Gotoh SD91-05M HAPM Locking 6L N

Instalados en un Squier CV Bass VI, que aparte de sus "peculiares" características, tiene un trémolo que puede poner en aprietos cualquier afinación. Los que llevaba de origen no me satisfacían y me decidí por este modelo de clavijas con bloqueo. Las hice instalar, encajan como un guante por diseño y funcionamiento y lo mejor, es algo considerable la mejora. Recomiendo hacer lo mismo a quien tenga el mismo modelo, las clavijas que vienen de serie sencillamente no dan el tipo.

Excellent tuners! These are very smooth keep the instrument in tune an are identical to vintage tuner - drop in replacement.

pros:
Highest quality tuners!
Very smooth action.
Drop in replasement for vitnage type instruments

Cons:
Non really, apart from the fact that they com with 8.8mm bushings only and in many cases Fender guitars are made with 9.2mm bushungs which are shallower too. I had to order 9.2 bushings from elsewhere.

Also beware these are from All Parts not directly supplied from Gotoh so no original packing... no bushing tool, no 9.2 busjings in the kit, only 8.8mm

My rating is not full on 5 stars because of the last thing I mentioned. Which is not Gotoh's fault.

I bought these to replace a a set of LSR 40:1 gearless tuners on my strat copy. These look the part of the original Kluson-style vintage tuners and function very well. There are a few installation things to be aware of though.

This set arrived with an included set of 8mm bushings, a bushing removal tool, a 1,5mm hex wrench for the post height adjustment and instructions.

The bushings were too small for my guitar which needed 10mm OD and which I needed to source separately. Why? Well the mounting holes had been opened to just under 10 mm to mount the LSR tuners years ago. Now the posts on these Gotoh heads have a 6mm diameter and you will need to find bushings with corresponding holes. Not 6,35mm which you will be tempted to buy because they fit (and which are good for non-HAPM SD91 tuners!). The reason is that the gears will wear out faster if the holes in the bushings are not a reasonably snug fit. If you have 8mm holes in your headstock the included bushing will be fine - congratulations!

I also installed the tuners with Gotoh C.A.R.D. (CFK spacers) which Thomann does not stock. These are optional but according to Gotoh do bring some (arguable) benefits. Installation was straight forward and post height adjustment a breeze (check out the instruction videos on the Gotoh site- e.g. unlock the posts for height adjustment by turning the hew wrench clockwise for this set).
These adjustable posts potentially let you loose the string trees on a strat or tele. I have kept them to reduce string resonances, cure a "rattly" G-string (sitar sounds on open G which I lived with for ages but ultimately annoyed me), and increase the guitar mids, (yes they do, check out utoob for a clear example with 0, 1 & 2 string trees - but whether you like the tonal change is of course your call). For me adjusting post and string tree heights gave great tone, playability and wonderful tuning stability.

The auto string locks on the gears work wellish: just wind the strings, they lock the strings and you just tune up. But I found the tuning going flat with time. Why? The auto locking mechanism itself was tightening down on the string further with time, sending the string flat. Creeping tuner lock. The solution was easy; just tighten the head manually after lock using a 2mm pick or something that won't damage the head, like a coin would. It doesn't have to be really tight. Just maybe 1/8 turn more and finger tight to not damage any threads. The result is terrific tuning stability.

Pros:
+ they are well made, finished and really look the part on strats and teles.
+ they operate smoothly, precisely and without noticeable backlash (might change with time of course).
+ The post height adjustment is a cool feature when setting up your guitar in the best way (break angles over the nut and or string trees).
+ Can help to provide excellent tuner stability for tremolo users such as myself.

Cons:
- Nothing major but:
- You will still be using your string winder, and some other thing to tighten the tuning lock.
- Don't think that string changes will be faster than with a standard non-locking tuner. They won't be. Not an issue for me as I simply don't break strings. Or gig :)
- I think that C.A.R.D. whilst not essential should be provided with this set. But of course it'd bump the price by 10 Teuros or so.
- Sourcing the correct bushings (with 6mm ID) can be as issue. If Gotoh supplied a second set it'd be appreciated by many I guess.

In summary - well recommended tuners at a reasonable price. They look and operate just fine with just a couple of limitations / niggles that you can easily work around. And to be honest I'd say this of the even higher quality and priced Gotoh set (not stocked by Thomann).