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Archived from groups: rec.audio.pro (More info?)

http://www3.telus.net/public/vintage1/kit.htm#JFET

on a side note, i aked this guy about crafting a mic pre mixer for me. he
wants to use discrete adm modules. for an 8 x2 with stereo limiting on the
mains the estimate is about 3k. is this reasonable

i am trying to vibe him out because alot of what he says i agree with, but
he was the one that is trying to turn me onto vhs analog recording.

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Archived from groups: rec.audio.pro (More info?)

"anon" <anonymousm@nyc.rr.com> wrote in message
news:Bjn9d.155051$4h7.28266253@twister.nyc.rr.com...
> http://www3.telus.net/public/vintage1/kit.htm#JFET
>
> on a side note, i aked this guy about crafting a mic pre mixer for me. he
> wants to use discrete adm modules. for an 8 x2 with stereo limiting on the
> mains the estimate is about 3k. is this reasonable
>
> i am trying to vibe him out because alot of what he says i agree with, but
> he was the one that is trying to turn me onto vhs analog recording.

Well, let's see; he's claiming it's a Millennia Media design, without their
permission, and he notes he has changed it. So it's not really their design
(or Fred Forssell's), quite.

He uses far too many exclamation points.

He makes extravagant claims. Maybe they're true. Maybe not.

And he's a fan of VHS-hifi analog recording?

I would be very, very cautious.

Peace,
Paul

Reply to Anonymous

Archived from groups: rec.audio.pro (More info?)

In article <Bjn9d.155051$4h7.28266253@twister.nyc.rr.com>,
anon <anonymousm@nyc.rr.com> wrote:
>http://www3.telus.net/public/vintage1/kit.htm#JFET
>
>on a side note, i aked this guy about crafting a mic pre mixer for me. he
>wants to use discrete adm modules. for an 8 x2 with stereo limiting on the
>mains the estimate is about 3k. is this reasonable
>
>i am trying to vibe him out because alot of what he says i agree with, but
>he was the one that is trying to turn me onto vhs analog recording.

The description is more or less incoherent, and seems to mention a whole lot
of totally irrelevant manufacturer's products without really saying much about
his own product.

I gather that his preamp kits consist of a transformer and a Millennia
Media MM990 module, which is a FET-input variant of the classic Jensen 990.

The Millennia Media 990 module is a nice-sounding piece of gear, but this
bears basically no connection at all to the Millennia Media preamps (which
don't have transformer front ends). If you got a module and stuck a
transformer in front of it, though, it would probably sound pretty good,
though.

$600 for two MM990 modules and two transformers seems a little high to me
but then I am a cheapskate.

Having him build an 8x2 mixer with this stuff may be a good idea, because
these modules are pretty foolproof. All the hard stuff is going on inside
the gain blocks and there really isn't very much design work that you need
to be doing. The only thing that is all that difficult is selecting the
values for the mix matrix in order to get lowest possible noise, and even
then it'll probably be just fine even if it's only in the general ballpark.
Oh yes, and the metalwork. The case and metal is probably much more work
than the electronics.

Using this stuff makes it reasonably foolproof and means there isn't much
real engineering needed to build consoles. But by the same token, you could
probably build the thing yourself too, for the same reason.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Reply to Anonymous

Archived from groups: rec.audio.pro (More info?)

Paul Stamler <pstamlerhell@pobox.com> wrote:
>
>Well, let's see; he's claiming it's a Millennia Media design, without their
>permission, and he notes he has changed it. So it's not really their design
>(or Fred Forssell's), quite.

No, I think he is reselling amplifier modules made by Millennia Media. So
even if the overall design has nothing at all to do with Millennia, the
gain block really is a Millennia Media design.

>He uses far too many exclamation points.
>
>He makes extravagant claims. Maybe they're true. Maybe not.
>
>And he's a fan of VHS-hifi analog recording?
>
>I would be very, very cautious.

It does look like he could use a good editor and layout person, doesn't it?
--scott

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

Reply to Anonymous

Archived from groups: rec.audio.pro (More info?)

It's Pat Morford , who as others have mentioned is really just reselling a
couple
of decent components ,
I recomend you research buying the parts yourself and the more you talk to
him
the better idea you'll get of what a deal may be like . Time reveals much .

regards gkb

"anon" <anonymousm@nyc.rr.com> wrote in message
news:Bjn9d.155051$4h7.28266253@twister.nyc.rr.com...
> http://www3.telus.net/public/vintage1/kit.htm#JFET
>
> on a side note, i aked this guy about crafting a mic pre mixer for me. he
> wants to use discrete adm modules. for an 8 x2 with stereo limiting on the
> mains the estimate is about 3k. is this reasonable
>
> i am trying to vibe him out because alot of what he says i agree with, but
> he was the one that is trying to turn me onto vhs analog recording.
>
>
>
>

Reply to Anonymous

Archived from groups: rec.audio.pro (More info?)

The transformers are Lunhdal , which you can get directly from them ,
although
there is a Canadian distributer which makes it easier to get them from
Canada
[ B.C ] when in Canada . but i would think you could save the double
exchange
rate by getting the Millenia modules direct from millenia though .

regards Greg

"Scott Dorsey" <kludge@panix.com> wrote in message
news:ck65kp$2r7$1@panix2.panix.com...
> In article <Bjn9d.155051$4h7.28266253@twister.nyc.rr.com>,
> anon <anonymousm@nyc.rr.com> wrote:
> >http://www3.telus.net/public/vintage1/kit.htm#JFET
> >
> >on a side note, i aked this guy about crafting a mic pre mixer for me. he
> >wants to use discrete adm modules. for an 8 x2 with stereo limiting on
the
> >mains the estimate is about 3k. is this reasonable
> >
> >i am trying to vibe him out because alot of what he says i agree with,
but
> >he was the one that is trying to turn me onto vhs analog recording.
>
> The description is more or less incoherent, and seems to mention a whole
lot
> of totally irrelevant manufacturer's products without really saying much
about
> his own product.
>
> I gather that his preamp kits consist of a transformer and a Millennia
> Media MM990 module, which is a FET-input variant of the classic Jensen
990.
>
> The Millennia Media 990 module is a nice-sounding piece of gear, but this
> bears basically no connection at all to the Millennia Media preamps (which
> don't have transformer front ends). If you got a module and stuck a
> transformer in front of it, though, it would probably sound pretty good,
> though.
>
> $600 for two MM990 modules and two transformers seems a little high to me
> but then I am a cheapskate.
>
> Having him build an 8x2 mixer with this stuff may be a good idea, because
> these modules are pretty foolproof. All the hard stuff is going on inside
> the gain blocks and there really isn't very much design work that you need
> to be doing. The only thing that is all that difficult is selecting the
> values for the mix matrix in order to get lowest possible noise, and even
> then it'll probably be just fine even if it's only in the general
ballpark.
> Oh yes, and the metalwork. The case and metal is probably much more work
> than the electronics.
>
> Using this stuff makes it reasonably foolproof and means there isn't much
> real engineering needed to build consoles. But by the same token, you
could
> probably build the thing yourself too, for the same reason.
> --scott
> --
> "C'est un Nagra. C'est suisse, et tres, tres precis."

Reply to Anonymous

Archived from groups: rec.audio.pro (More info?)

In article <p8bad.682794$M95.230478@pd7tw1no>, GKB <gboboski@shaw.ca> wrote:
> The transformers are Lunhdal , which you can get directly from them ,
>although
>there is a Canadian distributer which makes it easier to get them from
>Canada
>[ B.C ] when in Canada . but i would think you could save the double
>exchange
>rate by getting the Millenia modules direct from millenia though .

Lundahl is now selling their stuff in the US! They finally have a US
distributor, who is listed on their web site. I met him at the last
European AES show and he seems like a nice guy who very much cares about
the experimenter and hobby construction community.

Let me also say that the original JE990 modules are available from Jensen.
They have a bipolar input stage so you will need a lower step-up ratio on
the transformer to deal with the lower imput impedance. Also, Opamp Labs
still sells all kinds of really neat hybrid and semi-hybrid op-amp modules
built with 1970s technology. Not the lowest noise or distortion, but fun
sounds for very little money.

There were a lot of hybrid and discrete op-amp modules back in the seventies
before monolithic chips started catching up. I am always finding various
ones in the garage but mostly I have been sending them to my friend at
Burr-Brown to put in a glass case in the lobby. Most of them are much more
useful there than in actual audio circuits.
--scott

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

Reply to Anonymous

Archived from groups: rec.audio.pro (More info?)

The site claims that they are "custom" transformers, though. Any idea what
a good stock model would be from xformer would be?

George Reiswig
Song of the River Music

"GKB" <gboboski@shaw.ca> wrote in message
news8bad.682794$M95.230478@pd7tw1no...
>
> The transformers are Lunhdal , which you can get directly from them ,
> although
> there is a Canadian distributer which makes it easier to get them from
> Canada
> [ B.C ] when in Canada . but i would think you could save the double
> exchange
> rate by getting the Millenia modules direct from millenia though .
>
> regards Greg
>
>
>
> "Scott Dorsey" <kludge@panix.com> wrote in message
> news:ck65kp$2r7$1@panix2.panix.com...
>> In article <Bjn9d.155051$4h7.28266253@twister.nyc.rr.com>,
>> anon <anonymousm@nyc.rr.com> wrote:
>> >http://www3.telus.net/public/vintage1/kit.htm#JFET
>> >
>> >on a side note, i aked this guy about crafting a mic pre mixer for me.
>> >he
>> >wants to use discrete adm modules. for an 8 x2 with stereo limiting on
> the
>> >mains the estimate is about 3k. is this reasonable
>> >
>> >i am trying to vibe him out because alot of what he says i agree with,
> but
>> >he was the one that is trying to turn me onto vhs analog recording.
>>
>> The description is more or less incoherent, and seems to mention a whole
> lot
>> of totally irrelevant manufacturer's products without really saying much
> about
>> his own product.
>>
>> I gather that his preamp kits consist of a transformer and a Millennia
>> Media MM990 module, which is a FET-input variant of the classic Jensen
> 990.
>>
>> The Millennia Media 990 module is a nice-sounding piece of gear, but this
>> bears basically no connection at all to the Millennia Media preamps
>> (which
>> don't have transformer front ends). If you got a module and stuck a
>> transformer in front of it, though, it would probably sound pretty good,
>> though.
>>
>> $600 for two MM990 modules and two transformers seems a little high to me
>> but then I am a cheapskate.
>>
>> Having him build an 8x2 mixer with this stuff may be a good idea, because
>> these modules are pretty foolproof. All the hard stuff is going on
>> inside
>> the gain blocks and there really isn't very much design work that you
>> need
>> to be doing. The only thing that is all that difficult is selecting the
>> values for the mix matrix in order to get lowest possible noise, and even
>> then it'll probably be just fine even if it's only in the general
> ballpark.
>> Oh yes, and the metalwork. The case and metal is probably much more work
>> than the electronics.
>>
>> Using this stuff makes it reasonably foolproof and means there isn't much
>> real engineering needed to build consoles. But by the same token, you
> could
>> probably build the thing yourself too, for the same reason.
>> --scott
>> --
>> "C'est un Nagra. C'est suisse, et tres, tres precis."
>
>

Reply to Anonymous

Archived from groups: rec.audio.pro (More info?)

A. & G. Reiswig <NOSPAMreiswig@bigfoot.com> wrote:
>The site claims that they are "custom" transformers, though. Any idea what
>a good stock model would be from xformer would be?

Anything that sounds good and has between a 1:6 and a 1:15 step-up
ratio. The higher the ratio, the more free voltage gain you are getting
from the transformer and the better your S/N will be (since you are going
into a very high-Z FET). The higher the ratio, the harder the transformer
is to make and the poorer the high end (due to interwinding capacitance
on the transformer).

I might go for the Jensen JE-115. I might go for the Lundahl with the 1:8
ratio. Then again, if I were impoverished, I might go for one of the
Tamura Microtron types.
--scott

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

Reply to Anonymous

Archived from groups: rec.audio.pro (More info?)

"anon" <anonymousm@nyc.rr.com> wrote in message news:<Bjn9d.155051$4h7.28266253@twister.nyc.rr.com>...
> http://www3.telus.net/public/vintage1/kit.htm#JFET
>
> on a side note, i aked this guy about crafting a mic pre mixer for me. he
> wants to use discrete adm modules. for an 8 x2 with stereo limiting on the
> mains the estimate is about 3k. is this reasonable
>
> i am trying to vibe him out because alot of what he says i agree with, but
> he was the one that is trying to turn me onto vhs analog recording.

Maybe it should be obvious, but I'm having trouble seeing the
difference between the expensive gain block and an IC op amp.

Reply to Anonymous

Archived from groups: rec.audio.pro (More info?)

In article <O6had.267$MY.117@trnddc03> NOSPAMreiswig@bigfoot.com writes:

> The site claims that they are "custom" transformers, though. Any idea what
> a good stock model would be from xformer would be?

That could mean custom mounting holes. Equipment manufacturers like to
let people know that their stuff isn't make up of just plain ordinary
parts that you could buy yourself and make one just like it - no, it
has "custom" parts.

--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

Reply to Anonymous

Archived from groups: rec.audio.pro (More info?)

Detector195 <Detector195@yahoo.com> wrote:
>Maybe it should be obvious, but I'm having trouble seeing the
>difference between the expensive gain block and an IC op amp.

There is a pretty substantial difference in sound between the discrete
op-amp designs like the JE990 and MM990 and typical monolithic stuff.

Which is not to say that you can't just build a JE990 for a few dollars
from the schematics on the Jensen web site and be happy.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Reply to Anonymous

Archived from groups: rec.audio.pro (More info?)

Scott Dorsey wrote:

> Detector195 <Detector195@yahoo.com> wrote:
>
>>Maybe it should be obvious, but I'm having trouble seeing the
>>difference between the expensive gain block and an IC op amp.
>
>
> There is a pretty substantial difference in sound between the discrete
> op-amp designs like the JE990 and MM990 and typical monolithic stuff.

To what would you attribute that? Higher slew rate?

Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

Reply to Anonymous

Archived from groups: rec.audio.pro (More info?)

"Bob Cain" <arcane@arcanemethods.com> wrote in message
news:ckd7qg32e6l@enews1.newsguy.com...
>
>
> Scott Dorsey wrote:
>
> > Detector195 <Detector195@yahoo.com> wrote:
> >
> >>Maybe it should be obvious, but I'm having trouble seeing the
> >>difference between the expensive gain block and an IC op amp.
> >
> >
> > There is a pretty substantial difference in sound between the discrete
> > op-amp designs like the JE990 and MM990 and typical monolithic stuff.
>
> To what would you attribute that? Higher slew rate?

More likely higher bias on the output devices, and fewer problems with
thermal stuff at low frequencies.

Peace,
Paul

Reply to Anonymous

Archived from groups: rec.audio.pro (More info?)

Bob Cain wrote:

>
> Scott Dorsey wrote:
>
>> Detector195 <Detector195@yahoo.com> wrote:
>>
>>> Maybe it should be obvious, but I'm having trouble seeing the
>>> difference between the expensive gain block and an IC op amp.
>>
>>
>>
>> There is a pretty substantial difference in sound between the discrete
>> op-amp designs like the JE990 and MM990 and typical monolithic stuff.
>
>
> To what would you attribute that? Higher slew rate?
>
>
> Bob
> --

You might find some good information in my pdf file for the 990 op-amp at:

http://www.johnhardyco.com/pdf/990.pdf

Thank you.

John Hardy
The John Hardy Co.
www.johnhardyco.com

Reply to Anonymous

Archived from groups: rec.audio.pro (More info?)

"Bob Cain" <arcane@arcanemethods.com> wrote in message
news:ckd7qg32e6l@enews1.newsguy.com
> Scott Dorsey wrote:

>> Detector195 <Detector195@yahoo.com> wrote:

>>> Maybe it should be obvious, but I'm having trouble seeing the
>>> difference between the expensive gain block and an IC op amp.

>> There is a pretty substantial difference in sound between the
>> discrete op-amp designs like the JE990 and MM990 and typical
>> monolithic stuff.
>
> To what would you attribute that? Higher slew rate?

I at least partially attribute this belief to knowlege that was developed
before monolithic op amps became what the best ones now are.

To put this comment in perspective, consider that the earliest published
mention I can find of the JE990 dates back to 1982:

A New Approach to Audio Design with Emphasis on the Recording Console
Author(s): Barthelson, Peter A.
Publication: AES Conference Preprint 1921; Convention 72; October 1982
Abstract: While some of the audio industry continues to pursue improvement
in audio quality through better circuit topologies, the audio quality in the
recording industry has fallen victim to the integrated circuit with its many
limitations. An audio design philosophy is outlined which focuses on
improved audio quality beyond THD and slew-rate considerations and which
currently requires the use of discrete components.

Reply to Anonymous

Archived from groups: rec.audio.pro (More info?)

Detector195 <Detector195@yahoo.com> wrote:
>But isn't there much less need for matching in the first place? You
>start with an inter-digitated input transistor pair on a single piece
>of silicon, and you are effectively matched for material variations
>and even gradients.

Right. Also because everything is on the same substrate, the temperature
is the same on both.

>Maybe you clean things up with a bit of laser
>trimming.

This is when things start getting expensive. AD has a fancy system for
depositing resistor elements on the top layer of monolithic ICs and then
laser-trimming them. What they charge for some of the higher precision
monolithics becomes enough money that there's no cost savings any more.

>Devices have open loop gains of 120 dB, so the mismatch
>between devices can be at most 10 microvolts at the input terminals? I
>doubt that discretes can be matched at this level in all of their
>characteristics including tempco.

Yup, but remember that everything is DC coupled now, too.

>For subjective optimization, what do you want to control -- frequency
>response or distortion? If these are desired, they can be implemented
>in the feedback circuit. Otherwise, is there really any point in
>taking a nonlinear circuit and optimizing it into a different
>nonlinear circuit?

That's the thing about subjective optimization. You pick what sounds
best to you, and that is a complex matter. What I think sounds best
might be different than what you think sounds best. But yes, the whole
point is trading different sets of nonlinearities for the set that
sounds subjectively better than the others. That's what makes audio
circuit design an art form rather than just plugging and chugging with
SPICE.

Of course, you still get people who will try a dozen different monolithic
op-amps in a circuit and pick the one that sounds best to them in that
circuit. This is still a very common sort of thing to do. But you can't
get inside them and tweak things around.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

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