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3,968 posts
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Post by salteedog on Jan 6, 2020 18:56:37 GMT
If the pickups are P90s then either 250K or 500K can be used. 500K pots will give the guitar a slightly brighter tone. Type A or Type B for volume or tome is a matter of preference.
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Post by blindwilly3fingers on Jan 6, 2020 20:58:51 GMT
Back to what type of pups are in the JA60! The pups in my JA60 are the jazzmaster lookalikes. They are neck 7k bridge 11.5k (or there abouts). I don't know what the pots or caps are? Not needed to take it apart. Now if these are jazzmaster or P90s I don't know. I think hartonbenley took some apart and they are very similar to jazzmasters in dimensions. What I will say is they sound nothing like the P90s in my 450GT which are both just over 9k and are typical soapbar P90s. Tbh the JA60 is a lookalike without the additional tone circuit it will never sound like it.
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ttmax
Harley Benton Expert
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Post by ttmax on Jan 7, 2020 0:20:36 GMT
Are you saying that the original tone pot acted like a volume pot and now you've replaced them they still do the same thing ttmax? salteedog , I know the older JA60s came with P90s but didn't that swap to Roswell Jazzmaster types at some point? Looking online they seem to be P90s again. My Ja-60 has the volume B250k and the tone A250k. Since they are both really cheap, I wanted to replace them, but when I started I didn't have the volume but only the tone. I had a 1mega cts audio tone and an alpha A500k. I tested them both with a 0.047 capacitor. But I always got the same result, from 10 up to almost 0 no change of tone to 0 no sound practically as the volume potentiometer behaves. I know that both 250k and 500k can be used with the known frequency cut variants, but my question was different, how come both the A500k and the 1mega do not cut the tones depends on the volume that I left B250k or what else? Thank you Hb pot What have I tried And this is pickups roswell From thomann description Hb ja-60 Pickups: 2 Roswell AlNiCo-5 Vintage Style P90 single coils Squier cv 60s jazzmaster Pickups: 2 Fender Designed Alnico Single Coils I know that the fender ones are not p90* now everything is to understand if the roswells are like the fender and therefore the description of thomann is wrong or they are p90 with the appearance of the fender jazzmaster. On the roswell website there is no trace of these pseudo jazzmasters and if you remember in the older model they were just p90. All to understand if is better change pot with 500k (default p90) or use 1mega (default jazzmaster) or change only with best quality and left 250k value (actually more bright for me) but i don't know if cause is very cheap build *The P90 coil is twice as tall as the Jazzmaster coil. Jazzmaster pickups have magnetized alnico rod pole pieces while P90s have adjustable pole pieces magnetized by a pair of bar magnets attached underneath.
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DefJef
THBC Moderator
Due to musical differences I've decided I can't work with myself any more.
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Post by DefJef on Jan 7, 2020 1:11:43 GMT
It is very annoying this lookalike Jazzmaster pickups situation but I felt sure we had got to a point with Harley Benton that they were now using genuine Jazzmaster design ones instead of P90s. Perhaps hartonbenley can tell us about his? They do show some Jazzmaster-alike pickups at the Roswell manufacturer's site that look like yours but they DON'T show any that they say are P90s that LOOK like Jazzmaster ones! As for the pots, I wouldn't bother with 1meg ones as the circuit is nothing like a Jazzmaster's. In fact, even if it were, 250Ks will often suffice. Maybe try using the original pots but swapping their uses, the A for audio and the B for tone and see if that gets you there?
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3,457 posts
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Post by LeoThunder on Jan 7, 2020 8:27:48 GMT
I found on board vol pot B250k and tone pot A250k with 2A223J Capacitor (i presume 2.2nf) Normally on jazzmaster vol and tone are 1mega. I try to chance tone pot with cts Audio 1mg or alpha A500k (both 4,7nf Capacitor) but always have the same result or does not change tone but behave as if they were a vol pot. Where can the problem be? It is correct that the vol is type B and the tone type A. Wich are default value for this type of guitar? Fender use 1mega because have also rythm circuit or because your pickups not are p90 but a single fender patente pickups? Thank you References: HB JA-60 vol B250k tone A250K Yamaha RS502T vol A500k tone A250K HB CST-24P90 vol B500k tone A250K Why HB invert Pot type B for vol and A for tone? This is all a little weird but my SC-450 Plus came with one A tone pot and the other was B. There is no design reason for this, it was someone grabbing the wrong type while assembling. Both volume pots were A and all were 500KOhm. Volume pots are usually log while tone pots are sometimes linear. I remember reading that A and B are not always used consistently so you'll have to measure the resistance at mid course to know what you have. Half the value indicates a linear potentiometer. I think the B pot in my SC-450 Plus was linear and the A were logarithmic, also called "audio". Misconception: the value of the tone pot does not affect tone, only the effectiveness of the sweep. The higher the value, the less it will be effective in rolling highs off at the beginning of its course (from 10 downwards). The capacitance value determines the tone reached when the pot turns down. The value of the volume pot affects tone even when the volume is on full. A lower value reduces the cutting frequency of the system and takes high end away. Early Telecasters had 1 MOhm volume pots because amplifiers of the time were junk (my own suspicion) and possibly because Fender wanted to provide piercing highs for a certain style popular at the time. Or maybe they thought limits were better kept out of the instrument by principle and relied on amplifier EQ. Anyway, I also suspect the same "no limit" reasoning led to 1M being used in Jazzmasters: the "rhythm" circuit offered the toning down and the regular one was full spectrum. Since these pick-ups are single coils, I can see how they could still sound fine with a 250K volume pot but it really should be logarithmic. 500K will make it brighter. The JA-60 used to come with P90s but this changed to Jazzmaster-like pick-ups about a year ago. You can tell what you have by their size and the presence of screws on the smaller P90. The one in the middle has the new Jazzmaster-like pick-ups:
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3,457 posts
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Post by LeoThunder on Jan 7, 2020 8:39:50 GMT
And this is pickups roswell From thomann description Hb ja-60 Pickups: 2 Roswell AlNiCo-5 Vintage Style P90 single coils You have the recent Jazmaster-like pick-ups. And once again, the product description failed to be updated, reflecting the older version. The Thomann site is sadly sloppy with such things.
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3,457 posts
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Post by LeoThunder on Jan 7, 2020 8:51:19 GMT
My Ja-60 has the volume B250k and the tone A250k. Since they are both really cheap, I wanted to replace them, but when I started I didn't have the volume but only the tone. I had a 1mega cts audio tone and an alpha A500k. I tested them both with a 0.047 capacitor. But I always got the same result, from 10 up to almost 0 no change of tone to 0 no sound practically as the volume potentiometer behaves. I know that both 250k and 500k can be used with the known frequency cut variants, but my question was different, how come both the A500k and the 1mega do not cut the tones depends on the volume that I left B250k or what else? Thank you Strange. It's a little like the 500K tone pots on my SC-450 Plus. They are barely effective between 10 and 4. I wonder what is the impact of their matching with the volume pot in this regard. I never cared to dig into this question. Did the 250K tone pot work better?
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3,968 posts
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Post by salteedog on Jan 7, 2020 10:27:12 GMT
ttmax Is the guitar a left handed model?
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ttmax
Harley Benton Expert
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Post by ttmax on Jan 7, 2020 11:47:38 GMT
My Ja-60 has the volume B250k and the tone A250k. Since they are both really cheap, I wanted to replace them, but when I started I didn't have the volume but only the tone. I had a 1mega cts audio tone and an alpha A500k. I tested them both with a 0.047 capacitor. But I always got the same result, from 10 up to almost 0 no change of tone to 0 no sound practically as the volume potentiometer behaves. I know that both 250k and 500k can be used with the known frequency cut variants, but my question was different, how come both the A500k and the 1mega do not cut the tones depends on the volume that I left B250k or what else? Thank you Strange. It's a little like the 500K tone pots on my SC-450 Plus. They are barely effective between 10 and 4. I wonder what is the impact of their matching with the volume pot in this regard. I never cared to dig into this question. Did the 250K tone pot work better? No have idea, will buy two couple A/B250k and A/B500k actually no have any A250k other the default very cheap.
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3,457 posts
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Post by LeoThunder on Jan 7, 2020 16:02:45 GMT
Strange. It's a little like the 500K tone pots on my SC-450 Plus. They are barely effective between 10 and 4. I wonder what is the impact of their matching with the volume pot in this regard. I never cared to dig into this question. Did the 250K tone pot work better? No have idea, will buy two couple A/B250k and A/B500k actually no have any A250k other the default very cheap. Expensive pots are not better than cheap ones.
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ttmax
Harley Benton Expert
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Post by ttmax on Jan 8, 2020 15:45:49 GMT
It is very annoying this lookalike Jazzmaster pickups situation but I felt sure we had got to a point with Harley Benton that they were now using genuine Jazzmaster design ones instead of P90s. Perhaps hartonbenley can tell us about his? They do show some Jazzmaster-alike pickups at the Roswell manufacturer's site that look like yours but they DON'T show any that they say are P90s that LOOK like Jazzmaster ones! As for the pots, I wouldn't bother with 1meg ones as the circuit is nothing like a Jazzmaster's. In fact, even if it were, 250Ks will often suffice. Maybe try using the original pots but swapping their uses, the A for audio and the B for tone and see if that gets you there? Thank you for info, strange that on roswellpickups web site i don't found this pickups. Probably can use 250k value this pickups sbould be single coil family with only more output.
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