Found this Quad 57 Classified, and...

[Nemeske]

I recently came across this listing at eBay:

EARLY pair of 'MONO' QUAD ESL 57's...both work but need some repairs... | eBay

I read the description about 'mono' and a point of view of better sounding .

What do you think, what does the seller mean?

 

[stokessd]

The older original ESL's had banana connectors that are both the same color. But more importantly, those early one also have more limited crossovers that make the tweeters more prone to arcing with high power amplifiers. Those could be old enough that the rectifier blocks are epoxy (not rebuildable) rather than the beeswax boxes


Sheldon

 

[Nemeske]

I see, but I do not understand the seller's opinion about 'better sound' I am aware that these must have the 2 row*4 layout of resistors and maybe the audio input wire is a solid core instead of stranded wires but what is the difference except these he means?

 

[Andersonix]

Words in question:
"when working properly these 'mono' esl 57's have a much nicer 'tone' and sound much better than the later 57's"

My interpretation is they are early Quads that will sound much better after you repair them, so please hurry up and buy them.

 

[Nemeske]

And what causing the 'better' sound?
The difference in the crossover? The different method of the manufacture of the plastic panels? Different components used in the EHT?

 

[stokessd]

In my limited experience of over 20 years of original Quad ESL repair, the only differences are the crossover network and the non-repairable EHT blocks.

The panels are effectively identical, the grilles are identical, the rear grilles and damping mats are identical.

The only difference is the crossover, which I'd recommend that you upgrade to the latest design to protect your expensive tweeters.