Moko's DIY 834 Phono Stage Build

[Phil Y]

"does anyone know if having the valves poking out the top of the case would cause any problems as in the confined space this is all going to have to fit in it may allow a bit more cooling?"

Ideally, with a phono stage you would want all the valves inside the case. Having said that you may get away with it. I re-used an old chassis to build my phono and it seems to suffer no particular noise or hum issues. Also, a phono stage would not really be pumping out all that much heat, especially with a solid state PSU. Some ventilation holes should be enough I would have thought.

Phil.

[paulfromcamden]

Have you been raiding the bins out the back of the hi-fi shop again?   

Shame it didn't come with the lid - looks like it would have been quite suitable for your project:

[ZZMoko]

Yep more bin raiding and believe me I looked for the lid but with no luck....where did you find that photo?

[paulfromcamden]

Photo is just from a google image search.

If such a thing existed as a right-angle valve socket adaptor you could mount the valves horizontally to fit in your case like a Croft amp... though I guess ECC83s aren't so big - maybe they'll fit anyway?

[ZZMoko]

Lid problem solved found another old CD player which can supply perfect lid and front panel with only a couple of holes in it so not loads of bodging required 

[ZZMoko]

So that's the power board all soldered up...stage 1 complete 

[needlekiller]

my thoughts, a wooden case, inside covered with cooperfoil. it looks nicer, it`s also cheep. it can made with the right dimensions for the boards! and it will be unique!
ps: happy new year

[ZZMoko]

Does anyone know why this resistor has this metal sleeve on one of its legs?



And if has to stay how do you solder it?

[needlekiller]

in the early days it was used to make a more stable solderconnection at high temperature parts, like big resistores.

[ZZMoko]

It's just on one leg of the brown resistor on the Input /L side at the book of the photo above...

Not sure how to solder it in place if it's required any of the other builders have any idea if it's necessary?

[needlekiller]

ah,the 47kohm  input-resistor, i bet it is on the ground-side!

[ZZMoko]

Ok more questions as I'm fairly clueless when it comes to electronics......

I'm intending to have two inputs on this phono stage one for my regular Stereo tonearm and one for my Mono GE VRII arm will I need a selector switch to choose between the two inputs or will it be ok to just wire up both inputs to the board?

If a switch is required what sort should I be looking for?

Something like this http://www.cricklewoodelectronics.com/RTY2.html? Or does anyone have any other suggestions?

[ecosprog]

Does anyone know why this resistor has this metal sleeve on one of its legs?



And if has to stay how do you solder it?

That metal sleeve has nothing to do with the resistor. They have simply stuck it on the resistor leg so it doesn´t get lost. I is a post that fits in to the ground (earth) hole on the PCB. It isn´t really necessary, but makes attaching earth wires easier.

[ZZMoko]

Thanks for that I couldn't figure why if it was to do with that resistor why there wasn't one for the other channel....

So I might save it and use it for the ground terminal if it's needed

[ZZMoko]

This I probably a very embarrassing question to ask but here goes.....

Which side of the PCB are you supposed to put the solder joint when soldering the components.....The same side as the components (the top side) or the side where the legs come through the PCB (the bottom side)?