So, Ferrofluid in the gaps of tulips is not unique and not something nescessarily needing replacement. In fact, judging by Master MZM’s, most times it will NOT be required to change fluids.
There are however, a couple of situations that may induce a need to change Ferrofluid:
1: Oookups, leading to leakage of fluid, etc etc.
2: Damage to fluid due to overheating over time (not very relevant for household speakers, more relevant for PR).
3: Dirty fluid.
So in my limited experience I consider a few key take aways regarding Ferrofluid:
1: Ferrofluid ensures cooling of the tweeter diaphrahm. It’s viscosity and amount is mathematically deduced to match physical dimensions of the voice coil, gaps and operating conditions in order to provide desired frequency response through a wide variety of temperature and load conditions.
So:
2: Ensure the amount of fluid is equal in both tweeters, to provide equal operating conditions
3: Ensure correct type of fluid is applied if changing.
4: Ensure the fluid is clean.
5: Ensure the fluid is not damaged, ie that it has it’s original viscocity or close to it. See the following video to see what high temps may lead to (also, the vid shows a procedure for replacing ferrofluid, very nice, I plan to follow it):
Now, in my case, a combo of long time use, and an attempt to clean away dirt, has left me with dirty ferrofluid in both drivers and unequal amounts of Ferrofluid.
So I will also be servicing tweeters.
Step 1: Full clean, also of gap (to come)
Step 2: Regluing of magnet assembly, and then applying dammar to provide nice finish and ensure loose magnet bits stay in place (they are everywhere!!
)
3: Replacing Ferrofluid (with syringe, with drug addict needle to get properly into the gap)
Now, since Tannoy in 2006 provided a syringe with proper ferrofluid type and ampunt with the replacement tweeter diaphragm, I know the specified amount is 0,3mL, and the type to be APGS15N.
Now, I have somehow managed to get hold of another spare bottle of ferrofluid of the correct type. I have also bought several syringes, and greedy and not so greedy boyz have started to line up for leftovers
Hierarchy will rule, and I will take what I need first. With something to spare, not much.
Attached is a few pics that explain some of the reasons why I am servicing tweets too.
And yes, I did destroy one diaphragm, and yes - I wasted some ferrofluid from the provided replacement syringe, so now I needed more ferrofluid.
There are however, a couple of situations that may induce a need to change Ferrofluid:
1: Oookups, leading to leakage of fluid, etc etc.
2: Damage to fluid due to overheating over time (not very relevant for household speakers, more relevant for PR).
3: Dirty fluid.
So in my limited experience I consider a few key take aways regarding Ferrofluid:
1: Ferrofluid ensures cooling of the tweeter diaphrahm. It’s viscosity and amount is mathematically deduced to match physical dimensions of the voice coil, gaps and operating conditions in order to provide desired frequency response through a wide variety of temperature and load conditions.
So:
2: Ensure the amount of fluid is equal in both tweeters, to provide equal operating conditions
3: Ensure correct type of fluid is applied if changing.
4: Ensure the fluid is clean.
5: Ensure the fluid is not damaged, ie that it has it’s original viscocity or close to it. See the following video to see what high temps may lead to (also, the vid shows a procedure for replacing ferrofluid, very nice, I plan to follow it):
Now, in my case, a combo of long time use, and an attempt to clean away dirt, has left me with dirty ferrofluid in both drivers and unequal amounts of Ferrofluid.
So I will also be servicing tweeters.
Step 1: Full clean, also of gap (to come)
Step 2: Regluing of magnet assembly, and then applying dammar to provide nice finish and ensure loose magnet bits stay in place (they are everywhere!!
)3: Replacing Ferrofluid (with syringe, with drug addict needle to get properly into the gap)
Now, since Tannoy in 2006 provided a syringe with proper ferrofluid type and ampunt with the replacement tweeter diaphragm, I know the specified amount is 0,3mL, and the type to be APGS15N.
Now, I have somehow managed to get hold of another spare bottle of ferrofluid of the correct type. I have also bought several syringes, and greedy and not so greedy boyz have started to line up for leftovers
Hierarchy will rule, and I will take what I need first. With something to spare, not much.Attached is a few pics that explain some of the reasons why I am servicing tweets too.
And yes, I did destroy one diaphragm, and yes - I wasted some ferrofluid from the provided replacement syringe, so now I needed more ferrofluid.
Attachments
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Now, what ferrofluid is needed for your drivers?
Master MZM had cleverly explained to me that a lot of DC’s use the same tweeters as 3134, so if you own one of a certain few drivers, you need APGS15N ferrofluid and at least 0,3mL in each tweeter gap (after cleaning). Now, so that it is said: MZM/I will test both 0,3mL and 0,5mL and decide proper amount. It is likely better to use a tad too much than too little.
The following use this ferrofluid @ 0,3mL:
3134
3142
3139
3150
3833
3836
3840
And some MZM porn:
Master MZM had cleverly explained to me that a lot of DC’s use the same tweeters as 3134, so if you own one of a certain few drivers, you need APGS15N ferrofluid and at least 0,3mL in each tweeter gap (after cleaning). Now, so that it is said: MZM/I will test both 0,3mL and 0,5mL and decide proper amount. It is likely better to use a tad too much than too little.
The following use this ferrofluid @ 0,3mL:
3134
3142
3139
3150
3833
3836
3840
And some MZM porn:
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Now, where to get this drek?
Tannoy - it seems - will not be a reliable future provider. I have not checked V-Tech SMT LTD.
I have however spoke to Ferrotec. Unfortunately for me, only the US branch sells to private persons, and the minimum order is 250USD plus shipping. Nice for US greedy boyz, too heavy for me. I’d rather use beer in the gap.
Now, there is also an option of ordering ready filled syringes. But the minimum order is 600 syringes.
So there we are: possible absolutely, but not extremely easy. One could do a group buy, that would perhaps be best.
If interested, see contact info here: https://ferrofluid.ferrotec.com/contact-sales/
Now, I did get lucky and have fluid,
At least now through the help of Master MZM and Padawan Kuke Seronja (sissy moi), we have a reliable source of Ferrofluid, and type and amount for a set of drivers.
Unfortunately, my intel has it that there is no omnipotent list of drivers vs type and amount of ferrofluid, and I haven’t reached out to Tannoy, and also I am not sure if that would bare fruits anyways.
So now we are starting that list, I guess 🙂
Btw: next week I hope get the fluids and grow some balls, will post updates accordingly.
Tannoy - it seems - will not be a reliable future provider. I have not checked V-Tech SMT LTD.
I have however spoke to Ferrotec. Unfortunately for me, only the US branch sells to private persons, and the minimum order is 250USD plus shipping. Nice for US greedy boyz, too heavy for me. I’d rather use beer in the gap.
Now, there is also an option of ordering ready filled syringes. But the minimum order is 600 syringes.
So there we are: possible absolutely, but not extremely easy. One could do a group buy, that would perhaps be best.
If interested, see contact info here: https://ferrofluid.ferrotec.com/contact-sales/
Now, I did get lucky and have fluid,
At least now through the help of Master MZM and Padawan Kuke Seronja (sissy moi), we have a reliable source of Ferrofluid, and type and amount for a set of drivers.
Unfortunately, my intel has it that there is no omnipotent list of drivers vs type and amount of ferrofluid, and I haven’t reached out to Tannoy, and also I am not sure if that would bare fruits anyways.
So now we are starting that list, I guess 🙂
Btw: next week I hope get the fluids and grow some balls, will post updates accordingly.
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Bravo!…well done andynor, MZM and all those who helped!
I am lucky enough to make the list with my 3833GG drek…so now I know what I will be looking to horde for their eventual overhaul (prepare for the worst, hope for the best🤞).
Kind of hoping my k3149 gaps are fluid free. I’ll find out soon enough when I finish my baffles.
I’m tempted to say screw it and just place a minimum order with Ferrotec…they’re kind of within driving distance from me.
Doubt I can get filled syringes for the minimum though…might get a bit messy.
I am lucky enough to make the list with my 3833GG drek…so now I know what I will be looking to horde for their eventual overhaul (prepare for the worst, hope for the best🤞).
Kind of hoping my k3149 gaps are fluid free. I’ll find out soon enough when I finish my baffles.
I’m tempted to say screw it and just place a minimum order with Ferrotec…they’re kind of within driving distance from me.
Doubt I can get filled syringes for the minimum though…might get a bit messy.
few slight omissions in text above, but nothing critical/worthy of me typing
FFluid - role - better flux distribution in gap, thermal care of VC (not 'phragm) blahblah
don't care to try tweets with FFluid removed; logic sez that gap is probably wider than in case of construction sans FFluid, but who cares - I'm too old for logic
so, if there is doubt in FFluid state, chase new, remove old, sip new, assemble, wine time
FFluid - role - better flux distribution in gap, thermal care of VC (not 'phragm) blahblah
don't care to try tweets with FFluid removed; logic sez that gap is probably wider than in case of construction sans FFluid, but who cares - I'm too old for logic
so, if there is doubt in FFluid state, chase new, remove old, sip new, assemble, wine time
as far as I remember (lazy to check) K3149 is Pepperpot
I did cover that matter few posts back; you can add Pepper, but adding FFluid won't be cunning
3149 looks to me like a pepperpot, and MZM sez those do not EVER have ferrofluid.
Just ask your local dealer or heroinist to help out
Jokes aside: there are syringes that make retracting even such tiny amounts easy.
But no worries dude, I got you covered.
Yes…my k3149 do in fact have the pepperpot tweeters.
I wasn’t sure if “in general” was an all encompassing statement …or there was a chance for that nasty fluid to seep in and ruin my fun😉
no need for needle, 
gentle press on syringe right above gap and magnet is working instead of ya
edit: speaking of filling da FFl
for cleaning old one, paper shims, paper tissues, whatever
gentle press on syringe right above gap and magnet is working instead of ya
edit: speaking of filling da FFl
for cleaning old one, paper shims, paper tissues, whatever
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I know, but it will not hurt. I bought three syringes and two needles for 2 dollars. So who cares
Please note that there are syringes that have a rubber piston. This rubber part may be incompatible with ferrofluid. So for short period for just filling that is ok, you will not notice any problem. But do not use such syringes as a storage container. It may damage the ferrofluid and the piston. Other types of syringes which do not have this rubber piston are no problem at all.
Nice to see Ferrotech Europe joining the discussion
Also, a very good point. The 17 year old rubber in my syringe provided by Tannoy, looked as if it had started to dissolve.
good to know, as explanation, if my small Tanns one day starts shooting Gummi Bears from horn