Here is a picture of the power supply board, single bridge with heatsinks on the discrete diodes.
There are 6 - 35mm caps on the boards.
The pads allow for a CRC or CLC setup. If the stock application is desired, jumper wires can be installed instead.
I am looking into making a soft-start/relay board for the amp now.
--
Brian
There are 6 - 35mm caps on the boards.
The pads allow for a CRC or CLC setup. If the stock application is desired, jumper wires can be installed instead.
I am looking into making a soft-start/relay board for the amp now.
--
Brian
Attachments
The current idea is that there will be 2 pcbs made:
Amplifier pcb:
2 - amplifier pcbs
4 - output boards
size: 3.5" x 8.2"
Power supply board:
1 - power supply board
1 - soft start pcb
size: approx 3.5" x 8"
(boards scored for easy seperation, as with my gainclone boards)
For a dual mono, 2 power supply pcbs could be purchased.
For the soft start board, I am researching this now, and here are my ideas for the board:
- pcb mount AC recepticle for mounting against rear panel of chassis
- fuse for AC line coming in
- CL60 thermistors in series with AC lines
- transformer and relay circuit (similar to this )
- possible AC caps for filtering
- selectable for 120/240 power
The idea for the power supply is that the AC plug would plut into the soft start pcb, and then the transformer primaries would connect to that board. The transformer secondaries would connect to the power supply board. This would eliminate the chassis wiring, except for the central grounding setup. The goal is to allow for a momentary switch to be used, and handle the inrush current.
Let me know what you think. I want to get this design finalized soon and prototypes ordered so that we can get this design tested and get a production run of boards.
--
Brian
Amplifier pcb:
2 - amplifier pcbs
4 - output boards
size: 3.5" x 8.2"
Power supply board:
1 - power supply board
1 - soft start pcb
size: approx 3.5" x 8"
(boards scored for easy seperation, as with my gainclone boards)
For a dual mono, 2 power supply pcbs could be purchased.
For the soft start board, I am researching this now, and here are my ideas for the board:
- pcb mount AC recepticle for mounting against rear panel of chassis
- fuse for AC line coming in
- CL60 thermistors in series with AC lines
- transformer and relay circuit (similar to this )
- possible AC caps for filtering
- selectable for 120/240 power
The idea for the power supply is that the AC plug would plut into the soft start pcb, and then the transformer primaries would connect to that board. The transformer secondaries would connect to the power supply board. This would eliminate the chassis wiring, except for the central grounding setup. The goal is to allow for a momentary switch to be used, and handle the inrush current.
Let me know what you think. I want to get this design finalized soon and prototypes ordered so that we can get this design tested and get a production run of boards.
--
Brian
Absolutely🙂
Pyyyh, I am not the only one. What a relief😀 😀
The PSU design looks great, If people wants a regulator it can be
applied after the caps, with little effort.
Brian, very good idea with the softstart/fuse pcb. Be sure to include the AC cap as well.
Steen.
I'm still in.
Brian, would like to find out more about the soft start PCB. Might also work for our Krell KSA-50 Klone GB too.
Will it include all of the soft "switch" functions also such as the flip-flop?
Brian, would like to find out more about the soft start PCB. Might also work for our Krell KSA-50 Klone GB too.
Will it include all of the soft "switch" functions also such as the flip-flop?
rabstg said:
The idea is this:
- pcb mount IEC connector
- ac line fuse
- selection allowing for 120/240
- CL60 thermistors in series with AC primaries
- heavy duty relay used, controlled by the momentary switch with a flip-flop / debounce circuit for the AC switch
- For the board, CE guidelines should be followed so that people in the EU can use the board. (where can I find these guidelines?)
The CL60 thermistors should handle the inrush currents if they are put in series with the AC primaries.
This board would also be available separately for use with projects other than the Mini-A.
--
Brian
I have one of MaxHawks soft switch boards. Very nice. I am going to integrate it with Peranders' SST Soft Start circuit.
Decided for this approach rather than the thermistor approach, as is works with different current draws with fewer changes, and should last longer.
Decided for this approach rather than the thermistor approach, as is works with different current draws with fewer changes, and should last longer.
WorkingAtHome said:
Yeah, I have one of Rob's (MaxHawk) boards as well that he sent me, and I have been talking to him about doing a similar thing on my boards.
As for the soft start, I could move towards a resistor based solution like PA's if desired. But, I figured that since the current Pass Labs products use thermistors, even in their 1000w amp, so they should work rather well for most applications. I also appreciate the simplicity of the thermistor based solution.
--
Brian
I tried to use resistors with some of Pass amps, but it never worked well. Since the amps have a constant current draw, there will be always voltage drop on the resistor (it may be even 50% of mains supply). The caps will never charge completely, and when resistor is shorted, there will be more inrush.
Thermistors, while changing resistance, provide more dynamic behaviour, and seem to be a perfect choice for that type of applications.
Thermistors, while changing resistance, provide more dynamic behaviour, and seem to be a perfect choice for that type of applications.
I am asking this because I don't know:
How about a hybrid solution, using a thermistor in place of the resistor, but also using relays to cut the thermistor out of the circuit after inrush charging (when the thermistors resistance is low)? Probably overkill, but would make the thermistor last longer, though it sounds like it's longevity may not really be an issue (never used one).
Thanks for all your work on this guys!
How about a hybrid solution, using a thermistor in place of the resistor, but also using relays to cut the thermistor out of the circuit after inrush charging (when the thermistors resistance is low)? Probably overkill, but would make the thermistor last longer, though it sounds like it's longevity may not really be an issue (never used one).
Thanks for all your work on this guys!
Putting relay to cut thermistor off is a good idea (although more complicated to implement). It has advantage especially when you switch the amp on, right after it was put off: in that case thermistor might be still warm and doesn't perform well in inrush supressing.
So would it be as "simple" as swapping a thermistor for the resistor, then uping the delay time for the cutout relay?
I would thinks so. In case you are using relay, the thermistor's value could be even higher, for more suppressing action.
Member
Joined 2002
Im Wondering on what kinda performance we would get or hear for that fact if we did use a regulated Powerupply.
I was thinking about doig one of pass diys for the aleph min-a as the same one im useing for my own amps at home.
A soft power switch would be great.
Are we going for blue boards or black ?
Id like to see Black with White Lettering.
I was thinking about doig one of pass diys for the aleph min-a as the same one im useing for my own amps at home.
A soft power switch would be great.
Are we going for blue boards or black ?
Id like to see Black with White Lettering.
I will be in for some boards
I'm using a thermistor with a time delay relay and it works great. One thing I do notice is that the transformer hum from DC on the line is present more without the thermistor.
A board with DC filtering to prevent your transformer from humming would be a welcome addition and if not wanted could easily be jumpered.
The filter and softstart boards are great and can be used by all.
Thanks Brian
BDP
I'm using a thermistor with a time delay relay and it works great. One thing I do notice is that the transformer hum from DC on the line is present more without the thermistor.
A board with DC filtering to prevent your transformer from humming would be a welcome addition and if not wanted could easily be jumpered.
The filter and softstart boards are great and can be used by all.
Thanks Brian
BDP
Dear All,
I just read this subject and made me interested to build !
Would you please give me the "link" for latest ver. of the
schemtic , part list, pcb layout and information for adjustment !
What is the max output for the mini- X at 8 ohm load ?
Best Regards !
Thomas
I just read this subject and made me interested to build !
Would you please give me the "link" for latest ver. of the
schemtic , part list, pcb layout and information for adjustment !
What is the max output for the mini- X at 8 ohm load ?
Best Regards !
Thomas
Member
Joined 2002
thomasfw said:Dear All,
I just read this subject and made me interested to build !
Would you please give me the "link" for latest ver. of the
schemtic , part list, pcb layout and information for adjustment !
What is the max output for the mini- X at 8 ohm load ?
Best Regards !
Thomas
Were going to start a Group buy you are welcome to buy the boards. I am not giving the layout or schematic to any one. ANd i would think brian the person that put all the time into it will agree. : O ) THe boards will be a extream fair price..
thomasfw said:Dear All,
I just read this subject and made me interested to build !
Would you please give me the "link" for latest ver. of the
schemtic , part list, pcb layout and information for adjustment !
What is the max output for the mini- X at 8 ohm load ?
Best Regards !
Thomas
Thomas,
The layout is based off of the Aleph30/60 manuals posted on the Pass labs website:
http://www.passlabs.com/downloads.htm
As for the lastest layout, look at the last screenshots posted by me.
As for the adjustment, there isn't really any adjustment for the Aleph amps. Read over the service manuals for more information.
This is not the Mini-X circuitry, and it is just the normal mini-ALEPH circuitry.
--
Brian
jleaman said:
Hi-
Any chance we can get a time line for the GB?
Dates orders taken x-x
Date order placed for PCB's x/x/x
Expected arrival date x/x/x
Anticipated ship dates to customers x/x/x
And a guesstimate on price/ingredients?
rabstg said:
There will be 2 pcb sets,
- amplifier pcb set: 2 amplifier boards and 4 output boards
- power supply set: 1 power supply board and 1 soft start board
I am revising the amplfier board set currently, and will post a new picture when I finish. I should be ready to order prototype pcbs next week for this. As for the power supply pcb set, I am working to put together a circuit for prototyping the soft start / momentary switch pcb. If people are constrained on time, I could remove the momentary switch board (based on this design: http://maxhawk.bravepages.com/projects/Ampturnon/index.html ) and only make the soft start board be a board with an AC recepticle, AC fuse and thermistors for handling inrush current.
My goal is to make each pcb set around $20 each (depends on interest and production cost), and make them with a blue soldermask and 3 to 4oz copper for extra current handling on the traces.
There are no dates currently set for this project, but it is not on the back burner and is my primary focus when it comes to new projects.
--
Brian
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