Suffolk Tony
Aim low, achieve your goals, avoid disappointment.
Thanks Martin; I happen to have a spare transformer that'll fit the bill nicely.
Buffalo II - Assembly for the Electronically Bewildered.
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Tony,
If you are brave, replace the stock rectified bridges with Schotkty's(SP?) and put in a bigger smoothing cap may be worthwhile.
Regards
Suffolk Tony
Aim low, achieve your goals, avoid disappointment.
Hi Martin, I've just spotted your post re. EVO power supply on TP support forum. Excellent stuff!
Presumably you've removed the standard heatsinks because they were too tall for your nice case? I also notice you've removed the C3 capacitor but I can't quite work out how the Shottkys are fitted. I've got some hexfreds (?) Can I use those instead i wonder?
Presumably you've removed the standard heatsinks because they were too tall for your nice case? I also notice you've removed the C3 capacitor but I can't quite work out how the Shottkys are fitted. I've got some hexfreds (?) Can I use those instead i wonder?
Hi Tony,
Yes, the heatsinks were too tall and the case has no ventilation, so I needed to connect them to a plate. I had to make an ugly 'dead bug' arangements with the Schottky's as the originals on the Placid are bridges. I'll take a look at my spare board and see if I can sketch out the fitment. Hexfreds should b efine if you can make figure a way to fit them.
Regards
Suffolk Tony
Aim low, achieve your goals, avoid disappointment.
OK flashgo, I'll find the Hexfreds & see if I can figure out how to fit them. Help needed here please!
Suffolk Tony
Aim low, achieve your goals, avoid disappointment.
OK, I've dug out the Hexfreds & here's a photo of them next to the bridge rectifier fitted to the Placid -
Presumably I'll need the two, but how to connect them please?
Presumably I'll need the two, but how to connect them please?
tomek
pfm Member
Hi Tony,
You need four Hexfreds. The rectifier is composed of four diodes inside of one small case with only four legs.
http://en.wikipedia.org/wiki/Diode_bridge#Basic_operation
Each diode has "anode" and "cathode"
http://en.wikipedia.org/wiki/Diode#Semiconductor_diodes
You have to find out where is "anode" and "cathode" in your hexfred and build a simple bridge rectifier from four hexfreds.
You need four Hexfreds. The rectifier is composed of four diodes inside of one small case with only four legs.
http://en.wikipedia.org/wiki/Diode_bridge#Basic_operation
Each diode has "anode" and "cathode"
http://en.wikipedia.org/wiki/Diode#Semiconductor_diodes
You have to find out where is "anode" and "cathode" in your hexfred and build a simple bridge rectifier from four hexfreds.
Suffolk Tony
Aim low, achieve your goals, avoid disappointment.
Ahhh. Thanks tomek, now I understand why flashgo was having problems trying to fit Hexfreds...
I've been putting together my second Placid HD BP but, alas, I've hit a snag. On powering up, the three LEDS on the negative side glow really brightly. Needless to say I disconnected instantly. I've done the obvious things like resoldering the connections, checking the components are in the right place etc. but to no avail. All help gratefully received as usual!
On a brighter(!) note, got an E-mail this morning informing me that "Twisted pair Audio have sent you a package". That's my two HD Placids on their way. Now I just need those elusive little Tridents.
I've been putting together my second Placid HD BP but, alas, I've hit a snag. On powering up, the three LEDS on the negative side glow really brightly. Needless to say I disconnected instantly. I've done the obvious things like resoldering the connections, checking the components are in the right place etc. but to no avail. All help gratefully received as usual!
On a brighter(!) note, got an E-mail this morning informing me that "Twisted pair Audio have sent you a package". That's my two HD Placids on their way. Now I just need those elusive little Tridents.
Ahhh. Thanks tomek, now I understand why flashgo was having problems trying to fit Hexfreds...
I've been putting together my second Placid HD BP but, alas, I've hit a snag. On powering up, the three LEDS on the negative side glow really brightly. Needless to say I disconnected instantly. I've done the obvious things like resoldering the connections, checking the components are in the right place etc. but to no avail. All help gratefully received as usual!
On a brighter(!) note, got an E-mail this morning informing me that "Twisted pair Audio have sent you a package". That's my two HD Placids on their way. Now I just need those elusive little Tridents.
Can you post a picture Tony?
Suffolk Tony
Aim low, achieve your goals, avoid disappointment.
Here're a couple I posted on the TP forum earlier Martin. Not sure they're too good; have to take some better ones tomorrow :-
James Evans
Bedroom Bodger
Tony, diode D1b is the wrong way round
Suffolk Tony
Aim low, achieve your goals, avoid disappointment.
Correct James! You spotted the deliberate mistake!
(Oh b*gger, how silly am I! Many thanks for spotting this - I've been staring at the blasted thing for ages...)
(Oh b*gger, how silly am I! Many thanks for spotting this - I've been staring at the blasted thing for ages...)
flashgo
DIY Practitioner
Tony, here's a picture of a HexFRED bridge I did for a NAP140 supply:
It made zero difference. Likewise, some fancy IXYS bridges made no diff in a NAP250.
However, the first DIY project I ever did was to replace the bridges in a Hi-CAP with large HexFREDs. In that situation, the HexFREDs gave a profound improvement.
It made zero difference. Likewise, some fancy IXYS bridges made no diff in a NAP250.
However, the first DIY project I ever did was to replace the bridges in a Hi-CAP with large HexFREDs. In that situation, the HexFREDs gave a profound improvement.
Suffolk Tony
Aim low, achieve your goals, avoid disappointment.
They look like a group of robots having a chat!
flashgo
DIY Practitioner
I also found this picture of the stacked HexFREDs in the HiCAP:
There are just 2 (large) HexFREDs per + rail. The heatsinks made for a nice caddy system.
You'd think that one of these DIY places would make a small and tidy PCB to hold 4 separate diodes and provide connecting points as if it were a bridge.
[Edit: Ah, here's one from Avondale, although it's overkill for this application. Still looking for something smaller.]
There are just 2 (large) HexFREDs per + rail. The heatsinks made for a nice caddy system.
You'd think that one of these DIY places would make a small and tidy PCB to hold 4 separate diodes and provide connecting points as if it were a bridge.
[Edit: Ah, here's one from Avondale, although it's overkill for this application. Still looking for something smaller.]
tomek
pfm Member
Tony, when i am looking on the underside of the pcb, than i can see, that some of the joints are not "shiny silver" (or it is just a photo), IMHO maybe your soldering iron has to low temeparture (mine is ~360°C for a solder with LEAD), or you are applying the heat to short time.
When i am soldering, than always just after the joint is filled with the solder i am counting in mind "321, 323, 324" (it is around 3 seconds) and then removing the iron. I think this method was adviced by the gentlemen owning the Avondale Audio, or it was in some soldering advices on the net.
When i am soldering, than always just after the joint is filled with the solder i am counting in mind "321, 323, 324" (it is around 3 seconds) and then removing the iron. I think this method was adviced by the gentlemen owning the Avondale Audio, or it was in some soldering advices on the net.
Beat me to it!
Suffolk Tony
Aim low, achieve your goals, avoid disappointment.
Many thanks for all your help on this folks. All's now well & I'm currently using my 'Second" Buffalo to run it in, using new Placid HD BP & Legato 3.1.
In the process of sorting things & adjusting out the DC on the SE outputs this morning, I picked up a very useful tip which I'll freely pass on - when using a meter, always ensure the leads are properly connected to the meter itself before panicking...
In the process of sorting things & adjusting out the DC on the SE outputs this morning, I picked up a very useful tip which I'll freely pass on - when using a meter, always ensure the leads are properly connected to the meter itself before panicking...
Suffolk Tony
Aim low, achieve your goals, avoid disappointment.
Another question (!)
I noted that flashgo mentioned earlier that his HD BP Placid ran cooler than his old, pre-HD version but both of mine, although they now work fine, seem to be very hot, certainly no cooler than my original.
The manual on the new Placid isn't quite so clear as the old one & I'm slightly confused about the measurement across the shunt points adjacent to the output terminals. What should these read please? Is this the equivalent of the 0.5V - 0.6V specified on the old BP to be measured across R13 & R14?
I noted that flashgo mentioned earlier that his HD BP Placid ran cooler than his old, pre-HD version but both of mine, although they now work fine, seem to be very hot, certainly no cooler than my original.
The manual on the new Placid isn't quite so clear as the old one & I'm slightly confused about the measurement across the shunt points adjacent to the output terminals. What should these read please? Is this the equivalent of the 0.5V - 0.6V specified on the old BP to be measured across R13 & R14?
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