Vintage X-175 tone and volume knobs

[Gbart14]

I posted in another thread about the stiff tone pots on my 60 year old X-175. I loosened them up as best I could with Doxit F5 but I did not want to use my original tone knobs because they were starting to turn on the non-splined, non-split tone posts. So, I bought some 6mm knobs direct from Guild for their newer models and I am very impressed with the look. An expert could tell the differences but they are quite subtle and they will allow me to once again enjoy the guitar. Here are some side by side photos. The font is a tad different and the new one has the printing on top whereas the original was printed on the bottom but very hard to tell from a few feet away. Otherwise, for playing purposes, they look great. The originals will get stored away in the original case. The originals measure about 0.245 (interference fit on a 0.248 stem) and the new ones measure about 0.220 over the top of the splines. Note that the originals were also splined (see the inside shot of two knobs and note the wad of material as described by Hans) but have been significantly worn down on the smooth shaft. So, the challenge is to remove just enough material inside the knob to have an interference fit on the original stems. I may have to respline the new knobs once I get close so to allow some crush when they press on. I have some old pots with 1/4" splines that I could conceivably heat up and press in. The replacement knobs are cheap enough at $5.50 ea so I bought some spares to play with. Will revert with more detail as I progress.

 

[GAD]

Congrats! I did a whole write up on the clear Guild G-shield knobs here: https://www.gad.net/Blog/2019/09/17/identifying-guild-clear-g-shield-knobs/ As you say, the Newark St. knobs are pretty darn close.

 

[Gbart14]

Yes, thanks GAD. I used your info as a inspiration. My knobs still had the bits of cloth inside along with splines that were very nearly gone. I am thinking the splined knobs were originally to be used on splined stems and for some reason in 1960 they used solid non- splined stems. So, here is what I did so far. I held the new Guild knob in a drill press vice with a molded plastic vice clamp and carefully drilled out the 6mm splines to 15/64's. Then I took a brand new 1/4" drill and very carefully ran it into the hole. I then used a sharp triangular shaped jeweler's file to re-establish most of the original spines on the new knob and it fits perfectly on the volume pot and works like new. I have yet to put one on the tone pots and think they may need to be just a bit tighter to keep from spinning on the somewhat stiff double stacked pots. If this works as well as the volume knob, I will have accomplished the goal of keeping the original knobs in tact without destroying them trying in the effort to make them work.

 

[Gbart14]

Here is my finished product: 1960 X-175 with lubricated stacked tone pots reinstalled, new knobs from Guild are very close to the originals, especially when installed. Had to drill out the 6mm splined holes to 1/4" with a precision 1/4" drill on a drill press. Three of the knobs pressed on with just enough effort to know they are secure. One knob on the volume pot was a tiny bit loose so I added a bit of thread along the side of the shaft and pushed the knob on so that the thread stayed in place and it all works just great. The knobs are only $5.50 from Guild. Here is the finished product. Original knobs are stored away in the original case.