Ampex AG-440 voltage question

[Dan]

Hello,

Generally speaking, how hard is it to modify a domestic (north
american) 440 model for foreign voltage, 50 / 230?

Thanks,

Dan

[Scott Dorsey]

Dan > wrote:
>
>Generally speaking, how hard is it to modify a domestic (north
>american) 440 model for foreign voltage, 50 / 230?

If it's a regular 440B, it's very difficult because you need to replace the
capstan motor (it's synchronous).

If it's a 440C or one of the 440B machines retrofitted with the servomotor
capstan (which you can identify because the capstan is much larger in
diameter), it's not too bad.
--scott

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

[Dan]

On Nov 3, 1:02*pm, (Scott Dorsey) wrote:
> Dan > wrote:
>
> >Generally speaking, how hard is it to modify a domestic (north
> >american) 440 model for foreign voltage, 50 / 230?
>
> If it's a regular 440B, it's very difficult because you need to replace the
> capstan motor (it's synchronous).
>
> If it's a 440C or one of the 440B machines retrofitted with the servomotor
> capstan (which you can identify because the capstan is much larger in
> diameter), it's not too bad.

It's actually a B version with the servo motor. When you say it's not
too bad, voltage wise, what do you mean? As an alternative, would it
be perhaps less of a hassle just to get one of those step up / down
transformers? Thanks Scott.

[Scott Dorsey]

Dan > wrote:
>
>It's actually a B version with the servo motor. When you say it's not
>too bad, voltage wise, what do you mean? As an alternative, would it
>be perhaps less of a hassle just to get one of those step up / down
>transformers? Thanks Scott.

Right. If you have the servo motor, you CAN just get a step-down
transformer, and be done with it. Get a proper one that has an isolated
secondary and not one of the crappy construction site autotransformer
types. You will need to go through the tension alignment procedures in
the manual because the reel motor tensions will change with 50 Hz power.

If you have the synchronous motor, you cannot run it off of 50 Hz at
all without changing the motor out. Period.
--scott

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

[Wecan do it]

"Scott Dorsey" > wrote in message
...
> Dan > wrote:
>>
>>It's actually a B version with the servo motor. When you say
>>it's not
>>too bad, voltage wise, what do you mean? As an alternative,
>>would it
>>be perhaps less of a hassle just to get one of those step up
>>/ down
>>transformers? Thanks Scott.
>
> Right. If you have the servo motor, you CAN just get a
> step-down
> transformer, and be done with it. Get a proper one that has
> an isolated
> secondary and not one of the crappy construction site
> autotransformer
> types. You will need to go through the tension alignment
> procedures in
> the manual because the reel motor tensions will change with
> 50 Hz power.
>
> If you have the synchronous motor, you cannot run it off of
> 50 Hz at
> all without changing the motor out. Period.
> --scott
>
> --
> "C'est un Nagra. C'est suisse, et tres, tres precis."

Scott:

If everything he recorded with the 60 hz synchro at 50 hz was
played back on the same synchro motor machine would that work?
So long as he had no plans of exchanging tapes with someone
else of course.

peace
dawg

[Scott Dorsey]

Wecan do it > wrote:
>Scott:
>
>If everything he recorded with the 60 hz synchro at 50 hz was
>played back on the same synchro motor machine would that work?
>So long as he had no plans of exchanging tapes with someone
>else of course.

Sort of, but the flutter is going to be much higher because that motor is
really designed for 60 Hz. It will run slower 50 Hz but it will also run
much rougher.

Also, of course, not being able to interchange tapes kills most of the
benefit of having a tape machine in the first place.
--scott

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

[Dan]

On Nov 3, 7:11*pm, (Scott Dorsey) wrote:
> Dan > wrote:
>
> >It's actually a B version with the servo motor. When you say it's not
> >too bad, voltage wise, what do you mean? As an alternative, would it
> >be perhaps less of a hassle just to get one of those step up / down
> >transformers? Thanks Scott.
>
> Right. *If you have the servo motor, you CAN just get a step-down
> transformer, and be done with it. *Get a proper one that has an isolated
> secondary and not one of the crappy construction site autotransformer
> types. *You will need to go through the tension alignment procedures in
> the manual because the reel motor tensions will change with 50 Hz power.
>
> If you have the synchronous motor, you cannot run it off of 50 Hz at
> all without changing the motor out. *Period.

I have this one:
http://www.voltageconverters.com/itemdesc.asp?ic=VC2000W
Is this OK?
Thank you Scott.

[Scott Dorsey]

In article >,
Dan > wrote:
>On Nov 3, 7:11=A0pm, (Scott Dorsey) wrote:
>> Dan > wrote:
>>
>> >It's actually a B version with the servo motor. When you say it's not
>> >too bad, voltage wise, what do you mean? As an alternative, would it
>> >be perhaps less of a hassle just to get one of those step up / down
>> >transformers? Thanks Scott.
>>
>> Right. =A0If you have the servo motor, you CAN just get a step-down
>> transformer, and be done with it. =A0Get a proper one that has an isolate=
>d
>> secondary and not one of the crappy construction site autotransformer
>> types. =A0You will need to go through the tension alignment procedures in
>> the manual because the reel motor tensions will change with 50 Hz power.
>>
>> If you have the synchronous motor, you cannot run it off of 50 Hz at
>> all without changing the motor out. =A0Period.
>
>I have this one:
>http://www.voltageconverters.com/itemdesc.asp?ic=3DVC2000W
>Is this OK?

No, that's exactly the sort of autotransformer cheapie that is a problem.
Go to an electrical supply house and get a real 240-120 stepdown transformer,
not an autotransformer. You're going to want something with a much larger
iron core than these things have.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Dan]

On Nov 5, 6:25*am, (Scott Dorsey) wrote:
> In article >,
>
>
>
> Dan > wrote:
> >On Nov 3, 7:11=A0pm, (Scott Dorsey) wrote:
> >> Dan > wrote:
>
> >> >It's actually a B version with the servo motor. When you say it's not
> >> >too bad, voltage wise, what do you mean? As an alternative, would it
> >> >be perhaps less of a hassle just to get one of those step up / down
> >> >transformers? Thanks Scott.
>
> >> Right. =A0If you have the servo motor, you CAN just get a step-down
> >> transformer, and be done with it. =A0Get a proper one that has an isolate=
> >d
> >> secondary and not one of the crappy construction site autotransformer
> >> types. =A0You will need to go through the tension alignment procedures in
> >> the manual because the reel motor tensions will change with 50 Hz power.

[Scott Dorsey]

Dan > wrote:
>
>I'm not sure what you mean exactly.... or which specific product
>you're talking about. Do you mean a transformer that ONLY does step
>down, only one way? How do I tell which one is the quality you're
>talking about? Can you point me to an example? Most of the stuff
>available seems to be those step up / down transformers. The one that
>I have is 2000W and 35 lbs. Is it really a problem? Thanks.

The autotransformers have just one winding... they apply 240V across the
winding, then pull 120V from a center tap. This means you have no isolation
from the line.

What you want is a transformer that has a primary and a secondary, and
hopefully an electrostatic shield between them. Ask a real electrical
supply house for a step-down transformer that is an actual isolation
transformer and not an autotransformer.

Here is a typical 1KVA unit:
http://www.grainger.com/Grainger/items/1H721?cm_mmc=Google%20Base-_-Electrical-_-Transformers-_-1H721

You can probably find something cheaper if you look around, but you want
a regular transformer, not an autotransformer.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Dan]

On Nov 5, 1:25*pm, (Scott Dorsey) wrote:
> Dan > wrote:
>
> >I'm not sure what you mean exactly.... or which specific product
> >you're talking about. Do you mean a transformer that ONLY does step
> >down, only one way? How do I tell which one is the quality you're
> >talking about? Can you point me to an example? Most of the stuff
> >available seems to be those step up / down transformers. The one that
> >I have is 2000W and 35 lbs. Is it really a problem? Thanks.
>
> The autotransformers have just one winding... they apply 240V across the
> winding, then pull 120V from a center tap. *This means you have no isolation
> from the line.
>
> What you want is a transformer that has a primary and a secondary, and
> hopefully an electrostatic shield between them. *Ask a real electrical
> supply house for a step-down transformer that is an actual isolation
> transformer and not an autotransformer.
>
> Here is a typical 1KVA unit:http://www.grainger.com/Grainger/items/1H721?cm_mmc=Google%20Base-_-E...
>
> You can probably find something cheaper if you look around, but you want
> a regular transformer, not an autotransformer.

Wow, that is certainly not a typical retail store transformer. Yeah, I
see what you mean. Thanks Scott.

[Peter Larsen[_3_]]

Scott Dorsey wrote:

> The autotransformers have just one winding... they apply 240V across
> the winding, then pull 120V from a center tap. This means you have
> no isolation from the line.

Q: why would that be a problem?

> --scott

Kind regards

Peter Larsen

[Scott Dorsey]

Peter Larsen > wrote:
>Scott Dorsey wrote:
>
>> The autotransformers have just one winding... they apply 240V across
>> the winding, then pull 120V from a center tap. This means you have
>> no isolation from the line.
>
>Q: why would that be a problem?

A: It may not be, but it's MUCH better to be safe than sorry. In a perfect
world, we'd have everything on an isolated circuit anyway. Think of it as
free line filtering.

The major advantage is better regulation, though. The cheapie autotransformer
types aren't so good about that. And if you're going for an industrial
transformer that's actually rated for voltage change with load, you should
go with a full secondary instead of the autotransformer since the benefit
of the isolation is substantial and the price isn't much greater than that
of the industrial-grade autoformer.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Peter Larsen[_3_]]

Scott Dorsey wrote:

> Peter Larsen > wrote:

>> Scott Dorsey wrote:

>>> The autotransformers have just one winding... they apply 240V across
>>> the winding, then pull 120V from a center tap. This means you have
>>> no isolation from the line.

>> Q: why would that be a problem?

> A: It may not be, but it's MUCH better to be safe than sorry. In a
> perfect world, we'd have everything on an isolated circuit anyway.
> Think of it as free line filtering.

Aha, thank you.

> --scott

Kind regards

Peter Larsen