Moving cables to back?

Andrew · 20194

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Offline Andrew

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on: February 22, 2010, 03:57:08 PM
I'm considering a DIY phono stage and like what I've been reading about the Seduction. However, aesthetically I'm not crazy about the way the cables stick out of the top of the chassis. Would it be possible to modify things to move the cables to the back? I'm sure anything is possible, but I'm talking about something that could be done with basic skills and without modifying the design too much. Has anybody successfully done this before?

Thanks very much,

Andrew



Offline tbbenton

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Reply #1 on: February 22, 2010, 04:58:35 PM
The layout put me off at first too, but it's so practical and it really grew on me.  BTW, I have seen several builds with relocated jacks on the old forum, and based on my personal experience building the kits stock, it would not be hard to relocate the jacks anywhere you want, but you'll probably need extra cable, and of course, whatever panels you decide to use.

Tom Benton


Offline Paul Joppa

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Reply #2 on: February 22, 2010, 06:07:43 PM
The jacks are where they are in order to minimize the chances of picking up hum and noise from the power supply. You can move them to wherever you want; just use good shielding and wire routing practice. And, in my experience, allow for the possibility that you will want to revise it before you're done - we revised Seduction quite a number of times before, and another time after, the kit came out.

It's the inputs that are critical, since a phono preamp has very high gain. You can move the output jacks with much less risk.

Paul Joppa


Offline Andrew

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Reply #3 on: February 22, 2010, 06:11:41 PM
Thanks for the replies. I guess I would also have to replace the metal plate so I didn't have a bunch of empty holes in the top. Is it necessary to use metal for this, or could you use some other material like wood or acrylic? Something like that would be easier to work with, and easier to source.



Offline Paul Birkeland

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Reply #4 on: February 22, 2010, 07:46:52 PM
You will want an aluminum top plate (or steel), as cable shields are connected to the top plate here and there, and it provides some shielding.  I would say you could add another set of output jacks elsewhere, but putting the input jacks close to the power transformer could be very, very risky... 

You might consider rotating the Seduction 90 degrees and using right angle connectors to route the wiring to the back side.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Andrew

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Reply #5 on: February 23, 2010, 04:29:04 AM
Thanks again for the replies. Not surprisingly, it sounds like there are some very good reasons for the way things are laid out on the Seduction. It doesn't sound like it would be a good idea to mess with the design, so I'll have to consider whether it would work for me. I can appreciate the practicality of having the cables in the top, especially if you're in the habit of changing things on a regular basis, but I have a bit of a hang up about cables and clutter so I don't think I'd be happy with it.

I was really hoping this would work for me, because I just finished a custom walnut plinth for my Lenco and would like to build a matching phono stage to sit beside it.

Cheers,

Andrew



Offline bernieclub

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Reply #6 on: February 23, 2010, 05:08:07 AM
Since you have the skills to make a custom plinth, you might want to consider moving the power supply outboard to another small box.
Bernie

Bernie Zitomer


Offline Andrew

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Reply #7 on: February 23, 2010, 05:23:14 AM
Relocating the power supply might be a good idea. I'm pretty comfortable tackling a project that requires some wood working and electrical skills, but it would be nice to see if anyone else has gone down that road ahead of me. I like to plan things out in advance, so I'd need to know what kind of parts would be required to separate the PS and how much it would all cost. If it requires too much money and effort I would probably just go with a phono stage that already has a design more suitable to my needs.

Cheers,

Andrew



Offline Grainger49

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Reply #8 on: February 23, 2010, 06:56:39 AM
Andrew,

(You have a PM)

There have been several outboard power supply seductions made.  Mine was an early one.  Most of what causes induced hum is from the AC in the power supply, probably all.  

Look at the underside on this page:

http://www.bottlehead.com/store.php?crn=220&rn=429&action=show_detail

This makes it easy to see that the inputs and outputs were located to keep the signal path as short as possible.  But... with the power supply's 5 terminal strips moved to another chassis you can use some twisted shielded wire to transfer the inputs and  outputs to the "rear" of the chassis.

I used the hole that the IEC connector was to be mounted in to mount the receptacle for the incoming power.  Mine's pretty ugly you probably don't want to copy it.
« Last Edit: February 23, 2010, 02:13:34 PM by Grainger49 »



Offline Andrew

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Reply #9 on: February 24, 2010, 06:09:26 AM
I think an outboard power supply might work for me. I am also thinking I would then rotate the unit 180 degrees and use some right angle connectors for the input and output. That would place the cables near the back of the unit, and create a cleaner look while minimizing the amount of modifications required. I think I could also fill the unused holes for the IEC input, etc, in the top plate with epoxy or liquid metal and paint it black to match the top plate of my Lenco.

I was looking at some other phono stages that use outboard power supplies and the most common connection used for the umbilical power cord appears to be a 4-pin DIN connector. Would this be the best thing to use?

If anyone is interested here's a pic of my Lenco. It still needs a bit of tweaking, but it's basically finished and I think a Seduction in a matching walnut base would look great sitting beside it.

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi50.tinypic.com%2Fvo0sqp.jpg&hash=cfdcadb6d8c940b4b50e1c266ed1bfbd9d0d9889)

Thanks again,

Andrew
« Last Edit: February 24, 2010, 06:27:23 AM by Andrew »



Offline Grainger49

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Reply #10 on: February 24, 2010, 08:33:11 AM
Beautiful woodwork.  Was that one piece? 



Offline Andrew

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Reply #11 on: February 24, 2010, 09:29:12 AM
It's an internal plinth of layered mdf and baltic birch plywood with an external shell covered in walnut veneer. Hidden inside all that is a 5 lb brass tonearm pod with a 1" thick maple arm board.  If you want to see the whole process I have documented it here: http://www.lencoheaven.net/forum/index.php?topic=2228.0

Cheers,

Andrew



Offline Andrew

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Reply #12 on: February 25, 2010, 09:09:23 AM
I've been looking at the Eros as well today, but I have the same concerns about the cables. Since the power supply is outside the chassis would it still be a problem moving the rca jacks to the back?  It looks like the circuit board design might make it easier to remove the PS and place it in an outboard chassis, but would that tube at the back part of the PS? Would it have to be moved as well?



Offline Grainger49

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Reply #13 on: February 25, 2010, 09:26:45 AM
None of the current Bottlehead line have outboard power supplies.  The Eros power supply is at the "back" of the chassis, the inputs and outputs are at the front.

Moving the input would have to be carefully considered because of the delicate signal there.  I think over half of the chassis or base would be a safe relocation of the outputs.  Since you do woodwork you could drill the base thinner with a Forstner bit then drill through for the RCA jack to mount.  The RCA jacks for the Seduction and Eros are nice, an inprovement over the old RCA jacks and not nearly as expensive as designer jacks.