Tony L
Administrator
[This content reproduced from original pfm site. Original author Rico Powell - please assume NZ accent whilst reading...]
Board pulling
Board-pulling is a JFDI (Just f#*kin’ Do It!) game. The idea is to have as few boards in as possible (without losing needed functionality, of course), in an effort to eke more performance from your Naim pre-amp. The theory goes that the less non-essential circuitry that’s in there to suck power from the rails, the more clean power is available for what you do use. Note that this is a non-mod approach to improving the sound, and all boards removed can be re-instated later (they just clip in).
Board pulling: 32/32.5/72 series
Phono
Are you using Vinyl? If not you are a total wuss, or more realistically you may use a stand alone phono stage, yank out those 322 or 323 (S or K type) boards. Store ‘em away carefully for future use, or when you sell your pre-amp. They use up power from the supply, so if you pull ‘em, you should notice a suprisingly big improvement. If you are using vinyl, check the board revision, the revision being denoted by the /# where # is the revision number eg. NA323/4 are rev 4 boards. I think it is safe to assume later are always better – I have heard the difference between rev 2 and rev 3 323 boards – it is very noticeable, with the later boards being the best..
Aux/Phono 2.
Chances are you’ll have a 328 board (variable line level, with high-frequency roll-off) sitting in there, unused. Yank that out. If it is in use, and you don’t currently employ a crappy ‘80’s CD player, get your ass down to your Naim dealer, and order a set of 326 High Level link boards. They’re a straight-through link board for the input signal, and hence draw no power from the supply. Cleans up the sound on that input big-time.
Pull those tape buffer boards if you’re not using ‘em - it cleans up the sound a lot.
729 time-aligned input buffers (72 filter boards)
You can improve the 32.5 significantly by installing these boards in place of the existing 324 boards (the pair on the left when looking from the front). They’re from the 72, so you’ll need to order them from your Naim dealer (cost approx £108 for the pair), slot ‘em in yourself. Improvements include a substantial tightening and cleaning up of the sound – much leaner and more detailed to the point of making the old boards sound decidedly sloppy.
board descriptions
NA323 K/S Phono MC
NA322 MM Phono
NA326 Fixed Line Input (link board)
NA328 Variable Level Line input with some HF filtering
NA324 Tape Output Buffer
NA321 Main Gain, Output Drive
NA325 Switch on relay
NA729 Time-Aligned input buffer boards - AKA 72 Filter Boards
board pulling: 42/42.5/62 series
Not much to do on a 42/42.5 where board-pulling is concerned. You’ve only got 3 inputs (phono (RCA plugs), tuner, tape), and it’s all on the motherboard, with the exception of the phono boards. If you aren’t using phono, do pull the 322 or 323 boards in the slot there. Of course, a 326 high-level link board in it’s place would give you a second usable line-level input for say, CD.
board pulling: 52/82/102 series
It has been noticed here at pfm that owners of these preamps are far too timid and effete to dare to venture inside the case with out a dealer holding their hand (and dealers don’t want any improvement that doesn’t line their own pockets with gold) – thus we have no real data as to what level of improvement to expect. Comments please.
Board pulling
Board-pulling is a JFDI (Just f#*kin’ Do It!) game. The idea is to have as few boards in as possible (without losing needed functionality, of course), in an effort to eke more performance from your Naim pre-amp. The theory goes that the less non-essential circuitry that’s in there to suck power from the rails, the more clean power is available for what you do use. Note that this is a non-mod approach to improving the sound, and all boards removed can be re-instated later (they just clip in).
Board pulling: 32/32.5/72 series
Phono
Are you using Vinyl? If not you are a total wuss, or more realistically you may use a stand alone phono stage, yank out those 322 or 323 (S or K type) boards. Store ‘em away carefully for future use, or when you sell your pre-amp. They use up power from the supply, so if you pull ‘em, you should notice a suprisingly big improvement. If you are using vinyl, check the board revision, the revision being denoted by the /# where # is the revision number eg. NA323/4 are rev 4 boards. I think it is safe to assume later are always better – I have heard the difference between rev 2 and rev 3 323 boards – it is very noticeable, with the later boards being the best..
Aux/Phono 2.
Chances are you’ll have a 328 board (variable line level, with high-frequency roll-off) sitting in there, unused. Yank that out. If it is in use, and you don’t currently employ a crappy ‘80’s CD player, get your ass down to your Naim dealer, and order a set of 326 High Level link boards. They’re a straight-through link board for the input signal, and hence draw no power from the supply. Cleans up the sound on that input big-time.
Pull those tape buffer boards if you’re not using ‘em - it cleans up the sound a lot.
729 time-aligned input buffers (72 filter boards)
You can improve the 32.5 significantly by installing these boards in place of the existing 324 boards (the pair on the left when looking from the front). They’re from the 72, so you’ll need to order them from your Naim dealer (cost approx £108 for the pair), slot ‘em in yourself. Improvements include a substantial tightening and cleaning up of the sound – much leaner and more detailed to the point of making the old boards sound decidedly sloppy.
board descriptions
NA323 K/S Phono MC
NA322 MM Phono
NA326 Fixed Line Input (link board)
NA328 Variable Level Line input with some HF filtering
NA324 Tape Output Buffer
NA321 Main Gain, Output Drive
NA325 Switch on relay
NA729 Time-Aligned input buffer boards - AKA 72 Filter Boards
board pulling: 42/42.5/62 series
Not much to do on a 42/42.5 where board-pulling is concerned. You’ve only got 3 inputs (phono (RCA plugs), tuner, tape), and it’s all on the motherboard, with the exception of the phono boards. If you aren’t using phono, do pull the 322 or 323 boards in the slot there. Of course, a 326 high-level link board in it’s place would give you a second usable line-level input for say, CD.
board pulling: 52/82/102 series
It has been noticed here at pfm that owners of these preamps are far too timid and effete to dare to venture inside the case with out a dealer holding their hand (and dealers don’t want any improvement that doesn’t line their own pockets with gold) – thus we have no real data as to what level of improvement to expect. Comments please.