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Got my Blacktop JM this week... I am very happy with it, very quality for the cash.... but the tone knob does not work as well as I like, it does not do much untill you roll down to about 2..... so I think it will be cap replacement time....I will prolly go with orange drops as I have never used them, You guys think this will fix my issue with the tone knob functionality? I have not cracked the axe open yet but I assume it is a normal .033 JM cap...you think this should be a straight swap for the results I want or a .022 or .047?

what is your problem the functionality exactly? does it not get dark enough? does it get too dark? does it just not roll off smooth enough as you turn it?

well, alittle of all the above.... the roll off is deffinately not smooth, there is not a huge difference in sound from 4-10, then at about 3 and below it gets too flat and dull, I would just like it to be more functional thru out the whole range and darken up a bit sooner and more gradual, on my other guitars I love putting the tone to about 5 on the neck with fuzz and letting it sing....

sounds pretty normal to me. :) but you could try using a linear taper pot instead of an audio taper pot or vice versa.

Please do a video demo of the Blacktop JM.

so basically this is a Fender thing?.... as u can tell by my name I am a Gibson dude at heart, this is my first Fender I have had since 2007.... Well, I know most Jazzmasters have 1kB vol, 1kA tone pot..... maybe I will try changing the pot taper if u think that will help, along with a better cap

I usually change the pots for linear taper, work much better to my ears.

taylornutt wrote:Please do a video demo of the Blacktop JM.

sorry bro, no camcorder in my household

But if you have any questions I would be more than willing to answer them.... I really think that if you want an affordable JM you should buy this guitar

correction, pots are 1meg not 1k, tone 1mA, vol 1mB on most JM

yeah, so your tone pot is audio taper. something like 2 or 3 on this graph:



the cap doesn't really come into effect until around 3 or 4 on the knob (around .7 or .8 on this graph). this works well for volume adjustment but it's not always so good for tone pots. try using a linear taper pot, a 1MB.

Thanks Mages....The graph was a nice touch, u da man!

I will try this once I get to the electronics store or place a small bear order..... If this works then I will be COMPLETELY satisfied with my new purchase. This thing blows the MIM strat I use to have away...

decided to pop it open and vol is 500kB and tone is 500kB with a Panasonic brownie 100v .033 cap.... the cap is a good cap, its what I use in some pedals I build but the pots are cheaper ones...but I guess this debunks audio tone taper.... and I suppose they used 500k pots to tame it a bit cuz there is not separate lead and rhythm circuits and the humbucker....

I guess maybe I am just being to picky about the tone control taper.....maybe its just the difference between Fenders and the Gibsons I am use to?

Thom wrote:I usually change the pots for linear taper, work much better to my ears.

And I usually change to audio taper, cause that works better to my ears. You gotta just dick around and find what works FOR YOU.

yeah, what will said. also, I think you are left handed thom? so log taper for you would be reverse-log.

also, I think the pot value makes a difference as it takes the same amount of resistance to filter the signal through the cap but different pot values will take a different amount of turn to get to that resistance, if that follows. so you could try out some different pot values as well. or try tacking some different resistors in between the pot and the cap. this will have the effect of the pot being "fixed" at that point of resistance when all the way down.

if this was my guitar i would tear the tone knob off and rig up each pickup for independent volumes with 2 vol knobs. like the super sonic

Mages wrote:yeah, what will said. also, I think you are left handed thom? so log taper for you would be reverse-log.

Spot on - that's the reason I swap to linear. Though until now have never thought of getting a reverse-log, which I imagine would result in a lefty log pot - going to have to give that a go!

I am gonna forget about this for now and get back to enjoying my new sweet guitar... this is just taking away from the fact that I got a new axe I will mess with pot changes and such when I start to get bored and am craving something new.... But I truely do love this guitar.... I feel its gonna be a keeper like my LP and SG.... I will probably try alpha or cts pots orange drops and the audio taper for the tone in the future thou and I will let you guys know my result...Thanks for the input...very helpful

Thom wrote:

Mages wrote:yeah, what will said. also, I think you are left handed thom? so log taper for you would be reverse-log.

Spot on - that's the reason I swap to linear. Though until now have never thought of getting a reverse-log, which I imagine would result in a lefty log pot - going to have to give that a go!

Can't you just swap the wiring around for any pot to work backwards though? Y'don't need no reverse gubbins.

Oh, also wanted to throw out there when I put her back together I threw 10's on there and it made a very nice difference in the tone of this guitar.... the pick-ups sound more lively and punchy, whenever I get a professional set up I think this thing will love some 11's.... but I have never filed a nut so that's waiting too

Doog wrote:

Thom wrote:

Mages wrote:yeah, what will said. also, I think you are left handed thom? so log taper for you would be reverse-log.

Spot on - that's the reason I swap to linear. Though until now have never thought of getting a reverse-log, which I imagine would result in a lefty log pot - going to have to give that a go!

Can't you just swap the wiring around for any pot to work backwards though? Y'don't need no reverse gubbins.

Would't they then be on 10 when on 0 and vice versa though?