LP12/Prefix/HiCap question

Regards,
Jim Cash

Thanks for the reply. I've already tried that. While the booklet is pretty comprehensive it doesn't have that specific connection.

There is some nice connection info regarding the AV2 though that answers some questions I had about it.

Arthur Bye

Ray

from Prefix, via 5-pin DIN connection to socket 4 in the hicap - this is the furthest from the IEC socket. you should find that the Prefix cable cannot be connected to any other Hicap socket, because sockets 1-3 are 4-pin DIN.

from hicap input 3 to nac52 BNC sockets via a 4-pin DIN to BNC cable, assuming you are going to use the BNC sockets. Do make sure you have the right interface boards connected to the BNC's within the 52. In particular, make sure you do not already have phono boards like NA523 as the interface. if you make a mistake here, you could end up in tears. i believe you need straight thru boards NA526, but best get advice from Naim directly on what the correct interface board is.

i suppose you could connect the hicap input 3 to any high level input on the nac52. this implies you need a 4-pin to 5-pin DIN - dunno whether such a beast exists. ask naim including whether you need to worry about the appropriate interface board in this particular case.

right now, because my supercap is at naim for service, i am using the hicap that would ordinarily power the prefix for the snaxo. so the prefix is powered from the nac52. the prefix cable from my lp12 goes straight to input 2b on my 52. In this case, do make sure that input 2a is not used -- cover it with the plastic cover that came with your 52 to avoid mistakes when you possibly forget. mistakes here could end in tears too.

i would e-mail naim directly for more comprehensive advice specific to your set up. you should get a lightning fast response.

enjoy

ken

That is what I'm doing right now to power the Prefix. When I bought the Prefix it came with a HiCap so I'm trying to figure out how to hook it up.

Ken:

This is the answer I needed, thanks. I'll have to pull the MM board I have in the 52 and replace it with the straight through boards and do the Din(4 pin) to BNC thing. Looking at the rear of the HiCap the right most Din is a 5 pin (which I am calling #4). The Prefix plugs into that. one Din over is #3 which is where I plug a Din (4 pin). The 4 pin Din goes to two BNC's which go into the back of the NAC52.

Got it right?

Thanks,

Arthur Bye

The 4 pin Din goes to two BNC's which go into the back of the NAC52.

Got it right?

yes, sounds OK to me. certainly this is the way my dealer had it. hope naim will confirm for you, just for your peace of mind.

i am sure david dever @ nana will pick this up soon and provide any additional advice if needed.

enjoy

ken

AFAIK the standard connection method of a HiCap to PreAmp (for Prefix) is into one of the DIN inputs, not BNCs (i.e. a 270 degree 4-pin DIN to 180 degree 5-pin DIN).

If you use the BNC input the signal has to go through several unnecessary connections inside the preamp, even with straight-through boards.

Much worse than this, though, is that the negative signal from the cartridge has been commoned between the Prefix & HiCap, and you have to split it again between Hicap & PreAmp. This breaks the rules for star earthing, which is a fundamental design principle of the Naim "system".

If the cartridge is plugged directly into the BNCs (i.e. no Prefix) the the negative wires are kept separate all the way from the pins on the back of the cart through the BNCs and NA32x/NA52x boards, and then commoned after that.

cheers, Martin

Your explanation sounds reasonable. This means I will need a interconnect that goes from 4 pin Din to 5 pin Din.

Does Naim make such a cable?

And what happens to the extra lead, or is it superfluous?

Arthur Bye

many thanks. i actually didnt know that the BNC route compromises things somewhat. i wonder why my dealer didnt mention this?

so this means there are 3 ways of connecting prefix to 52:

(a) directly to input 2b on the 52, i.e. no hicap, prefix's power from supercap via 52.

(b) via hicap and then to 52 BNC sockets via 4 pin din to BNC cable

(c) via hicap and then to any available 52 high level input via 4 pin din to 5 pin din cable.

i conjecture that (c) is the best. from what you say martin about earthing, could be (b) is worst??

grateful if naim could confirm and also i am interested in Arthur's question -- is there such a cable 4 pin din to 5 pin din? if so, and (c) is really the best connection, then i would like to get hold of this cable asap and adopt the config. presumably the aux input will be OK for this purpose.

arthur, once you use method (c), then yes, the BNC cable will be redundant. i am suprised that this option if offered at all when as martin says it break naim's critical earthing rules. i wonder if the BNC sockets can be converted to 5 pin DIN?

enjoy

ken

The standard cable supplied with the prefix is a 4 pin DIN to 5 pin 180 degree. This connects between one of the unpowered 4 pin DIN's of the HiCap and the preamp.

The cable has no part number on it, but uses the same cable as the standard CD interconnects (grey / lavendar).

Andy.

now, wait a minute. my prefix was supplied with 4 pin din to BNC, and i wrongly assumed this was the std. i will try to get the 4 pin to 5 pin din asap. i will connect this to aux on the 52 as i gather this is "unbuffered", whatever this means (perhaps you cannot connect a recorder to it?)

many thanks and enjoy

ken

quote:

---

now, wait a minute. my prefix was supplied with 4 pin din to BNC, and i wrongly assumed this was the std

---

I may be wrong, but my Prefix wasn't ordered with any specific requirements w.r.t. connections, and I received the DIN-DIN cable.

Martin's comments about star earthing are correct though, and I would expect the DIN-DIN to be better.

The BNC's aren't a problem for a phono cartridge. Since the earths are not connected together at the cartridge end, there are no potential earth loops to cause degradation.

I would not expect, intuitively, massive improvements, but let us know!

Andy.

the outputs on sockets 4, 5 & 6 are buffered.

The inputs are not buffered on any of the sockets.

Whatever, I seem to remember that socket 3 sounds slightly better than 2, and 4, 5 & 6 much worse then either of those.

cheers, Martin

lucky you!!! my dealer when i bought the prefix supplied the din to BNC and i simply assumed this was the std. ah well...

yah, will let you know when i change. what input on the 52 (i assume) do you use for the 4 to 5 cable from the prefix's hicap?

enjoy

ken

i remember hearing this too. probably because of the extra 2a/2b circuitry for input 2. whereas input 3 has not such baggage. and 4, 5 and 6 outputs are "buffered" as you clarified. thanks.

the outputs on sockets 4, 5 & 6 are buffered. The inputs are not buffered on any of the sockets.

what exactly is "buffered" output in this context? the sense in which i recall this term being used is the process of storing data in a temp store till a certain "buffer" size is reached, upon which the data is released. yest another meaning, IIRC, is an circuit arrangement whereby one stage in that circuit feeds voltage to the next stage, where this next stage presents theoretically infinite (very high) impedance to the previous feeder stage. grateful for correct explanation so when i say "buffered output" i know roughly what i am talking about.

i wonder whether connecting hicap prefix's 4 pin to 5 pin DIN to input 6 is worse than connecting to BNC's? or even dispensing with prefix's hicap altogether and using input 2b? any views in case anyone has tried this. i will try it when my 52 comes back from naim.

enjoy

ken

Good stuff guys! Thanks for the help. I think this sorts it all out for me with the Prefix/Hicap. Gotta get a Din to Din 4/5 cable. Meanwhile i'll just continue using the 2b (2a?) connection that works fine for now.

Since I have a second turntable (P9) I assume that it's okay to leave it in place with the existing MM internal board and BNC's. I've been wanting to compare the two TT's.

By the way there seems to be plenty of stuff around on the care and setup of an LP12, but I can't find anything on the Aro. Do you know of any sites out there with care and feeding info? I've already got past issues of Listener which helps, but I'd like to see a bit more. Naim provided manual was typically pathetic.

Arthur Bye

i know i am labouring the point a bit, so apologies. but when you have your prefix connected to 52 input 2b (i.e not using hicap), please make sure that you do not then try to use input 2a as you will overload input 2, and performance may be affected. i have made this mistake once, and suffered for it.

to be safe, as recommended in the manual, cover input 2a in this case. you probably got this when i mentioned it in my earlier posting, so my apologies for repeating it.

enjoy now

ken

I'm not even remotely near the dizzy heights of a 52 (:

I'm using input 6 of a 112 (which can power the prefix if not using a PSU, like the 52 input).

Mine's run from a SNAPS - way better than the Flatcap 2 secondary output I originally used. Hicap's next on the list.

Andy.

just to clarify, the connection that you need on the pre-amp end of your cable has the 180 degree configuration suitable for plugging into any of the 5 DIN inputs, rather than the 270 degree setup for a SNAIC.

If you used one of these you might blow your HiCap or SuperCap or both!

cheers, Martin

I get 2a and 2b mixed up cause they are not in proper alphabetical order (1, 2b, 2a, 3, 4, 5, 6).

I don't see your concern here though as the 270 degree 5 pin Din won't fit into the 180 5 pin Din and vice versa. Or am I wrong here? Can it be forced by mistake?

Arthur Bye

if i am looking at a 4pin DIN to 5pin DIN cable, how can i tell that it has the 180 deg config rather than the 270 deg. is this referring to some angle(s) somewhere? if so, which one(s)? apologies bit thick here...

enjoy

ken

presumably this is using the Prefix powered straight off the 52, and not using the HiCap for now.

When you start using the HiCap you'll obviously have to switch to the other socket.

Ken,

try an experiment - find a SNAIC lead, and a Cd-to-preamp interconnect.

Look into the end of the two DIN plugs - you will see that all of the pins are within a 180 degree arc on the interconnect, and the sweep of the pins on the SNAIC covers 270 degrees.

cheers, Martin

We are talking about 5 pin Dins only. There are two types.

The first type is typically what you plug into your pre from CD player, tuner, other source, etc.
If you look at this 5 pin layout you will see that it is approximately 1/2 of a circle or 180(more like 200 though) degrees. The cable is usually fairly skinny.

The second type of 5 pin Din is typically what you use to connect your HiCap to your Pre. This cable is usually much fatter as well. The five pins are laid out in a circle with one pin missing. Hence the 270 degrees (or should it be 300?)

Just look at the 5 pin Din from your CD player and then look at the 5 pin Din from your HiCap. If you have a Supercap, it's the smaller Sniac cable (not the Burndy)

If you look at the Din inputs on your 52 you will see that Din 2b and 2a are different. 2b takes the 270 degree Din, while 2a takes the 180 degree one.

The 2b input on your pre is there to provide an alternative power source for the Prefix(via the power rails in the SuperCap), along with inputting the TT cartridge signal.

Arthur Bye

you guys got a view on which of the 3 alternative prefix configs is best?

enjoy

ken

From the different postings i've seen the general opinion seems to be that using the Prefix with the HiCap into Din 3 is the best setup. But there seem to be several dissenting opinions about this. Some seem to feel that the Supercap powered Prefix into the 2b input is just fine.

So far all I can tell you is that my Rega P9 with Grado "Reference" MM cartridge (internal boards) is soundly thrashing the LP12/Armageddon/Prefix/Aro/Lyra Lydian(MC). I imagine that this will not last though as i've a ways to go with tweaking the LP12/Aro. Think I need further tweaking instructions on the Aro.

Arthur Bye