The Mellotron Group

Hi all, I'm in the process of calibrating my SMS4 card and am at the
point of tuning. DK's instructions suggest tuning A to 440, and I hope
this doesn't sound too stupid, but which A are we talking about? I
assume it's the low A on the keyboard. Also, I have cello, three
violins, and 8 voice in my frame - which would be the best (most stable)
for tuning? I've been trying to use an old korg guitar tuner, and it
pretty much bouces all over the place. I was thinking of tuning by ear
to a sample played off my computer? Any thoughts?
johnb
1407

Hey,
Somebody want to help me explain the strobe markers to John? I would, but I've forgotten which ones were which, and sadly, I no longer have a mellotron to check on it with.
John, each 'tron has strobe markers on the flywheel. You can use a low level incandescent bulb (as they naturally strobe) to set the tuning for the SMS4. It's so easy, it's like setting the speed on a Technics turntable, but there are two sets of markers. One for power on this side of the pond and one for the other.
Hopefully some kind and able member of the group can help to clarify.
-Jack

--- On Wed, 6/25/08, john barrick <astroboy@cinci.rr.com> wrote:

> From: john barrick <astroboy@cinci.rr.com>
> Subject: [newmellotrongroup] tuning
> To: newmellotrongroup@yahoogroups.com
> Date: Wednesday, June 25, 2008, 7:35 PM
> Hi all, I'm in the process of calibrating my SMS4 card
> and am at the
> point of tuning. DK's instructions suggest tuning A to
> 440, and I hope
> this doesn't sound too stupid, but which A are we
> talking about? I
> assume it's the low A on the keyboard. Also, I have
> cello, three
> violins, and 8 voice in my frame - which would be the best
> (most stable)
> for tuning? I've been trying to use an old korg guitar
> tuner, and it
> pretty much bouces all over the place. I was thinking of
> tuning by ear
> to a sample played off my computer? Any thoughts?
> johnb
> 1407

Thanks, Jack. I thought you needed some kind of timing gun or something
like that. So I can just bring my trouble light in from the garage and
that'll work? I guess I could bring my old Technics DD turntable down
from the living room...
john b


Jack Younger wrote:

>
> Hey,
> Somebody want to help me explain the strobe markers to John? I would,
> but I've forgotten which ones were which, and sadly, I no longer have
> a mellotron to check on it with.
> John, each 'tron has strobe markers on the flywheel. You can use a low
> level incandescent bulb (as they naturally strobe) to set the tuning
> for the SMS4. It's so easy, it's like setting the speed on a Technics
> turntable, but there are two sets of markers. One for power on this
> side of the pond and one for the other.
> Hopefully some kind and able member of the group can help to clarify.
> -Jack
>
> --- On Wed, 6/25/08, john barrick <astroboy@cinci.rr.com
> <mailto:astroboy%40cinci.rr.com>> wrote:
>
> > From: john barrick <astroboy@cinci.rr.com
> <mailto:astroboy%40cinci.rr.com>>
> > Subject: [newmellotrongroup] tuning
> > To: newmellotrongroup@yahoogroups.com
> <mailto:newmellotrongroup%40yahoogroups.com>
> > Date: Wednesday, June 25, 2008, 7:35 PM
> > Hi all, I'm in the process of calibrating my SMS4 card
> > and am at the
> > point of tuning. DK's instructions suggest tuning A to
> > 440, and I hope
> > this doesn't sound too stupid, but which A are we
> > talking about? I
> > assume it's the low A on the keyboard. Also, I have
> > cello, three
> > violins, and 8 voice in my frame - which would be the best
> > (most stable)
> > for tuning? I've been trying to use an old korg guitar
> > tuner, and it
> > pretty much bouces all over the place. I was thinking of
> > tuning by ear
> > to a sample played off my computer? Any thoughts?
> > johnb
> > 1407
>
>

Yes, U.S. power (assuming you are in the the States) runs at 60 cycles, so if you shut out all the lights in the room and plug in a small lamp and shine it on the flywheel while you turn the tuning pot, it should line things up at 440. Keep in mind, incandescent strobing is pretty quick and the dots on the flywheel are pretty far apart so you may need to adjust your eyes to see it. Pretty brilliant of them to consider this, although with the CMC-10's that were in many of these things, I'm sure they needed all the help they could get until the SMS's were made.
-Jack

--- On Wed, 6/25/08, john barrick <astroboy@cinci.rr.com> wrote:

> From: john barrick <astroboy@cinci.rr.com>
> Subject: Re: [newmellotrongroup] tuning
> To: newmellotrongroup@yahoogroups.com
> Date: Wednesday, June 25, 2008, 11:01 PM
> Thanks, Jack. I thought you needed some kind of timing gun
> or something
> like that. So I can just bring my trouble light in from
> the garage and
> that'll work? I guess I could bring my old Technics DD
> turntable down
> from the living room...
> john b
>
>
> Jack Younger wrote:
> >
> > Hey,
> > Somebody want to help me explain the strobe markers to
> John? I would,
> > but I've forgotten which ones were which, and
> sadly, I no longer have
> > a mellotron to check on it with.
> > John, each 'tron has strobe markers on the
> flywheel. You can use a low
> > level incandescent bulb (as they naturally strobe) to
> set the tuning
> > for the SMS4. It's so easy, it's like setting
> the speed on a Technics
> > turntable, but there are two sets of markers. One for
> power on this
> > side of the pond and one for the other.
> > Hopefully some kind and able member of the group can
> help to clarify.
> > -Jack
> >
> > --- On Wed, 6/25/08, john barrick
> <astroboy@cinci.rr.com
> > <mailto:astroboy%40cinci.rr.com>> wrote:
> >
> > > From: john barrick <astroboy@cinci.rr.com
> > <mailto:astroboy%40cinci.rr.com>>
> > > Subject: [newmellotrongroup] tuning
> > > To: newmellotrongroup@yahoogroups.com
> > <mailto:newmellotrongroup%40yahoogroups.com>
> > > Date: Wednesday, June 25, 2008, 7:35 PM
> > > Hi all, I'm in the process of calibrating my
> SMS4 card
> > > and am at the
> > > point of tuning. DK's instructions suggest
> tuning A to
> > > 440, and I hope
> > > this doesn't sound too stupid, but which A
> are we
> > > talking about? I
> > > assume it's the low A on the keyboard. Also,
> I have
> > > cello, three
> > > violins, and 8 voice in my frame - which would be
> the best
> > > (most stable)
> > > for tuning? I've been trying to use an old
> korg guitar
> > > tuner, and it
> > > pretty much bouces all over the place. I was
> thinking of
> > > tuning by ear
> > > to a sample played off my computer? Any thoughts?
> > > johnb
> > > 1407
> >
> >

Frank,
Which set of strobe markers are the U.S. ones?
-Jack

--- On Thu, 6/26/08, lsf5275@aol.com <lsf5275@aol.com> wrote:

> From: lsf5275@aol.com <lsf5275@aol.com>
> Subject: Re: [newmellotrongroup] tuning
> To: newmellotrongroup@yahoogroups.com
> Date: Thursday, June 26, 2008, 10:20 AM
> In a message dated 6/26/2008 7:04:10 A.M. Eastern Daylight
> Time,
> e4103s@yahoo.com writes:
>
> Yes, U.S. power (assuming you are in the the States) runs
> at 60 cycles, so
> if you shut out all the lights in the room and plug in a
> small lamp and shine
> it on the flywheel while you turn the tuning pot, it
> should line things up at
> 440. Keep in mind, incandescent strobing is pretty quick
> and the dots on the
> flywheel are pretty far apart so you may need to adjust
> your eyes to see it.
> Pretty brilliant of them to consider this, although with
> the CMC-10's that
> were in many of these things, I'm sure they needed all
> the help they could get
> until the SMS's were made.
> -Jack
>
>
>
>
> Any florescent light makes it easy.
>
> Frank
>
>
>
> **************Gas prices getting you down? Search AOL Autos
> for
> fuel-efficient used cars.
> (http://autos.aol.com/used?ncid=aolaut00050000000007)

Yep. Either an AC-driven fluorescent bulb, or AC-driven neon bulb would be ideal. The question is whether one set of dots is for 60 Hz, and the other set is for 50 Hz. I'll have to test it, I guess.

-Bruce D.

--- On Thu, 6/26/08, lsf5275@aol.com <lsf5275@aol.com> wrote:

From: lsf5275@aol.com <lsf5275@aol.com>
Subject: Re: [newmellotrongroup] tuning
To: newmellotrongroup@yahoogroups.com
Date: Thursday, June 26, 2008, 8:20 AM

In a message dated 6/26/2008 7:04:10 A.M. Eastern Daylight Time, e4103s@yahoo. com writes:

Yes, U.S. power (assuming you are in the the States) runs at 60 cycles, so if you shut out all the lights in the room and plug in a small lamp and shine it on the flywheel while you turn the tuning pot, it should line things up at 440. Keep in mind, incandescent strobing is pretty quick and the dots on the flywheel are pretty far apart so you may need to adjust your eyes to see it. Pretty brilliant of them to consider this, although with the CMC-10's that were in many of these things, I'm sure they needed all the help they could get until the SMS's were made.
-Jack

Any florescent light makes it easy.

Frank

Gas prices getting you down? Search AOL Autos for fuel-efficient used cars.

OK - I'm in the states with 60 HZ. I'm using a little fluorescent shop
light. It appears to be the inner ring of dots that works for 60.
Here's the problem. The only time I can get the dots stationary, the
motor appears to be running at half speed. It'll sit still a while and
then they'll begin a slow creep, then they'll sit still again. I
thought the tach head was in the loop to provide feedback to the speed
control so that everything would remain constant under varying loads.
Would this not also keep the speed constant also if you're receiving
power fluctuations? I got my power supply back from Jerry Korb at the
beginning of May (I was lucky to have him take the project on before the
situation with his mother developed) and it's go brand new huge caps
that are beyond spec - so I doubt the problem is there. Should I look
at the tach head?


Bruce Daily wrote:

>
> Yep. Either an AC-driven fluorescent bulb, or AC-driven neon bulb
> would be ideal. The question is whether one set of dots is for 60 Hz,
> and the other set is for 50 Hz. I'll have to test it, I guess.
>
>
>
> -Bruce D.
>
>
>
>
>
> --- On *Thu, 6/26/08, lsf5275@aol.com /<lsf5275@aol.com>/* wrote:
>
> From: lsf5275@aol.com <lsf5275@aol.com>
> Subject: Re: [newmellotrongroup] tuning
> To: newmellotrongroup@yahoogroups.com
> Date: Thursday, June 26, 2008, 8:20 AM
>
> In a message dated 6/26/2008 7:04:10 A.M. Eastern Daylight Time,
> e4103s@yahoo. com writes:
>
> Yes, U.S. power (assuming you are in the the States) runs at
> 60 cycles, so if you shut out all the lights in the room and
> plug in a small lamp and shine it on the flywheel while you
> turn the tuning pot, it should line things up at 440. Keep in
> mind, incandescent strobing is pretty quick and the dots on
> the flywheel are pretty far apart so you may need to adjust
> your eyes to see it. Pretty brilliant of them to consider
> this, although with the CMC-10's that were in many of these
> things, I'm sure they needed all the help they could get until
> the SMS's were made.
> -Jack
>
>
> Any florescent light makes it easy.
>
> Frank
>
>
>
> ------------------------------------------------------------------------
> Gas prices getting you down? Search AOL Autos for fuel-efficient
> used cars <http://autos.aol.com/used?ncid=aolaut00050000000007>.
>
>
>

According to Frank, it's the outside set of dots, which may be your problem. Also, it may help for you to try to tune a middle note on the key board (A, or C) by ear, or to a tuner first so you are in the ballpark first. Is it a CMC board or an SMS? There can be a few reasons for drift.
-Jack

--- On Thu, 6/26/08, john barrick <astroboy@cinci.rr.com> wrote:

> From: john barrick <astroboy@cinci.rr.com>
> Subject: Re: [newmellotrongroup] tuning
> To: newmellotrongroup@yahoogroups.com
> Date: Thursday, June 26, 2008, 7:58 PM
> OK - I'm in the states with 60 HZ. I'm using a
> little fluorescent shop
> light. It appears to be the inner ring of dots that works
> for 60.
> Here's the problem. The only time I can get the dots
> stationary, the
> motor appears to be running at half speed. It'll sit
> still a while and
> then they'll begin a slow creep, then they'll sit
> still again. I
> thought the tach head was in the loop to provide feedback
> to the speed
> control so that everything would remain constant under
> varying loads.
> Would this not also keep the speed constant also if
> you're receiving
> power fluctuations? I got my power supply back from Jerry
> Korb at the
> beginning of May (I was lucky to have him take the project
> on before the
> situation with his mother developed) and it's go brand
> new huge caps
> that are beyond spec - so I doubt the problem is there.
> Should I look
> at the tach head?
>
>
> Bruce Daily wrote:
> >
> > Yep. Either an AC-driven fluorescent bulb, or
> AC-driven neon bulb
> > would be ideal. The question is whether one set of
> dots is for 60 Hz,
> > and the other set is for 50 Hz. I'll have to test
> it, I guess.
> >
> >
> >
> > -Bruce D.
> >
> >
> >
> >
> >
> > --- On *Thu, 6/26/08, lsf5275@aol.com
> /<lsf5275@aol.com>/* wrote:
> >
> > From: lsf5275@aol.com <lsf5275@aol.com>
> > Subject: Re: [newmellotrongroup] tuning
> > To: newmellotrongroup@yahoogroups.com
> > Date: Thursday, June 26, 2008, 8:20 AM
> >
> > In a message dated 6/26/2008 7:04:10 A.M. Eastern
> Daylight Time,
> > e4103s@yahoo. com writes:
> >
> > Yes, U.S. power (assuming you are in the the
> States) runs at
> > 60 cycles, so if you shut out all the lights
> in the room and
> > plug in a small lamp and shine it on the
> flywheel while you
> > turn the tuning pot, it should line things up
> at 440. Keep in
> > mind, incandescent strobing is pretty quick
> and the dots on
> > the flywheel are pretty far apart so you may
> need to adjust
> > your eyes to see it. Pretty brilliant of them
> to consider
> > this, although with the CMC-10's that were
> in many of these
> > things, I'm sure they needed all the help
> they could get until
> > the SMS's were made.
> > -Jack
> >
> >
> > Any florescent light makes it easy.
> >
> > Frank
> >
> >
> >
> >
> ------------------------------------------------------------------------
> > Gas prices getting you down? Search AOL Autos for
> fuel-efficient
> > used cars
> <http://autos.aol.com/used?ncid=aolaut00050000000007>.
> >
> >
> >

Hi all-

Yes, a 60Hz strobe should be applied to the outer dot ring. I found an LED nightlight that worked nicely, and verified our little science fair project (it also worked on my turntable). In my case there was very little variation in the flywheel stability.

-Bruce D.

--- On Fri, 6/27/08, lsf5275@aol.com <lsf5275@aol.com> wrote:

From: lsf5275@aol.com <lsf5275@aol.com>
Subject: Re: [newmellotrongroup] tuning
To: newmellotrongroup@yahoogroups.com
Date: Friday, June 27, 2008, 8:01 AM

In a message dated 6/26/2008 5:33:34 P.M. Eastern Daylight Time, pocotron@yahoo. com writes:

Yep. Either an AC-driven fluorescent bulb, or AC-driven neon bulb would be ideal. The question is whether one set of dots is for 60 Hz, and the other set is for 50 Hz. I'll have to test it, I guess.

-Bruce D.

That's it exactly. I believe the outside ring is for 60 Hz.

Gas prices getting you down? Search AOL Autos for fuel-efficient used cars.

Damn! I'm feeling worse about this all the time. I've just rechecked my
voltage across the big cap on the SMS4 - it reads 22 volts rock solid
with my analog multimeter and with my digital jumps up and down between
22.0 and 22.3 volts. I'm using a fluorescent trouble light, plugged
into the same 60 Hz circuit that the tron is running on, and the only
strobe dots I can freeze (and they do hold fairly steady) is the inner
ring - at two different positions on the SMS4's center speed pot (vr3).
Of the two "freeze" positions, one is way too slow and the other is way
too fast.
I cannot, no matter what I do, get the outer ring of strobe dots to
freeze. I can get the tron in tune by ear, but neither ring of dots is
anywhere near a freeze speed at that point. I think I'm going to pull
it out of the cabinet, check the tach head and then belt tension and
start all over again. Don't know what else to do.
johnb
1407




Bruce Daily wrote:

>
> Hi all-
>
>
>
> Yes, a 60Hz strobe should be applied to the outer dot ring. I
> found an LED nightlight that worked nicely, and verified our little
> science fair project (it also worked on my turntable). In my case
> there was very little variation in the flywheel stability.
>
>
>
> -Bruce D.
>
>
>
>
> .
>
>

Thanks for the heads up, Rick. I figured that I would try and run this
by some of the learned ones in North America before disturbing the great
one. Besides, I've probably done something incorrectly that's caused
this. I can already feel the shame.
Happy Friday Night,
johnb
1407


Rick Blechta wrote:

>
>
> On Jun 27, 2008, at 8:41 PM, john barrick wrote:
>
>> I cannot, no matter what I do, get the outer ring of strobe dots to
>> freeze. I can get the tron in tune by ear, but neither ring of dots is
>> anywhere near a freeze speed at that point. I think I'm going to pull
>> it out of the cabinet, check the tach head and then belt tension and
>> start all over again. Don't know what else to do.
>> johnb
>> 1407
>
> You need (and you have to imagine the trumpet fanfare here) the other
> JB, meaning John Bradley, who very likely had something to do with the
> building of your mellotron. Only he can tell you EXACTLY what's wrong
> and how to fix it. Usually this involves a ball peen hammer and a cold
> steel chisel, but in your case, it might be something less drastic.
>
>