Celef - Mini Pro Monitor - Restoration.

[BuzzzFuzzz]

Thanks @misternavi

 

Please feel free to add anything to this thread, that may assist others on the same path.

 

Same goes for all you other DIY'ers.

 

Regards.

Ant.

[Gordon Macfarlane]

On 30/04/2021 at 9:56 AM, BuzzzFuzzz said:

The crossovers are a nice bit of work...  I don't think I will do anything to them.

 

I would desolder the caps and check their values as I think they are electrolytics and could have driffted a lot in value given the age of the speakers

[BuzzzFuzzz]

2 hours ago, Ozcall said:

I would desolder the caps and check their values as I think they are electrolytics and could have driffted a lot in value given the age of the speakers.

 

Nice one.  Thanks again.  

I'll have to have a look back on the What are you building thread and find the comment, but someone pointed them out as 'firecrackers'.

 

I'll copy it here later.

 

Now I look at the picture again, it wouldn't hurt to make a nice crossover board for these.  Spread the kit out a little and make it a sub-feature of the cabinets.

 

Cheers 

Edited May 2, 2021 by BuzzzFuzzz

[BuzzzFuzzz]

On 02/05/2021 at 5:23 PM, BuzzzFuzzz said:

Nice one.  Thanks again.  

I'll have to have a look back on the What are you building thread and find the comment, but someone pointed them out as 'firecrackers'.

 

I'll copy it here later.

G'day @Ozcall...  'twas @muon* mentioned it.

Can you shed any light please buddy?

[muon*]

38 minutes ago, BuzzzFuzzz said:

G'day @Ozcall...  'twas @muon* mentioned it.

Can you shed any light please buddy?

 

 

Yes, eletro's

They drift, and can explode

 

Example of drift, one i replaced in Matts B&W speakers, they were all way out with them between plus 50% to near 100% extra capacitance values, crossover points will be way out.

 

 

 

 

Edited May 3, 2021 by muon*

[BuzzzFuzzz]

27 minutes ago, muon* said:

 

 

Yes, eletro's

They drift, and can explode

 

Example of drift, one i replaced in Matts B&W speakers, they were all way out with them between plus 50% to near 100% extra capacitance values, crossover points will be way out.

 

 

 

 

 

Awesome.  Thankyou, will definitely desolder and check, replacing if required.

 

Edited May 3, 2021 by BuzzzFuzzz
Oops.

[BuzzzFuzzz]

G'day Folks.

 

First 2 coats of Japan Black stain & varnish, with a light sand in between.

 

Removed old grille cloth, filled in some corners on the frames...  rounded the edges and applied grey undercoat.  I've ordered some cheaper grille fabric from ebay for my first attempt at re-covering.  Planning on using a hot glue gun for application.

 

 

 

 

Edited May 6, 2021 by BuzzzFuzzz

[Pigpen]

From memory, Celef was founded by Stewart Tyler in the early 70’s with him also founding ProAc in the late 70’s.

 

I vaguely remember the 2 brands co-existing for quite a while (magazine reviews of both brands at the same time) but Celef no longer manufactures speakers - they were however, no slouches.

[BuzzzFuzzz]

I've just messaged ProAc...  eagerly awaiting a reply.

 

Thanks guys.

[Peter-C]

I had a pair of these for years, bought new in ‘78 for around $750.

Excellent speakers and people are correct that Celef changed their name to ProAc in ‘79.

Had mine refurbed by Boyd at Total Recoil, refoamed, reconed, and the crossover redone. They sounded excellent. They should have plastic surrounds around the bass/mids. I’d try and get the original Peerless tweeters (they were copied for a reason), some of the copies like some Polk ones, apparently weren’t that good, from what I’ve read.

Definitely worth saving, Good luck with the refurb!

 

[BuzzzFuzzz]

23 hours ago, Peter-C said:

I’d try and get the original Peerless tweeters (they were copied for a reason), some of the copies like some Polk ones, apparently weren’t that good, from what I’ve read.

 

Thanks Peter.

 

I did have the originals, and coincidentally, gave them to Boyd.  After not receiving any reply for months, I'm getting a little concerned.

 

I've almost resigned to buying some copies on eBay, but, now feel hesitant.  I don't think originals will be easy to source, so I'm really hoping to correspond with Boyd again...  even knowing they may not be repairable...  at least I'll know.

 

Great pictures thanks.  I didn't know the drivers had surrounds, they look great.  I don't have those either, unfortunately.  I am re-covering the grills, so that will help hide the rough, cast metal of the driver.

 

Regards.

Ant.

 

 

[Peter-C]

17 hours ago, BuzzzFuzzz said:

I've almost resigned to buying some copies on eBay, but, now feel hesitant. 

I’m sure there’s good replacements out there. Can’t remember the tweeter model number off hand, but maybe contact Falcon Acoustics and ask their advice?

https://www.falconacoustics.co.uk/audax-hd12x8d25-12x8-tweeter.html

[BuzzzFuzzz]

G'day Folks.

 

I received a reply from ProAc requesting some pictures, which I've sent...  waiting for a reply.

 

Thanks for all the helpful info and links..

 

I've posted elsewhere about grille fabric, receiving many links for products.  Being a tad cautious about my upholstery, I didn't want to spend too much to begin.  I ordered a basic cloth, tagged 'acoustically transparent', for $20 ( 1.5 x 1m ).  It arrived and I'm pretty happy, seems like a nice fabric.

 

I've done one grille...

 

 

 

Using a cheap KS Bond, chloroprene cement.

I did try a water based glue, but that soaked into the fabric, and peeled off easily after setting. 

Applying the glue and leaving it for 10 min ( set a timer ), it was very easy to work with and only a little glue came to the top of the fabric as I was pressing down.

As instructed on youtube, I didn't glue the corners, using a single staple only.

 

I was nervous about getting the threads running straight on the edges, but it was quite easy and I didn't rush it.

There was a couple of issues...  The frame is chip board and quite rough.  I did fill some corners, sanded and undercoated them, but they are still a bit rough and we're catching the fabric.  I did get a couple of very minor pulls in the fabric as a result.  Not so bad that I would do it again...  and, I'm a bit picky.

 

Most of my speaker grilles are in very good, to excellent condition...  but, I can see myself replacing more, using different colours.

 

 

[BuzzzFuzzz]

A few pics of the gluing...

 

 

 

 

The grille pins are long gone, and someone had glued the frames to the baffle.  I was fortunate that someone removed them without damage, and I was able to remove the glue from both the frame and the baffle plugs.  I still have the plugs, but no pins.  I'm inclined to use Velcro instead, unless you kind folk have some suggestions?

 

Regards.

Ant.

 

 

 

[BuzzzFuzzz]

 

Got the second one done...

 

...  easy peasy, lemon squeezy.

 

I was tempted to do the Richter Dragons, about to start peeling the old fabric off, I realised I should make sure there was enough, new fabric left...  Lucky I did, 'cos there wasn't.

 

There's a fair sized stain on this one, and the white marks around the top edges.

 

I've been wanting to try a nice blue.

 

 

[BuzzzFuzzz]

Slow and steady wins the race.

 

 

 

 

That's six coats of Japan Black stain & varnish...  sanded back each coat.

They came out darker than I hoped, not much of the grain visible any more.

 

In hindsight, I should have practiced on something else first, 'cos I really would have liked more of the grain to show.

 

My first experience with stain & varnish, and I'm very happy with the gloss finish.

 

The corners and edges were a little tricky, trying not to go over the edges.  You have to work quickly as it goes tacky very fast.

 

I tried diluting with turps, but ended up using less turps for each coat as I wanted the gloss finish... but, they are very dark.

At first I was applying the stain with a brush and wiping off with a cloth, but I was getting an uneven finish and no gloss.

The last two coats were applied by roller.

 

I made some mistakes...  I didn't do the whole of each cabinet at the same time, resulting in darker and lighter applications on sides and baffle.

I didn't dilute enough at one time, and had to stop and mix more halfway through, and of course, I didn't measure and ended up with thicker and thinner mixes.

 

I learned something new with each coat, applied a thicker coat each time, finished with a roller, and pretty happy with the result.

 

I'm trying to organise a friend in The States to ship some replacement tweeters over for me.  I can buy two for $120au, but the shipping is $180.

 

I have two surrounds to replace on the woofer.  Next step is to source upgraded capacitors, re fit the crossovers, then all that's left is mounting the magnets on the baffle and grille.

[BuzzzFuzzz]

Howdy Folks.

 

Thanks to the valued efforts of @VinylChef, the Celefs are moving forward once again.

 

A while back I noticed a listing in the SNA classifieds, by @Phydeaux III, for some Infinity Monitor II speakers, and saw that they use the same Peerless tweeters.  He wrote that they had been worked on by @VinylChef, which included tweeter repairs.

 

I was straight to the PM's and got in touch with David.  He has been more than willing to help me out, and actually has 2 spare tweeters he can move on, they are in the post as I type.  I'm looking forward to upcoming Sydney, and Melbourne runs, so I can meet some SNA members for the first time, and catch up with others.

 

VinylChef has kindly offered to replace the surrounds on the Celef woofers.

I've removed the surround from one, and did a bit of butchery.  It's not too bad, but I sliced the cone two times, very small cuts, and I've glued them very carefully.  But, I need advice about how badly I've damaged them, and have decided to have an expert look at them and do the refoaming.  The cabinets will look too nice to have shoddy looking drivers.

 

It's time to check the old crossover values, and replace any drifters.

I've got some small magnets for the grilles, but I'm not sure if they are big enough, still looking at options for attachments.

 

Then these little babies will be singing again.

 

 

[Janus77]

I reckon to attach the grill frames, try and get some circular velcro patches, easy and not too much of an eyesore if placed strategically.

 

 

https://www.officeworks.com.au/shop/officeworks/p/j-burrows-hook-loop-heavy-duty-adhesive-dots-16mm-20pk-jbhl1620bk?cm_mmc=Google:SEM:OW|Shopping:PLA&istCompanyId=0403b0ba-0671-498f-aeb7-e2ff71b61924&istFeedId=ea709c9a-279e-40be-951f-2668243ec753&istItemId=ptmlxamal&istBid=t&cm_mmc=Google:SEM:Always_on:RP|Office+Supplies|Office|Stationery||||SH||&s_kwcid=AL!12073!3!433088512993!!!g!910496373273!s_kwcid=AL!12073!3!433088512993!!!g!910496373273!&gclid=Cj0KCQiAkNiMBhCxARIsAIDDKNVe9oXsZJNHaXn3N0gOagpvlhLPHZ8Lwz3wYYIu3YHVXgesgvnl-AsaAojHEALw_wcB&gclsrc=aw.ds

Edited November 18, 2021 by Janus77