[Roy W. Rising[_2_]]

The Beyer M130 and M160 mics are "Dual Ribbon" types. How are the ribbons
configured? Thanks.

--
~
~ Roy
"If you notice the sound, it's wrong!"

[Scott Dorsey]

Roy W. Rising wrote:
The Beyer M130 and M160 mics are "Dual Ribbon" types. How are the ribbons
configured? Thanks.

There is a second ribbon _behind_ the first one. This changes the acoustical
loading and damping of the front ribbon, but because the ribbons are corrugated
in both vertical and horizontal directions (like RCAs) the damping is already
a little odd. It also means the magnet assembly needs to create constant
flux over more than twice the area that it would otherwise have to.

It's totally different than the crappy Chinese mikes that take two Wes
Dooley motors and fuse them side-by-side.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Roy W. Rising[_2_]]

(Scott Dorsey) wrote:
Roy W. Rising wrote:
The Beyer M130 and M160 mics are "Dual Ribbon" types. How are the
ribbons configured? Thanks.

There is a second ribbon _behind_ the first one. This changes the
acoustical loading and damping of the front ribbon, but because the
ribbons are corrugated in both vertical and horizontal directions (like
RCAs) the damping is already a little odd. It also means the magnet
assembly needs to create constant flux over more than twice the area that
it would otherwise have to.

It's totally different than the crappy Chinese mikes that take two Wes
Dooley motors and fuse them side-by-side.
--scott

Thanks, Scott. That's about what I'd imagined.

I've examined an RCA 77DX ribbon replaced by ENAK, only vertical
corrugations are evident. Can you enlarge on the horizontal aspect?

Creating constant flux over the larger area does not seem to be a problem,
given the attractively linear response.

--
~
~ Roy
"If you notice the sound, it's wrong!"

[hank alrich]

Roy W. Rising wrote:

(Scott Dorsey) wrote:
Roy W. Rising wrote:
The Beyer M130 and M160 mics are "Dual Ribbon" types. How are the
ribbons configured? Thanks.

There is a second ribbon _behind_ the first one. This changes the
acoustical loading and damping of the front ribbon, but because the
ribbons are corrugated in both vertical and horizontal directions (like
RCAs) the damping is already a little odd. It also means the magnet
assembly needs to create constant flux over more than twice the area that
it would otherwise have to.

It's totally different than the crappy Chinese mikes that take two Wes
Dooley motors and fuse them side-by-side.
--scott

Thanks, Scott. That's about what I'd imagined.

I've examined an RCA 77DX ribbon replaced by ENAK, only vertical
corrugations are evident. Can you enlarge on the horizontal aspect?

Creating constant flux over the larger area does not seem to be a problem,
given the attractively linear response.

Some folks consider their low sensitivity a "problem". It just means one
needs a capable preamp.

--
ha
Iraq is Arabic for Vietnam

[Ty Ford]

On Thu, 10 Jul 2008 01:54:53 -0400, hank alrich wrote
(in article ):

Roy W. Rising wrote:

(Scott Dorsey) wrote:
Roy W. Rising wrote:
The Beyer M130 and M160 mics are "Dual Ribbon" types. How are the
ribbons configured? Thanks.

There is a second ribbon _behind_ the first one. This changes the
acoustical loading and damping of the front ribbon, but because the
ribbons are corrugated in both vertical and horizontal directions (like
RCAs) the damping is already a little odd. It also means the magnet
assembly needs to create constant flux over more than twice the area that
it would otherwise have to.

It's totally different than the crappy Chinese mikes that take two Wes
Dooley motors and fuse them side-by-side.
--scott

Thanks, Scott. That's about what I'd imagined.

I've examined an RCA 77DX ribbon replaced by ENAK, only vertical
corrugations are evident. Can you enlarge on the horizontal aspect?

Creating constant flux over the larger area does not seem to be a problem,
given the attractively linear response.

Some folks consider their low sensitivity a "problem". It just means one
needs a capable preamp.


To which I will add, get an AEA TRP preamp from Wes Dooley. In addition to
what I hear on the R84, I'm hearing more from my M160 and 77DX with the TRP.

Wes did a nice job on that preamp.

Regards,

Ty Ford





--Audio Equipment Reviews Audio Production Services
Acting and Voiceover Demos http://www.tyford.com
Guitar player?:http://www.youtube.com/watch?v=4RZJ9MptZmU

[Scott Dorsey]

Roy W. Rising wrote:

Thanks, Scott. That's about what I'd imagined.

I've examined an RCA 77DX ribbon replaced by ENAK, only vertical
corrugations are evident. Can you enlarge on the horizontal aspect?

Err... I mean the corrugations on those mikes are perpendicular to the
ribbon.

On the Beyer, there are corrugations in both directions, and some diagonal
ones. They appear to be corrugated with a die rather than being run through
coarse gears.

Creating constant flux over the larger area does not seem to be a problem,
given the attractively linear response.

Well, the other trick is that the Beyers have very high ribbon tension
compared with the old RCAs, so the ribbon doesn't actually move so much.
This reduces the amount of area over which the flux needs to stay constant.
They are very impressive designs.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Roy W. Rising[_2_]]

(hank alrich) wrote:
[snip]

Some folks consider their low sensitivity a "problem". It just means one
needs a capable preamp.

Here's an example of a Beyer M160 with a "capable" preamp. In this case
it was a McCurdy AT242 easily handling the output of a boom-mounted M160.
The orchestra was mic'd with EV RE15s, I used a Neumann U67 for the choir.

http://www.youtube.com/watch?v=bsGm-DqbmSA

--
~
~ Roy
"If you notice the sound, it's wrong!"

[Paul Stamler]

"Ty Ford" wrote in message
. ..
Some folks consider their low sensitivity a "problem". It just means one
needs a capable preamp.


To which I will add, get an AEA TRP preamp from Wes Dooley. In addition to
what I hear on the R84, I'm hearing more from my M160 and 77DX with the
TRP.

Wes did a nice job on that preamp.

Correct me if I'm wrong, but I believe the preamp was designed by Fred
Forssell, working under contract to AEA. Whomever, it's a nice job for sure.

Peace,
Paul

[Scott Dorsey]

Paul Stamler wrote:
"Ty Ford" wrote in message
...
Some folks consider their low sensitivity a "problem". It just means one
needs a capable preamp.


To which I will add, get an AEA TRP preamp from Wes Dooley. In addition to
what I hear on the R84, I'm hearing more from my M160 and 77DX with the
TRP.

Wes did a nice job on that preamp.

Correct me if I'm wrong, but I believe the preamp was designed by Fred
Forssell, working under contract to AEA. Whomever, it's a nice job for sure.

It is indeed. And the concept of high-Z loading of ribbon mikes is actually
due to Jon Sank. But it took Wes Dooley to redescover it and to get Fred
Forssell to design a box for him.

It really is a nice job. It's like having a completely different set of
microphones.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Roy W. Rising[_2_]]

(Scott Dorsey) wrote:
Paul Stamler wrote:
[snip]
Correct me if I'm wrong, but I believe the preamp was designed by Fred
Forssell, working under contract to AEA. Whomever, it's a nice job for
sure.

It is indeed. And the concept of high-Z loading of ribbon mikes is
actually due to Jon Sank. But it took Wes Dooley to redescover it and to
get Fred Forssell to design a box for him.

It really is a nice job. It's like having a completely different set of
microphones.
--scott

The idea of non-loading ribbon mics predates Jon Sank's tour with RCA
beginning in 1960. The gents who designed and built TV and Radio audio
facilities in the 1940s and 1950s held to the rule that the *actual* mic
pre input impedance must be 2000 ohms or greater, to avoid loading ribbon
mics. Tube preamps fed the secondary of the input transformer directly to
the grid of the first stage, which was very high impedance.

The Dooley TRPs use new technology to deliver an input impedance greater
than 30K ohms. No wonder ribbon mics love them!

--
~
~ Roy
"If you notice the sound, it's wrong!"

[Roy W. Rising[_2_]]

(Scott Dorsey) wrote:
Roy W. Rising wrote:

Thanks, Scott. That's about what I'd imagined.

I've examined an RCA 77DX ribbon replaced by ENAK, only vertical
corrugations are evident. Can you enlarge on the horizontal aspect?

Err... I mean the corrugations on those mikes are perpendicular to the
ribbon.

On the Beyer, there are corrugations in both directions, and some
diagonal ones. They appear to be corrugated with a die rather than being
run through coarse gears.

Creating constant flux over the larger area does not seem to be a
problem, given the attractively linear response.

Well, the other trick is that the Beyers have very high ribbon tension
compared with the old RCAs, so the ribbon doesn't actually move so much.
This reduces the amount of area over which the flux needs to stay
constant. They are very impressive designs.
--scott

So ... what happens to the performance when Steve Sank re-ribbons one with
an RCA 77DX type of ribbon?

Also, aren't the very short ribbons of the Beyers likely to be more
accurate than the 2" giants found in Royers and others? It would seem
similar to the large vs. small diaphragm issue among condenser mics.

--
~
~ Roy
"If you notice the sound, it's wrong!"

[Mike Rivers]

Roy W. Rising wrote:

So ... what happens to the performance when Steve Sank re-ribbons one with
an RCA 77DX type of ribbon?

I have a Mackie 800R preamp with a couple of channels that have
adjustable input impedance. I like the sound of my M260DX btter at the
highest impedance setting (2400 ohms) than at any of the lower impedance
settings. I haven't tried it into a TRP though.

--
If you e-mail me and it bounces, use your secret decoder ring and reach
me he
double-m-eleven-double-zero at yahoo -- I'm really Mike Rivers
)

[Scott Dorsey]

Roy W. Rising wrote:

So ... what happens to the performance when Steve Sank re-ribbons one with
an RCA 77DX type of ribbon?

It is totally changed, and it sounds a lot more like a 77DX than a Beyer.
Whether this is a good thing or a bad thing depends on your point of view.
I already have plenty of 77s in the closet and I don't need any more.

Also, aren't the very short ribbons of the Beyers likely to be more
accurate than the 2" giants found in Royers and others? It would seem
similar to the large vs. small diaphragm issue among condenser mics.

Absolutely. The Royers are funny, though... they are also under very high
tension. But the top end on the Beyer and Royer mikes is going to be better
than anything RCA ever made (even the BK-11, which is a hard thing to beat),
specifically because of the ribbon size and tension.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Richard Kuschel]

On Jul 10, 6:10 am, Ty Ford wrote:
On Thu, 10 Jul 2008 01:54:53 -0400, hank alrich wrote
(in article ):



Roy W. Rising wrote:

(Scott Dorsey) wrote:
Roy W. Rising wrote:
The Beyer M130 and M160 mics are "Dual Ribbon" types. How are the
ribbons configured? Thanks.

There is a second ribbon _behind_ the first one. This changes the
acoustical loading and damping of the front ribbon, but because the
ribbons are corrugated in both vertical and horizontal directions (like
RCAs) the damping is already a little odd. It also means the magnet
assembly needs to create constant flux over more than twice the area that
it would otherwise have to.

It's totally different than the crappy Chinese mikes that take two Wes
Dooley motors and fuse them side-by-side.
--scott

Thanks, Scott. That's about what I'd imagined.

I've examined an RCA 77DX ribbon replaced by ENAK, only vertical
corrugations are evident. Can you enlarge on the horizontal aspect?

Creating constant flux over the larger area does not seem to be a problem,
given the attractively linear response.

Some folks consider their low sensitivity a "problem". It just means one
needs a capable preamp.

To which I will add, get an AEA TRP preamp from Wes Dooley. In addition to
what I hear on the R84, I'm hearing more from my M160 and 77DX with the TRP.

Wes did a nice job on that preamp.

Regards,

Ty Ford

--Audio Equipment Reviews Audio Production Services
Acting and Voiceover Demoshttp://www.tyford.com
Guitar player?:http://www.youtube.com/watch?v=4RZJ9MptZmU

I just demo'd one of the AEA TRP preamps yesterday and i was blown
away by it! I have never had enough gain for a decent ribbon mic. Now
to save a few dollars and get one!

[Scott Dorsey]

Roy W. Rising wrote:
Kludge wrote:
It is indeed. And the concept of high-Z loading of ribbon mikes is
actually due to Jon Sank. But it took Wes Dooley to redescover it and to
get Fred Forssell to design a box for him.

The idea of non-loading ribbon mics predates Jon Sank's tour with RCA
beginning in 1960. The gents who designed and built TV and Radio audio
facilities in the 1940s and 1950s held to the rule that the *actual* mic
pre input impedance must be 2000 ohms or greater, to avoid loading ribbon
mics. Tube preamps fed the secondary of the input transformer directly to
the grid of the first stage, which was very high impedance.

See, in the seventies, I was told by many people that the important thing
was to make sure the ribbon mikes were loaded enough, and that they had
a somewhat inductive load. I was told (and it seemed common wisdom at
the time) that the microphones were designed to go into step-up transformers
with an almost-open secondary, and so they were voiced to give proper
response with the parasitic load of a typical primary.

This seems perfectly reasonable on the face of it, but it also turns out
to be totally wrong. The first I ever heard of it being wrong was a paper
by Sank in which he specifically says the mikes will perform better into
an open load. There may be some earlier reference to this, and if so I
would love to see it.

The Dooley TRPs use new technology to deliver an input impedance greater
than 30K ohms. No wonder ribbon mics love them!

Makes me think about what a transformerless tube input would do, if you
could get the thermal noise down enough.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Mike Rivers]

Scott Dorsey wrote:

Makes me think about what a transformerless tube input would do, if you
could get the thermal noise down enough.

James Boyk, the "there's stuff above 20 kHz worth recording" guy from
CalTech, wrote about removing the input transformer from his toob Ampex
mic preamps and getting great sound from his ribbon mics.


--
If you e-mail me and it bounces, use your secret decoder ring and reach
me he
double-m-eleven-double-zero at yahoo -- I'm really Mike Rivers
)

[Richard Crowley]

"Mike Rivers" wrote ...
Scott Dorsey wrote:
Makes me think about what a transformerless tube input would do, if you
could get the thermal noise down enough.

James Boyk, the "there's stuff above 20 kHz worth recording" guy from
CalTech, wrote about removing the input transformer from his toob Ampex
mic preamps and getting great sound from his ribbon mics.

Maybe that is more a reflection on the quality of the mic
transformers they put into that stuff.

[Roy W. Rising[_2_]]

(Scott Dorsey) wrote:
Roy W. Rising wrote:
Kludge wrote:
It is indeed. And the concept of high-Z loading of ribbon mikes is
actually due to Jon Sank. But it took Wes Dooley to redescover it and
to get Fred Forssell to design a box for him.

The idea of non-loading ribbon mics predates Jon Sank's tour with RCA
beginning in 1960. The gents who designed and built TV and Radio audio
facilities in the 1940s and 1950s held to the rule that the *actual* mic
pre input impedance must be 2000 ohms or greater, to avoid loading
ribbon mics. Tube preamps fed the secondary of the input transformer
directly to the grid of the first stage, which was very high impedance.

See, in the seventies, I was told by many people that the important thing
was to make sure the ribbon mikes were loaded enough, and that they had
a somewhat inductive load. I was told (and it seemed common wisdom at
the time) that the microphones were designed to go into step-up
transformers with an almost-open secondary, and so they were voiced to
give proper response with the parasitic load of a typical primary.

This seems perfectly reasonable on the face of it, but it also turns out
to be totally wrong. The first I ever heard of it being wrong was a
paper by Sank in which he specifically says the mikes will perform better
into an open load. There may be some earlier reference to this, and if
so I would love to see it.

The Dooley TRPs use new technology to deliver an input impedance greater
than 30K ohms. No wonder ribbon mics love them!

Makes me think about what a transformerless tube input would do, if you
could get the thermal noise down enough.
--scott

Although he does not directly address this with regard to ribbon mics,
Howard M. Tremaine touches on it in his Audio Cyclopedia (Second Edition,
1969) wherein he discusses mic loading. ["What effect does the terminating
impedance have on microphone characteristics?" 4.76 pp 188-9]

--
~
~ Roy
"If you notice the sound, it's wrong!"

[Chris Hornbeck]

On Fri, 11 Jul 2008 17:32:10 -0700, "Richard Crowley"
wrote:

"Mike Rivers" wrote ...
Scott Dorsey wrote:
Makes me think about what a transformerless tube input would do, if you
could get the thermal noise down enough.

James Boyk, the "there's stuff above 20 kHz worth recording" guy from
CalTech, wrote about removing the input transformer from his toob Ampex
mic preamps and getting great sound from his ribbon mics.

Maybe that is more a reflection on the quality of the mic
transformers they put into that stuff.

Goes without saying that high-ratio transformers are tricky
and problematical. The mic pretty much has to have one inside
itself to get up from the mouse-fart level of the "winding" to
something passable as "mic level". Turns ratios in the big 10's
to small 100's are expected - very, very tough gig.

Then, a mic preamp's input might include another one, smaller
ratio, for noise matching. Lotsa iron if the goal is hi-fi.

A few years back, when I was first introduced to this
newsgroup, and the topic arose, I did a calculation for
how many parallel 12AX7's it would require, per mic, and
with no "excess noise", to get a 1dB noise figure from a
Coles straight off the ribbon. My memory without looking
was 576 triode sections, or half that number of tubes.

Could definitely be done, but 12AX7's wouldn't be the
best valve choice. Arf.

OTOH, a much smaller number of the Toshiba large geometry
FET's (2SK146/2SJ72, IIRC) can definitely do the gig. A
MegOhm input is easy.


My theory, "and what it is too", is that the fundamental
resonance of the ribbon falls into (very low, but) the audio
range and can't be damped by loading without incurring
large frequency response variations. But then, my first
question to all physical issues is to look at the two-pole
resonances. World's full of 'em and almost *all* seem to
matter to us sound guys.


Much thanks, as always,
Chris Hornbeck

[Scott Dorsey]

Mike Rivers wrote:
Scott Dorsey wrote:

Makes me think about what a transformerless tube input would do, if you
could get the thermal noise down enough.

James Boyk, the "there's stuff above 20 kHz worth recording" guy from
CalTech, wrote about removing the input transformer from his toob Ampex
mic preamps and getting great sound from his ribbon mics.

I am sure, but I bet he got a lot of hiss too...
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Mike Rivers]

Scott Dorsey wrote:

I am sure, but I bet he got a lot of hiss too...

Well, he was recording to analog tape, even though it may have been with
the Magnesaurus.

--
If you e-mail me and it bounces, use your secret decoder ring and reach
me he
double-m-eleven-double-zero at yahoo -- I'm really Mike Rivers
)

[[email protected]]

On 2008-07-11 (ScottDorsey) said:
James Boyk, the "there's stuff above 20 kHz worth recording" guy
from CalTech, wrote about removing the input transformer from his
toob Ampex mic preamps and getting great sound from his ribbon
mics.
NOw there's a name I hadn't even seen when last reading the
pro-audio reflector a year or so ago when I was still
reading there.

I am sure, but I bet he got a lot of hiss too...
Yah but if he's recording a brass section or something like
that possibly the signal source would overcome it g.





Richard webb,
replace anything before at with elspider