B&O BM5 Stereo Ribbon Microphone

[Rick Ruskin]

Selling on behalf of a friend. The mic is perfect working order, was
lightly used, and always stored upright in a custom-built case. It has
a custom-machined stand mount and original cable. He's asking
$1000.00 + any shipping/insurance but will cosider serious offers.

Direct contact:

[George Graves]

On Saturday, September 28, 2013 2:09:58 PM UTC-7, Rick Ruskin wrote:
> Selling on behalf of a friend. The mic is perfect working order, was
>
> lightly used, and always stored upright in a custom-built case. It has
>
> a custom-machined stand mount and original cable. He's asking
>
> $1000.00 + any shipping/insurance but will cosider serious offers.
>
>
>
> Direct contact:

I had one of these once. It sounded marvelous, with excellent bass and a very clean midrange. As far as I could see, it had only two drawbacks. (1) it needed a LOT of gain. And in those days, that gain, without noise, was difficult to come by. Today, probably, not so much. (2) it's high-end frequency response was limited to 13 KH, so the top was very soft. I remember that it was a great chorus mike and it is a beauteous thing to behold!

[Peter Larsen[_3_]]

George Graves wrote:

> On Saturday, September 28, 2013 2:09:58 PM UTC-7, Rick Ruskin wrote:

>> Selling on behalf of a friend. The mic is perfect working order, was
>> lightly used, and always stored upright in a custom-built case. It
>> has a custom-machined stand mount and original cable. He's asking
>> $1000.00 + any shipping/insurance but will cosider serious offers.

I paid DKK 250 for mine.

>> Direct contact:

> I had one of these once. It sounded marvelous, with excellent bass
> and a very clean midrange. As far as I could see, it had only two
> drawbacks. (1) it needed a LOT of gain. And in those days, that gain,
> without noise, was difficult to come by.

Not at all, it was designed for use with the Beocord 2000-series transformer
balanced input.

> Today, probably, not so
> much.

> (2) it's high-end frequency response was limited to 13 KH, so
> the top was very soft.

You are so very polite, I'd say 10.

> I remember that it was a great chorus mike and
> it is a beauteous thing to behold!

It is blast sensitive beyond belief, but great for vox at 5 feet and
probably also for brassband as MS and it might be just the thing as drum or
piano sans lid overhead.

Kind regards

Peter Larsen

[George Graves]

On Monday, September 30, 2013 12:13:26 AM UTC-7, Peter Larsen wrote:
> George Graves wrote:
>
>
>
> > On Saturday, September 28, 2013 2:09:58 PM UTC-7, Rick Ruskin wrote:
>
>
>
> >> Selling on behalf of a friend. The mic is perfect working order, was
>
> >> lightly used, and always stored upright in a custom-built case. It
>
> >> has a custom-machined stand mount and original cable. He's asking
>
> >> $1000.00 + any shipping/insurance but will cosider serious offers.
>
>
>
> I paid DKK 250 for mine.
>
>
>
> >> Direct contact:
>
>
>
> > I had one of these once. It sounded marvelous, with excellent bass
>
> > and a very clean midrange. As far as I could see, it had only two
>
> > drawbacks. (1) it needed a LOT of gain. And in those days, that gain,
>
> > without noise, was difficult to come by.
>
>
>
> Not at all, it was designed for use with the Beocord 2000-series transformer
>
> balanced input.

I found it impossible to find a correct transformer for it. B&O obviously had one
installed in their Beocord 2000, but here in the 'States, I couldn't find any transformers
for sale that had the required specs. As I recall, one transformer company with whom I
spoke said that they could wind me a custom pair, but it would have been prohibitively
expensive. I tried to build one using op-amps. While that could be done today, in the
1970's when I owned the mike, asking for that much gain out of even the quietest of
op-amps was an invitation to a waterfall of hiss.
>
>
>
> > Today, probably, not so
>
> > much.
>
>
>
> > (2) it's high-end frequency response was limited to 13 KH, so
>
> > the top was very soft.
>
>
>
> You are so very polite, I'd say 10.

I was merely quoting B&O's published specs as I remember them.


> > I remember that it was a great chorus mike and
>
> > it is a beauteous thing to behold!
>
>
>
> It is blast sensitive beyond belief, but great for vox at 5 feet and
>
> probably also for brassband as MS and it might be just the thing as drum or
>
> piano sans lid overhead.

Yeah, ribbon mikes can be like that. OK for a chorus where the voices are some
distance away, but I wouldn't put it anywhere near a brass instruments bell or a
solo singer's mouth! For piano, it sounded nice, but was a bit dull as I remember.
I still have a nice solo classical guitar recording I made with the thing. That
sounds nice.

Regards,
George Graves

[Peter Larsen[_3_]]

George Graves wrote:

> I found it impossible to find a correct transformer for it.

Joergen Schou probably manufactured one, anyway I went a different route and
built a preamp for mine using a hitachi mc-preamp chip - my memory insists
that it was a 12017 - worked - and presumeably works - reasonably well,
except for some touch-hum on the upper mic, probably caused by the bal-unbal
conversion.

>> It is blast sensitive beyond belief, but great for vox at 5 feet and
>> probably also for brassband as MS and it might be just the thing as
>> drum or piano sans lid overhead.

> Yeah, ribbon mikes can be like that. OK for a chorus where the voices
> are some distance away, but I wouldn't put it anywhere near a brass
> instruments bell or a solo singer's mouth!

Its purpose in life - as I understand it - is to be a main pair on an
ensemble.

> For piano, it sounded nice, but was a bit dull
> as I remember. I still have a nice solo classical guitar
> recording I made with the thing. That sounds nice.

I haven't had an occasion that was suitable for running it in parallel with
another setup .... even though that was what I built the preamp for.

> Regards,
> George Graves

Kind regards

Peter Larsen

[George Graves]

In article >,
"Peter Larsen" > wrote:

> George Graves wrote:
>
> > I found it impossible to find a correct transformer for it.
>
> Joergen Schou probably manufactured one, anyway I went a different route and
> built a preamp for mine using a hitachi mc-preamp chip - my memory insists
> that it was a 12017 - worked - and presumeably works - reasonably well,
> except for some touch-hum on the upper mic, probably caused by the bal-unbal
> conversion.

In the mid 1970's chips like this didn't exist. A 741 was a "high-performance" OP-Amp.

Kind Regards,
George Graves

[Scott Dorsey]

George Graves > wrote:
>In article >,
> "Peter Larsen" > wrote:
>
>> George Graves wrote:
>>
>> > I found it impossible to find a correct transformer for it.
>>
>> Joergen Schou probably manufactured one, anyway I went a different route and
>> built a preamp for mine using a hitachi mc-preamp chip - my memory insists
>> that it was a 12017 - worked - and presumeably works - reasonably well,
>> except for some touch-hum on the upper mic, probably caused by the bal-unbal
>> conversion.
>
>In the mid 1970's chips like this didn't exist. A 741 was a "high-performance" OP-Amp.

In the mid-1970's, the MAT-03 and MAT-06 transistor arrays were the solution
to that particular problem. These days the THAT arrays more or less have
that same market wrapped up.

But there's still something to be said for a step-up transformer and a 6AU6...
--scott

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

[George Graves]

In article >,
(Scott Dorsey) wrote:

> George Graves > wrote:
> >In article >,
> > "Peter Larsen" > wrote:
> >
> >> George Graves wrote:
> >>
> >> > I found it impossible to find a correct transformer for it.
> >>
> >> Joergen Schou probably manufactured one, anyway I went a different route
> >> and
> >> built a preamp for mine using a hitachi mc-preamp chip - my memory insists
> >> that it was a 12017 - worked - and presumeably works - reasonably well,
> >> except for some touch-hum on the upper mic, probably caused by the
> >> bal-unbal
> >> conversion.
> >
> >In the mid 1970's chips like this didn't exist. A 741 was a
> >"high-performance" OP-Amp.
>
> In the mid-1970's, the MAT-03 and MAT-06 transistor arrays were the solution
> to that particular problem. These days the THAT arrays more or less have
> that same market wrapped up.
>
> But there's still something to be said for a step-up transformer and a
> 6AU6...
> --scott

Those "potted" MAT-03 and MAT-06 arrays were also tres cher in those days. Much more than I wanted to spend on that project! I would have gone
for mike transformers and a tube (or op-amp) preamp had I been able to find suitable, pre-made transformers. When I found that I couldn't really use the B&O mike the way I wanted, I sold it (in it's gorgeous rosewood box!).