March 6th, 2012, 05:43 AM
are the type of snap-in amp pots that use support brackets using the support brackets merely as ground points?
i want to replace the old pots in my amp (crackly and scratchy sounding) but i'm wondering if i absolutely have to use these kind of pots. If i match the values properly and jumper the terminals to the correct locations on the board shouldn't i be able to use standard pots with wire terminals?
I intend to replace them, i have no desire to simply try and clean them out to save a buck.
March 6th, 2012, 09:56 AM
Yes, you can do what you've described if there is room to hand wire it. Personally, I much prefer it the way you have described. The "flying lead" design removes a possible stress fracture point from your amp, and in my opinion increases reliability for many amplifier designs. It is, however, rather labor intensive.
You may know much, all or even more than I'm listing below. This is for everyone's benefit.
When replacing pots, make SURE you are getting the proper value and type...not just the correct resistance, but also the correct physical design, wattage and taper. The "taper" is the rate at which resistance rises when the potentiometer control is rotated. If you put the incorrect taper in your amp, your controls will function oddly...excessively twitchy volumes, overdrives, tones or tremolos...or knobs which suddenly seem unresponsive or sluggish.
There are three main tapers used in guitar amps
1. linear taper
2. logarithmic taper (sometimes called "audio taper")
3. REVERSE logarithmic taper (sometimes called "reverse audio taper")
There are a number of other specialty tapers available, including tapped, combination linear/log, and non-linear with tapers defined for a specific application.
Potentiometer taper values are indicated by the vendor, along with the resistance. Here is a decoder for many OEM manufacturers' potentiometer taper and other manufacturing mysteries.
The above link is a very helpful file which can help you accurately decipher the NOS OEM major brand codes. (CTS, IRC, Clariostat, Mallory, etc.)
Foreign brands, good luck with those. They're like so many other foreign parts - shoddy and inconsistent. I'd stick with a quality American part for this, if possible. You may be surprised and shocked by the difference in price between a CTS pot and an cheap foreign knock off. There's a reason for that price difference. Not trying to politic here, but buy US made OEM pots if you can afford them. They're just a much better and more consistent part.
Note that foreign made parts also often use metric threaded shafts and nuts, which are slightly smaller than US made OEM units. If you choose to go with American made units, you will have to ream out the holes in your chassis to get the US made pots to fit. Not hard, but it is a commitment. Once you go there, you'll never go back. :-)
Finally, note that potentiometers also come in different shaft lengths and different shank lengths. (longer or shorter threaded portions, as well as longer or shorter control shafts). They also come in knurled, split knurled shafts for push on knobs (like a Stratocaster volume knob) or solid shafts (for knobs with set screws, like Fender amp knobs) and also solid relieved shafts (A round shaft with a flat section on it, which both indexes the knob and provides for extremely secure lock-down when using set screw type knobs.)
Good soldering with your new setup. Hope it goes well.
March 6th, 2012, 07:02 PM
Yes, you can do what you've described if there is room to hand wire it. Personally, I much prefer it the way you have described. The "flying lead" design removes a possible stress fracture point from your amp, and in my opinion increases reliability for many amplifier designs. It is, however, rather labor intensiveThat's great. ya there should be plenty of room to hand wire it in.
I can see where this kind of installation would help prevent fractures in the joints where they're connected to the PCB. I really do hate the cheap plastic components used in amps like this, but not much i can do about it.
Also I was hoping to swap out the knobs for some vintage round style knobs, but those are meant to fit standard 1/4" shaft pots - if i hand wire the pots in then this might be a possilbility. Purely aesthetic of course.
As for the labor intensive part of things, that doesn't deter me one bit. I'm a hobbyist and have no problem tinkering away on this thing and learning via experimentation.
I'm so tired of asking about options and techniques and having people tell me "oh don't do that, its too hard/not worth it/too much work, just do it MY way (the easy way/cheap way)".
I didn't ask what's the "easiest way to do this" i asked "is this method possible".
thanks so much for answering the question i asked initially!
March 6th, 2012, 07:43 PM
Thanks to you and good luck. Glad to see folks doing it for the joy and learning...not strictly to turn a buck and ask "how cheap and fast".
Enjoy the soldering!