... Could you provide a practical value and type for this cap? And would it have any influence on the Fq response? Thanks! Steve...
4805
Scott Helmke
scott_helmke
Dec 2, 2005 12:52 am
Umm.... 10pF, maybe? I actually haven't done this myself. A good film capacitor at 10pF will be both cheap and tiny, and that's the way many commercial mics...
4806
umashankar mantravadi
umashanks
Dec 2, 2005 1:40 pm
thanks for straightening up my rough and ready drawing. but what transformer are you using? (except in situations of extreme electrical noise, i prefer the...
4807
Rönnberg Niklas
nikroswe
Dec 2, 2005 3:18 pm
It's a Lundahl transformer, LL1659. http://www.lundahl.se/pdfs/datash/1659.pdf Actually I use LL1659 with center pin. I will update the schematic next week....
4808
poorlyconditioned
poorlycondit...
Dec 4, 2005 3:37 pm
I'm thinking of building a high-quality stereo preamp based on INA217 or INA103. I need to get a dual-sided (+-) supply out of a single 6-9VDC battery. The...
4809
Oswaldo Felipe
oswaldoayacuzo
Dec 4, 2005 10:41 pm
Hi! I have some doubts on the connection of the zener diode used in the phantom circuit . I am using TSB140. The first circuit that I constructed was...
4810
Scott Helmke
scott_helmke
Dec 5, 2005 12:34 am
Oswaldo, The zener diode does seem to be backwards, but that is correct. A zener diode is like a regular diode which "breaks down" at high voltage, but a ...
4811
Dominique M
ampgeek7
Dec 5, 2005 1:43 pm
... That's what I'm thinking about too, at the moment. I gathered some datasheets that I'll post some time later today, but I didn't try that voltage...
4812
Larry Nicks
larrynicks
Dec 5, 2005 4:09 pm
I've been trying to reach Eric for the past ten days and all of my emails seem to disappear into the ether. I wonder if he is OK. Larry...
4813
ebenj@...
ericbenjamin2
Dec 5, 2005 5:46 pm
Larry, Rumors of my demise have preceded the actual fact. To quote Little Bill Daggett: "Hell, even I thought I was dead 'til I found out it was just that I...
4815
scott@...
scott_helmke
Dec 5, 2005 8:15 pm
The wire is probably covered with lacquer or similar coating. Try using a flame to burn it off before testing and soldering. It's probably not shielded, which...
4816
Larry Nicks
larrynicks
Dec 5, 2005 8:55 pm
... was in ... I have ... my email ... exact moment ... favorite ... can't send ... to you. ... Hi Eric, Glad to hear you haven't fallen off the edge. Sorry...
4817
Dominique M
ampgeek7
Dec 5, 2005 11:48 pm
... Looking at the datasheets I gathered, I had to realize that those parts may not please you, on one hand, my project is lower voltage than yours, I plan to...
4818
nikroswe
Dec 6, 2005 4:02 pm
Hi! I have uploaded some files in my folder (Nikro). In the folder UEC-14AT you can find a microphone based on Scott Helmke's design with the UEC-14AT capsule....
4819
micbuilders@yahoogrou...
Dec 6, 2005 7:06 pm
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the micbuilders group. File :...
4820
poorlyconditioned
poorlycondit...
Dec 7, 2005 12:07 am
... Can you give some specs on the UEC-14AT element? Where did you get these? Thanks, Richard...
4821
Eric Benjamin
ericbenjamin2
Dec 7, 2005 12:33 am
Hi Richard, Great minds think alike. I was curious about that myself and searched around and found this: ...
4822
Scott Helmke
scott_helmke
Dec 7, 2005 12:40 am
... Hey, I think I've got a couple of those - I bought them while working in Norway last year. I'm not sure I've even tried hooking them up yet, though. ...
4823
luCa
lucazenari
Dec 7, 2005 9:06 pm
hi.
i'm building an "alice matched pair", i just select transistors with the same hfe measuring it with a cheap tester...
i'm using bf256 (fet for the...
4824
qw1209po
Dec 7, 2005 10:31 pm
... Found it in Canada: Mogami 2697 at 0.82 USD Need some lumber? ... Steve...
4825
Scott Helmke
scott_helmke
Dec 8, 2005 1:09 am
The resistor isn't strictly necessary - it just makes it quicker for the circuit to settle at the desired bias point. Maybe your noisy mic's FET needed a...
4826
luCa
lucazenari
Dec 8, 2005 2:16 am
thank you scott.
in my electronic shop said me that bf256 is equal to 2n4416...i don't know if the bias is the same...i'm not so good in elctronic theory......
4827
grp_viewer
Dec 8, 2005 8:59 pm
I have a need to know. Please email pointers (as in the msg # here of suggestions for doing this or a procedure that is well thought that does not equate to...
4828
Eric Benjamin
ericbenjamin2
Dec 8, 2005 10:36 pm
PC, Just a quick response to tide you over until I have a chance to write a longer one. The principle method for testing microphones is the substitution...
4829
p c
grp_viewer
Dec 8, 2005 11:46 pm
Thank you Eric for your response. Quite helpful actually. I have a reference mic, so that is not an issue. The issue is I have yet to do the step below with...
4830
Eric Benjamin
ericbenjamin2
Dec 9, 2005 1:34 am
I know what smaartPro is, but I haven't personally used it. So I don't know how easy it is to get the data out. So I'll describe the process using something...
4831
p c
grp_viewer
Dec 9, 2005 2:37 am
Wow, what a great resource you and this group already are to me. Thank you Eric! phil... "The goal is to live with godlike composure, on the full rush of...
4832
Richard Lee
ricardo_lee
Dec 9, 2005 8:47 pm
If I understand, you first tried to change the FETs, capsules & 1G resistor but there was no difference. Then you removed the 1G resistor and the noise went...
4833
Scott Helmke
scott_helmke
Dec 10, 2005 12:51 am
Well, I've never found a noisy 1gOhm resistor, but then I haven't actually looked for one. The noisy mics I've built have generally been fixed by replacing...
4834
luCa
lucazenari
Dec 10, 2005 2:07 pm
i tried to change the 1 giga resistor with another one that sounded good on another alice...
...no difference..so the problem is not the 1 giga res. i think....
