AMEK M2000 Recapping

[ilfungo]

hello
I'm about to start a recapping Amek M2000 ....
32 x 1000UF 25v axial
96 x 220uF 40v axial
240 x 47UF 40v axial
you know some good advise capacitors that do not cost so much?
the originals were Philips + ITT (1000UF)
thanks

 

[ilfungo]

???

 

[QUEEF BAG]

you can use radial caps, if they physically fit into the space.
either standing up or layin' down.

the length of the leads of the 1000uf caps may be an issue if you wanna put in a radial there

panasonic FM or nichicon HE are both very good and good price.

if you need to go with an axial for the 1000uf first choice (and expensive) is the vishay BC 138 series
for less money the nichicon TVX is okay too.

the 47uf could be replaced with 56uf by 50v

 

[ilfungo]

thanks for the answer
I found all the values ​​with Vishay BC Series
these capacitors are good?
Thanks

 

[QUEEF BAG]

the BC caps are good...expensive, and in my opinion, over rated.

they last a long time though.  and i use them.

 

[ilfungo]

hello all
I just finished recapping all the MIXER
I have a problem
I also ricapped PSU
console connected
+17.4 Go down to +16.7
- 17.4 remains -17.4

Is this normal?
thanks

 

[ilfungo]

???

 

[Balijon]

There is a AMEK doctor in the house: Jensenmann... 

 

[ilfungo]

Thanks  Balijon!!!
Now I try to contact Jensenmann...

 

[tony dB]

did you measure the voltage (where it drops) before the recap? I'm sure you had the same figures or even worse.
Much, if not all, has to do with the length and diameter of the PSU cable going to the desk.
The difference in - compared to + is normal as the + draws way more current then the - rail.

 

[ilfungo]

unfortunately I have not measured before recapping ....
The cable is about 8-10 feet long
this difference between + and -  may create some problems?
Thanks for the help ....

 

[ilfungo]

Sorry guys I need help
after 20 days of work the power of the Amek M2000 broke again .....
+ 18 does not work
I double checked all the parts but can not find nothing broken
continued to burn the fuse (no load)
I decided to change it to make it adjustable LM338
A 5 may be enough for any tension? (32 channel + 2 stereo returns + master)
The original card has 1x +2 x UA7818 MJ2955
I found this schematic, this may be fine?
thanks

 

[tony dB]

we had similar experiences... replaced the LM338 to find out in a few days that it gone bad again... we thought (!)
But then, Colin 'Slenderchap' hinted us to hardwiring those LM338 and this took care of the problem. It also raised the +rail a little.
The desk is already a few months stable now and the + and -17 V voltages stay perfect. Try it, I'm sure you're having the same problem we had.

 

[jensenmann]

Exactly, those TO3 sockets tend to have problems at that age. Maybe these will fit (if you want to stick with sockets): http://de.rs-online.com/web/p/kuehlkoerper/1897912/

 

[ilfungo]

Thanks for your help!!!

 

[ilfungo]

my console is alive!
I finished recapping and everything seems to work well
I only have a problem with a channel, when I insert EQ, level increases by 4 dB (flat).
I tried to replace the IC but nothing changes.

I would like to replace all the IC

LF353
TDA1034B

What do you recommend?

I thought
LF353 =  NE5532
TDA1034B = NE5534

It may be fine?
They are direct replacement?
thanks

 

[ilfungo]

???

 

[jensenmann]

TDA1034 is the Philips brand name for NE5534, so these are the same. They are fine chips, I don´t see a need to replace these. There are very few chips that outperform 5534 upto today. And these will cost $ and need extra work and tweaks to make them work stable. (try to convince a racehorse to pull a car ;-)

LF353 are FET input chips, while 5532 are BJT input type chips. In high impedance or direct coupled circuits you will run into trouble when you swap FET for BJT chips. I did some tests with replacing LF353 with modern highspeed FET chips and could not get the circuit to sound better than it was stock. So in my book these are pretty good sounding chips which will perform great as long as the circuit is well designed. Back in the days LF353s were regarded as Mercedes solution while TL072s were considered to be the Volkswagen.

 

[ilfungo]

THANKS  jensenmann!!!!

 

[jensenmann]

Btw, consider to pull all chips and stick them back in. Contacts may have suffered over time. If there´s a socket which obviously has not much force left to hold the chips then replace it. I´ve been told that there were few desks with red sockets which are known as troublemakers. These should be replaced anyway.