I need some advice, please.
I have 2 monoblock amps that came out of an AKAI M8 R2R tape recorder. I want to power them up, but don?t know how, and don?t want to mess anything up. I have seen them working, in the original suitcase, and know they power up, and all the valves light up.
Each monoblock has its own power transformer, and in the main box was a third, or main, transformer, that connects to normal 220v power through a standard 3-prong SA wall plug. I shall call this the M8MT (main transformer), and the other two the LMT (left monoblock power transformer) and the RMT (right monoblock power transformer).
Inside the original suitcase the M8MT fed the LMT and the LMT fed the RMT.
The small black round plug coming from the M8MT has 5 wires: Black, Red, Green, Grey and Yellow.
When I measure the voltage coming from the M8MT, I get the following:
Grey and Black = 234v
Grey and Red = 234v
Grey and Green = 234v
Grey and Red = 234v
Grey and Yellow = 234v
Yellow and Black/Red/Green = 0v
Black and Red/Green = 0v
Red and Black/Green = 0v
Green and Red/Black = 0v
So, without Grey in the mix, there is no voltage. Also, as there is no other reading in any combination than 234v, it would seem that the M8MT must feed 234v to the LMT?
The next step is that the 5 wires coming from the M8MT go to a large round black connector (female) with 6 pins, but only the Black, Red and Green wires coming from the M8MT are connected to 3 of the pins of this female connector. The Yellow wire is not connected to this plug ? they were connected somewhere else in the main suitcase, the the actual tape recorder part where, e.g. the motor lived. The Grey wire went to a Shut Off - Stop switch on the main body of the R2R, and a Blue wire returned from this Shut Off - Stop switch. I can't remember where the Blue wire coming back from this switch was (if it was) connected to this large connector!*
The male side of this large round connector comes from the LMT, and has 6 wires connected to the pins: Red, Black, Green, Yellow, Blue and White. So when the M8MT female side is connected to the LMT male side, Black=Black, Red=Red, Green=Green and Blue=empty, White=empty and Yellow=empty.
Arriving at the LMT, the power transformer has two ?strips? on the input side: one has 3 connectors saying [250v-C.T.-250v] and the other has 3 connectors saying [117v-100v-0].
The 6 wires that come from the connector between the LMT and the M8MT go as follows:
Black goes to the C.T. connector on the [250v-CT-250v] strip
Red goes to the 0 connector on the [117v-100v-0] strip
Blue goes to the on/off switch, and from there comes back (as a green wire) to the 100v connector on the [117v-100v-0] strip.
Red and Green both show a connection (my multimeter beeps) with all 3 connectors on the [117v-100v-0] strip?
Yellow and White go into the body of the Left mono block, but are not connected to the LMT, as far as I can tell.
Oh, and from the 100v and the 0 connectors on the LMT two wires go to a female plug, into which two wires from the RMT plug in, and then go to the 100v connector of the RMT and the on/off switch of the Right Monoblock amp.
I know this is a long and badly explained story, but it leaves me with some questions:
Are these monoblocks 220v or 110v?
If the Grey wire needed to be in the mix in order to measure any current coming from the M8MT, and it became a Blue wire coming back from the Shut Off switch, should this Blue wire go to the LMT?
If the Blue wire on the LMT side of the connector go to the LMB on/off switch, indicating "power coming in", should this blue wire be connected to the blue wire coming from the Shut Off switch, and before that from the M8MT?
Would this mean that 234v go into the LMT?
If the M8MT only puts out 234v (as it seems), can the monoblocks be 110v?
And if the M8MT feeds 234v into the LMT, why does it look like the LMT only feeds 100v to the RMT?
Will this blow anything up?
What do I do? Please help!
Many thanks,
Johan
I have 2 monoblock amps that came out of an AKAI M8 R2R tape recorder. I want to power them up, but don?t know how, and don?t want to mess anything up. I have seen them working, in the original suitcase, and know they power up, and all the valves light up.
Each monoblock has its own power transformer, and in the main box was a third, or main, transformer, that connects to normal 220v power through a standard 3-prong SA wall plug. I shall call this the M8MT (main transformer), and the other two the LMT (left monoblock power transformer) and the RMT (right monoblock power transformer).
Inside the original suitcase the M8MT fed the LMT and the LMT fed the RMT.
The small black round plug coming from the M8MT has 5 wires: Black, Red, Green, Grey and Yellow.
When I measure the voltage coming from the M8MT, I get the following:
Grey and Black = 234v
Grey and Red = 234v
Grey and Green = 234v
Grey and Red = 234v
Grey and Yellow = 234v
Yellow and Black/Red/Green = 0v
Black and Red/Green = 0v
Red and Black/Green = 0v
Green and Red/Black = 0v
So, without Grey in the mix, there is no voltage. Also, as there is no other reading in any combination than 234v, it would seem that the M8MT must feed 234v to the LMT?
The next step is that the 5 wires coming from the M8MT go to a large round black connector (female) with 6 pins, but only the Black, Red and Green wires coming from the M8MT are connected to 3 of the pins of this female connector. The Yellow wire is not connected to this plug ? they were connected somewhere else in the main suitcase, the the actual tape recorder part where, e.g. the motor lived. The Grey wire went to a Shut Off - Stop switch on the main body of the R2R, and a Blue wire returned from this Shut Off - Stop switch. I can't remember where the Blue wire coming back from this switch was (if it was) connected to this large connector!*
The male side of this large round connector comes from the LMT, and has 6 wires connected to the pins: Red, Black, Green, Yellow, Blue and White. So when the M8MT female side is connected to the LMT male side, Black=Black, Red=Red, Green=Green and Blue=empty, White=empty and Yellow=empty.
Arriving at the LMT, the power transformer has two ?strips? on the input side: one has 3 connectors saying [250v-C.T.-250v] and the other has 3 connectors saying [117v-100v-0].
The 6 wires that come from the connector between the LMT and the M8MT go as follows:
Black goes to the C.T. connector on the [250v-CT-250v] strip
Red goes to the 0 connector on the [117v-100v-0] strip
Blue goes to the on/off switch, and from there comes back (as a green wire) to the 100v connector on the [117v-100v-0] strip.
Red and Green both show a connection (my multimeter beeps) with all 3 connectors on the [117v-100v-0] strip?
Yellow and White go into the body of the Left mono block, but are not connected to the LMT, as far as I can tell.
Oh, and from the 100v and the 0 connectors on the LMT two wires go to a female plug, into which two wires from the RMT plug in, and then go to the 100v connector of the RMT and the on/off switch of the Right Monoblock amp.
I know this is a long and badly explained story, but it leaves me with some questions:
Are these monoblocks 220v or 110v?
If the Grey wire needed to be in the mix in order to measure any current coming from the M8MT, and it became a Blue wire coming back from the Shut Off switch, should this Blue wire go to the LMT?
If the Blue wire on the LMT side of the connector go to the LMB on/off switch, indicating "power coming in", should this blue wire be connected to the blue wire coming from the Shut Off switch, and before that from the M8MT?
Would this mean that 234v go into the LMT?
If the M8MT only puts out 234v (as it seems), can the monoblocks be 110v?
And if the M8MT feeds 234v into the LMT, why does it look like the LMT only feeds 100v to the RMT?
Will this blow anything up?
What do I do? Please help!
Many thanks,
Johan
