The Opposite Of A 10db Pad
 

"Ian Bell" wrote in message
...
It does make a note about
selecting the right position for the mic type switch which appears to
provide power for suitable electret types. If your mic has a built in
battery then I would recommend setting this switch to the dyn position to
avoid sending power to it.

Interesting. Since the 66B is, so far as I know, a condenser (it certainly
has an internal double AA battery driving it), I just assumed I should set
the R-1 to Condenser rather than Dynamic. But that sounds like an
interesting idea so I'll try it. Thanks.

Cheers,

Charles

The Opposite Of A 10db Pad
 

"Charles H. Riggs, III" wrote in message
...
Interesting. Since the 66B is, so far as I know, a condenser (it
certainly
has an internal double AA battery driving it), I just assumed I should set
the R-1 to Condenser rather than Dynamic. But that sounds like an
interesting idea so I'll try it. Thanks.

I've tried it. I don't have test tones or anything like that to drive it,
but I believe I am getting a slightly higher level, so I'll try it in a for
real situation and see whether it gains me something. Thanks again for the
suggestion.

Cheers,

Charles

The Opposite Of A 10db Pad
 

Charles H. Riggs, III wrote:

"Charles H. Riggs, III" wrote in message
...
Interesting. Since the 66B is, so far as I know, a condenser (it
certainly
has an internal double AA battery driving it), I just assumed I should
set
the R-1 to Condenser rather than Dynamic. But that sounds like an
interesting idea so I'll try it. Thanks.

I've tried it. I don't have test tones or anything like that to drive it,
but I believe I am getting a slightly higher level, so I'll try it in a
for
real situation and see whether it gains me something. Thanks again for
the suggestion.

Cheers,

Charles

My pleasure. One thing to note is that your mic probably has an AC coupled
output via an electroltytic capacitor. If the electret setting send a
voltage to the mike is may just possibly have done some damage to this.
Unlikely but possible nonetheless.

Ian
--
Ian Bell

The Opposite Of A 10db Pad
 

In article ,
"Charles H. Riggs, III" wrote:
An ECM 66 is a DIN output standard mic, so it's unlikely it's the
problem. Although I don't know your recorder. How is it connected to
it?

The ECM 66B has a male XLR connector (you probably knew that!). I'm
using a Shure transformer to convert to a male mini stereophone plug to
accomodate the R-1's mic input.

Ah. Wonder if this transformer is high impedance mic to low impedance
input matcher?

If so, this accounts for the level loss as the mic is a low impedance one.

You need a simple XLR to jack adaptor, not transformer.

P.S. By the way, I gave the ECM66B a healthy knock against a cardboard
box within minutes of bringing the brand new mike home with me. Could
that have damaged it and affected its output level?

They tend to get a fair bit of abuse in my hands and survive. ;-)

With this type of mic, the cable is usually the first thing to go.

--
*A hangover is the wrath of grapes.

Dave Plowman London SW
To e-mail, change noise into sound.

The Opposite Of A 10db Pad. It's a 10dB Dab!
 

In article ,
Jim Gregory wrote:
Ah, a xformer! If it is not a 1:1 ratio (used merely for isolation), I
hope the *low* side of the given ratio of your device is used at the
*mic* end (ergo it steps up into channel i/p). So if it's about 1:3.2,
can we rename it a 10dB Dab?

If it is a transformer, I'd guess it's for matching a high impedance
dynamic mic (Shure make these) to a low impedance input.

Or, indeed, the other way round.

Something like 7:1.

--
*Remember not to forget that which you do not need to know.*

Dave Plowman London SW
To e-mail, change noise into sound.

The Opposite Of A 10db Pad
 

"Dave Plowman (News)" wrote in message
...
"Charles H. Riggs, III" wrote:
The ECM 66B has a male XLR connector (you probably knew that!). I'm
using a Shure transformer to convert to a male mini stereophone plug to
accomodate the R-1's mic input.

Ah. Wonder if this transformer is high impedance mic to low impedance
input matcher?
If so, this accounts for the level loss as the mic is a low impedance one.
You need a simple XLR to jack adaptor, not transformer.

Hmmm. According to B & H, where I purchased this mike, this is what Sony
recommends to convert an XLR to a stereo miniphone. It's called a Shure
A96F Line Matching Transformer. Since it's called Line Matching, does that
mean it is NOT an impedance conversion thingy? I'm not very familiar with
all this terminology (obviously!).

Cheers,

Charles

P.S. By the way, I fed this mike, followed by another mike, into one of my
DAT recorders and the levels were the SAME (using the same transformer).
That would appear to indicate that the problem is with the level inside of
the R-1, not the level coming out of the mike into the device.

The Opposite Of A 10db Pad
 

In article ,
"Charles H. Riggs, III" wrote:
Hmmm. According to B & H, where I purchased this mike, this is what
Sony recommends to convert an XLR to a stereo miniphone. It's called a
Shure A96F Line Matching Transformer. Since it's called Line Matching,
does that mean it is NOT an impedance conversion thingy? I'm not very
familiar with all this terminology (obviously!).

Looking at :-

http://www.shuredistribution.co.uk/s...ssories_23.htm

it suggests this is a convertor from XLR to *mono* mini-jack. How many
rings does the jack end have?

P.S. By the way, I fed this mike, followed by another mike, into one of
my DAT recorders and the levels were the SAME (using the same
transformer). That would appear to indicate that the problem is with the
level inside of the R-1, not the level coming out of the mike into the
device.

I've not seen a dat with a stereo mini jack input - although I have seen
one on a MiniDisc.

--
*He who laughs last, thinks slowest.

Dave Plowman London SW
To e-mail, change noise into sound.

The Opposite Of A 10db Pad
 

"Dave Plowman (News)" wrote in message
...
Looking at :-
http://www.shuredistribution.co.uk/s...ssories_23.htm
it suggests this is a convertor from XLR to *mono* mini-jack. How many
rings does the jack end have?

It has two all right.

I've not seen a dat with a stereo mini jack input - although I have seen
one on a MiniDisc.

This is a Sony TCD-D8 Walkman.

Cheers,

Charles

The Opposite Of A 10dB Pad - 1:3 tranny
 

*Repeating my rec.audio.tech post reply for this NewsGroup*

Plenty of probably Taiwanese step-up transformers, eg, in line 1/4" to 1/4"
or inline XLR barrel to 1/4" here for about $12.
Try Maplin for the latter
http://www.maplin.co.uk/Module.aspx?...TabID=1&source

The Opposite Of A 10dB Pad - 1:3 tranny
 

"Jim Gregory" wrote in message
...
*Repeating my rec.audio.tech post reply for this NewsGroup*

Plenty of probably Taiwanese step-up transformers, eg, in line 1/4" to
1/4"
or inline XLR barrel to 1/4" here for about $12.
Try Maplin for the latter
http://www.maplin.co.uk/Module.aspx?...TabID=1&source



It has been interesting reading this thread and some of the replies
considering the header title "The Opposite Of A 10dB Pad".

A pad is an attenuator - a device that reduces the power level of a signal.
In this case in an impedance matched circuit a 10dB pad would result in a
x10 power loss. So the opposite of a loss is a gain - hey? So would not
10dB of amplification be the answer?

Many have suggested using a transformer. Transformers do not give you a
power gain. If anything, the average transformer may introduce a loss of
0.3dB or possibly more.

Transformers are impedance or voltage conversion devices not amplifiers or
gain devices as it appears to the common misconception in this thread.

If the input to the mixer / amplifier / recorder is high impedance (say
10kohms) and the microphone is a low impedance source (say 600 ohms) then a
step up transformer will solve the problem of low output voltage level.

The Sony ECM-66B has a balanced output impedance of 100 ohms @1kHz.
The Eridol R1 has an unbalanced microphone input impedance of 6.8kohms with
a sensitivity of -10dBu (~345mV) which is quite a high voltage level for a
microphone IMHO.

An impedance matching transformer with a 1:68 impedance transformation ratio
would be ideal and provide more than enough voltage increase to overcome the
problem. Now all that is required is to source a suitable unit.


Not perfect but and inexpensive DIY solution :

If you are handy with a soldering iron (or know someone who is) and want
make a unit for yourself a 600 ohms to 10 kohms tapped microphone
transformer can be found here -
http://www.altronics.com.au/index.as...=item&id=M0705 Specs exceed the
microphone's capability.

Connect your microphone across the red and green wires (600 ohm side) and
the yellow and blue wires (10 kohm side) to the microphone input on the R1.
This should give you a healthy voltage increase. If you need more output
voltage try connecting the microphone across the red and black wires (300
ohm winding).

XLR sockets and 1/8" line jacks can be obtained form the same source as well
as suitable shielded cable and a neat little box to put it all in.

Cheers,
Alan