Bigbottle MM/MC Hybrid Valve Phonostage PCB

[Blues ea]

i get my board. It is a piece of art. When I can build that amplifier on that same level, it can only become great. Thanks.

 

[Bigman80]

i get my board. It is a piece of art. When I can build that amplifier on that same level, it can only become great. Thanks.

Great news, and thank you

 

[grey1]

My board just arrived. It's so nice looking I'm almost sorry to solder on it. Now I just have to wait for transformer to arrive

 

[Bigman80]

My board just arrived. It's so nice looking I'm almost sorry to solder on it. Now I just have to wait for transformer to arrive

Thanks for letting me know....its a good looking PCB isnt it!

Your Transformer was posted this morning 🙂

 

[ringeraja]

@Bigman80
Hi mate.
I have a question regarding “LOAD” positions, left and right, on board - what is the function?
Could you explain me a little bit, please.
Kind regards.
S.

 

[Bigman80]

@Bigman80
Hi mate.
I have a question regarding “LOAD” positions, left and right, on board - what is the function?
Could you explain me a little bit, please.
Kind regards.
S.

The load sockets are to use with MM or MC carts. If you need more Capacitance for your MM carts, you can add a capacitor there, or if you need 400ohm for you MC cart, you can add the requisite resistor there instead.

I usually install RCA socket and make loading plugs to insert with whatever value resistor I need, soldered to the RCA plug.

 

[Ryssen]

The load sockets are to use with MM or MC carts. If you need more Capacitance for your MM carts, you can add a capacitor there, or if you need 400ohm for you MC cart, you can add the requisite resistor.

Or you kan add a switch to make it variable .

 

[Bigman80]

Or you kan add a switch to make it variable .

Absolutely

 

[ringeraja]

Many thanks to both od you.
Think it will be variable 🙂

 

[stoN_Cold]

I usually install RCA socket and make loading plugs to insert with whatever value resistor I need, soldered to the RCA plug.

OK, RCA plug with resiestor or capacitor.

 

[stoN_Cold]

Does anyone have any idea regarding the values of resistors and capacitors if make it variable with rotatory multi contact switch?

 

[Bigman80]

Does anyone have any idea regarding the values of resistors and capacitors if make it variable with rotatory multi contact switch?

You add whatever values are required fornthe cartridges you have.

 

[ringeraja]

Or you kan add a switch to make it variable .

Do you have some “know how” example to help me?
Thank you in advance.

 

[Ryssen]

I have used 6 posision multi swich with 10-47-100-248-474-1000 ohms resistors.
Thats for my Denon 2 MC pickup.

 

[sebmeb]

I have used 6 posision multi swich with 10-47-100-248-474-1000 ohms resistors.
Thats for my Denon 2 MC pickup.

And for MM-?

 

[Ryssen]

For MM I dont know,sommeone else will have to answer that.

 

[craigtone]

MM is almost always 47k. But, there are others that have had good luck at up to 100k. Your best bet is to trial and error and use what sounds good. Or look at many famous phono stages and copy what they use.

 

[Vivant]

The usual variable to try with MM is the total capacitance of interconnects plus additional capacitance added to the 'load' connection/socket.

The board has 150pF as built, you can add in say 50pF increments to give total 200/250/300pF etc.

 

[stoN_Cold]

What about sch?

 

[Bas Horneman]

What about sch?

The person who designed this phonostage only agreed to a GB if the schematic was not published.