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-   -   The SLB (Smooth Like Butter) Active Rect/CRC/Cap Mx Class A Power Supply GB (https://www.diyaudio.com/forums/group-buys/336479-slb-smooth-butter-active-rect-crc-cap-mx-class-power-supply-gb.html)

Mark Johnson 5th May 2019 04:50 PM

1 Attachment(s)
Quote:

Originally Posted by C37 (https://www.diyaudio.com/forums/group-buys/336479-slb-smooth-butter-active-rect-crc-cap-mx-class-power-supply-gb-post5781453.html#post5781453)
I have often wondered what such psu could bring to class A/B. there are some hints on Eliott projects page but it stays generic. What would you advice if used foi A/B? Is it a waste of resources?

The Akitika GT102 is a class AB chipamp. It's got a regulated power supply, which is equivalent to the highest possible performance capacitance multiplier (you can imagine it as a Mx with Cap=infinity). This drops an even larger number of volts than a capacitance multiplier, but the result is ultra low impedance, super clean supply.

How does it sound? Fantastic. What does it cost? More than a Cap Mx. Photo below. Notice that the voltage regulator PCB is bigger than an amp channel PCB, and the voltage regulator heatsink is bigger than a (class AB) amp channel heatsink.

_

Roundtoit 5th May 2019 05:29 PM

I've watched this thread hoping to find a candidate for a discrete power-pcb/tranfo build to move between Class A projects while building and testing. SLB is the one to start with! Wow and Thanks to X, Hugh and jhofland! I think more about using a refined modular power supply component approach to simplify build layout and to reduce amp chassis size (not sink size) and make a long, narrow footprint. Makes it easy to A/B compare different PSUs.

Roundtoit - 2 SLB boards - 2 SLB-SR boards

Watch out MOFO!

(Hot, elegant, and delivery on difficult details; These are qualities of items to keep close to home...:)

tubesguy 5th May 2019 05:48 PM

Quote:

Originally Posted by xrk971 (https://www.diyaudio.com/forums/group-buys/336479-slb-smooth-butter-active-rect-crc-cap-mx-class-power-supply-gb-post5781489.html#post5781489)
I would do the dual mono lock personally. The stereo separation and imaging is better. Plus the ground loops possibility is reduced. I will add you to list when I get a chance.

Both will get you circa 24v after the SLB.

Thanks x -

I'll do the single SLB and do stereo in the 4U chassis. Dual monoblocks would be cool, but there's going to be some belt tightening going on around here soon (no, really) and I don't want to invest in another chassis. - Pat

xrk971 5th May 2019 05:53 PM

GB Status Update:

Quote:

baswamin - 2 boards - Paid
meanie - 2 boards - Paid
jwjarch - 2 boards - Paid
gary s - 2 boards - Paid
nautibuoy - 2 boards - Paid
antoniopf1972 - 2 boards - Paid
ravid - 2 boards - Paid, Simple PSU Paid, ship at same time
Gricko - 2 boards - Paid
poseidonsvoice - 2 boards - Paid
Bkdog - 2 boards - Paid
Jazzfan - 4 boards - *invoice sent*
yoaudio - 2 boards - Paid
van of monks - 2 boards - invoice sent
Wtl - 4 boards - Paid
cerole - 2 boards - Paid
s610adam - 4 boards - Paid
pbergstrom - 2 boards - *need PayPal address*
ferret - 2 boards - Invoice sent
Jimk04 - 2 SLB boards, 2 SLB-SR boards - invoice sent
Roundtoit - 2 SLB boards, 2 SLB-SR boards - Invoice sent
Tubesguy - 1 SLB board - Invoice sent

jwjarch 5th May 2019 05:55 PM

This is really an exciting PSU design. Can’t wait to try it out. Thanks Jhofland, X and Hugh!

I know it was discussed early in the thread that too much capacitance in the bulk caps may not be a good thing. Is 15mF the limit here? I have a stash of 22mF caps I’d like to use.

nautibuoy 5th May 2019 06:14 PM

baswamin - 2 boards - Paid
meanie - 2 boards - Paid
jwjarch - 2 boards - Paid
gary s - 2 boards - Paid
nautibuoy - 2 boards - Paid
antoniopf1972 - 2 boards - Paid
ravid - 2 boards - Paid, Simple PSU Paid, ship at same time
Gricko - 2 boards - Paid
poseidonsvoice - 2 boards - Paid
Bkdog - 2 boards - Paid
Jazzfan - 4 boards - *invoice sent*
yoaudio - 2 boards - Paid
van of monks - 2 boards - *need PayPal address*
Wtl - 4 boards - Paid
cerole - 2 boards - Paid
s610adam - 4 boards - Paid
pbergstrom - 2 boards - *need PayPal address*
ferret - 2 boards - Invoice sent
Jimk04 - 2 SLB boards, 2 SLB-SR boards - invoice sent
Roundtoit - 2 SLB boards, 2 SLB-SR boards - Need PayPal address
Tubesguy - 1 SLB board - need PayPal address
nautibuoy - 2 SLB-SR boards - Awaiting invoice (dual rail boards already paid for)

xrk971 5th May 2019 06:19 PM

Hi Jwjarch,
If your current draw is not too high, the 22,000uF can work. If the ripple current of the system exceeds the ripple current rating of the cap, its lifetime is decreased. I think you are going to be ok if you use for 25W Class A amp.

xrk971 5th May 2019 06:59 PM

5 Attachment(s)
Some close up photos of the SLB verification build (v1). Note that the production v2 will be a bit longer to accommodate extra output FASTOn spade connectors for use as a stereo PSU.

https://www.diyaudio.com/forums/atta...5&d=1557082791

With output slave BJT's (2SA1943N and 2SC5200N) mounted on a cheap $5 aluminum heatsink. The chassis floor plate or the actual side finned hetasink of an amp enclosure will be fine. I love the AMP quick disconnect cables (I use 18ga silicone super soft and flexible wire from RC model cars) - it makes removing the PSU board literally a snap. You also have the choice of mounting the transistors directly to the board in an underhung fashion:
https://www.diyaudio.com/forums/atta...6&d=1557082791

Another view:
https://www.diyaudio.com/forums/atta...7&d=1557082791

End view of the Cap Mx part with the CFP master on the small local heatsinks and the NTC and 22nF ground loop breaker for connection to chassis GND and mains earth GND:
https://www.diyaudio.com/forums/atta...8&d=1557082791

Closeup of the LT4320 active bridge and MOSFETs:
https://www.diyaudio.com/forums/atta...9&d=1557082791

Input AC snubbers are also provided.

jhofland 6th May 2019 12:36 AM

use of 22,000 caps
 
Hi jwjarch,

X's comments on the ripple current are on the mark. The other piece of information that may be of use to you is the pc board is set for a 35mm diameter cap, 10 mm lead spacing.

jwjarch 6th May 2019 01:17 AM

Thanks for the info guys. Sounds like itís not really worth the risk. May as well order some 15mF caps. Iím sure the 22ís will get used for something else anyway. ;)


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