IMF TLS 50 MKIIa

[Marcus50IIa]

These speakers have lived.

I have just bought them and wondered if anyone may have any tips and tricks for someone who’s keen to restore but hasn’t got much of a clue!

The label on the back is handwritten and says:

Model TLS 50IIa

Serial 12732L (&R)

The cabinets are not in good condition (pics). There are several chips and the tops are stained and faded. Suggestions for improvement will be very welcome.

The 8”, the Audax 12x8 and the super tweeter all come off but the 4” mid seems to be glued on each speaker. The surrounds on both 4” are disintegrating. (pics)

Everything about the construction is solid. They ooze ‘made to last’. When I came to unscrew the drivers I wondered if the feeling was the same for Howard Carter as he prepared to enter Tutankhamen’s tomb for the first time. I get the strong impression daylight hit the foam for the first time since they were sealed in 1980 - 36 years ago. Both 8” have Aug 1980 stamped on them.(pic)

I can see the crossover board and glimpse the caps sunk into the foam at the back. They seem solidly fixed with plastic clips.(pic) How do I get them out?

I was reminded of the closing line from the film ‘The Pit and the Pendulum’ a Vincent Price/Roger Corman horror classic. “No one shall ever enter this room again.” Well I just have. I just hope it doesn’t turn into a horror story!

There are hints of greatness about the sound but I’m sure they can be so much better. I am UK based but will be grateful for help from anywhere on the planet.

Marcus

 

[captouch]

I had the non-A's, but similar.

My mids came out pretty easily - mine needed reforming too. Wasn't a tough job, though it was messy getting all the old foam off.

Recapping is a good idea and Falcon Acoustics in the UK is a good source for caps to match the originals. Shipping will be better for you. I can't remember how my crossover board was attached though - and it might be different for the A anyway.

Can't help on the woodwork, but lots of info out there.

 

[cubdog]

Those will restore nicely. You're in for a treat.

 

[Marcus50IIa]

I had the non-A's, but similar.

My mids came out pretty easily - mine needed reforming too. Wasn't a tough job, though it was messy getting all the old foam off.

Recapping is a good idea and Falcon Acoustics in the UK is a good source for caps to match the originals. Shipping will be better for you. I can't remember how my crossover board was attached though - and it might be different for the A anyway.

Can't help on the woodwork, but lots of info out there.

Thanks for the response. I appreciate it.

Did you use anything to heat the area around the mids or was it a case of leveraging them off?
What difference did the refoaming make to the sound of the mids?

I'm going to have to fish around inside to get a better idea of how to get the crossover out to recap

 

[captouch]

No, as I recall, they came right out. I'm trying to remember whether the mids have a tube behind them - they might. If so, I'm not sure if they were originally attached to the tube or not and if that's what could be causing resistance to removal. There are a few IMF owners here, so hopefully someone will chime in.

I don't think I turned it up too loud before the mids were refoamed. I guess it's not generally advisable to do so if the surrounds aren't there to support the cone. So I can't say for sure, but I'm thinking the recap will make more of a difference than the surrounds. If the were a woofer, it might be a different story.

If you could get a closer shot of how the crossover board is attached, we may be able to help more.

 

[Marcus50IIa]

Thanks for the response. I appreciate it.

Did you use anything to heat the area around the mids or was it a case of leveraging them off?
What difference did the refoaming make to the sound of the mids?

I'm going to have to fish around inside to get a better idea of how to get the crossover out to recap

A task for the weekend. Thanks for taking the time to respond.

 

[Johnny_Law]

http://www.audiokarma.org/forums/index.php?threads/imf-owners-thread.509555/

Just got a pair of TLS 50 II's myself and got acquainted with IMF by reading that great thread!

 

[canuckaudiog]

Ah cool, the TLS 50 IIA! These are pretty uncommon. They were made before IMF went with new naming conventions for their speakers.

Did you get the stands with yours?

Regarding restoration, captouch has it right. Replace the capacitors on the crossover (and don't forget to do the ones located on the terminal cup where the binding posts are) and refoam the midrange drivers. Refoaming the midrange drivers will make a significant difference, without a proper seal there will be strange phase cancellations going on, not to mention a reduction in dBs! The recap will rebalance the speaker back to its original status.

They're lovely speakers. I owned IMF speakers for about four years, in that time I had the TLS 50 II, TLS 80 II, Super Compact and also the big daddy IMF RSPM Mk IVs. I moved them on because I didn't have the space for the Mk IVs (which is what I had last), although now that I do I might go out and find a pair (but I sure do dig my Wharfedales quite a bit). They're a unique speaker in the vintage world, with a transmission line for the bass loading. It's something you don't see often and John Wright (the designer) did a fantastic job executing it. I have no doubts you will be thrilled with the sound after a bit of work!

 

[sachind4u]

Ermel Audax 3 way speakers, can anyone tell me about it. I am gettinng one from one of our Family Friend. Don't know what to do about it, can I connect it to My Quad II which is hooked on Jensen currently. Thanks !

 

[Marcus50IIa]

Ah cool, the TLS 50 IIA! These are pretty uncommon. They were made before IMF went with new naming conventions for their speakers.

Did you get the stands with yours?

Regarding restoration, captouch has it right. Replace the capacitors on the crossover (and don't forget to do the ones located on the terminal cup where the binding posts are) and refoam the midrange drivers. Refoaming the midrange drivers will make a significant difference, without a proper seal there will be strange phase cancellations going on, not to mention a reduction in dBs! The recap will rebalance the speaker back to its original status.

They're lovely speakers. I owned IMF speakers for about four years, in that time I had the TLS 50 II, TLS 80 II, Super Compact and also the big daddy IMF RSPM Mk IVs. I moved them on because I didn't have the space for the Mk IVs (which is what I had last), although now that I do I might go out and find a pair (but I sure do dig my Wharfedales quite a bit). They're a unique speaker in the vintage world, with a transmission line for the bass loading. It's something you don't see often and John Wright (the designer) did a fantastic job executing it. I have no doubts you will be thrilled with the sound after a bit of work!

No stands with these. I have been having a good listen for the last couple of days and the sound, to me, fits the description of an unrestored pair: flat and a little muddy with recessed mids. There are hints of what is possible though.

I am grateful to Johnny Law (above)for the gentle and polite prod to check out the fantastic resources on this site. It's a great help. I have some questions before I get the replacement caps. I am planning to get them from falcon as that seems to be the place everyone here recommends.

a. 5% or 2% tolerance?

b. Polyester or not?

Otherwise it's time to stop listening and start doing.

 

[listen to it]

I was also lucky enough to recently score a pair of TLS 50 IIa and even luckier to get the matching stock stands. Does anyone know if Falcon's crossover recap kit for TLS50 II version is compatible with TLS50 IIa model speaker. Seems the bass driver and super tweeters are different between the two models so I would just like to verify that crossover capacitors are all the same or not. Like Marcus I intend to get crossover kit from Falcon but they haven't responded to that question. And is it fair to assume the price upgrades to 2% tolerance and poly caps translate to upgrade in sonic qualities?

 

[canuckaudiog]

Oops, I forgot to respond to your questions Marcus.

Regarding the 2% tolerance, I personally always go for the 2% option if I can afford it. Honestly, it's debatable if it really makes a difference or not (over 5% that is) but I always feel like having the speakers as closely matched as possible will allow for better imaging between the two.

As for the poly caps, that's not necessary. The old poly caps should still be just fine so there's no reason to replace them. Jerry only offers that as an option if you are missing them or if one is burnt out or something.

 

[sax6]

Wish I had this luck to grab a pair of those TLS.

Enjoy restoring them and play them.

 

[Marcus50IIa]

Oops, I forgot to respond to your questions Marcus.

Regarding the 2% tolerance, I personally always go for the 2% option if I can afford it. Honestly, it's debatable if it really makes a difference or not (over 5% that is) but I always feel like having the speakers as closely matched as possible will allow for better imaging between the two.

As for the poly caps, that's not necessary. The old poly caps should still be just fine so there's no reason to replace them. Jerry only offers that as an option if you are missing them or if one is burnt out or something.

That is a huge help - thank you. I'm sure 'listen to it' (above) will also be pleased with the clear cut guidance from an expert.

I am also trying to work out which new foams to get for the mids. I have been in touch with Good Hi-Fi in The Netherlands. They responded very quickly. I have to measure the cone size. I'm away for the next ten days so it'll be on hold until then.

This is a new experience for me so it'll be taken slowly. But I'm delighted I found this website. The info is fascinating and I really appreciate the assistance people offer.

I shall update on my (slow) progress and will be interested to hear how 'listen to it' gets on.