The famous but unknown (in Europe) ESS AMT

[markusliechti]

Hi together!

I'm new in this forum (this is the first forum I write!). My name is Markus and I live in Switzerland. I love all the very nice vintage stuff of the 70ies. I've a pioneer SX-1080 and a pair of ESS amt-1b and other nice things!

I never met people who know the AMT....???

This is the reason for me to write in this forum.

I love my ESS speakers but there is a problem: one is ok, but the other one sounds much more quiet.

The electrolytic caps are worse...but after replacing (because I read somewhere that old ESS AMT speakers will sound much better by replacing the old caps with MKP (foil)), the speakers sound awful

I think, that the ESS engineers calculatet the "bad characteristics" of electrolytic caps by developing the crossover....and so, with the completely different MKP they sound very, very bad (no bass, no middle, no 3-D). The AMT need the inductance of the electrolytics...

A Test with new ELKOS was very well, both speakers sound the same, but still not like "sound as clear as light" because the 3-d sound was better with the old caps. Only the dynamic and power of the AMT was better (louder) than before

Are the old black 15 and 5uF caps with red endings and the inscription "MEXICO" also electrolytic?

Is there anyone who has ever upgraded/repaired the crossover of the 1b model?

Thanks for helping

Kind regards

Markus


PS: I opened this thread because i don't find something matching exactly my problem...

 

[ondesx]

The ESS is very well known in Europe too... You first have to check several things before thinking to the caps. IMHO, you first have to tests the drivers themselves, then the XO. I think the FR will give you a good idea about what is going wrong.

A very good idea, provided the drivers are OK, will be to actively amplify the ESS. You'll definitely improve your listening...

 

[markusliechti]

Hi ondesx, thanks for your answer! Everything is ok, except the caps. One speaker is like new and the other sounds quiet and bad. The only thing I want is that the speaker stay like original and sound as good as possible with the original configuration (except parts inside). I won't take the AMT away and I won't make a completely new crossover (not yet).

I need information from a member that still has had the same experience about replacing the old electrolytic caps.

Because this speaker is a collector's item, I leave it original.


PS: sorry for my english!

 

[JohnL]

I have replaced the caps in an AMT1B and it did sound better after they were replaced. The woofers they put in the AMT1's were not very good, I would recommend removing the AMT and pairing with another woofer. They can be removed without damaging the original set-up. I think once you have a well designed speaker with the AMT tweeter, you will not look back to the AMT1.

 

[hrgraves]

1 B xovers from ePay might be another viable option for you.

automojo on AK posted a very nice piece on recapping of AMT3, and there are several threads discussing the merits of the different types of caps.

re a scrqtch build using the AMT- If I recall correctly THE Nelson Pass had the thought of using multiple small drivers ala Bose 901--
I suppose the fact that no one has persued this is a good indication that there are either too many inherant problems with this approach or that there are much better alternative designs

just some thoughts for you