Ortofon 445

[breuter]

Anyone want to post photos of the crossover? The aperiodic loading and driver load are surely interesting....

Hello
I know this is and old string, however, I'm restoring 3 pairs of 445's hoping to recreate my quadraphonic setup from the '70's. A nice guy on vintagehifi.dk (I'm located in Denmark) made some diagrams of the crossovers from photos I took. I asked ScanSpeak, if they had som diagrams of the filters, but no (The filters are made by ScanSpeak). The d2008/851200 just went out of production. This is the dome tweeter that will fit the 445 and other Ortofon speaker. So they will now only be availble on the second hand market, but are already scarce. There are two filters in cirkulation on the 445. I have a very early verison (S/N 000018). This has the woofers that has Ortofon printed on the dust caps. Later units like S/N 002595 and later versions has the final version of the filter. You can see this in the diagrams. Mk2 is the latest version. I have huge expectation when I'm done. ScanSpeak units are good quality units, used also in Dynaco and ScanDyna and others. I have both Dynaco A25X and XL as well as ScanDyna A50X, which I all love. Hope this will help some owners of 445's in their possible restoration work. They are worth keeping alive.

 

[bolero]

Hello
I know this is and old string, however, I'm restoring 3 pairs of 445's hoping to recreate my quadraphonic setup from the '70's. A nice guy on vintagehifi.dk (I'm located in Denmark) made some diagrams of the crossovers from photos I took. I asked ScanSpeak, if they had som diagrams of the filters, but no (The filters are made by ScanSpeak). The d2008/851200 just went out of production. This is the dome tweeter that will fit the 445 and other Ortofon speaker. So they will now only be availble on the second hand market, but are already scarce. There are two filters in cirkulation on the 445. I have a very early verison (S/N 000018). This has the woofers that has Ortofon printed on the dust caps. Later units like S/N 002595 and later versions has the final version of the filter. You can see this in the diagrams. Mk2 is the latest version. I have huge expectation when I'm done. ScanSpeak units are good quality units, used also in Dynaco and ScanDyna and others. I have both Dynaco A25X and XL as well as ScanDyna A50X, which I all love. Hope this will help some owners of 445's in their possible restoration work. They are worth keeping alive.

Fantastic, thanks for posting this

If you have pics please post them here?

How did you get your woofers out? Mine are stuck in there & I don't want to damage the frames or the cabinet prying them out

 

[breuter]

Hi!
That is one of the tricky points, getting started.
There are two ways. You can use a corkscrew, or make a small steel hock and insert it in one of the screw holes, then use a small crowbar to lift the woofers slowly, letting the tare glue slip.

Do NOT pry them out with a screwdriver. This would damage the edges of the baffle, leaving visible marks.

Visit https://vintagehifi.dk/forum/viewtopic.php?f=557&t=17087 with translation, as it’s Danish. It will give you a few hints.

As you can see on the picture, you may not succeed 100%.
I used a carving chisel, to remove what stuck to the driver, and glued it back on the baffle.

If too uneven I evened it out with plastic wood, and grinding it even with sandpaper.

To reassemble, I use sealing strip. That would make it easier to dismantle at a later stage.

Have fun! They are worth it.

 

[bolero]

Thanks!

Glad I am not alone struggling with those

I wonder if injecting solvent under the edge of the speaker might help dissolve the glue?

And where is the woofer crossover located? Is it necessary to remove the speakers to get to it? Maybe it's behind the potentiometer

My 445's appear to be mk2 with the bypass caps

 

[breuter]

Thanks!

Glad I am not alone struggling with those

I wonder if injecting solvent under the edge of the speaker might help dissolve the glue?

And where is the woofer crossover located? Is it necessary to remove the speakers to get to it? Maybe it's behind the potentiometer

My 445's appear to be mk2 with the bypass caps

I thought about using solvent, but decided, that it might dissolve the baffle edges too.
The crossover is located in the lower left corner. It’s suppose to be glued to the firm thin layer of rock wool glued to the inside walls of the box. It’s likely loose and hidden under the second layer soft Rock Wool. You may want to repack the boxes with new soft insulation. It’s a mess in there, and they are slightly overstuffed. I’m replacing most of the Rock Wool with glass wool 37 lambda.

Others who has restored the Ortofon 445, claims that the bass is freed up if there’s a bit more air in the boxes. But that would tie to your personal taste.

 

[bolero]

Great info, thanks again!

Yes the bass is lacking, I am sure because the capacitors are old & dried up. I might just recap the tweeters for now as I already got them out.

It's too bad they glued the frames in. I'll do the same as you & repair any damage.

 

[bolero]

I translated that Danish audio forum link & there's good history there: these 445's are similar to & maybe a more evolved version of the Dynaco A45, which used a pair of woofers with aperiodic vents too.

Dynaco A25's are highly regarded & pretty common, Dynaco A45's are rare.

The fellow involved with these Ortofons went on to start Dynaudio afterwards.

So pretty good provinance, and some backstory to it all.

 

[bolero]

Here is a thorough history of scanspeak, dynaco, dynaudio, ortofon speakers. This fellow has done remarkable detective work:

History of Scan-Speak

History of Scan-Speak

www.cfuttrup.com

 

[breuter]

Just finished retoration work of the first pair of three. recapped filters, new tweeters, and less damping materiel in the cabinets. They are some great speakers. I compared them to a set of ScanDyna A50X, made a kind of shoot out The A50X has a very dominants bass ourput, and I like them a lot, however, the Ortofon speakers, har crystal clear in the high and midrange. Bass more defined and leveled with the rest og the frequncy specter. They all have ScanSpeak drivers. This has been a fun compare. The filter in the A50X is basically only a capasitor protecting the tweeter from the lower frequencies. The filter in the 445's, are a "real" three way cross over. The Ortofon is growing hard on me. Seems like the A50X's are good for jazz and heavy rock, as the 445's are a real great all round speaker, highly detailed sound it provides.

 

[bolero]

Looking good!