]一：使用衰減器[/FONT][FONT=新細明體]，[/FONT][FONT=新細明體]它接在head[/FONT][FONT=新細明體]輸出[/FONT][FONT=新細明體]和cab輸入之間[/FONT][FONT=新細明體]，通過產品特殊設計材質對輸出進行分流，把大部分的功率吸收掉 ，[/FONT][FONT=新細明體]音量自然就變小聲。[/FONT] [FONT=新細明體]大家都知道，挑選衰減器必須要跟head輸出、cab組抗值一樣！（如thd）[/FONT] [FONT=新細明體]但對岸論壇也有提到說：如果想接其他不同組抗[/FONT][FONT=新細明體]，衰減器的組抗[/FONT][FONT=新細明體]一定要大於或等於head輸出組抗[/FONT][FONT=新細明體]，[/FONT][FONT=新細明體]ex：[/FONT][FONT=新細明體]4歐姆的輸出可以接到8歐姆的衰減器上，反之則不行！[/FONT] [FONT=新細明體]二：拔後級管[/FONT] [FONT=新細明體]http://www.modernmusician.com/forum/showthread.php?t=19039&page=2[/FONT] [FONT=新細明體]http://www.modernmusician.com/forum/showthread.php?t=16260&highlight=George 喜歡 Lynch[/FONT] [FONT=新細明體]這兩篇都有討論～在此不討論[/FONT] [FONT=新細明體]三：[/FONT] [FONT=新細明體]看[/FONT][FONT=新細明體]到網友說[/FONT][FONT=新細明體]，[/FONT][FONT=新細明體]head[/FONT][FONT=新細明體]的輸出小於cab組抗，[/FONT][FONT=新細明體]因阻抗不同會使出力大約減半[/FONT].[FONT=新細明體]但是是安全的[/FONT]…[FONT=新細明體] 反之不行 ！比如：head 8歐姆接cab 16歐姆，ok～但接cab 4歐姆就不行！會燒毀..[/FONT] [FONT=新細明體]問題來了～假設上述紅色字是正確的話！[/FONT] [FONT=新細明體]那是否可以head輸出4歐姆[/FONT][FONT=新細明體]→[/FONT][FONT=新細明體]接4歐姆衰減器→16歐姆cab…[/FONT] [FONT=新細明體]如果這樣行得通….那其實衰減器不就都買4歐姆就好…也無須購買相同的組抗值了...且參數還不用衰減太多...是這樣嗎？？[/FONT]
可行, 可是 safe-mismatch 會影響到音色, 而且不建議作長久的 set-up Q&A from the THD website : Q: Can I still use the Hot Plate if it has a different impedance than my amp? A: Basically, whatever follows the amp (e.g. Hot Plate and speaker cabinet) must be EQUAL TO OR 1-IMPEDANCE STEP GREATER THAN the amplifier's output. Therefore, ONLY if the impedance of the Hot Plate is EQUAL TO OR 1-IMPEDANCE STEP GREATER THAN that of the amplifier’s output. For example, with a 4-ohm amp you could use an 8-ohm (1-impedance step greater) Hot Plate. However, a 1-impedance step up mismatch will lessen the effectiveness of the Hot Plate’s tone controls. Q: If I am using just one speaker cabinet, can I still use the Hot Plate if it has a different impedance than my speaker cabinet? A: Again, whatever follows the amp (e.g. Hot Plate and speaker cabinet) must be EQUAL TO OR 1-IMPEDANCE STEP GREATER THAN the amplifier's output. Therefore, ONLY if the impedance of the speaker cabinet is EQUAL TO OR 1-IMPEDANCE STEP GREATER THAN the amplifier’s output AND the impedance of the Hot Plate is EQUAL TO OR 1-IMPEDANCE STEP GREATER THAN the amplifier’s output. Again, a 1-impedance step up mismatch will lessen the effectiveness of the Hot Plate’s tone controls.
最近又有幾款新的 attenuator 面市了 Rivera RockCrusher http://www.rivera.com/products/power/rockcrusher.php Faustine Phantom DX2 http://www.faustineamps.com/phantom_production.html Two Notes Torpedo LB-202 http://www.two-notes.com/en/Two-Notes-Products/Torpedo-LB-202.html
原來真的可以～謝謝！長知識了！ 但其實也不會是長期的setup 會用衰減器也只是讓音量保持在耳朵靈敏度的範圍！ 太大聲，第一對耳朵有傷害，第二對於真的音色也會有些偏差！ 畢竟人的耳朵對於音色上在某些分貝的範圍才比較靈敏！ 太大聲反而失去判別能力（這是個人見解） 而提起此問題是小弟手頭上有之前為了4＊12cab而購入的4 歐姆hot plant...由於cab賣出去很久了！就臨時想起它的存在＝＝ 這樣的話就可以去接其他組抗值的cab了！（爽了一下） 且衰減器本身也可以去調整～～ 白天的時候可以去設定-0db的狀態～ 晚上練琴時就衰減多一點（不太要求音色） 其實這樣挺方便的！ 總之謝謝回應︿︿