Amek m2500?

[ilfungo]

does anyone know where I can find the little white caps for EQ section?
there are some missing and want to replace them but I can't find them...
Thanks

 

[ilfungo]

Brand?

 

[ilfungo]

For who is searching the same thing:

http://ward-beck.com/rohs-7mm-matte-grey-elma-cap-with-line-for-10mm-knob.html

I hope they are the right ones....

I need some info abount TL074 :

TL074 CN    = input offset 10mV
TL074 ACN  = input offset 6mV
TL074 BCN  = input offset 3mV

Sorry but I don't know ....
It's important to have a low offset voltage in this circuit?
Thanks

 

[jensenmann]

IIRC these caps were custom made by Sifam. It´s quite possible that you still can get similar looking ones - unfortunately not exactly the same - from them. Measure yours and compare them to Sifam´s current products: http://www.sifam.co.uk/knobsSelector.asp?cat=Knobs_Collet

If the circuit around your chip is directly coupled (without coupling caps) then you want the lowest possible offset.

Edit: these WBS knobs indeed do look VERY similar to the original ones.

 

[ilfungo]

Hi
I need a little help for 2500C module...
I've recapped all but I've done a little mistake:
I don't know the polarity of 2 caps on the main board (I've removed them but there isn't an indication on the board).
They aren't present on  schematics or I can't see them...
Thanks!

 

[ilfungo]

The pin are 77 -78
they are missing on the schematics...
They come from mute relay, could be + to relay?
Thanks!
???

 

[jensenmann]

My desk has a slightly different PCB layout. But somewhere upstream it has pairs of elctrolytics in a bipolar configuration. So I guess your caps are supposed to be bipolar which explains the missing + sign.

 

[ilfungo]

Thanks
I don't have bipolar caps but I've read somewhere that it's possible to use 2 polarized caps and built a bipolar.
like: + -- +
Could work?
Thanks!

 

[jensenmann]

That´s exactly how it´s done in my desk.

 

[ilfungo]

I've a lot of LF353...
can I use them in place of the TL072 without problems?
Thanks!

 

[ilfungo]

???

 

[jensenmann]

It depends on the particular circuit. There´s no simple generalized answer to this. Since Graham Langley did implement bandwith limitation consequently I´d say it´s quite possible. But there will be no real benefit from that, except the risk of problems. LF353 are sidegrades with other problems, not upgrades. They double the current draw e.g.

 

[ilfungo]

Hi Jensenmann
thanks for all the info!!!
the console is recapped and sound great!!!
I've just 3 channels to be tested....
I need help for the LED 40A...
I can't find how to calibrate them.
4 trimmer on every card  ???
Thanks!

 

[ilfungo]

nobody knows anything about L40A light meter?
Thanks

 

[jensenmann]

Drop me a pm on monday when I´m back in my workshop. I´ll have a look at the schematics there.

 

[ilfungo]

Thanks !!!

 

[jensenmann]

R66 1Meg is an offset trim for the rectifier circuit inside the meter
R23 10k is the meter circuit input trim
R24 22k is the analyzer circuit input trim

The 1Meg trimmer without a name trims the analyzer timeconstant/ballistic.

 

[ilfungo]

Thanks Jensenmann
Just yesterday I've solved all... Now all the meter are working very well! ( I hope)
THANKS!!!

 

[ilfungo]

Hi Jensenmann!
I've started to install the M2500 on the studio, and I've a little problem with monitor output...
Amek m2500 (unbalanced output) to Adam  A7 ( balanced input)
Nothing connected , only the monitors...
I've a strange noise like ground problem I think (buzz noise).
Have you ever had the same problem?
Suggestions?

Thanks!!!

 

[jensenmann]

No, my monitor output has been working properly with the poweramp connected. Try to connect different speakers to see if it´s a problem of the Adams or the desk.