Alpha vs CGE Pots

[straycat]

Has anybody used the CGE pots and what is the difference between Alpha and CGE pots?

[bluze81]

Has anybody used the CGE pots and what is the difference between Alpha and CGE pots?

Both good pots, the CGE solder much better when grounding to the back of pots, Alphas dont like to hold the solder well, I prefer the CGE pots, bluze

[GUITARmole]

Has anybody used the CGE pots and what is the difference between Alpha and CGE pots?

The difference? A little over $3 isn't it?

[straycat]

Thanks bluze81 good luck on the JTM50 .How did you like your JPM50's that you built?

[Flames1950]

The CGE pots are nice but their action almost feels too loose to me, like you could bump your amp and change the settings. Mind you, that's not actually happened, just feels floppy when I turn the knobs. Alphas typically have a nice smooth turn to them. PEC's are stiff and have kind of a scratchy, rough feel to them when you turn the knob.

[Billy Batz]

Alphas get that way tho and some in a short time.

[Flames1950]

Alphas get that way tho and some in a short time.

Loose and floppy, or stiff and scratchy?

[bluze81]

Thanks bluze81 good luck on the JTM50 .How did you like your JPM50's that you built?

the JMP50 build I did is awsome, I gig with the amp on a regular basis,its so creamy sounding, I get many a complement on tone when other players come to the shows,I also have a Metro/Blueflame 45 that Flames1950 built,that gets played out alot as well, these amps are killer tone, and dont break the bank...bluze

[straycat]

I have used PEC and Clarostat pots before and prefer the PEC over the Clarostat. I know you can not solder on the back of Clarostat pots. Can you solder on the back of PEC pots?

[bluze81]

I have used PEC and Clarostat pots before and prefer the PEC over the Clarostat. I know you can not solder on the back of Clarostat pots. Can you solder on the back of PEC pots?

I think theres a picture of one of the Metro amps in the store with pec pots that have the ground buss wire soldered to the back of the pots, so it looks like George does it,I think?[need to check the picture of the JTM45/100 build in the store] if so it would be wise to use a heat sink when soldering to back of any pots.

[Billy Batz]

Alphas get that way tho and some in a short time.

Loose and floppy, or stiff and scratchy?

Former.

[neikeel]

I have used all three types in my builds.

I prefer the CGE pots for ability to solder. The PEC pots feel more solid, don't find them scratchy. They are very similar to the original RS pots found in early plexis. I believe that they do not solder well (aren't the backs stainless steel?). I did not even try and copied Flames by putting a straight bus wire looped through the lugs of my PEC pots.

Alphas are ok but do not solder nicely even after polishing a strip of the plating off with a grinding wheel.

CGE feel and look closest to the originals and solder well.

[Joe Popp]

I have tried Alpha, PEC, and CGE. Out of all of them I like the CGEs the best. CGEs do use a plastic stop which can break if you are putting on tight knobs. I use a buss bar so soldering to the back of the pot is not an issue for me, but I think the PEC pots are stainless. You could use a buss bar for grounding or do it the way Germino does. Not authentic but it works great.

[GUITARmole]

if so it would be wise to use a heat sink when soldering to back of any pots.

How do you heat sink the back of a pot while at the same time getting it hot enough for solder to stick?

Beside looking cool what's the point of grounding the backs anyway? Aren't the backs all grounded anyway by the front being attached to the chassis by a metal shaft sleeve and nut?

[wdelaney72]

if so it would be wise to use a heat sink when soldering to back of any pots.

How do you heat sink the back of a pot while at the same time getting it hot enough for solder to stick?

Beside looking cool what's the point of grounding the backs anyway? Aren't the backs all grounded anyway by the front being attached to the chassis by a metal shaft sleeve and nut?

The grounding bus on the back of the pots is not necessary. A while back Rockstah posted this grounding scheme for the amp, which is very quiet:
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v1-v2 cathodes grounded on pot buss between the input jacks and first volume pot -

the pot grounding buss( the presence pot is not in this buss ) should be grounded to the choke screw under the main board closest to the front of the amp. run a wire from your buss to this screw with a lug there

preamp cap on main board goes to same screw as the pot buss

pt grounds on PI cap screw closest to the front of amp along with the bias supply and mains grounds.

screens ground along with PI cap and presence on the other PI cap screw towards the back off the amp.

the ac plug gets its own screw and lug ( i threw a lug on one of the PT mounting screws.

In keeping with the above scheme the bias pot grounds would stay with the regular bias supply ground. An added gain stage like Bainzy's you could run the added stages grounds together, then to the lug the preamp ground goes to, or even just the preamp ground buss would likely do. The switch the same, though it only grounds the added tubes grid to ground to silence it when not in use, so shouldn't be too important exactly where it grounds as no circuit current flows through there.
Also a good general idea if using the scheme discussed here is to NOT solder the preamp buss wire to the control pot backs. Doing this creates potential ground problems, though you very often will get away with it just fine in these amps. Best though for there to be one path to ground, and each pot back that is soldered to the buss creates string of multiple ground points through the metal pots themselves.