I got sound out of one tweeter the other nothing. Sound was horrible. There is a pair of speakers with working original tweeters, im gonna arrange some kind of deal to get them. The guy knows his way around tech, fixing amps and speakers. Personally I have a few items to offer, once fixed can fetch a tidy sum so im going in this direction. Also helps to get rid of hifi got stuff everyware. Regarding the 737r tweeters, too small by 10mm diameter, i will have to screw new hole's for them, the opening left from the H211's is not leaving much to go into.
Speakers have been prepared. I can naw dye the cabinets.
Speakers have been prepared. I can naw dye the cabinets.
Those findings are to be expected if the voice coils are gummed up with thickened ferrofluid.
Do you actually have a multimeter with which to measure the DC resistance of the voice coils?
Your Mission 737 speakers appear to have 94mm Vifa D19TD05-08 tweeters, not 104mm SEAS ones:
https://willys-hifi.com/products/peerless-d19td05-08-tweeter
They come apart a bit like this for removal of old solidified ferrofluid:
https://www.seas.no/index.php?option=com_content&view=category&id=45&Itemid=462
This is skilful work to lift off vertically without damaging the voicecoil.
You must undo the three clips.
But tweeters will run without ferrofluid, just keep the level down until you get some fresh stuff from Blue Aran in the UK.
Best Regards from Steve in Portsmouth, UK.
https://willys-hifi.com/products/peerless-d19td05-08-tweeter
They come apart a bit like this for removal of old solidified ferrofluid:
https://www.seas.no/index.php?option=com_content&view=category&id=45&Itemid=462
This is skilful work to lift off vertically without damaging the voicecoil.
You must undo the three clips.
But tweeters will run without ferrofluid, just keep the level down until you get some fresh stuff from Blue Aran in the UK.
Best Regards from Steve in Portsmouth, UK.
I fixed a pair of tweeters on Mission speakers a couple of years ago.
My brother gave me a pair, he hadn't noticed by neither tweeter worked.
A close look showed that inside, the thin wire connections between the terminals and the voice coil had melted. These wires are perhaps the ones to get hottest and burn out first.
If you see any tweeters with these connecting wires on the faceplate, I think that's to help cooling of them.
Anyway, I managed to scrape a little enamel from the remaining bits on the voice coil, and solder a strand of copper to repair them.
It was fiddly work, but I managed to solder them in and repair both tweeters. Then he wanted tham back, so they went - not my favourite speaker anyway, especially after seeing what Grundig were making at the same time, but an interesting repair job!!
So - just to say, these tweeters can be DIY fixed 😀
Sounds like my brother.
Then again it's probably more likely he would demand to borrow the speakers from me in the first place.
Then they come back dead.
And it would be my fault.
But the new speakers he's bought are absolutely fantastic!
Do I sound mentally scarred? 🤔😉
Thanks but it's the seas h211 tweeter that needs ferrofluid change. Hopefully I will be getting a working pair from mission speakers on Friday so fingers crossed. ..
Are all elder brothers the same in that department? I think so. .
Robski, I kit I would like. Anyway with all the bits and bobs left over I'm sure I could build something. .was thinking about this last night. The left over cabs I will not touch and tallied all parts I would have was quite allot. But that's another thread another time.
What really amused me was that he'd not even noticed!
- "Oh, really, well, thanks!"
Maybe we're too fussy - tweeters, who needs 'em? 😀
Haha, yes he is older.
In Exodus 11, 12 and 13 the firstborn is mentioned specifically - perhaps now in the 'modern' world the effect is simply reduced to a 'matter of fact' usage of vintage audio gear that misses the subtlties and finesse of younger brothers LOL.
Recently some radio he had was blowing fuses - not sure if the item was faulty or not, but he complained that he'd changed the fuse and it kept blowing.. so I looked at the fuse he'd used, 750mA, and then looked at the PCB, 2AT written clearly on the board...
- "What value fuse did you use?"
"Oh I don't know, I assumed that one was Ok!"
- "But it's only 750mA, and you need a time delay 2A fuse it says here"
"Really? Oh, that's interesting, I didn't see that"
Then he gave me a gentle lecture of the type of faults that were easy to fix, and those that were difficult, as he generously endowed me with his electronics genius.
- "Have you got a multimeter, so I can measure this item please?"
"No, haven't ever had one of those!"...
I can only conclude that we live in slightly different worlds, each has their merits 😀
At least he likes the pretty older audio gear, so there's good to be seen!
As a starving student, with youth as an excuse, I had a quite good FM only tuner that decided to repeatedly blow its fuse.
Being skint and stupid I put a bit of silver foil around the old fuse and put it back in.
There was a really loud bang from the tuner, a new outward pointing dent in its case, and a rattle. Oh yes - it blew the trip on the house sockets circuit too!
Reset the trip, opened the tuner and the remains of the poly cap that had been across the main switch fell out. I decided to get a somewhat closer value fuse and fired up the tuner again. Aside from a small mains thump when switched on / off it worked fine!
I guess the difference between younger and older brothers is us younger ones learn from our mistakes!
Not my funniest cap story. Had a CB radio mains power supply that the regulator had died in. I had a bit of a look inside, removed lots of dust and crud and put it back together. On turning it on the two small (50uF 12V or so) electrolytics on the main board decided to 'explode'. More outward dents in the case! The funniest thing was that the caps had actually fired just their cans off the board - all the wadding and foil from inside the caps were still on the board and were wrapped in the plastic that had been around the cans!
Being skint and stupid I put a bit of silver foil around the old fuse and put it back in.
There was a really loud bang from the tuner, a new outward pointing dent in its case, and a rattle. Oh yes - it blew the trip on the house sockets circuit too!
Reset the trip, opened the tuner and the remains of the poly cap that had been across the main switch fell out. I decided to get a somewhat closer value fuse and fired up the tuner again. Aside from a small mains thump when switched on / off it worked fine!
I guess the difference between younger and older brothers is us younger ones learn from our mistakes!
Not my funniest cap story. Had a CB radio mains power supply that the regulator had died in. I had a bit of a look inside, removed lots of dust and crud and put it back together. On turning it on the two small (50uF 12V or so) electrolytics on the main board decided to 'explode'. More outward dents in the case! The funniest thing was that the caps had actually fired just their cans off the board - all the wadding and foil from inside the caps were still on the board and were wrapped in the plastic that had been around the cans!
There's an awful lot to learn about electrics and electronics! Any amateur mistakes usually "Let The Magic Smoke Out" as the old joke goes! 😀
Often with a bang and a flash too... 😱
However, speakers are usually fairly simple. You can actually (and amazingly) electrically test a speaker with just a metal screwdriver, but a 1.5 Volt pen battery and a paperclip can often tell you something about tweeters too.
You listen for a scratchy noise when connecting.
@bazza31, you really need a multimeter, like this £9.99 Screwfix jobbie:
Tweeters are usually 3-6 ohms resistance if intact. Naturally I have something much more impressive and expensive that can measure coils, capacitors and even voicecoil inductance on woofers. 😎
Cleaning wooden cabinets might employ furniture polish or Danish Oil from places like Robert Dyas. I have used Surgical Spirit (denatured alcohol) from the chemists on occasion, then light coloured furniture polish.
Not rocket science! Try it on a test hidden area.
Speakers should be mounted on 4 rubber or felt self adhesive pads. Stops scratching and improves vibration problems. They can cost a fortune in bags of 4 at places like B&Q, but I bought a huge bag called a Parkside Parquet Floor Pad Set at LIDL for £1.49.
Ferrofluid? Blue Aran are real Pro-Audio experts and repairers. The man at the counter usually knows a lot.
http://www.bluearan.co.uk/index.php?id=SONFF05
A SEAS tweeter comes apart with 4 screws, and can run with or without ferrofluid. That Sonitus syringe is enough for 5 x 3/4" tweeters, or 3 x 1" ones I'd guess. It's not very critical.
Ferrofluid is not strictly necessary in modern tweeters which have better glues and materials, it is an option. Some people think ferrofluid makes the sound worse. It is popular because it reduces warranty failures.
https://www.seas.no/index.php?optio...dc&catid=45:seas-prestige-tweeters&Itemid=239
https://www.seas.no/index.php?optio...fc&catid=45:seas-prestige-tweeters&Itemid=239
Sorry for long post. But many gaps in your knowledge to fill, it seems. Don't worry, we were all n00bs once. 🙂
Often with a bang and a flash too... 😱
However, speakers are usually fairly simple. You can actually (and amazingly) electrically test a speaker with just a metal screwdriver, but a 1.5 Volt pen battery and a paperclip can often tell you something about tweeters too.
You listen for a scratchy noise when connecting.
@bazza31, you really need a multimeter, like this £9.99 Screwfix jobbie:
Tweeters are usually 3-6 ohms resistance if intact. Naturally I have something much more impressive and expensive that can measure coils, capacitors and even voicecoil inductance on woofers. 😎
Cleaning wooden cabinets might employ furniture polish or Danish Oil from places like Robert Dyas. I have used Surgical Spirit (denatured alcohol) from the chemists on occasion, then light coloured furniture polish.
Not rocket science! Try it on a test hidden area.
Speakers should be mounted on 4 rubber or felt self adhesive pads. Stops scratching and improves vibration problems. They can cost a fortune in bags of 4 at places like B&Q, but I bought a huge bag called a Parkside Parquet Floor Pad Set at LIDL for £1.49.
Ferrofluid? Blue Aran are real Pro-Audio experts and repairers. The man at the counter usually knows a lot.
http://www.bluearan.co.uk/index.php?id=SONFF05
A SEAS tweeter comes apart with 4 screws, and can run with or without ferrofluid. That Sonitus syringe is enough for 5 x 3/4" tweeters, or 3 x 1" ones I'd guess. It's not very critical.
Ferrofluid is not strictly necessary in modern tweeters which have better glues and materials, it is an option. Some people think ferrofluid makes the sound worse. It is popular because it reduces warranty failures.
https://www.seas.no/index.php?optio...dc&catid=45:seas-prestige-tweeters&Itemid=239
https://www.seas.no/index.php?optio...fc&catid=45:seas-prestige-tweeters&Itemid=239
Sorry for long post. But many gaps in your knowledge to fill, it seems. Don't worry, we were all n00bs once. 🙂
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I'm back! What a ball ache. ..anyhows I've been caught up at a crossroads, I said I was expecting another set of speakers so I may use there tweeters. ..the speakers were in fact a wonderful pair of vintage mission 720! Yes them drivers all sealed and working except 1 midrange but I will get to that. Thay sound and this was just a 2min test lovely. The type of sound I like. So why not enjoy these for a while right! I opened the one with the midrange not working and saw it had the positive wire disconnected "YES" I said out loud what an easy fix and a pair of speakers for keeping. All connected up and no..still no sound. The crossover had been detached and laying between the 2 rolls of dampening. I forgot to mention the first time I opened them up I felt arround inside and my hands were wet from the midrange tubular housing and back of bass speaker magnet, "thay were stored away in a garage for some time"!! I removed the drivers and set the cabs in a warm room to dry.
I began reading threads about the 720 speakers. I tried the battery test on the midrange and it was positive that they worked so close inspection on the crossover was in hand. TO BE CONITNUED.
I began reading threads about the 720 speakers. I tried the battery test on the midrange and it was positive that they worked so close inspection on the crossover was in hand. TO BE CONITNUED.
"System 7" sir I saw your input valuable on the threads you commented in. Please help me. ...my crossover's are different to the ones in the threads. I will show pics. First lot is crossover with midrange problem. Yes some very bad images you do not want to see on a crossover. Visually does the last image showing the end of coil a break in sercuit?
