Correct way to wire this board ?? Dual L/R Volume Pots

[Big_T]

Hello,

I'm having a bit of trouble understanding what is going on with this board by way of wiring Dual Left / Right Volume pots. My first thought was to intercept the positive wires with the Pot and run the pot ground to the negative, and do the same for both left then right channels. Looking at the board though it seems there is a dedicated array of ports to do just that but I cannot make heads or tails as to what is going on.

The Board is a EAR 834p Clone by Zhiliaudio.

Any ideas?

Please the Attached images. Many thanks.

Big_T

 

[sae-7125]

any useful info at this link?

My own version of the EAR 834P Clone

I'm building my own version of the EAR 834P Phono preamp, using the modified Thorsten version. Here the schematic I'm using.

www.diyaudio.com

E.A.R. Phono Stage

Just curious if any or many of those who listen to vinyl as a first choice and use a stand alone phono stage have used E.A.R. phono stages ? I believe there tube stage starts at around 800 dollars new so a bit above the standard price for a stage. From what I picked up on a search is that they...

audiokarma.org

*basic discussion.

depending on if R- and L- are using a common ground the pots should be easy to wire. each channel positive into the wiper of each pot (center pot lead) and then one of the outer pot leads (depending on clockwise volume up movement) goes to the board input to complete the series variable resistor in the signal path.

The Potentiometer: Pinout, Wiring, and How It Works

This is a potentiometer tutorial where you'll learn how it works and with examples of how potentiometers can be wired for various circuits.

www.build-electronic-circuits.com

*help with basic pot wiring.

 

[Big_T]

any useful info at this link?

My own version of the EAR 834P Clone

I'm building my own version of the EAR 834P Phono preamp, using the modified Thorsten version. Here the schematic I'm using.

www.diyaudio.com

E.A.R. Phono Stage

Just curious if any or many of those who listen to vinyl as a first choice and use a stand alone phono stage have used E.A.R. phono stages ? I believe there tube stage starts at around 800 dollars new so a bit above the standard price for a stage. From what I picked up on a search is that they...

audiokarma.org

*basic discussion.

depending on if R- and L- are using a common ground the pots should be easy to wire. each channel positive into the wiper of each pot (center pot lead) and then one of the outer pot leads (depending on clockwise volume up movement) goes to the board input to complete the series variable resistor in the signal path.

The Potentiometer: Pinout, Wiring, and How It Works

This is a potentiometer tutorial where you'll learn how it works and with examples of how potentiometers can be wired for various circuits.

www.build-electronic-circuits.com

*help with basic pot wiring.

Thank you for all of this info. I have also been scouring lencoheaven for any information. I could not find a solid answer but there seems to be some discussion as to whether or not a 68K resistor needs to be added.

I did come across a photo of a pot dropped directly into the board into those holes/ports. This seems to be for use with a slim casing design and separated boards preamp/Power so I cannot fit the same way in my configuration but at least I can see how it was mounted.


I will try with (2) 50K pots tonight or tomorrow and report back with my findings.

Attached is a photo I found online.

 

[Big_T]

Ok I wired the two separate 50K Pots in the same fashion as would be in the attached photo above. I soldered wire leads to the ports and attached those to the respective terminals of the pots. It makes sense that ports were spaced to allow a pot to be dropped in.

There was no effect at all on the sound turning the pots in both directions. This was surprising. I think that the ports need to be activated.

Referencing the image attached it is my guess that "Ra" Needs to be bridged to "R+" and "La" bridged to "L+" to activate the ports and facilitate the usage of the pot (or pots).

I am not confident enough to do this at the moment as I have company coming soon and need to button everything back up for now and cannot risk bricking the unit. I will use a Pot in the Box with RCA connectors for now to bring the overall level down.

I will say to anyone reading this that buying 5751 tubes in hopes of bringing the volume down (as suggested on many forums) has almost no effect at all on output level. I have done this and measured/recorded the output before and after. I can't remember exactly but the result was no more than about 0.5db of gain reduction with (3) 5751 tubes in all 3 sockets. There was a subtle reduction in bass performance noted also.



T