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Power supply rectifiers [message #8810] Fri, 04 February 2005 17:57 Go to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18670
Registered: January 2001
Illuminati (33rd Degree)

While building the Stoetkit, I noticed that it uses 1N400x rectifiers. All of the signal capacitors are nice, and the transformers are great. But the power supply uses electrolytics and plain ol' 1N400x diodes. So I think maybe I could probably improve some there, just with component substitutions.

We've had discussions on this forum about fast recovery diodes, FREDs and HEXFREDs and also about Schottky diodes. I'm thinking one of my first upgrades will be to improve the rectifiers, but I'm wondering which to go with. I'll probably grab some datasheets and give this some thought, and I'd also like to hear your experiences.


Re: Power supply rectifiers [message #8811 is a reply to message #8810] Sat, 05 February 2005 06:23 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
I replaced all the 5014's in my AES pre-amp with schottkey's. It actually made quite a difference in the sound, more full and sweet with better, deeper bass and lot's more prescence.

SiC Schottky by Cree [message #8813 is a reply to message #8810] Sat, 05 February 2005 20:26 Go to previous messageGo to next message
PakProtector is currently offline  PakProtector
Messages: 935
Registered: May 2009
Illuminati (2nd Degree)
i think tube Builder i Maryland stocks these. They were an improvement over Fairchild Stealth ( fast/soft recovery ) in one of my amps. I would not have paid $12.50 each for the 1k2V/5A versions, but since Cree saw fit to sample me 8 of them...I share my positive experience when ever possible.
regards,
Douglas

Re: Power supply rectifiers [message #8814 is a reply to message #8810] Sun, 06 February 2005 06:23 Go to previous messageGo to next message
BillEpstein is currently offline  BillEpstein
Messages: 886
Registered: May 2009
Illuminati (2nd Degree)
I had trouble getting Tube Builder to reply when I bought my second set so went to Digikey for Infineon brand:
Infineon 600V @ Digikey
The Infineons seemed a bit less fragile also.
No question they are MUCH quieter and allow more detail of the music thru.

Re: Try a Snubber Filter, too... [message #8815 is a reply to message #8810] Sun, 06 February 2005 10:50 Go to previous messageGo to next message
TubeCraft is currently offline  TubeCraft
Messages: 30
Registered: May 2009
Baron
The Bottleheads swear by them. I think all the parts can be had at the Rat Shack. It's just like a Pi filter but with an identical resistor in both lines. Use RS ceramic .01 1.5kv for the caps and cheap 10R 10W cement resistors (the more inductive the better). The resistors really help the inrush problem too. I built my regulated bench supply this way.

Transformer>snubber>diodes>PS filter

--|--VVVV--|--->|---
= = |
--|--VVVV--|--->|--

Just a thought.

Regards,

TC


Re: So much for my attempt at ASCII.... [message #8816 is a reply to message #8815] Sun, 06 February 2005 10:52 Go to previous messageGo to next message
TubeCraft is currently offline  TubeCraft
Messages: 30
Registered: May 2009
Baron
...schematic drawing :>)

I gotcha [message #8817 is a reply to message #8816] Sun, 06 February 2005 11:50 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18670
Registered: January 2001
Illuminati (33rd Degree)
I understood what you meant. An RF filter on the AC input.

I gotcha [message #8818 is a reply to message #8817] Sun, 06 February 2005 16:38 Go to previous messageGo to next message
PakProtector is currently offline  PakProtector
Messages: 935
Registered: May 2009
Illuminati (2nd Degree)
Hey-hey!!!,
I got forced into using a common TX for both the B+ and a DC filament supply. It is Schottky rectified and L-C, but there is still a little bit of buzz which matches the switching of the diodes. It is just at edge of perception, but knowing why it is there is bugging me.

Guess I'll put a dedicated TX under there and be done with it. this'll give me a few more options for other experiments. I am going to put .01 uF caps across each of the Schottky diodes and see if that helps first...
regards,
Douglas


Re: Power supply rectifiers [message #8832 is a reply to message #8810] Sat, 19 February 2005 20:45 Go to previous messageGo to next message
Poindexter is currently offline  Poindexter
Messages: 108
Registered: May 2009
Viscount
Hey, Wayne,

Sorry to enter the fray so late.

My budget fave is Diodes, Inc. ultrafast switching rectifiers, their number UF1007, which have otherwise the exact same specs as 1N4007.  Digi-Key sells these for 29¢, if you buy a hundred; a lifetime supply for a hobbyist.  They are not 'soft' recovery, but their PN burst is very high-freek and short duration; thus very easily shuntable.  I use a .01µF 716P on each side of the diode set (transformer and filter), and have gotten very good results; clear, fast, quiet.

How many you need for your Stoetkit? I'll send them along.

Poinz

Re: Power supply rectifiers [message #8834 is a reply to message #8832] Sun, 20 February 2005 04:06 Go to previous messageGo to previous message
Wayne Parham is currently offline  Wayne Parham
Messages: 18670
Registered: January 2001
Illuminati (33rd Degree)

Cool, thanks! The Stoetkit uses four.


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