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Re: Trigger finger is itchy [message #92130 is a reply to message #92120]

Tue, 28 July 2020 21:40

gofar99
Messages: 1949
Registered: May 2010
Location: Southern Arizona

Illuminati (5th Degree)

Hi, Yes some feed back would be nice. The write up makes me want to mention something about signal to noise. I notice that the preamp is listed as DBA for S/N. This is a common way to do it but..... it might not tell the whole story. DBA uses a roll off for noise below say 200 HZ and is really steep below 50HZ. I personally prefer DBV. That is flat without any roll off. At about 20HZ the difference is about 40 to 50 db. So at 20HZ a device with a -80DBA S/N could actually have only a S/N of -40 DBV. Since the DBA curve is supposed to be related to the sensitivity of our hearing that may not matter to most folks. I personally have the feeling that low frequency junk can alter the quality of the sound. I was really chagrin when I measured my pre-production tube phono preamps at -53DBV at 20HZ. The DBV for 300HZ and up was -93. A less scrupulous designer would say fine -53 DBV at 20 is about -90 DBA and let it go. Not my style. I thrashed it and made several changes so that at any frequency below 300HZ it was at -80DBV and still at -90 to -95 above that. Is it quiet....yes indeed. So my message is beware of specifications and know what they mean. I encourage folks to listen to devices and determine if they are suitable and pass on the numbers. Smile

Good Listening
Bruce

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[Message index]

		Trigger finger is itchy By: Rusty on Mon, 27 July 2020 12:53
		Re: Trigger finger is itchy By: Wayne Parham on Mon, 27 July 2020 13:14
		Re: Trigger finger is itchy By: gofar99 on Tue, 28 July 2020 21:40
		Re: Trigger finger is itchy By: Rusty on Wed, 29 July 2020 12:51
		Re: Trigger finger is itchy By: Wayne Parham on Wed, 29 July 2020 13:33
		Re: Trigger finger is itchy By: Rusty on Wed, 29 July 2020 19:30
		Re: Trigger finger is itchy By: gofar99 on Wed, 29 July 2020 20:27
		Re: Trigger finger is itchy By: Rusty on Sat, 15 August 2020 11:13
		Re: Trigger finger is itchy By: Wayne Parham on Sat, 15 August 2020 15:10
		Re: Trigger finger is itchy By: Rusty on Mon, 31 August 2020 16:02
		Re: Trigger finger is itchy By: Wayne Parham on Mon, 31 August 2020 17:33
		Re: Trigger finger is itchy By: johnnycamp5 on Tue, 01 September 2020 12:05
		Re: Trigger finger is itchy By: Rusty on Sun, 13 September 2020 15:07
		Re: Trigger finger is itchy By: Wayne Parham on Sun, 13 September 2020 16:29
		Re: Trigger finger is itchy By: johnnycamp5 on Mon, 05 October 2020 14:25
		Re: Trigger finger is itchy By: Rusty on Mon, 05 October 2020 15:59
		Re: Trigger finger is itchy By: johnnycamp5 on Mon, 05 October 2020 19:18
		Re: Trigger finger is itchy By: Rusty on Tue, 06 October 2020 15:36
		Re: Trigger finger is itchy By: gofar99 on Thu, 08 October 2020 21:46
		Re: Trigger finger is itchy By: Rusty on Fri, 09 October 2020 08:41
		Re: Trigger finger is itchy By: gofar99 on Fri, 09 October 2020 21:51
		Re: Trigger finger is itchy By: Wayne Parham on Sat, 10 October 2020 09:58
		Re: Trigger finger is itchy By: Rusty on Sat, 10 October 2020 12:12
		Re: Trigger finger is itchy By: Wayne Parham on Sat, 10 October 2020 15:25
		Re: Trigger finger is itchy By: Rusty on Fri, 23 October 2020 05:29
		Re: Trigger finger is itchy By: Rusty on Tue, 17 November 2020 14:59
		Re: Trigger finger is itchy By: Wayne Parham on Tue, 17 November 2020 15:10
		Re: Trigger finger is itchy By: johnnycamp5 on Thu, 19 November 2020 16:19
		Re: Trigger finger is itchy By: johnnycamp5 on Sun, 22 November 2020 18:33
		Re: Trigger finger is itchy By: Rusty on Mon, 23 November 2020 07:30
		Re: Trigger finger is itchy By: Rusty on Sun, 20 December 2020 13:56
		Re: Trigger finger is itchy By: johnnycamp5 on Mon, 21 December 2020 06:43
		Re: Trigger finger is itchy By: Rusty on Mon, 21 December 2020 11:57

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