i need schematic or service manual for this model of preamplifier made by Electrocompaniet 1976. Preamplifier manufactured in Norse Ecosse Electric in Glenrothes, Scotland.
impulsyu@nadlanu.com
impulsyu@nadlanu.com
Good luck with that. If you get a copy could you email me one too? i searched for ages a while back and got nothing....
Fran
Fran
I wrote to electrocompaniet and answer is:
"I’m sorry but we don’t send schematics to others the EC- authorized service points.
Please contact our distributor in your country for service."
That words not stop me to draw schematic looking in the PCB. I will save three hours with schematic but: men`s got a do what men`s got a do!
"I’m sorry but we don’t send schematics to others the EC- authorized service points.
Please contact our distributor in your country for service."
That words not stop me to draw schematic looking in the PCB. I will save three hours with schematic but: men`s got a do what men`s got a do!
The 2 Channel Audio Preamplifier
Hi!
I just got this preamplifier from Scotland but in non working condition-few parts missing including cover plate so looks like this will be my first diy project.
Any advice on missing parts or original schematic would be welcome.
Here are some pics and original ebay listing.
electrocompaniet ,The 2 channel preamplifier,faulty. | eBay
Hi!
I just got this preamplifier from Scotland but in non working condition-few parts missing including cover plate so looks like this will be my first diy project.
Any advice on missing parts or original schematic would be welcome.
Here are some pics and original ebay listing.
electrocompaniet ,The 2 channel preamplifier,faulty. | eBay
Attachments
Phono Stage.
The phonostage shows the correct transistors.
Buffer and preamp main output stage.
Power supply.
The semiconductors show in the buffer and psu are just what was in LTspice.
The phonostage shows the correct transistors.
Buffer and preamp main output stage.
Power supply.
The semiconductors show in the buffer and psu are just what was in LTspice.
Thanks msdin for your help!
Unfortunately previous owner adapted amp for some extra phono stages so it will be difficult task to restore it to its original condition. Also there are few random parts across pcb missing. Ill post soon as i make some progress.
Unfortunately previous owner adapted amp for some extra phono stages so it will be difficult task to restore it to its original condition. Also there are few random parts across pcb missing. Ill post soon as i make some progress.
Thank you again msdin!
Fortunately pcb is almost same version, so pictures helped a lot.
I still have some parts that i dont know right values.
Two resistors on phono circuit and some in corner of pcb.
I attached photos with circled areas. If you know anything about these values would be in great help to finish repair.
Fortunately pcb is almost same version, so pictures helped a lot.
I still have some parts that i dont know right values.
Two resistors on phono circuit and some in corner of pcb.
I attached photos with circled areas. If you know anything about these values would be in great help to finish repair.
Attachments
I'll have a look later today and take some more photo also I'll let you know the values of the missing component.
Sharif.
Thanks msdin for all the hard work.
What I like about this RIAA circuit is that the resistor and capacitor values are all standard within the 5% stock range. The LM49860 datasheet has an RIAA stage example with resistor values you can only buy in 100000 quantity, if that.
My computer cant read these jpg files (linux lubuntu 11 op system), so I put the phono board as best as I can read it in a png format through geda schematic editor. My appologies if I misread the values. My apologies also, the image uploaded can't be read. the png file has sufficient detail to blow up and look at, but I can't figure out how to list the file for download instead of the picture which is just a blur.
What I like about this RIAA circuit is that the resistor and capacitor values are all standard within the 5% stock range. The LM49860 datasheet has an RIAA stage example with resistor values you can only buy in 100000 quantity, if that.
My computer cant read these jpg files (linux lubuntu 11 op system), so I put the phono board as best as I can read it in a png format through geda schematic editor. My appologies if I misread the values. My apologies also, the image uploaded can't be read. the png file has sufficient detail to blow up and look at, but I can't figure out how to list the file for download instead of the picture which is just a blur.
Attachments
Last edited:
Thx guys for going into this project!
I have used this very good sounding pre from 1990 till 2014 and it never let me down.
It came with a reverse engineered schematic which was not good powersupply-wise. Someone adapted the PS to something else... Now, thx to you I maybe Upgrade it back to original!
I don't use it that much at the moment, but I will never give it away.
I never switched it off, because it sounds realy a big lot better when warm!
Good luck with bringing it back to life!
I have used this very good sounding pre from 1990 till 2014 and it never let me down.
It came with a reverse engineered schematic which was not good powersupply-wise. Someone adapted the PS to something else... Now, thx to you I maybe Upgrade it back to original!
I don't use it that much at the moment, but I will never give it away.
I never switched it off, because it sounds realy a big lot better when warm!
Good luck with bringing it back to life!
Very often, on gear older than five years, sounds better warm is caused by dried up electrolytic capacitors with leaky cheap rubber seals. Replace them with similar values and see if it sounds better cold. You can buy caps with 3000 to 10000 hours service life these days, for only about 30% more money. Digikey has service life in the cap selector table. Farnell lets you choose service life as one of the selection criteria. don't put a limit in farnell, they don't sort in correct order. Mouser makes you download and read the manufacturer's datasheet.
Good luck.
As you can see in the pics, I changed all caps mid 1990ies. The sound got better. But the Pre amp sounds a lot better when allways on.
Actually I already have some new caps in stock for my Pre, but changed my amp, so its not priority atm.
The Volume control is a bit of a problem. Till now it works but balance is uneven. If someone has an idea or Part which fits nicely I will consider changing the pot.
Actually I already have some new caps in stock for my Pre, but changed my amp, so its not priority atm.
The Volume control is a bit of a problem. Till now it works but balance is uneven. If someone has an idea or Part which fits nicely I will consider changing the pot.
I just finished rebuild ( just cover still missing but that is...) , all voltages are in limits.
PCB trail was cut out on few places- dont know for what purpose. There were two Naim phono stages extra built in. Few photos of original attached. Ill do some listening tests with electro 25w and post some comments later on. Still connected to external psu- also that connections have been tampered.
Thanks all for help!!!
PCB trail was cut out on few places- dont know for what purpose. There were two Naim phono stages extra built in. Few photos of original attached. Ill do some listening tests with electro 25w and post some comments later on. Still connected to external psu- also that connections have been tampered.
Thanks all for help!!!
Attachments
- Status
- Not open for further replies.