Making M7 Preamp

[jerrylong]

I am starting making a M7 preamp, this circuit comes from a experience DIYer of Singapore. It is not origenal version of Marantz 7, it is a mod version
This is amplifier circuit

This is PSU

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[jerrylong]

This is the case I used for this preamp

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[jerrylong]

I planed to use two separated PSU for each channel



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[jerrylong]

and I used another case for the PSU

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[jerrylong]

In this preamp circuit, the most important things to do is the method to place the GND
of different amplifier stage
the order is:
PSU->RCA-in->Vol pots->1# vacuum tube->2# vacuum tube->3# vacuum tube->RCA-out->cap(3n3) and res(100R)->GND

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[jerrylong]

this is the transfomer I ordered
prim:0-220V-230V
secend:0-140V/100ma(2X); 0-15V/1.5A;0-15V(150ma);0-6.3V-7V/1.5A

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[jerrylong]

I have used PCB for this preamp
1, the amplifier PCB

2, the cathode res PCB, the most improtant thing of this PCB is the order of each GND

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[jerrylong]

3, the PSU PCB

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[jerrylong]

this is the way I install the PSU case

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[jerrylong]

this is the way I install the AMP case

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[jerrylong]

I planed to use two aviation plug to connecte the PSU case and AMP case
1, High Volt
0-282V, 2X
2, Low Volt
DC 0-6.3V, for the heater
AC 0-6.3V, for the heater
(I put two power wire for the heater for test, which is best?)
AC 0-15V, for the UV meter PCB


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[jerrylong]

I had posted a thread for the solution of put a Balance Pots in the circuit
How to install Potentiometer for Balance?


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[jerrylong]

I have designed the back pad of the AMP case

and I used my CNC to make it

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[jerrylong]

the heater regulater DC power PCB is finished

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[jerrylong]

Today, I finished this part used for aviation plug

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[jerrylong]

This is the DC power PCB for the UV meter

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[jerrylong]

I have finished the PSU case

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[jerrylong]

And the PSU PCB and transformer have been settled down

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[stocktrader200]

Great job here, I bet it will sound fantastic. Power supply looks awesome

 

[jerrylong]

The amplify case arrangements, 5 PCBs have been settled down

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