Harryconover

So I did one box and contact cleaner repaired it.Nice sound without scratching noise.I´m so happy:-) On friday I´m going to repair second box, then I have to change bipolars on mids and bass in the xover, but I have to think about which one(22 and15uF) to buy... I think Visaton are ok.And that is all.Have a nice day!

Thanx a lot, Harry.I saw some in U.S.shops.And not so expensive.But here, in the Czech rep., I can´t get any. I´ll try to use contact spray and I hope it will help.Here is the picture of the wiring. http://www.bcae1.com/lpad.htm

But now this scratching sound is getting even worse.Should I apply some lubricant as well, or is it already damaged?I can´t buy them anywhere.Well I could, but not 8 Ohm pots. Please, could you give me some advice?Thank you very much.

Hi Harry.I´ve got problem with wirewound pots in my speakers.They are 8 Ohm.One is for treble and the second one for mids.When I was turning pots, it made scratching sound.So I put them to 99% isopropyl solution.

Thank you Harry.I will use standard PU surrounds.I don´t have many choices.But it has to be done by someone whoś more experienced than me.I´m afraid to do it by myself.
Have a nice day!

The material for surrounds is from special PU material, which lasts nearly forever.But maybe I can use "normal" PU surrounds.Bass drivers are from paper and going from 20Hz.I can´t find any similar bass driver in my country.

This is a nice restoration of Aurex.I wish I was able to do it like this.But I don´t know how he did it.(I mean the cone restoration)
https://www.facebook.com/oldplayer.ru/photos/pcb.800827110026247/800824213359870/?type=3&theater

The diameter is 30 cm.But surrounds have a very special design:
http://audio-heritage.jp/AUREX/speaker/ss-810.html

Hi Harry, I bought Toshiba Aurex SS-810.Very very nice sounding speakers.But surrounds on bass drivers are a little bit damaged.Do you think, I can get some original surrounds somewhere?Please, could I ask you to do me a favour and take a look around your country?Maybe you know, where to buy them.Thank you very much.Jan.

Hi Harry, what do you think about those speakers?How to get inside to upgrade xover?And is the price $1000 ok?Many thanx!
https://elektro.bazos.cz/inzerat/76222763/HECO-LAB-2.php

Many thanx, yes I will do it.The main reason of replacing R555,556 is, that the small cooler for voltage stabilizers(Q519,520) is getting very hot.I can put my finger on it for 15 seconds max.So I will try to check it again after replacing resistors.

Ok Harry, thank you very much again, yes I will check the voltage.But after replacing those fuse resistors ( R555,R556) 10 Ohm.This is the weak point of this amp.
Someone has replaced those two resistors and DC offset was +-10mV again and buzzing in the speakers has disappeared.
(I´m hearing some very slight hum in both speakers.(50Hz from transformer).But I have to put my ear very close to the speaker cone).Jan.

Hi Harry.Thanx a lot for your comment.Everything is ok by now.It´s going up to 20- 30mV.I put new trimmers for DC offset biasing.I think it was some bump to the trimmer before(580mV).I can´t explain this DC deviation.I´m going to change two fuse resistors, it should help to minimize offset as well.(I hope :-).But first I have to order it from some e-shop.Have a nice day.Jan.