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Help with Nac72 Regs wiring please

Discussion in 'd.i.y.' started by Mynamemynaim, Aug 22, 2021.

  1. Mynamemynaim

    Mynamemynaim 38yrs a Naim owner

    So I want to wire my ALWSRs in to my Naim 72 in a more permanent and neat way than I had them before (though I was happy with the previous sound improvement)

    I just want to run the 4 regs to the two gain and two time alignment boards (these are Ryan Sound Labs boards) Should I just remove the 4 positive pins that I have marked with a red dot in the picture, and solder power to the back of the boards?

    I guess this will bypass the speaker relay, so I will probably have problems with "thump" if done this way?

    do I have to worry about the 27ohm resistor (that Ive read about but cannot find on the motherboard?)

    Lastly ...what about the illuminated Naim logo? I guess if I want to keep it, I will have to make provision to power that from somewhere too?

    Ohh and almost forgot...I have created a common bar between the main power in return and the case return (copper wire seen in the picture) that I can easily strap the ALWSRs returns to it....will i get problems with an "earth loop" doing that (bearing in mind I have two power supply's coming in and I'm using the Mr Tibbs return mod

    In other words....those that have done this before / have experience of this...what's the best way to proceed please??

    [​IMG][/url]IMG_20210822_164440~2 by rock solid, on Flickr

    [​IMG][/url]2021-08-22_06-03-09 by rock solid, on Flickr
    Last edited: Aug 23, 2021
    chrisn likes this.
  2. Mynamemynaim

    Mynamemynaim 38yrs a Naim owner

    I can only really get a maximum of 4 boards into the 72
    What about the two gain boards have one each...the time alignment share one....and the last board powers the motherboard?

    The two supplies into the 72
    One powers the motherboard
    The other powers the 4 other boards? it worth removing the balance pot and if so... should this be just linked out or do I have to put equivalent resistors in its place?

    Any chance thoughts on this please

    @mega lord
    Last edited: Aug 23, 2021
  3. Mynamemynaim

    Mynamemynaim 38yrs a Naim owner

    ok the absence of any advice on how to do it otherwise
    I've pulled the 4 power supply pins mention previously and bypassed the speaker relay board

    Ive also pulled the pins for the extra phono cards slot make room for some regs

    [​IMG][/url]2021-08-23_03-47-24 by rock solid, on Flickr
  4. chiily

    chiily PFM Special Builder

    I was very naughty when I installed ALWSRs to power a 32.5, I cut the power supply to each board by cutting the tracks on the 32.5's PCB and wiring the SR directly to the plugin boards.

    I'm unfamiliar with a 72, is it just the illuminated Naim badge on the front that is powered from the PCB. If it is I wouldn't use an SR just for an led.

    Use 4 ALWSRs, one for each board and power the illumination from any one on them.
  5. Mynamemynaim

    Mynamemynaim 38yrs a Naim owner

    [​IMG][/url]2021-08-23_09-33-44 by rock solid, on Flickr

    thanks @chiily ...the mods are finished...and doesn't work!!

    well the regs all work...the remote control does its thing..clicks like always...but no sound comes out
    I know power is getting in ....its getting to the boards....but the music isn't coming out

    I can only think that its because ALL power has been removed from the motherboard
    I thought bypassing the speaker relay (assuming i have done it correctly as pictured) was enough with each of the 4 boards powered...but obviously not

    Is there another component on the motherboard that needs power for this to work?...another relay or something

    [​IMG][/url]2021-08-23_09-33-44 by rock solid, on Flickr

    Could it be the components arrowed above
    I have tried both the CD and the phono inputs BTW
    Last edited: Aug 23, 2021
  6. DaveMc64

    DaveMc64 pfm Member

    Yes, in your picture above, the relay arrowed on the right is activated in normal use. It gets deactivated when the front switch goes to mute or mon.

    The relay on the left is for tape monitoring and is activated when switch goes to mon.
    Mynamemynaim likes this.
  7. Mynamemynaim

    Mynamemynaim 38yrs a Naim owner

    AHH so basically the amp is now muted permanently

    I'll have to power the M board after all

    I could bypass the relay I have mute built in already on the RSL remote control boards !
  8. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    There are so many possible permutations... (and possible issues!) with all those super regs in use together that it pretty much impossible to give a definitive answer.... which is probably why you haven't gotten one!:)
    Mynamemynaim likes this.
  9. DaveMc64

    DaveMc64 pfm Member

    Yes, either would work.
    If the power pin to the remote card only powers the remote section then you could power motherboard and remote board from same supply as long as it doesn't need too much power from your regulator. In the non-remote rsl cards, that power pin is unconnected. Maybe RSL could confirm.
  10. Mynamemynaim

    Mynamemynaim 38yrs a Naim owner

    I've removed the mother board power pins and have wired direct to the boards
    The remote has a mute button that works directly on the remote board to kill sound

    I'm thinking the easiest option is to jump the relay as I don't really need it
    Anyone know the signal pins on the 8 connection cp Clare relays?
    Guess I could just following the tracts tho
  11. DaveMc64

    DaveMc64 pfm Member

    On each side, the outer pins are the signal pins. So 1 & 4, 5 & 8 (officially, 1&7, 8&14 as they count the missing pins as well)
    Mynamemynaim likes this.
  12. Mynamemynaim

    Mynamemynaim 38yrs a Naim owner

    Looks like I found a wiring diagram

    Pins 1 and 7
    Pins 14 and 8
    To be linked
  13. Mynamemynaim

    Mynamemynaim 38yrs a Naim owner

    Beat me to it....yes the outer pins each end on the same side to be linked....they just number them differently to you.. thanks !!:)
  14. DaveMc64

    DaveMc64 pfm Member

    You beat me to the edit!
    Mynamemynaim likes this.
  15. Mynamemynaim

    Mynamemynaim 38yrs a Naim owner

    Thanks again to all that have helped me with this little upgrade
    The relay is bypassed and every thing is working well
    Even though the pre and the amps have been off for a day and a half...I do believe that I've immediately identified a noticeable improvement in the quality of reproduction
    There's more impact to instruments and a better defined sound stage.
    Just listening to some Ryan Adams as I type this and he sounds on top form!
    chrisn and DaveMc64 like this.
  16. Mynamemynaim

    Mynamemynaim 38yrs a Naim owner

    Quick update now everything has warmed up and settled in

    Wow ...the only word for it!!
    Much more than expected given that this was a relatively minor change...totally worthwhile!

    As a recap, I went from
    Diy Hicap (with 2 x Alwsr set to 37V) feeding 2 more (Alwsr set to 24.8v) connected to the original two (24V inlet) points on the motherboard
    The above using 2 x return lines as per Mr Tibbs mod

    Diy Hicap (with 2 x Alwsr set to 37V) feeding 4 more (Alwsr set to 24.8v) connected directly to the two gain boards and the two time alignment boards
    By directly I mean the Alwsr outputs (pos and return) soldered directly to the back of the cards (with the 4 positive motherboard pins removed)
    All returns were connected to a link bar at the back of the amp, which joins the two returns (standard and Mr Tibbs) to the hicap.
    Mute relay bypassed / speaker relay card bypassed
    Motherboard not powered (so no logo illumination)

    So essentially a quite minor change...for what turned out to be a huge improvement (considering the 72 has a full complement of ALREADY REGULATED Ryan sound Labs boards)
    Kit Ryan did say it would benefit from extra Regs....and boy he must be the master of understatement!!

    For all those that are thinking "its only a bloody 72 how good can it be?"
    well I've climbed the Naim tree in the past...had a Serviced 252 with Supercap DR
    This is without doubt the nicest and most natural Pre I've owned by far...a real eye opener for what DIY can achieve

    [​IMG][/url]2021-08-25_09-43-04 by rock solid, on Flickr

    Above picture
    All installed and working well
    [​IMG][/url]2021-08-25_09-42-12 by rock solid, on Flickr

    Above picture
    Direct connection onto RSL boards

    For anyone thinking "he's still got that standard volume pot connected"
    well yes....but its set to full volume permanently, the RSL cards are set to minimum...and the volume is controlled by the remote control
    This in its self makes a nice improvement if you have RSL remote cards!
  17. chiily

    chiily PFM Special Builder

    That looks the biz, and sounds good to boot.

    I'm not sure how wedded you are to the Naim in house sound, it took me awhile to move on from it, even with a 32.5 driven by 6 ALWSRs and a heavily modded pair of MC cards.

    Anyway great mod....
    Mynamemynaim likes this.
  18. Mynamemynaim

    Mynamemynaim 38yrs a Naim owner

    I guess I have moved on somewhat
    My last 3 power amps have been Avondale
    Currently ncc300 monos (as I think your already aware) and I'm hooked on them now

    Naim prices are just too high to stomach now... thought the actual cost of ownership isn't that bad really...and I think they have lost their way a little
  19. sq225917

    sq225917 Bit of this, bit of that

    The rsl boards have local regs, don't they? Are they better than the Alwsr? If not, wouldn't you be better bypassing the onboard regs?

    It's never ending.... ;)

    Makes me misty eyed for my quad superteddyregged 72 with Neil's boards.
  20. Mynamemynaim

    Mynamemynaim 38yrs a Naim owner

    I just think the boards benefit from three levels of regulation?
    The first is my alwsr regs in the hicap
    Second is onboard alwsr
    Last is RSL onboard regs

    As mentioned previously...Kit himself has gone on record as saying three levels of regulation is beneficial (to his ears)

    And now I can the difference is really noticeable ( to me)

    As has been said many times...the only real difference between top naim amps and lower the amount of regulated lines hooked up to them!
    I think my (previous) 252 had something like 11 rails going in from the supercap dr !
    It was a nice preamp...not great...but don't look at the current list price of the 252/scap without sitting down first !!
    Last edited: Aug 26, 2021

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