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Newbie - Broken Valve amp, help needed!

B

bloodtype

New Member
Hi All,

Thanks for reading my post.

I have clumsily broken a transformer on a hand built (not by me) valve amp. I can't find a like for like replacement so was wondering if anyone here could point me in the direction of an equivalent?

The make is Telefunken
Netz Transformator
Bv.40-5112.065-12 Bv/Pv

Any help gratefully recieved!

Cheers
Ben

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Thanks for looking Jegor.

Apologies, the previous photo only showed the makers name etc. The photos below show the damage where it seems to have split. Not sure if this is a problem or if it can be repaired or if I should replace it. I haven't fired the amp up beacuse I was worried what the damage might do if it is an issue. Any advice gratefully received. Cheers, Ben

22351663831_cb5ca32cbc_b.jpg

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Hi Jegor,

The replacement has arrived and I just wanted to see if you could give me some help re wiring? Generally the wiring looks the same on the left hand side but on the right there are extra connections on the new telefunken. Do I mimic the positioning of the wires or follow the colours? I have made an image which shows what I mean. Any help gratefully received!

22476699362_42cb4bee3f_b.jpg
 
Thanks Jegor, how do I go about checking voltage on the new transformer? Apologies if this is a really stupid/amateur question!
 
That's a purdy transformer.

Do you have a schematic for the amp? Can we determine which wires feed which parts of the circuit? We know voltages on the secondary based on the inscription on the bottom, so it should likely be pretty straightforward once we know a few more variables. The 6.3v windings are used by the cathode heaters or filaments, but using the right tap is important.

Mike
 
rave0035 said:
That's a purdy transformer.

Do you have a schematic for the amp? Can we determine which wires feed which parts of the circuit? We know voltages on the secondary based on the inscription on the bottom, so it should likely be pretty straightforward once we know a few more variables. The 6.3v windings are used by the cathode heaters or filaments, but using the right tap is important.

Mike
Click to expand...

Hi rave0035, thanks so much for your message. As I understand it, the amp is based on the Weber 5f2a schematic: http://www.tedweber.com/media/kits/5f2a_schem.jpg
 
Ha! Would like to avoid that if possible!!!

I've got someone with more experience with valve amps taking a look at it one evening this week so I'll report back. Getting a bit nervous about fiddling with high voltages involved!!!
 
How is he supposed to take voltage measurements without the transformer connected to the mains?
 
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