I have the (perceived) problem that the volume from my head-set headphones is much lower than the equivalent speaker volume. I'm using a Danmike head-set (32 Ohm, 97dB @ 1mW (IEC 318)) Is there any w
I have an Orion with the same problem. I think it is common to the Orion & Orion II with low-Z phones. 73, Duane AC5AA --Original Message-- I have the (perceived) problem that the volume from my head
Author: "Jim Brown K9YC" <k9yc@audiosystemsgroup.com>
Date: Fri, 28 Aug 2009 08:56:39 -0700
Most output stages used to drive headphones are really small power amplifiers, and have rather low impedance. For these output stages, the lower the impedance of headphones, the more current they wil
This is a well-documented problem in the Orion II that has to do with a different attenuator/chip scheme between the speaker circuit and headphone circuit. It's not impedance related, although large
Use higher impedance headphones, they are more sensitive. Stuart K5KVH _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/li
Author: "Jim Brown K9YC" <k9yc@audiosystemsgroup.com>
Date: Fri, 28 Aug 2009 22:57:59 -0700
No. In terms of voltage sensitivity, it's exactly the opposite. 73, Jim K9YC _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mail
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 29 Aug 2009 09:57:55 -0600
Not at all necessarily. The original post said 97DB/milliwatt, which shows high power sensitivity. Higher impedance will just raise the required voltage, though if the driver has a large series resis
The headphone output IC in the OII is a stereo IC LM4811. I measured about 2.75 ohms output impedance at the headphone jack before I installed the RF filter . The RF filter in later OII's and the boa
Hank: It would interesting to see the difference in output levels to the phones with the new firmware. It's definitely louder, but I haven't measured how much. Ron N6IE www.N6IE.com _________________
Author: "Jim Brown K9YC" <k9yc@audiosystemsgroup.com>
Date: Sat, 29 Aug 2009 22:05:47 -0700
Thanks for the detailed analysis, Hank. That's pretty much what I expected. Consider the output stage a constant voltage source with 27 ohms in series. In general, output stages don't want to be heav
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 30 Aug 2009 10:48:27 -0600
27 ohms Z with 32 ohm phones cuts the available power by a factor of 4. 6 dB. When the headphones are weak already, that's a serious drop. There might be a need for old fashioned, non tiny inductors
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 30 Aug 2009 11:05:41 -0600
Like a pair of RS 277-1008 or single 55021916 or single 33-118 or others from other sources. The first ones you'd have to make a custom cable, the rest just plug in. A sound card external speaker pow
Author: "Jim Brown K9YC" <k9yc@audiosystemsgroup.com>
Date: Sun, 30 Aug 2009 11:19:15 -0700
This is crazy unless the user has very severe hearing loss. There is no good reason the existing output stage shouldn't work just fine with enough GAIN in the audio chain and headphones of reasonable
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 30 Aug 2009 12:58:55 -0600
True. But in the absence of a firmware fix, a $30 amplifier can solve the problem in a couple days. 73, Jerry, K0CQ _______________________________________________ TenTec mailing list TenTec@contesti
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 30 Aug 2009 12:59:14 -0600
True. But in the absence of a firmware fix, a $30 amplifier can solve the problem in a couple days. 73, Jerry, K0CQ _______________________________________________ TenTec mailing list TenTec@contesti
Author: "Jim Brown K9YC" <k9yc@audiosystemsgroup.com>
Date: Sun, 30 Aug 2009 12:23:58 -0700
Lemme see if I understand this. I should spend a week finding and buying parts, making a circuit board, putting it into some kind of reasonable package, designing and testing it, all because the manu
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 30 Aug 2009 13:58:41 -0600
Naw, its not that hard. Go to the RS page on line, search for a head phone amplifier and pick from those numbers I gave for a module ready to plug into the head phone jack and ready for the head phon
Yep - for the phones - different strokes for different folks - they like it better that way - and other than losing the stereo or main sub separation it works just fine , and covers the "slurp/echo
Author: "Jim Brown K9YC" <k9yc@audiosystemsgroup.com>
Date: Sun, 30 Aug 2009 14:44:38 -0700
That's the point. Jim _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/tentec
Jim Brown K9YC skrev: So allow me to sum it up: A) Others are experiencing the same problem; B)There's no user accessible adjustment available; and C) It's really something that TT should fix in the