Have a blown power transformer in an Ampex 400a PSU (similar to 350) and need a replacement option.
transformer has 4 secondary windings instead of the usual 3 and there is no regulation, so the transformer voltages need to be exactly correct.
transformer has 4 secondary windings instead of the usual 3 and there is no regulation, so the transformer voltages need to be exactly correct.
E core transformers of any type are rare and expensive these days, much less a special 4 winding one.
UTC has been sold to a global megacorporation that sells a few things through newark.com etc. No 4 winding anythings. the UTC plant used to be in Indiana, I believe it is now an abandoned shopping mall.
The cheapest solution is to build a transformer out of several toroids with the main VAC paralleled (through appropriate fuses and surge limiters) to the various ones. Surge limiters because toroids are nasty at turn on. Use the GE CL-xx datasheet from datasheetcatalog.com to calculate which device to use on which transformer.
US source of toroids to diyaudio seems to be antekinc.com. haven't used them but here are lots of good words on here. They tend to have a transistor output voltage plus an op amp stage voltage (+-15).
If youre Ampex is a tube ampex, you may start with an e-core transformer from tubesandmore.com or triodeelectronics.com. They sell hammond brand e-cores and triode has some special magnetic specialties brand ones.
There is a custom transformer shop in Massachusetts, where you wind your own bobbins. I forget the name. I tried to rewind a transformer once and DO NOT RECOMMEND THIS although a plastic bobbin may help the shorting to frame problem I had.
UTC has been sold to a global megacorporation that sells a few things through newark.com etc. No 4 winding anythings. the UTC plant used to be in Indiana, I believe it is now an abandoned shopping mall.
The cheapest solution is to build a transformer out of several toroids with the main VAC paralleled (through appropriate fuses and surge limiters) to the various ones. Surge limiters because toroids are nasty at turn on. Use the GE CL-xx datasheet from datasheetcatalog.com to calculate which device to use on which transformer.
US source of toroids to diyaudio seems to be antekinc.com. haven't used them but here are lots of good words on here. They tend to have a transistor output voltage plus an op amp stage voltage (+-15).
If youre Ampex is a tube ampex, you may start with an e-core transformer from tubesandmore.com or triodeelectronics.com. They sell hammond brand e-cores and triode has some special magnetic specialties brand ones.
There is a custom transformer shop in Massachusetts, where you wind your own bobbins. I forget the name. I tried to rewind a transformer once and DO NOT RECOMMEND THIS although a plastic bobbin may help the shorting to frame problem I had.
- Status
- Not open for further replies.