Krell processor 110-220V

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piqachu

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Joined 2009
#1
hello, I want to convert my krell hts 7.1 U.S. 120V/60Hz to do work in Europe 240V/50Hz.
toroidal transformer is:
part: TC0075-0013
cust: hts2
input: 2x0-100-120 volts

Fuse F1: 250v no amperage, dark gray

processor U1: motorola
MC68HC16Z1VFC16
OH35S
QQHDO126

U3: M114636
U4: M2146136

SWITCH:
SW1: 2
SW2: 1
SW3: 2

the back of the unit, next to the IEC power there 50/60hz

I read the whole post and I think I have to put the switch to 2-2-2 for 240V.
I have to do something else?
how we recognize a processor that works in 60hz to another who works in 50/60hz?
thank you for your help
 
#3
In fact,
it's not possible to convert krell HTS without an EEPROM because HTS detect wrong frequency ( 60hz in USA and 50hz in Europe).
I just move the switch in 240v position's and a friend made an EEPROM parallel what deceive the original EEPROM .
the 220v 50hz enter in This parallel EEPROM just believe in 60hz ( modify the clock information.
sorry,is less difficult to explain in French
 
#4
piqachu said:
In fact,
it's not possible to convert krell HTS without an EEPROM because HTS detect wrong frequency ( 60hz in USA and 50hz in Europe).
I just move the switch in 240v position's and a friend made an EEPROM parallel what deceive the original EEPROM .
the 220v 50hz enter in This parallel EEPROM just believe in 60hz ( modify the clock information.
sorry,is less difficult to explain in French
Click to expand...
Yesterday I have get this model for checking the main voltage select switches. In the attachement you will find the diagrams of the primary windings part include the switches. I have draw eight possible switching modes. Such a complicated mains voltage select I have never see before - actually only four configurations (i. e. four voltages) are necessary: 110V-120V-220V-240V
What could be the reason for the choice of twice of them ?

By two modes I don't understand the aim (No 2 and No 5) - perhaps a drawing error was happen and is the reason therefore.

Concerning the main AC frequency I have the same effects observe.
Who can post the appropriate program for burning an EPROM (for using Krell 60 Hz audio components in Europe) ?


BTW - even the fuses seems to be custom made for Krell (have a look in the schematic). Who know the right parameters (value of ampere, slow-blow, fast-blow) ??
I guess, 2A slow-blow must be a good value at this place because relatively large inrush current (through toroidal transformer) while switch-on.
 

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#6
Tekko said:
Why not just bypass that stupid processor board, there must be a relay somwhere to bridge to disable that 50/60Hz sense processor.
Click to expand...
If there would been exactly data sheet of the main processor and a schematic diagram of the complete processor front PCB, it would be possible.
Because the error message comes from the display I asume, that data interchange between the EPROM (with software for 50/60Hz detecting) and the main processor is present.
 
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