IMF owners thread!
- Thread starter canuckaudiog
- Start date
Yvan_donald
Well-Known Member
Hi,Thank you John for replying to me on the meter subject, I suppose the price of these meters according to the % of precision.I have a capacitor meter but not for ESR and I did check some capsvalue when I change them the 5X 2.2uf was like 2.13, 2.15, 2.19, 2.21, 2.23 + or - the same for , The 60 uf is the one with more difference like 72uf and 75uf, the 100 uf arround for both 98uf, the 6uf around 6.8 and 7.7uf, the 12 uf like 12.7uf and 13.1uf. the .47uf was okey. The .47uf and the 2.2uf I really think it"s important tu put a very good quality one for the small value in the X-over
For now , I only did replace the bipolar electrolytes.I did not take out , the polyester/mylar 2.2uF caps.The values , that you wrote here , are presumably ,
from the new Mundorf or Jensen polypropylene , that you put in ???
These are very expensive , when at 2% tolerance.
I bought just , standard , 10% bipolar electrolytes.The old and new 100uF , were measuring 110uF.I also bought , 4x 2.2uF/100V , electrol , so to make 4 uF ,
when it would be necessary.
But the 3.9uF/100V , were measuring 4.6uF , so I used them.
For now , I will listen to the new electr bipolars , and at a later stage , I will pull the old Erie mylar/polyester caps.And measure them.
But , I can tell you , that only replacing the bipolars , already made a big positive change.
As for the ESR meter , in the US , you can buy the Blue ESR meter , but I don`t know , what it will cost.It`s about the same method , like my
ESR meter.
I did not ask , to pair the bipolar electr , because , I can do it myself.Those Jantzen , were just a random pick , from the shop.
The Era raw electr bipolar , were the same.Maybe in the future , I will put them in to see , if or what difference , it can / will make to the sound.
The 60uF , I had to use 2x 33uF.The new ones were measuring 36.6 and 36.7 uF (so not bad , for 4 electr in total).
The 6.8 was 7.6uF.
When soldering the parallel elcos , I did pay attention , to put all 4 , in the same direction.Like the beginning of the silk tekst , in the same way.
And , also , put them on the 2 xover boards , in the same direction.So , as not to mix things up.
The single elcos , I also put in the same way , on the 2 xovers.
So , that they would be identical.I know , you don`t need to pay attention , to which side , is on what end.
But , when paralleling the elcos , I`m not so sure , if you will not introduce ,small differences.
For polypropylene , it should not be a problem , but I will follow this same method , when I will replace the mylars.
from the new Mundorf or Jensen polypropylene , that you put in ???
These are very expensive , when at 2% tolerance.
I bought just , standard , 10% bipolar electrolytes.The old and new 100uF , were measuring 110uF.I also bought , 4x 2.2uF/100V , electrol , so to make 4 uF ,
when it would be necessary.
But the 3.9uF/100V , were measuring 4.6uF , so I used them.
For now , I will listen to the new electr bipolars , and at a later stage , I will pull the old Erie mylar/polyester caps.And measure them.
But , I can tell you , that only replacing the bipolars , already made a big positive change.
As for the ESR meter , in the US , you can buy the Blue ESR meter , but I don`t know , what it will cost.It`s about the same method , like my
ESR meter.
I did not ask , to pair the bipolar electr , because , I can do it myself.Those Jantzen , were just a random pick , from the shop.
The Era raw electr bipolar , were the same.Maybe in the future , I will put them in to see , if or what difference , it can / will make to the sound.
The 60uF , I had to use 2x 33uF.The new ones were measuring 36.6 and 36.7 uF (so not bad , for 4 electr in total).
The 6.8 was 7.6uF.
When soldering the parallel elcos , I did pay attention , to put all 4 , in the same direction.Like the beginning of the silk tekst , in the same way.
And , also , put them on the 2 xover boards , in the same direction.So , as not to mix things up.
The single elcos , I also put in the same way , on the 2 xovers.
So , that they would be identical.I know , you don`t need to pay attention , to which side , is on what end.
But , when paralleling the elcos , I`m not so sure , if you will not introduce ,small differences.
For polypropylene , it should not be a problem , but I will follow this same method , when I will replace the mylars.
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Yvan_donald
Well-Known Member
Hi, yes John I spend a fortune on these 2.2uf mundorf evo silver,gold and oil come to $120.00 CDN, the real price is $135.00 US a piece so 10 times is a good amount,I have paid $1300.00 CDN for in 1979 from a friend,but for me the price of a new pair of speakers I will have to pay much more to get the same quality and bass extension 10-16hz. I don"t regret buying these mundorf they do a spendid job on my system.The .47 uf mundorf silver,gold in oil cost me like $80 each CDN.
Yvan ,
I know what you mean.Yes , if you can spend the money , it is worth while , to go for the best.For me , at this moment ,
the new bipolars , already have some big improvement.
In the future , I will see , if I can put in the Jantzen xover caps , instead of the elcos.But , it may take a while.
Like I said , what I will do next (some time in future) , is to replace the mylar/polyprop for either Jantzen or Audyn foil caps.
And then listen , to how big a change , it is going to give.
So , thank you for your info.I am sure that you enjoy your IMF`s to the fullest.
Cheers
I know what you mean.Yes , if you can spend the money , it is worth while , to go for the best.For me , at this moment ,
the new bipolars , already have some big improvement.
In the future , I will see , if I can put in the Jantzen xover caps , instead of the elcos.But , it may take a while.
Like I said , what I will do next (some time in future) , is to replace the mylar/polyprop for either Jantzen or Audyn foil caps.
And then listen , to how big a change , it is going to give.
So , thank you for your info.I am sure that you enjoy your IMF`s to the fullest.
Cheers
Yvan_donald
Well-Known Member
Hi,Monday I went to a store selling LP's new and used,they have some electronics:used like turntables, receivers and speakers. I found a pair of IMF Als 40 MK II for sale $100.00 CDN,I give a deposit and believe the pair is one of the first batch of Als 40 MK II because it have the old "IMF" logo with a lower logo "International", it have the woofer with the white rubber surround and I think it have the Peerless midrange.They have a rough life,the veneer have almost no lacquer on it, small scratches,but the corners seems to be in good shape.I will get them in the next two weeks.
BoPtiljudrop
New Member
Hi, this is my very first post on this great forum. I really hope to find some help to understand and repair the crossovers in my new speakers. Actually, I'm quite lost by now.
I found a pair of TLS 50 IIa, dirt cheap, in the local second hand shop. 27€! what a luck! At first they sound all wrong. Obviously the Coles 4001's has been swapped to some unknown 8ohm driver. But even worse, the crossover has been tampered with badly.
The layout is very different to a TLS 50 II and there where some major value differences between the repairs on the two crossovers.
I have tried to change the serial caps, the first one to a 60uf, a 44uf and a 22uf. It looks like it should be 60uf, but one speaker had 22uf and the other one had 44uf. I don't have the equipment to measure the 100uf, the other parallel caps are not all to bad, but of course, I would like to recap it all.
Nothing I have tried, seems to make the speakers sound right. Way to much high middle and treble. The amp is a ST70 clone, sounds wonderful together with my Richard Allan NG8 in ACE horns.
I found a pair of TLS 50 IIa, dirt cheap, in the local second hand shop. 27€! what a luck! At first they sound all wrong. Obviously the Coles 4001's has been swapped to some unknown 8ohm driver. But even worse, the crossover has been tampered with badly.
The layout is very different to a TLS 50 II and there where some major value differences between the repairs on the two crossovers.
I have tried to change the serial caps, the first one to a 60uf, a 44uf and a 22uf. It looks like it should be 60uf, but one speaker had 22uf and the other one had 44uf. I don't have the equipment to measure the 100uf, the other parallel caps are not all to bad, but of course, I would like to recap it all.
Nothing I have tried, seems to make the speakers sound right. Way to much high middle and treble. The amp is a ST70 clone, sounds wonderful together with my Richard Allan NG8 in ACE horns.
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Radfordman
Super Member
The woofer seems too have a black nose as well! Looks like the units and cabinets are in good condition, a great start. Get the crossovers right and a pair of Coles 4001's and you should have some lovely speakers.
BoPtiljudrop
New Member
I'm sure they will be great, with a little tlc.
There is a pair of Coles coming up, looking forward to get that right. But, does anybody know how the crossovers should be put together? I badly need some help, found the layout for the TLS 50 II here:
http://www.hifisentralen.no/forumet...ndring-av-delefilter-til-imf-tls50-mk-ii.html
But mine are quite different, five coils instead of four, only one of those has a core.
Radfordman
Super Member
You will need to find out which Coles 4001 is required, the 8 Ohm version, or the so called 16 Ohm version. I say so called, because it's DC resistance is 23 Ohms.
redkiteart
New Member
One by one remove your capacitors substituting Alcap or better still Claritycap capacitors to the values shown on the TLS 50 schematics
. Falcon have both replacements.
The inductors appear correct, leave them as they are.
Replacement Coles 4001K Super Tweeter 16 Ohm super tweeters from Falcon
Well done on the price.
boptiljudrop: Welcome to AK! besides us here at AK, there are a few places for help. First, there is also a somewhat dormant IMF Yahoo Groups newsgroup that may be able to help. Also, folks Pinkfishmedia forums have experience with IMF too.
I don't know if any of us have seen the TLS50 Mk. IIa. That unit, according to canuckaudiog here at AK, should have the Elac 8" bextrene woofer (yours does), an Elac 4/200 midrange (appears yours does but what is the condition of the surrounds, soft and reasonably pliable, or very firm or cracked?), the IMF TW2100 tweeter (not sure if it is or not, label on back), and the Coles 4001 (16 Ohm) supertweeter?
On the supertweeter, it may be the later IMF TW2100 judging by the look and size of the protective cover. Maybe the unit was field modified from a TLS50 Mk. II? If you eventually have no need for the TW2100, let me know as I could use some spares.
For the crossovers, first, is your schematic one that is published (if so, from where?) or something that you drew up? Your crossover looks like it was recently worked on because of the newer blue Alcap capacitors. I don't know that we've seen this particular model of crossover before - but if memory serves, more than one of those inductors should be iron cored (but not all) - look to see if there is any evidence of scratching inside the core tubes, possible one or more laminated cores could had fallen out. That could easily play havoc with your speaker's response, as would the odd cap values unless the drivers are mismatched and someone tried to equalise them with the crossover. Also, the last picture's crossover has a burned and charred area under the resistor, indicating fault damage from excessive HF drive, amp fault, or other anomaly. The crossover itself also doesn't look quite like the other unit, but need more pics to tell.
Important to pull all the drivers and photo document any and all labels and writing - some may even have writing on the magnets. Then do the same with the crossovers, taking closeup high resolution pics from various angles to give an idea of values and voltages used since the crossovers differ from each other. Also, take pictures of the solder side to see if there is any identification on the board itself.
best might be to contact Jerry Bloomfield at Falcon Acoustics. They can supply the correct Coles 4001G 16 ohm supertweeters (the K model is the 8 ohm):
http://www.falconacoustics.co.uk/drive-units-1/coles-4001-drive-units.html
and may have information on the Mk. IIa crossover, including correct values and ideas about the inductors. In your case, unless you have the correct meters to test the inductors, you may have to consider replacing all of them if values are unknown, along with the caps to get to the correct values and renew them. Or see if Jerry can do the renew work for you, and test them first if he has them in possession.
I don't know if any of us have seen the TLS50 Mk. IIa. That unit, according to canuckaudiog here at AK, should have the Elac 8" bextrene woofer (yours does), an Elac 4/200 midrange (appears yours does but what is the condition of the surrounds, soft and reasonably pliable, or very firm or cracked?), the IMF TW2100 tweeter (not sure if it is or not, label on back), and the Coles 4001 (16 Ohm) supertweeter?
On the supertweeter, it may be the later IMF TW2100 judging by the look and size of the protective cover. Maybe the unit was field modified from a TLS50 Mk. II? If you eventually have no need for the TW2100, let me know as I could use some spares.
For the crossovers, first, is your schematic one that is published (if so, from where?) or something that you drew up? Your crossover looks like it was recently worked on because of the newer blue Alcap capacitors. I don't know that we've seen this particular model of crossover before - but if memory serves, more than one of those inductors should be iron cored (but not all) - look to see if there is any evidence of scratching inside the core tubes, possible one or more laminated cores could had fallen out. That could easily play havoc with your speaker's response, as would the odd cap values unless the drivers are mismatched and someone tried to equalise them with the crossover. Also, the last picture's crossover has a burned and charred area under the resistor, indicating fault damage from excessive HF drive, amp fault, or other anomaly. The crossover itself also doesn't look quite like the other unit, but need more pics to tell.
Important to pull all the drivers and photo document any and all labels and writing - some may even have writing on the magnets. Then do the same with the crossovers, taking closeup high resolution pics from various angles to give an idea of values and voltages used since the crossovers differ from each other. Also, take pictures of the solder side to see if there is any identification on the board itself.
best might be to contact Jerry Bloomfield at Falcon Acoustics. They can supply the correct Coles 4001G 16 ohm supertweeters (the K model is the 8 ohm):
http://www.falconacoustics.co.uk/drive-units-1/coles-4001-drive-units.html
and may have information on the Mk. IIa crossover, including correct values and ideas about the inductors. In your case, unless you have the correct meters to test the inductors, you may have to consider replacing all of them if values are unknown, along with the caps to get to the correct values and renew them. Or see if Jerry can do the renew work for you, and test them first if he has them in possession.
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Redkiteart, I agree with the replacement caps, but his drive units (woofer and tweeter) are substantially different from the original KEF woofer, Audax tweeter, and early Coles 4001 mic capsule tweeter so not sure the TLS50 Mk. II schematic is completely accurate for his units. new Coles tweeter model correction as noted above.
It is also possible the tweeters were replaced with newer Audax tweeters of similar design, but incorrect efficiency so important to get the model numbers off the drivers to see.
Am looking at translated version of your Danish forum posts:
http://www.vintagehifi.dk/forum/viewtopic.php?f=557&t=8017&start=0
Am looking at translated version of your Danish forum posts:
http://www.vintagehifi.dk/forum/viewtopic.php?f=557&t=8017&start=0
Radfordman
Super Member
The 4001K is the 8 Ohm unit
BoPtiljudrop
New Member
Hi and thanks everyone!
The plague on the back of the speakers says its TLS 50 IIa's, and I made the drawing, because there obviously is an inductor more in my filters, than on all other drawings I have found on the Internet.
There is no sign that there has been a core in the L2 inductor, and according to the colored dots on the inductors, they are different from the schematics except L4. The extra inductor is parallel to the super tweeter.
Another major difference to the TLS 50 II filter, is the extra capacitor on the bass filter. It is paralleled with the resistor that has burned the board.
The blue caps are cheap Philips caps, they are way out of their specs, presumably since new. It seems like a local shop, or some amateur (like me), has made some very bad repair here? Something like "well, let's see, what do I have in my drawers? 60uf, don't have it, let's smash 22 in one speaker and 44 in the other one. Nobody will notice anyway!"
Except for the super tweeters, all drivers are original; Elac bextrene woofer, Elac midrange and Audax tweeter. The midrange surrounds is merely held together by the coating, I have done new surrounds before, but never something this small and fragile. I have a pair of 16ohm Coles 4001 arriving soon. A good fella on the Danish forum sold me a pair.
I switched a handful of the caps, but I made the drawing first with the values of the existing caps. The first serial caps (22/44uf), the extra cap in bass filter (15uf), the second of the serial caps (6uf) and the serial cap on the super tweeter was unoriginal. I see that I have made an error in the drawing, this last cap was 0,2uf, not 2,2uf. I'm sorry, change that to morrow.
Cool you found my postings on the Danish forum mech986. I wasn't shure if this was the right place to post this, so I held back a little. This forum is big, I tried to read this part of it, haven't succeeded yet.
Edit: numbers from the drivers, of course, you are right, if these Audax has been changed to.
The plague on the back of the speakers says its TLS 50 IIa's, and I made the drawing, because there obviously is an inductor more in my filters, than on all other drawings I have found on the Internet.
There is no sign that there has been a core in the L2 inductor, and according to the colored dots on the inductors, they are different from the schematics except L4. The extra inductor is parallel to the super tweeter.
Another major difference to the TLS 50 II filter, is the extra capacitor on the bass filter. It is paralleled with the resistor that has burned the board.
The blue caps are cheap Philips caps, they are way out of their specs, presumably since new. It seems like a local shop, or some amateur (like me), has made some very bad repair here? Something like "well, let's see, what do I have in my drawers? 60uf, don't have it, let's smash 22 in one speaker and 44 in the other one. Nobody will notice anyway!"
Except for the super tweeters, all drivers are original; Elac bextrene woofer, Elac midrange and Audax tweeter. The midrange surrounds is merely held together by the coating, I have done new surrounds before, but never something this small and fragile. I have a pair of 16ohm Coles 4001 arriving soon. A good fella on the Danish forum sold me a pair.
I switched a handful of the caps, but I made the drawing first with the values of the existing caps. The first serial caps (22/44uf), the extra cap in bass filter (15uf), the second of the serial caps (6uf) and the serial cap on the super tweeter was unoriginal. I see that I have made an error in the drawing, this last cap was 0,2uf, not 2,2uf. I'm sorry, change that to morrow.
Cool you found my postings on the Danish forum mech986. I wasn't shure if this was the right place to post this, so I held back a little. This forum is big, I tried to read this part of it, haven't succeeded yet.
Edit: numbers from the drivers, of course, you are right, if these Audax has been changed to.
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Yvan_donald
Well-Known Member
Hi,welcome ,on my TLS 50 MK I and have also 5 inductors, during production probably improving the design IMF made some mods,who knows maybe is one off the latest production. If Falcon or Wimslow can not help you should try to find another owner with the same Tls 50 Mk a , easier to say than find, is like your super tweeter TW2100 are priceless.Or perhaps temporaly made these like a normal Tls 50 Mk II.
BoPtiljudrop
New Member
Hi Yvan. Yes it would be wonderful if somebody knew the specs on this cross over, eventually by takin a look inside another pair of mkIIa's. I tried to ask Falcon Acoustics, no answer so far. Maybe my question was a bit to unclear, struggling along with the English.
Here's pictures of the units backsides. And a better drawing with more data. Maybe this will tell what units it really is?
The foam is rather cracked. Maybe they have turned hard and the Fs has become to high?
Both labels are torn:
Here's pictures of the units backsides. And a better drawing with more data. Maybe this will tell what units it really is?
The foam is rather cracked. Maybe they have turned hard and the Fs has become to high?
Both labels are torn:
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As you've id'ed so far on this speaker (L or R?) woofer is 8/28BR, tweeter is 4/200, both ELAC / TDL sourced units. The tweeter is of the 25DT family (yours circa 1990), of which there are numerous model numbers, however looks like an early unit because its not an aluminum / magnesium cone. Would not be surprised to find the supertweeter is either the TW2100F (19DT01) or the 19DT/06, both 19mm mylar units.
Correction: your Danish site pic already identifies the 19DT/06 as one of the supertweeters.
does the other speaker yield any better labeling?
A helpful datasheet chart from Falcon:
http://www.falconacoustics.co.uk/downloads/Elacimftdl.pdf
Correction: your Danish site pic already identifies the 19DT/06 as one of the supertweeters.
does the other speaker yield any better labeling?
A helpful datasheet chart from Falcon:
http://www.falconacoustics.co.uk/downloads/Elacimftdl.pdf