Bottlehead Forum
Bottlehead Kits => Legacy Kit Products => Foreplay III => Topic started by: dtaylo1066 on December 14, 2011, 03:49:18 PM
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I have a Foreplay but I cannot recall if it is a I or a II, but it is at least 10 years old. Back when cost was still below $200 I think.
The transformer is getting kind of old.
What is a good replacement tranny? I can't find my building directions that listed some of the specs. What were the tranny specs?
Thanks.
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I have transformers running that are 60 years old. They last longer than just about any other part on an amp. If that is the reason for replacing it, I say don't bother.
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Unless the output windings draw too much current, a short or too high a load, it will last a very long time. I thought my FP 2 transformer had gone out a month or two back. It was a solder joint that had popped off the power switch lug. In the mean time I got a replacement Allied transformer thanks to PB supplying a number (6K27VF). As Paully points out, you probably don't need it, I didn't either.
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The specs were different for the first two versions. My notes are incomplete and my memory is also(!) but here are the differences:
The high voltage winding is either 120-150v or 240-300vCT, using either a full-wave bridge (four diodes) or a full-wave CT (two diodes). The current demand is quite low, so any transformer of similar weight will likely have enough.
The heater winding is either 12.6v or 6.3v, which calls for different tube socket connections. the 12.6v winding goes to pins 4 and 5, with pin 9 to the heater-bias voltage divider. The 6.3v winding has 4 and 5 connected to each other, and the winding goes to that juncture and to pin 9. Current demand is 0.3A at 12.6v or 0.6A at 6.3v.
If you have the CT high voltage and the 6v low voltage, the Seduction transformer PT-1 has more than enough power capability, but it has exposed high voltage solder terminals and must be mounted below the chassis. Otherwise, many parts suppliers have suitable transformers - let us know which arrangement you have and I'll find some part numbers for you.
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On closer inspection, I think mine is OK. The coating on the leads looked like it was cracking or deteriorating, but there appears to be a very thin, clear-coat type coating on the colored leads and only that is what is cracking and flaking, so I should be good to go for a while.
thanks.
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On closer inspection, I think mine is OK. The coating on the leads looked like it was cracking or deteriorating, but there appears to be a very thin, clear-coat type coating on the colored leads and only that is what is cracking and flaking, so I should be good to go for a while.
thanks.
Yes, that sounds pretty normal. I could be mistaken but I always thought it was epoxy or enamel (or whatever they use for potting the transformer) that ends up getting on the wires and chips off over time.