Elektro artist W8 GDR tube amp

[georgerarnold]

Hello,

I have a slightly unusual request and I can't say I'm confident that anyone would be able to help me.

I have an old East German tube amp (elekro artist w8 I believe) which I'd love to get working. I have a little bit of time and I'd love to try to fix it myself.
The trouble is my knowledge of electronics is very limited. I am good with a soldering iron though and I'm not a complete idiot.

I was wondering if there are any kind and knowledgeable souls out there who wouldn't mind seeing me through and pointing me in the right directions and answering my questions.
There are a few schematics on the internet but I can't verify how accurate they are and I imaging that these amps are not very standardized.

I'd be very grateful if anyone could help me, I do realise I'm asking quite a lot.

Cheers,

[g1]

Please post the schematics you have found. If you don't have sufficient privileges yet, post links.
Do you have other tools such as multimeter, etc. ?
Have a look at this 'light bulb limiter' which is something you should consider building for troubleshooting purposes: http://www.geofex.com/article_folders/spo_test.htm

[georgerarnold]

Please post the schematics you have found. If you don't have sufficient privileges yet, post links.
Do you have other tools such as multimeter, etc. ?
Have a look at this 'light bulb limiter' which is something you should consider building for troubleshooting purposes: http://www.geofex.com/article_folders/spo_test.htm

Thanks for your reply.
Yes I have a multimeter. I'll look into the light bulb limiter in greater detail as I'll need to be absolutely sure what I'm doing.

Unfortunately it won't let me upload the schematic I found.

This is the link https://images.app.goo.gl/u4dyce2UBfp3JYFy6

[J M Fahey]

LOVE the "Eye of Horus" front panel

And find it weird they used banana plugs for inputs

[g1]

Here is that schematic:

[vintagekiki]

His Electro Artist does not have tube EL12N

[Helmholtz]

I see 4 tubes: First one on the right is an ECC81, second one should be a pentode, then an EL84, fourth one in the back might be another EL84 but more probably an EZ 81 rectifier.

OP should clarify.

[dmeek]

Here is the complete W10 schematic. Maybe the power supply is similar.

[vintagekiki]

Here is the complete W10 schematic. Maybe the power supply is similar.

His Electro Artist does not have tube EL34 and no Baxandall color tone control.
May be ¹⁾
https://www.vintageandrare.com/product/Herrnsdorf-Elektro-Artist-Red-brown-68087

[nickb]

First, It obviously hasn't been used in a long time so don't turn it on. The electrolytics will have deteriorated and need to be treated with care. I'll come back to this is a mo.

Next, it would help to have an accurate schematic and it seems there are quite a few variations of this. Post, link, or p.m. me and I'll post, several clear images of the guts at different angles. We / you should be able to draw a schematic from that.

Now the caps, it you want a reliable amp you should simply replace the electrolytics and be done with it. Some people carefully remove the innards ( take care) of the old can ones and fit new caps in there so it looks the same from the outside. Or you can leave them in place, cut the connections and mount the new ones in the chassis. You can also try to get it to work using the old ones. The way I do this is to remove all the tubes and replace the rectifier with a silicon diode in series with a 1K 5W resistor. I then use a variac to gradually apply increasing voltage while monitoring the voltage drop across the 10k resistor to check the current is not too high, i.e. under 5V, or is increasing which would indicate a failure. Increase the variac, the current will increase and then gradually fall as the capacitors recover ( reform). Then increase the variac a bit more. Repeat until you are at full voltage.

[Mick Bailey]

My approach with an unknown or unusual amp is;

1. Get hold of reference pictures of the same model amp in good condition, as well as schematics and any other information that may be useful.
2. Take as many pictures as necessary to document the amp as it stands. Make comprehensive notes of what goes where (including tube positions), the general layout and any fragile wiring or parts that may easily be broken or disturbed.
3.Carefully remove the tubes.
4. Make a note of any broken, damaged or missing parts
5. Carefully clean off the chassis and inside of the cabinet - I use a soft paintbrush and vacuum cleaner at this stage.
6. Remove the chassis. If any connections need to be unplugged or unsoldered, or parts removed, photograph where they go and take notes if necessary. At the time some things may seem obvious but if the amp takes a while to restore it may not be so clear when the time comes to put everything back.
7. Get the chassis on the bench and give it a wipe over with a damp cloth. Make a note of the values marked on the capacitor cans.
8. Photograph the underside of the chassis and make notes of burnt components, damaged wiring, leaking capacitors.
9. Establish whether the amp corresponds to available schematics. If not, draw up the schematic as far as possible.

After this I proceed with repairs and restoration. Before carrying out any repair work or component replacement on an old amp I first check the mains transformer for earth leakage, as a replacement transformer can be a high cost item and sometimes not straightforward to find something that physically fits.

[vintagekiki]

well done old school.