Thomastik JF344

I absolutely love these strings but I don't understand why there's no mention anywhere on the packaging that these are roundcore strings which needs some precautions to avoid potential damage?

For anyone not aware of this: google it. Short version: roundcore strings need crimping or bending 90 degrees to avoid risking the outer wrapping separating from the inner core. Loosening the tension completely again after installing them may also be a bad idea.

I actually didn't realise these were roundcore strings until after I had ruined my first set. After removing the strings for a pickup replacement the A-strings never sounded right again. It had developed weird clanking noises when tuning it up to pitch, sounded permanentely more metallic than the other strings and had developed a slight buzzing sound originating from the string itself.

But even if you do things correctly these strings have a weird thing were they may suddenly break during tuning. I've never experienced them breaking during playing but twice when tuning. I've also heard others complain about this.

That's the negative, now for the positive:

They sound absolutely gorgeous! They definitely sound like flatwounds but they have a more orchestral quality than the classic "soul" flatwounds like LaBellas, GHS, etc. The Thomastisk Jazz flats are also much brighter than any other flats I've tried, with the possible exception of a fresh set of Rotosound 77. But the Roto's settle into their smoother "70s rock" signature sound while the Thomastik Jazz Flats STAY bright. They're not metallic bright like roundwounds though. Think flatwounds with a hint of crisp highs on top. The sound is extremely clear and balanced from top to bottom. It makes most other flatwounds seem very muddy by comparison. The lows are deep/tight rather than warm/pillowy. Mids are very organic/woody sounding and well balanced.

The Thomastik Jazz Flatwounds also have a very snappy/bouncy attack that is truly unique. They do have a touch of the flatwound "thump" but with far better sustain than most other flatwounds. The Pyramid Golds are the only strings I've tried with a similarly "bouncy" attack but the Pyramids are much less snappy/crisp and also have far less sustain. They're both great though, just depends on what you're looking for.

The tension is VERY low and may take some time getting used to. Opinions are very divided on these strings. Definitely not the best allrounders.

Personally I love them but they have a very distinct sound and "feel" that will not suit everyone. Plus there's the reliability issues...

I still highly recommend them because of the wonderful sound and the fact that no other string will provide anything remotely similar.

I put these strings on an Epiphone EB3 bass as I found it a tad uncomfortable/tight and boomy/indistinct with a few different roundwound brands. After rewiring the bass to 50s style wiring and still not quite achieving the clarity I was wanting I decided to try these TIs out as I'd read somewhere that Carol Kaye was a user - I thought I'd go for the fundamental and forsake clarity altogether. Really, who can argue with the bottom end of the Wrecking Crew?! These strings are fabulous - just superlative. They feel relatively low tension compared to the rounds I had previously installed, super comfortable and slinky, yet paradoxically the clarity is much improved. There's no metallic clang, just simply sublime string to string and low end frequency balance. Not as idiosyncratic as Pyramids, not the best for growl or zing. Just really, really fantastic flatwound punchy and thumpy musical performance. And they are immaculately wound too - totally flawless. They're aging beautifully, maintaining their string to string clarity yet sweetening/dulling on the top end in just the right way. Superb flats - highly recommended.

I've tried many brands of flatwound strings and love many of them, but they fade in comparison with Thomastiks!

They're quite a light gauge string and low tension, which isn't to everyone's taste from a flatwound, but they are absolutely lovely under the fingers - smooth to the touch.

Although the feel of them alone is worth the asking price, it's the sound and this is where I feel no other string compares. On fitting them, you still get a fair bit of brightness while they settle in - not roundwound bright, but not the dull thud some people associate with flatwound strings. This in itself sounds great, but it's as the strings break in and mellow out that they really come into their own - rich and warm, full or presence, despite the light gauge. They genuinely sound better the older they get and I had a set on a Precision Bass for 5 years with no need to change them (obviously, I wipe my strings down after playing). They were still on the bass when I sold it!

The good thing, is that they sound great on a Precision and Jazz Bass - I've found that some flats sound better on a Precision (La Bella deep Talking) while some sound better on a Jazz (Rotosound) but I'd happily have Thomastiks on both!

They are more expensive than some strings, but given that you will get years out of them if cared for, they are worth every penny!

I knew the tone I was looking for on this instrument, and had the opportunity to play these strings on a Fender Precision before I made the purchase. First off, if you are dreading tense-feeling flat wounds (tenser than equivalent round wounds, at any rate), you are in for a pleasant surprise with these. I'd rate the tension as about the same as regular 45-105 round wounds. Also, the string-to-string tension is remarkably even too.

Another surprise has been that they have proved less of a problem to intonate than any other set of flat wounds I've fitted, which I'd say was a major plus.

These strings are a little more expensive than average, but they arrived in perfect condition, no tarnishing or poor wraps and only minor setup tweaks were needed to get my bass sounding the best it's ever done. Very happy indeed with these strings.

It took 25 years of playing before I discovered these amazing flats....
I play a lot of fretless with a ebony fingerboard. Have tried a large number of strings, and now I have stopped searching.

Very very good quality and tonal response. These strings are similar to the "red" double bass strings from Thomastik, made for the electric bass.

The strings are very bright at once, but when they have settled in. the get a mellow feel. Sounds fantastic on my fretless. They are so easy to play and very responsive. Another thing is that these strings stay in tune better than other I have tested.

Not the cheapest strings, but oooh what quality! Simply the best flats I have had on my electric bass. Since I also have the red Thomastik on my double bass they felt very familiar. Same light tension.

I really cannot find anything negative to say about these flats..

Buy a set now and never look back!

I love the low tension feel of Thomastik JF344 Jazz flatwounds. They enable me to play with a very light touch and still get a string tone.

They are perfect on my Fender Precision basses and I also use them on an active jazz bass. They are particularly good on my fretless precision with an ebony fingerboard and when the bass is setup with a little to no relief they produce a very pleasing 'mwahhh' tone.

They are initially fairly bright out of the packet, so rolling off the bass's tone control may be required after fitting new strings. As they age they lose some of the brightness and settle into becoming a lot more mellow but remaining punchy. My oldest set are coming up for their tenth birthday and they're still going strong.

SOUND: I use TI JF344 on my beloved Fender J Bass. They tend to be a little bright when you mount them. Let's say that in the first 20-30 hours I've experienced quite a roundwound-like sound. As time goes by (playing time of course!) I've seen that the timbre went warmer and warmer. But not like most of strings, which often goes duller and duller. The more you play them, the more it gets interesting and outstanding. Once you've passed the "trial stage" -which often irritates people, who change them way before the time- you'll have fantastic strings, perfect for recording: nice fundamental, cutting the mix as much as you want without too much post-production. Live sound is nice as well. One thing I noticed is that they tend to change (more than other strings) the personality of a bass guitar. TIs are so recognisable. Don't lean too much on "occasional" string reviews: they often show you the sound of brand new TIs which is quite different from the real one. If you want to hear real TI sound, check Carol Kaye or some other real long time endorser.

QUALITY: If you come from "popular" strings, you'd think "now that's luxury". Soft, smooth, silky they don't go out of tune. Last forever. They are pretty loose, if you are a punk rocker you're gonna bend them accidentally all the time and claim nonsensical tuning issues. But if you like tasty bendings (even microtonal ones) or vibrato it's another good feature for you.

OVERALL: Great strings, great price.

I had bought these strings to see if they could work for me.
They didn't work acually. But I am giving these strings a high mark because, if you need what they are good for in my opinion, they really deserve a high mark.
These are quite bright and trebly strings. I kept these for some time, and the sound didn't settle that much, definitely not as much as other flatwounds would do. I was searching for some more thuddy strings with less overtones, instead.
If you still want some overtones and harmonics in your flatwounds, these are the way to go. They are quite low tension due to their peculiar gauge, but really not that much floppy as you might read on the internet. Just raise your action a little if you need it, and you're set. I didn't have many problems even with a pick with a hard touch, when properly set.
One thing I didn't expect you should be aware of, is that the G and D strings are a little more mellow, with less treble emphasis than the A and E strings. You can even see if you look closely that these two strings have a little less gaps in the windings than the other two strings. I guess that the A and E strings have a little different winding in order to maintain those harmonics that they manage to maintain with time.
So, if you need flatwounds with a brighter tone, definitely go for these Thomastiks!!