From: Hornstein Subject: Setting the mic sensitivity on the TCD-D8 Date: Thu, 28 Mar 96 10:20 +0100 Hi DAT-Heads, the professionals of you are asked to excuse this topic here, but I think it can be helpful to the ones who are new to the taping business, espacially TCD-D8 users. A coupla days ago I made some microphone test recordings. Beautiful and time consuming arrangements were made, levels were set to be just below 0 dB in order to have comparable results on different DAT machines. Some disappointment rose when I listened to the recordings, which showed distortion at certain points (High bass volume), although the 0 dB mark was never reached. What happened? A friendly sound engineer, A. Viranyi, gave me a hint, and later I also found it in Bruce Bartletts "Live taping to DAT": >What if the sound is distorted, even though you did not reach 0 on >your meters? Chances are, the mics put out a signal strong enough >to overload your DAT mic preamp. To prevent this, switch on the >pad (attenuator) on your DAT or mic preamp. If you find that >you're setting the record-level knob less than halfway up to >prevent excessive meter peaks, you probably need to use the pad. Exactly this I didn't have in mind. We recorded an organ in a church, and the high sensitivity setting of the attenuator seemed me to be right (no rock concert level...). Some measurements after the recording sessions revealed: Mic input, High sensitivity, allows max 12 mV at the input jack without audible overload of the DAT mic preamp. This gives 0 dB on the level display at Rec Level position = 4.5 . Mic input, Low sensitivity, allows max 130 mV at the input jack without audible overload of the DAT mic preamp. This gives 0 dB on the level display at Rec Level position = 4.5 . Line input, allows max 1,6 V at the line input jack without audible overload of the DAT preamp. This gives 0 dB on the level display at Rec Level position = 4.2 . This means: Do not record with record level settings below 4.5 (mic) or 4.2 (line) on the TCD-D8. If you do, the preamp is likely to overload, since you will have more than 12mV/130mV/1.6V at the input jack when the peak meter comes to 0 dB. Instead of that, you should try to record music in the "Low mic sensitivity" position or even on the line input, especially if you are using (electret) condenser mics or PZM mics, which give a higher output than most dynamic mics. Only if you do not reach the desired peak meter reading, you should change to the "High" position. The noise is _not_ increased with the higher position of the Rec level knob. It is not wrong to record loud music with a mic on the line input, provided the mic does not need the power supply from the D8 mic jack. If you record on "line in" and need a Rec Level setting <4.2 , you should use an attenuator. For those interested I give here the levels for 0 dB peak meter reading, rec level = 10 (fully opened), measured at 100 Hz: Mic H Mic L Line U(mV) 2 20 220 approx dB -52 -32 -11 Hope this is clear enough and helps the newcomers. Greetings from Freiburg, Germany Ulrich Hornstein