Rane HC6 Psu Help

[r2d2]

Hi and Happy New Year everyone,

a friend got from a PA service a bundle of some devices no longer used
(Lexicon MX, Yamaha Spx 90, Dbx 166, Aphex dual pre, and some other...)

among them also a Rane HC6 headphones "hub" ,
checking the condition and operation of the various devices,
it was noticed that the HC6 do not have the classic external switchable main voltage input (110/240)
not even inside,
as showed on the attached images,
but only 110v input,

please someone know if there is any chance to set the main power transformer for accept the 220-240v as input ?

Much thanks in advance for any help about !

 

[radardoug]

How many wires on the transformer primary? If only two, then you are out of luck.

 

[Audio1Man]

Buy a Triad 553-FD8-120 (Mouser)
Connect 240vac as input and 120vac as output. place it inside a box.
Duke

 

[r2d2]

How many wires on the transformer primary? If only two, then you are out of luck.

Hi and hanks for post,
next days let you know about.

 

[r2d2]

Buy a Triad 553-FD8-120 (Mouser)
Connect 240vac as input and 120vac as output. place it inside a box.
Duke

Hi and thanks for post and the good option indicated !
which however would need an external box
because not enough room inside the HC6 box for 2 transformers,

maybe a dimensions compatible transformer with 230v input
or better more switchable 230/120v
and the appropriate voltage output required for the pcb
would be more suitable ?

 

[r2d2]

A little time to get more info
and unfortunately

How many wires on the transformer primary? If only two, then you are out of luck.

only 2 primary wires : /
(the 2 blue at input)
here the attached images about.

 

[r2d2]

Here also a traced of routes
as well.
(among others, no v-reg ic after diodes bridge)

 

[Voyager10]

Do you have (or can you borrow) a 230-110V stepdown transformer, so you can temporarily apply the correct power and measure various voltages?

If not can you post some more photos of the whole circuit board, including the voltage ratings on the capacitors etc, and we can perhaps work out a safe maximum voltage.

 

[abbey road d enfer]

Here also a traced of routes

Black goes to center tap of secondary, reds go to start and end.
Apart from that, the xfmr is clearly 115V only.
An external drop-down xfmr is a simple solution.
You may also want to find a compatible xfmr with a 230V primary.
You need to measure the secondary voltages and hopefully find a similar one with a 230V primary.
Looking at the pictures, it seems the original xfmr is higher than the box...?

 

[moamps]

The IC used are 741 type, no voltage stabilization, so IMO a small 20VA toroidal transformer with 18V CT (2x9VAC) on secondary would be perfectly adequate.

 

[r2d2]

Black goes to center tap of secondary, reds go to start and end.
Apart from that, the xfmr is clearly 115V only.
An external drop-down xfmr is a simple solution.
You may also want to find a compatible xfmr with a 230V primary.
You need to measure the secondary voltages and hopefully find a similar one with a 230V primary.
Looking at the pictures, it seems the original xfmr is higher than the box...?

Do you have (or can you borrow) a 230-110V stepdown transformer, so you can temporarily apply the correct power and measure various voltages?

If not can you post some more photos of the whole circuit board, including the voltage ratings on the capacitors etc, and we can perhaps work out a safe maximum voltage.

Much thanks for post !
Unfortunately no 230v to 115v under hand at the moment,
for check voltages on post transformer section,

as in attached images , "big" caps on each channel say 16v 470uf
asap i check others and post values,
on the first image attached in this post
is visible the psu section post main transformer
and apart the diodes and the 2 "lytics" caps there are only some ceramic cap,

the main transformer seems more hi than the box
because unscrewed from its location
and placed vertically to see what is written on it,
and the number of in-out cables.
on one of the attached images you can see it in the operating position.

 

[abbey road d enfer]

he main transformer seems more hi than the box
because unscrewed from its location
and placed vertically to see what is written on it,
and the number of in-out cables.
on one of the attached images you can see it in the operating position.

OK, just follow moamps' advice.

 

[r2d2]

Here caps images and info,
on the psu section
the 2 caps are 25v - 1000uf
on channels small caps are 16v - 10uf .

 

[abbey road d enfer]

That really suggests a 2x9V xfmr.

 

[SIXTYNINER]

Hi to all
only as little help
after googling a bit
found a scheme that seems so similar to that on the images,
and probably one of the first HC6 versions,
the later version have different type of onboard psu
and also external transformer as described on their manuals,

but checking capacitors values and topology
seems the values are the same
(1000uf-25V on psu , and 10uf , 470uf-16v on channels)
here the doc that say : +13,5v and -13,5v after diodes bridge and capacitors,
https://www.ranecommercial.com/legacy/pdf/old/hc6sch82.pdf
also aside of psu main transformer section there is signed 120/240V primary
and 22VAC secondary,
and over the transformer there is a primary configuration scheme
for the 2 input voltages,
on the page 2 seems that the version of the scheme is with 120-240V switch,
possible it Is a later version than the one under "investigation" 8-I ?

 

[abbey road d enfer]

here the doc that say : +13,5v and -13,5v after diodes bridge and capacitors,

Consistent with a 2x9Vac xfmr.

 

[Voyager10]

That schematic looks like a good match to the photos. Looks like those 470uF/16V caps are on the supply rails, so it doesn't want to go over 13.5V.

A 2x9V secondary might end up bit lower, but 2x12V would be too high IMO.

 

[moamps]

A 2x9V secondary might end up bit lower, but 2x12V would be too high IMO.

Small toroidal transformers have a voltage regulation over 10%, so in this case, where the transformer will be loaded most of the time below 10% of its rated power, it should be calculated that the secondary AC voltage will be 10 to 10.5V.
Someone will ask why I did not suggest a lower power transformer, simply because they are less often produced, and 20 or 25VA power is usually the minimum power of toroidal transformers that can be obtained.

As a final argument, data from the following Rane model can be taken, which has an external transformer with a secondary voltage of 18VCT, and the following circuitry is quite similar to the earlier model. Case closed.