Destroying/modifying my Puritys

[Astacus]

Ive also psoted this in my 'hello' post, but thought it also makes sense to add it here.. since this is where we find the similarly minded!

Good day all,
I'm not sure you're going to let me stay on here


I have had a pair of ML Puritys for over 15 years, and recently, they have both developed problems, one with an amp board, the other with a PSU fault (which I might have exacerbated doing electronic swaps for fault finding!). The repair cost in the UK is more than I paid for them in the first instance, and I'm not so heavily invested in ESL as I was 20 'better hearing' years ago (previously had ESL57 and ESL 63)

So, here's my current thinking, and I am already a way down this route.

• Removed ESL panels from speakers (still have them if anyone in the UK wants them) - tick!
• Remove all internal electronics -tick! Recycle said electronics - tick!
• The backplate now only has the heavy duty binding posts and the AC input IEC connector - of this, more anon

I now have two rather attractive looking cherry veneer cabinets, with some oddness on the front faces - see pics - the fabric grille at the top covers nothing.
These cabinets are still heavy and 'dead'
Each speaker seems to have two identical woofers, both 6 or 6.5in, 6ohm

This is what I propose to do:

1. Replace top woofer with a similarly sized midrange unit
2. Maybe replace the odd hole (was the ESL connection port) with a ribbon or diaphragm tweeter
3. Install a three way passive second order crossover to feed all three units, suitably rated

(A different though was to place the tweeter behind the top fabric cover, and cover the square hole with some fancy, bespoke vanity plate!

And then, the more esoteric

• Maybe install a class D amplifier INSIDE the cabinet (there's plenty of room and access). Can even get one of Fosi units with inbuilt bluetooth for non-audiophile use
• Maybe install my old SONOS ZP80 preamplifier to feed the Fosi with a stereo signal (I still run an old Sonos S1 network as well as a Sonos S2 network)

With the new electronics power from the IEC power port, and a single speaker wire from one cabinet to the other, I could have the makings of an 'interesting', certainly unique, speaker system!
Easy job to create new fabric covers held on with velcro.

I just cannot bring myself to throw these away!
This is a light hearted project from someone who is technologically overstimulated and has some time on their hands.

Is this bonkers?
Rob

 

[JonFo]

Is this bonkers?

Not at all. It's better to repurpose the leftover boxes and drivers and do something interesting with them rather than send them to a landfill.

• Replace top woofer with a similarly sized midrange unit
• Maybe replace the odd hole (was the ESL connection port) with a ribbon or diaphragm tweeter
• Install a three way passive second order crossover to feed all three units, suitably rated

Converting to a three-way seems reasonable, and there are some nice AMT or ribbon tweeters these days. Not sure about location, I'd think centered would be more effective than where that connector hole is.

I have strong opinions about crossovers and am firmly in the active is best camp. It is also much, much easier to dial in the balance between drivers with an active. It also permits correcting impulse response alignment with some delay. The ability to use a fourth-order low-pass XO on the tweeter is very helpful at minimizing distortion near the XO point.

While it's audiophile heresy to suggest this, I will anyway. Look to automotive stereo for multi-way active crossovers and multi-channel amps. They are small, can be installed inside the cabinets, and all you need is a beefy mains to 12v power supply.

Finally, consider doing a 2.1 setup with a sub, as a single 6.5" 'woofer' is not going to be satisfactory.

Keep us posted.

 

[portway]

Ive also psoted this in my 'hello' post, but thought it also makes sense to add it here.. since this is where we find the similarly minded!

Good day all,
I'm not sure you're going to let me stay on here


I have had a pair of ML Puritys for over 15 years, and recently, they have both developed problems, one with an amp board, the other with a PSU fault (which I might have exacerbated doing electronic swaps for fault finding!). The repair cost in the UK is more than I paid for them in the first instance, and I'm not so heavily invested in ESL as I was 20 'better hearing' years ago (previously had ESL57 and ESL 63)

So, here's my current thinking, and I am already a way down this route.

• Removed ESL panels from speakers (still have them if anyone in the UK wants them) - tick!
• Remove all internal electronics -tick! Recycle said electronics - tick!
• The backplate now only has the heavy duty binding posts and the AC input IEC connector - of this, more anon

I now have two rather attractive looking cherry veneer cabinets, with some oddness on the front faces - see pics - the fabric grille at the top covers nothing.
These cabinets are still heavy and 'dead'
Each speaker seems to have two identical woofers, both 6 or 6.5in, 6ohm

This is what I propose to do:

1. Replace top woofer with a similarly sized midrange unit
2. Maybe replace the odd hole (was the ESL connection port) with a ribbon or diaphragm tweeter
3. Install a three way passive second order crossover to feed all three units, suitably rated

(A different though was to place the tweeter behind the top fabric cover, and cover the square hole with some fancy, bespoke vanity plate!

And then, the more esoteric

• Maybe install a class D amplifier INSIDE the cabinet (there's plenty of room and access). Can even get one of Fosi units with inbuilt bluetooth for non-audiophile use
• Maybe install my old SONOS ZP80 preamplifier to feed the Fosi with a stereo signal (I still run an old Sonos S1 network as well as a Sonos S2 network)

With the new electronics power from the IEC power port, and a single speaker wire from one cabinet to the other, I could have the makings of an 'interesting', certainly unique, speaker system!
Easy job to create new fabric covers held on with velcro.

I just cannot bring myself to throw these away!
This is a light hearted project from someone who is technologically overstimulated and has some time on their hands.

Is this bonkers?
RobView attachment 25149

Not at all. It's better to repurpose the leftover boxes and drivers and do something interesting with them rather than send them to a landfill.



Converting to a three-way seems reasonable, and there are some nice AMT or ribbon tweeters these days. Not sure about location, I'd think centered would be more effective than where that connector hole is.

I have strong opinions about crossovers and am firmly in the active is best camp. It is also much, much easier to dial in the balance between drivers with an active. It also permits correcting impulse response alignment with some delay. The ability to use a fourth-order low-pass XO on the tweeter is very helpful at minimizing distortion near the XO point.

While it's audiophile heresy to suggest this, I will anyway. Look to automotive stereo for multi-way active crossovers and multi-channel amps. They are small, can be installed inside the cabinets, and all you need is a beefy mains to 12v power supply.

Finally, consider doing a 2.1 setup with a sub, as a single 6.5" 'woofer' is not going to be satisfactory.

Keep us posted.

Hi, what do you want for the panels?

 

[Astacus]

Hi, what do you want for the panels?

I was thinking of £100. Plus carriage (though they would be a pain to pack up and ship securely). I'd much prefer collection from my home.

 

[Leporello]

Kind of like doing a budgie job on a terrier. But agreed, anything beats dumping the beautiful casework into the landfill. My own inclination would be to attempt to build my own ESL panels. But that's just me, and would be a bigger project. There's an ESL builder who is occasionally on this forum, if interested. Classic references include "The Electrostatic Loudspeaker Design Cookbook" by Roger Sanders (whose amplifiers are much talked about on this forum lately) and Ronald Wagner's "Electrostatic Loudspeaker Design and Construction". Sanders' designs are closer to the Martin Logan model, and there is a construction of a curved ESL panel as an advanced project. But good luck with whatever you decide to do.

Just re-read your post and the problem is apparently not in the panels but the electronics. To me, even more tempting to restore the ESL's (if you haven't already sold the panels). The main hard to find items would be the step-up signal transformers. If those are still good, almost any amplifier good for driving ESL's would be suitable for driving them. High voltage bias supplies are amply covered in the above references. But if you don't have a background in electronics and are not inclined to learn, I guess your approach makes more sense.

 

[Astacus]

Not at all. It's better to repurpose the leftover boxes and drivers and do something interesting with them rather than send them to a landfill.



Converting to a three-way seems reasonable, and there are some nice AMT or ribbon tweeters these days. Not sure about location, I'd think centered would be more effective than where that connector hole is.

I have strong opinions about crossovers and am firmly in the active is best camp. It is also much, much easier to dial in the balance between drivers with an active. It also permits correcting impulse response alignment with some delay. The ability to use a fourth-order low-pass XO on the tweeter is very helpful at minimizing distortion near the XO point.

While it's audiophile heresy to suggest this, I will anyway. Look to automotive stereo for multi-way active crossovers and multi-channel amps. They are small, can be installed inside the cabinets, and all you need is a beefy mains to 12v power supply.

Finally, consider doing a 2.1 setup with a sub, as a single 6.5" 'woofer' is not going to be satisfactory.

Keep us posted.

Maybe I'll keep both woofers and add a mid and a high?

 

[Astacus]

Kind of like doing a budgie job on a terrier. But agreed, anything beats dumping the beautiful casework into the landfill. My own inclination would be to attempt to build my own ESL panels. But that's just me, and would be a bigger project. There's an ESL builder who is occasionally on this forum, if interested. Classic references include "The Electrostatic Loudspeaker Design Cookbook" by Roger Sanders (whose amplifiers are much talked about on this forum lately) and Ronald Wagner's "Electrostatic Loudspeaker Design and Construction". Sanders' designs are closer to the Martin Logan model, and there is a construction of a curved ESL panel as an advanced project. But good luck with whatever you decide to do.

Just re-read your post and the problem is apparently not in the panels but the electronics. To me, even more tempting to restore the ESL's (if you haven't already sold the panels). The main hard to find items would be the step-up signal transformers. If those are still good, almost any amplifier good for driving ESL's would be suitable for driving them. High voltage bias supplies are amply covered in the above references. But if you don't have a background in electronics and are not inclined to learn, I guess your approach makes more sense.

I'd love to know what a 'budgie job on a terrier' means! Not on I have heard before.
I don't have the energy or skill to embark on an ESL route, and tbh, I rather like the low assymetric cabinets of the remains of the Purities!

Still considering what to do. I know they could end up sounding like crap, but they should be nice to look at

 

[Leporello]

I'd love to know what a 'budgie job on a terrier' means! Not on I have heard before.
I don't have the energy or skill to embark on an ESL route, and tbh, I rather like the low assymetric cabinets of the remains of the Purities!

Still considering what to do. I know they could end up sounding like crap, but they should be nice to look at

From a classic Monty Python skit. A man (I believe it's John Cleese) walks into a pet store wanting to buy a cat. The pet store owner (probably Michael Palin) offers instead that he has a lovely terrier. He subsequently offers to modify the terrier to order. At one point he calls to his back room assistant "'arry, can you do a budgie job on a terrier straight away?" and 'arry replies in some barely intelligible Cockney to the effect that he has other work to complete first. Doing a budgie job on a terrier has become my slang among friends for modifying something beyond recognition. You can probably find it on You Tube or Netflix if interested.

If it ends up sounding like crap you can try try again. That's the beauty of DIY audio. The nice looks can inspire your dedication. There are lots and lots of resources and you will definitely end up learning along the way, no matter how it turns out.

I'd make an offer for the ESL panels if they're not spoken for by now, but I'm in the US. Collection from your home is right out.

Surprisingly, I couldn't find a video of the Python I alluded to, but here's a link to the script:

https://montycasinos.com/montypython/scripts/terrier.php.html

In this version it's "parrot" but in the version I'm familiar with (from an LP I have) it's "budgie", which I think is funnier. We call them "parakeets" here.

Years ago I ordered some Woodmark kitchen wall cabinets with glass door fronts. The doors did not fit correctly. Woodmark, instead of exchanging them, simply sent me new doors that did fit correctly. I've been saving the old doors thinking they might be good for ESL panel frames (possibly curved panels from the Sanders book) when I get the proper tool (a round tuit). I would use them for surround speakers. If it could somehow work out that I could get your panels they might actually fit.

 

[Russr]

I'm thinking that you might consider adding an external (little) box on top of your existing enclosures with a ribbon tweeter in there... something like this:
https://www.aliexpress.com/i/3256803008310174.html?gatewayAdapt=4itemAdapt
... but maybe with a higher-end ribbon/folded tweeter.

Or, depending on existing crossover points and enclosure volumes, as somebody might have mentioned above, take a page out of our Auto audio friends' book, and look at something like this:
https://www.amazon.com/Midrange-Tweeter-Speaker-Universal-Enclosures/dp/B07T3PDR9Q

Just a couple of thoughts...

 

[Astacus]

I'm thinking that you might consider adding an external (little) box on top of your existing enclosures with a ribbon tweeter in there... something like this:
https://www.aliexpress.com/i/3256803008310174.html?gatewayAdapt=4itemAdapt
... but maybe with a higher-end ribbon/folded tweeter.

Or, depending on existing crossover points and enclosure volumes, as somebody might have mentioned above, take a page out of our Auto audio friends' book, and look at something like this:
https://www.amazon.com/Midrange-Tweeter-Speaker-Universal-Enclosures/dp/B07T3PDR9Q

Just a couple of thoughts...

Thanks for these thoughts.... there's plenty of room in the cabinet for a tweeter and a midrange, in addition to the two woofers. The top of the Purity box slopes backwards at about 25 degrees, so not an easy fit for an external box.

What I do need to do it to dismantly one again and get my hands inside. I don't know if there are baffles that could make mounting new drivers a problem. Not a priority at the moment, the vegetable garden has sudddenyl had a grwoth spurt!

 

[Astacus]

From a classic Monty Python skit. A man (I believe it's John Cleese) walks into a pet store wanting to buy a cat. The pet store owner (probably Michael Palin) offers instead that he has a lovely terrier. He subsequently offers to modify the terrier to order. At one point he calls to his back room assistant "'arry, can you do a budgie job on a terrier straight away?" and 'arry replies in some barely intelligible Cockney to the effect that he has other work to complete first. Doing a budgie job on a terrier has become my slang among friends for modifying something beyond recognition. You can probably find it on You Tube or Netflix if interested.

If it ends up sounding like crap you can try try again. That's the beauty of DIY audio. The nice looks can inspire your dedication. There are lots and lots of resources and you will definitely end up learning along the way, no matter how it turns out.

I'd make an offer for the ESL panels if they're not spoken for by now, but I'm in the US. Collection from your home is right out.

Surprisingly, I couldn't find a video of the Python I alluded to, but here's a link to the script:

https://montycasinos.com/montypython/scripts/terrier.php.html

In this version it's "parrot" but in the version I'm familiar with (from an LP I have) it's "budgie", which I think is funnier. We call them "parakeets" here.

Years ago I ordered some Woodmark kitchen wall cabinets with glass door fronts. The doors did not fit correctly. Woodmark, instead of exchanging them, simply sent me new doors that did fit correctly. I've been saving the old doors thinking they might be good for ESL panel frames (possibly curved panels from the Sanders book) when I get the proper tool (a round tuit). I would use them for surround speakers. If it could somehow work out that I could get your panels they might actually fit.

Found it! Had forgotten that one - but can recire the parrot sketch almost word for word! I reckon the easiest way to get the anels would be for you to fly into Manchester and collect them! Exporting stuff like, this is a nightmare!

 

[Astacus]

Kind of like doing a budgie job on a terrier. But agreed, anything beats dumping the beautiful casework into the landfill. My own inclination would be to attempt to build my own ESL panels. But that's just me, and would be a bigger project. There's an ESL builder who is occasionally on this forum, if interested. Classic references include "The Electrostatic Loudspeaker Design Cookbook" by Roger Sanders (whose amplifiers are much talked about on this forum lately) and Ronald Wagner's "Electrostatic Loudspeaker Design and Construction". Sanders' designs are closer to the Martin Logan model, and there is a construction of a curved ESL panel as an advanced project. But good luck with whatever you decide to do.

Just re-read your post and the problem is apparently not in the panels but the electronics. To me, even more tempting to restore the ESL's (if you haven't already sold the panels). The main hard to find items would be the step-up signal transformers. If those are still good, almost any amplifier good for driving ESL's would be suitable for driving them. High voltage bias supplies are amply covered in the above references. But if you don't have a background in electronics and are not inclined to learn, I guess your approach makes more sense.

Sadly, the electronics have been recycled (except for the inductors, stained glass is one of my hobbies and the enamelled copper wore is lovely).

 

[Astacus]

Thanks for all the suggestions. I'm not minded to invest a huge amount in this project, but am giving serious consideration to the auto audio option - the next step for me is to strip out the woofers and do some exploration of the internal baffle structure, about which I can find nothing...