Hi mcandmar. Thanks so much for your message and apologies for opening an extra thread - along with being a newbie to valve amp DIY, I'm also fairly new to forums. I'll make sure to stick to one thread next time.
The amp is indeed a Fender clone. As I understand it from the builder it is built using the Weber amps 5f2a schematic. All the components are the same, barring the master volume.
How would I find out what windings are connected? Would be great if an alternative could be suggested - that would be amazing. As before, thanks so much for the advice, it's really useful.
You seem to have gotten an exact replacement at the audiokarma Forum.
Check that wire colours match; if so just take note where each wire colour goes and reproduce how the original was wired.
if not, write a short matching table, such as, for example:
Original .............. Replacement
270V Red-Red ..... 270V Blue-Blue (or whatever) as a guide.
Of course, what really matters is matching voltages, rather than colours.
Check that wire colours match; if so just take note where each wire colour goes and reproduce how the original was wired.
if not, write a short matching table, such as, for example:
Original .............. Replacement
270V Red-Red ..... 270V Blue-Blue (or whatever) as a guide.
Of course, what really matters is matching voltages, rather than colours.
Thanks JMFahey. I'm hoping the replacement will arrive soon and I'll tackle it as per your suggestion. With a bit of luck the replacement will be the solution. Thanks again for your help.
Hi all,
Thanks as always for all your help.
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!
Thanks as always for all your help.
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!
Hello bloodtypb,
the replacement transformer you got is not exactly the one that was initially installed. These transformers were used in tape recorders from Telefunken in the 1960ties and 1970ties and a lot of varieties were produced over the years. However the one you got should be usable.
As far as I can see, only the two secondary reds are used (rt-rt in german) for HV and the blue and black one for heater (bl and sw in german)
The remaining yellow green (ge-gr) pair is an aditional 6,3V additional heater winding and the blue/yellow/red (bl - ge / bl-rt) are a 29V winding with a 24V tap. Isolate these and don't use them.
All wires on the left side (and most probably the large black on the right side are the primary with a couple of taps for the different mains voltages around the world. For the UK you should use the white and brown one (ws - br, 240V AC)
The large black one seems to be the 198V tap on the primary - this one was used to power the capstan motor.
Hope this helps
the replacement transformer you got is not exactly the one that was initially installed. These transformers were used in tape recorders from Telefunken in the 1960ties and 1970ties and a lot of varieties were produced over the years. However the one you got should be usable.
As far as I can see, only the two secondary reds are used (rt-rt in german) for HV and the blue and black one for heater (bl and sw in german)
The remaining yellow green (ge-gr) pair is an aditional 6,3V additional heater winding and the blue/yellow/red (bl - ge / bl-rt) are a 29V winding with a 24V tap. Isolate these and don't use them.
All wires on the left side (and most probably the large black on the right side are the primary with a couple of taps for the different mains voltages around the world. For the UK you should use the white and brown one (ws - br, 240V AC)
The large black one seems to be the 198V tap on the primary - this one was used to power the capstan motor.
Hope this helps
That is a huge help, thank you aboos!
So if I understand you correctly, I should use the following wires when replacing the transformer - these all seem to match with the original set-up in terms of colours etc:
Left side:
Brown & White
Right side:
Red
Red
Blue
Black
I have circled in purple the ones I mean.
The rest should be isolated from each other and left unused.
Does this sound right?
Thanks again.
So if I understand you correctly, I should use the following wires when replacing the transformer - these all seem to match with the original set-up in terms of colours etc:
Left side:
Brown & White
Right side:
Red
Red
Blue
Black
I have circled in purple the ones I mean.
The rest should be isolated from each other and left unused.
Does this sound right?
Thanks again.
Sounds right!
The only wire I would check again is the one thick black one on the right side. When looking again on your images I saw that there is already one black wire on the left side.
Please check continuity of this black wire on the right side to any other wire as the label only lists one black wire on the primary side and only one black wire for the secondary windings! So one black wire left???
The only wire I would check again is the one thick black one on the right side. When looking again on your images I saw that there is already one black wire on the left side.
Please check continuity of this black wire on the right side to any other wire as the label only lists one black wire on the primary side and only one black wire for the secondary windings! So one black wire left???
Thanks aboos!
How do I check the continuity of this wire?
Not sure if it means anything but this black wire was labelled 'Masse' when I received it?
'Masse' means 'ground',
so please check with a simple DVM (Multimeter) if there is any low resistance between this wire and any other wire - there schould be no connection.
Then check if you can measure a low resistance value between this wire and the iron parts of the transformer. Most probably you will find that this wire is connected to the iron core. In that case you can leave the wire open or connect it to the amp chassis.
One more hint on safety:
If you are a real newbie and have no experience with electronics and especially with high voltages (I conclude this from your question how to measure continuity between wires) - please ask someone who knows how to handle mains voltages and to teach you!! Mains voltage and high voltages in valve amps can be lethal!!!
so please check with a simple DVM (Multimeter) if there is any low resistance between this wire and any other wire - there schould be no connection.
Then check if you can measure a low resistance value between this wire and the iron parts of the transformer. Most probably you will find that this wire is connected to the iron core. In that case you can leave the wire open or connect it to the amp chassis.
One more hint on safety:
If you are a real newbie and have no experience with electronics and especially with high voltages (I conclude this from your question how to measure continuity between wires) - please ask someone who knows how to handle mains voltages and to teach you!! Mains voltage and high voltages in valve amps can be lethal!!!
Bloodtypw, please stop what you're doing and read all this; we don't want to loose you.
This is on the FORUMS page - tubes-valves. Just be careful, Dale
http://www.diyaudio.com/forums/tubes-valves/30172-safety-practices-general-ultra-high-voltage.html
This is on the FORUMS page - tubes-valves. Just be careful, Dale
http://www.diyaudio.com/forums/tubes-valves/30172-safety-practices-general-ultra-high-voltage.html
Hi Stevens in SC, thanks for your message. Don't worry - I have decided I am out of my depth and I am going to be looking for a local valve amp repair service instead. The last message from aboos made me think twice!
As much as I want it fixed I want to be alive to enjoy it!!!
Thanks for your concern and for your help.
If anyone knows of a valve amp repairer in the Cambridgeshire (UK) area, please let me know!
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