ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hi all,I got off Ebay this amazing amp i always wanted to have.The problem i have is that I cannot work out the values on two white FeSi inductors 8020094 that are next to the main filter capacitors as they are both bad and couldn't do any reading.I did try to look at the schematic but couldn't see any details of it.Can you help.THANKS
HI AGAIN,IS THERE ANYONE THERE WHO CAN HELP
THANKS
It's very unusual to see these components go bad.I can't remember seeing it one single time, and I've done hundreds of these Beomasters.
Why do you think they're bad?
Having said that, Beomaster 1000 was produced in countless versions, - can we see a photo of the parts in question?
And you said "next to the main filter capacitors"... There is only one filter capacitor.
Martin
I now know what you mean. Next to the output series capacitors.I never saw them fail. Are you sure?
Hi Martin,the app is not letting me to attach a file and have few in my media.
Ok.As i was cleaning the board and went over this two parts flakes of this enamel started to come off.Soon after i noticed that the coper wier was badly danaged as wellas the coil.Then i hought i coud find the inductance of the second one .When i did all the prepattion i realised that couln't get sny readings because the other one was bad too.
The look of the amplifier from outside was good but inside found residues and deposits of filth,dust and rust.
I'm not an expert but have fix few of them.
My question is what inductors i need to get to replacethe old once.Thanks.Will try to post some photos if i could.
Goran
Still there.The bronze membership is letting me down.The site is behaving strangely.
this photo was taken before cleaning.afterwards i removed one which flaked and completely dissembled it just to see what thickness the magnetic wire is and how many turns were around coil.I'd tested the other inductor for continuity but couldn't get any reading.if the other one was ok was thinking to try to read its inductance.yes, it is strange this parts to go bad.
will be good if anyone knows how many Henry's and all other parameters the replacement should be cos the other option is to get magnetic wire and two make 2 replicas by which i found it very tricky as i haven't done before.
It's usually a fairly small coil.0,5uH or so.But I wonder why they went bad. Has the output series capacitors shorted?
good morning,no.capacitors are ok.it seemed like someone was playing with them snd the reason why they're both shorted is that the insulation coat got damaged.
would prefer to solder new ones
They are not particularly critical as they are in theory merely parasitic suppressors - to avoid self-oscillation if driving capacitive loads etc.If there are no resistors inside the original coils - and there doesn't seem to be from the schematics - you can make some simple air-coils.8-10 rounds of a suitable gauge insulated copper lead coiled to apprx 6-7mm diameter will most likely come somewhat close.
Thanks Martin.I'll try to re- use the ferrit coils and make the same amount of turns using insulated wire making sure i use same length of it.Found plastic clips that are going around coil on Ebay.It will be a challenge winding the wire as it isn't only once around.If this doesn't work i can do this air loops as you're suggesting.
Hi Martin,Thanks for your advice.I did one of the coils and managed to safe the other.I'm facing a big dilemma now regarding replacing the filter capacitor.
Had realised that on my 2136 (serie 29) i have 8000uF filter capacitor.I searched the net and couldn't not find on any schematic that this one should be replaced with 8000uF.
My question was:Do i replace the 50V 8000uf with a capacitor of a same value or use 3000uf as it is on every schematic on the net.
I doubt that the 8000uF filter capacitor is original. They are usually 2000uF or 3000uF, which is absolutely adequate.
If you can get 3300uF 50V, you can fit that for all three.
Thanks Martin,
Rushed a bit and order 10000uf 50Vbut I'm not going to use.Will try to get 3000uf.At the moment I've replaced the output with 2x 3300uf 35v and the filter capacitor with used 68000uf 50v.Established better current as the old outputs were causing big transformer hum.
Now i have distorted sound on both channels and no radio.When the inductors ate concerned ,they both ok.Will take some readings after I'll fit the filter capacitor.At list got somwhere.Keep you posted