[Jens]

Guys,

The CD a few of you are referring to is a compilation I put together a few years back. I called it "My Music"

The tracklist is here:

1.   Yello: Get On (from Motion Picture)
2.   Eva Cassidy: Over the Rainbow (from Songbird)
3.   Mussorgsky: Pictures at an Exhibition, Promenade/Gnomus (from Dorian DOR-99117, gold version)
4.   Mickey Hart: Temple Caves (from Planet Drum)
5.   Jennifer Warnes: The Panther (from The Well)
6.   Johan Strauss: Die Fledermaus, Act III, excerpt (from Deutsche Grammophon 457 766-2, Original-Image Bit-Processing version)
7.   Anúna: She Moved through the Fair (from the compilation The Celtic Circle)
8.   Titanic: Hard to Starboard (from the original soundtrack)
9.   Sinead O’Connor: In My Heart (from Universal Mother)
10.   Kodo: O-Daiko (from Heartbeat Drummers of Japan)
11.   Shostakovich: Symphony No. 5, 2nd Movement, Allegretto (from Decca 425 066-2)
12.   Gladiator: The Wheat/The Battle (from the original soundtrack)
13.   Patricia Barber: Romanesque (from Café Blue)
14.   Bliss: Song for Olabi (from Afterlife)

Please note that some of the CDs where tracks are taken from are no longer "in print". But you may be able to source most of these CDs second hand.

I'm working on a second "My Music - the Emotions" compilation, but it's slow work, and my private life is getting in the way (divorce, selling house, moving etc.).

It will get there, eventually 

[curly joe]

My long time ,favorite disc, at least for female vocals has been Diana Kralls, Love Scenes. Live in Paris is another DK disc I pull out when evaluating gear, fantastic live recording .... Oh, and add another vote for Private Investigations on the best of CD.

Ron,

I too will put my vote in for Dire Straights. Make sure you listen to Walk of Life!

Andy, I laughed pretty hard when you called me Westy, as that is my nickname. For whatever reason, no matter where I go, people slowly gravitate towards Westy. Luckily I don't mind it at all. (Another common nickname has been 'North'...from all those true comedians out there)

While Ron kindly handles all the testing, I have another question to throw out there into this thread. Has anyone experimented with putting in an ELMA or other rotary switch? Has the difference over Hugh's been noticeable? I know Curly Joe used reed relays, but I would rather stick with a good rotary switch.

-West

Hi whubbard, my choice of reed relays was based more on keeping my signal paths as short as possible. I originally modified the input switching board so that the HT bypass switch acted on only one dedicated HT input (bit safer with kids and wife using the gear) and relocated the switch to  the front panel (for convenience). However, this created a lot of extra wiring  for my signal to travel through and  I was never really happy with that. Using reed relays has allowed me to cut a chunk of extra cabling out and I feel It's a more professional finish now. Oh, and I have more flexibility with where I can mount switches as well. I went with Coto relays, figured if they where good enough for use in the Bent passives ( I think they use 120 of 'em from memory) they'd be good enough for me.

Cheers
CJ

[lonewolfny42]

In the meantime, I'm open to suggestions for CD tracks to test with. Ideally, I'd like something with lots of fine detail in the background, and a mix of styles, instruments, acoustics, etc.

From the first NYAR 2006 Cd.....

1 - Copland - Fanfare For The Common Man
2 - Wynton Marsalis  Quartet - Feeling Of Jazz
3 - The Bad Plus -  Keep The Bugs Off Your Glass, And The Bears Off Your Ass
4 - Bozzio, Levin, Stevens - Duende
5 - Ben Harper - Gold To Me
6 - Morphine - Buena
7 - Bernadette Peters - Blackbird
8 - Kalman Olah Trio - Inspiration Of Variation XXI
9 - Mino Cinelu - Oncoming Horizons
10 - Nils Lofgren - Keith Don’t Go
11 - Groove Troopers - Bearing Bears and Boring Boars
12 - Stevie Ray Vaughan - Tin Pan Alley (w/ Johnny Copeland)

A nice variety....

[whubbard]

Oh, and I have more flexibility with where I can mount switches as well. I went with Coto relays, figured if they where good enough for use in the Bent passives ( I think they use 120 of 'em from memory) they'd be good enough for me.

Cheers
CJ

Curly,

I understand the basics about reed relays, but not much more than that. What did you use for selecting the relays? Would you mind explaining exactly how you set the reed relays up.

I still think I will use either Hughs switch, or an ELMA, as for some reason I think it will be of better quality than a reed relay. The reeds will shorten the path, but the rotary will sound better. If I'm wrong in thinking this, please correct me.

-West

[RonR]

Hi All,

Many thanks for the track lists, I feel a trip to a CD fair coming on.....

West,

If you want to have an Elma switch AND keep the paths short, you could use a shaft extension like CMScott's one here: http://www.audiocircle.com/index.php?action=gallery;area=browse;album=326&pos=5

Cheers,

Ron

[whubbard]

Hi Ron,

Can't wait to 'hear' the results from your listening tests. Hopefully you can get a bunch of the songs listed.

I am probably going to use some sort of extension shaft, but it will be wood. I am decent at working with metal, but very good at working with wood. What most people do with metal, I plan to do with wood. A dowel will work just fine for an extension shaft, and not only will it be easier to attach, it will also be much cheaper. The only metal that will appear in my GK-1 and Lifeforce amps will be to shield the transformers. The other nice thing about working with wood is that I don’t have anything confining my layout. I can make it as spread out as a wish, and it will just mean a bigger box, which is fine by me.

-West

[andyr]

The only metal that will appear in my GK-1 and Lifeforce amps will be to shield the transformers.

-West

Hi West,

But how are you going to shield the GK-1 internals from RFI?    It's all very well to stop transformer and mains emanations from getting to the PCBs but there is also external RFI which a metal case (earthed to the IEC earth tag) shields against.

If you're going to use wood (and please use wood, not MDF!  ) then I suggest you need to do what I think Kyrill did ... which is glue (thin) copper foil on the insides of the wooden case and make sure this is earthed.

Hugh specifies that shielded ICs should be used with a GK-1 but this assumes that the PCB itself is shielded from RFI.

Regards,

Andy

[curly joe]

Oh, and I have more flexibility with where I can mount switches as well. I went with Coto relays, figured if they where good enough for use in the Bent passives ( I think they use 120 of 'em from memory) they'd be good enough for me.

Cheers
CJ

Curly,

I understand the basics about reed relays, but not much more than that. What did you use for selecting the relays? Would you mind explaining exactly how you set the reed relays up.

I still think I will use either Hughs switch, or an ELMA, as for some reason I think it will be of better quality than a reed relay. The reeds will shorten the path, but the rotary will sound better. If I'm wrong in thinking this, please correct me.

-West

Hi whubbard,

My last post, about my reasons for using reed relays was just  my long winded and unclear way of saying that it wasn't for any supposed sonic benefit. 
 Any improvements in the sound of my GK-1 are certainly due to the Sonicap platinums (maybe some from the DACT) rather than using relays, I wouldn't expect that changing a rotary switch for relays, or vice versa would be audible.

As for the implementation, I'm fortunate in that I have screen printing facilities available at my workplace so I was able to redesign a circuit to incorporate them. I use a bank of three relays for each input (L,R and Gnd) and switch them with a rotary switch. I have a PCB mounted encapsulated transformer used as a power supply for the relays and LEDs so as to keep it separate from the audio circuits. I also had (ambitious?) plans to someday use a micro-processor to run all the switching etc. So having the relays in place will help facilitate that if I ever get around to it.

Cheers
CJ

[stvnharr]

In the meantime, I'm open to suggestions for CD tracks to test with. Ideally, I'd like something with lots of fine detail in the background, and a mix of styles, instruments, acoustics, etc.

My short-list so far:

Steely Dan - Two against Nature
Eagles - Hell freezes over
Delius - Summer night on the river - Beecham / RPO
Nirvana - Nevermind
Nitin Sawney - Beyond skin

All suggestions gratefully received.

Cheers,

Ron

Ron,
FWIW, I don't think specific discs matter very much, but discs that you know VERY WELL do matter.  That's really the only way you can tell if there is a difference.  And because it takes a bit of time to swap out caps, musical memory can play tricks.
This cap change is suppose to lower the electronic "noise" and is not in the signal path, thus the benefit should be a lowered sound floor and an increase in low level information, if it's there at all.  Classical discs have this in spades, but if that's not what you listen to, well, then.......

Steve

[whubbard]

Andy,

Thanks for the advice. I think I'll get a 5 foot roll of .01 copper just to put in the whole case, and also a few pieces of TI shield for the transformers.

Curly,

That makes sense, but for me, would not be very practical, especially because I don't want another transformer in my case. However, hopefully it has worked well for you. Did you find it introduced any extra noise?

-West

[kyrill]

use as well next to the copper foil, kitchen aluminum foil, 1+1=3 

[whubbard]

Kyrill,

That should be easy to do. It will also have the added benefit that aliens will not be able to take over my amplifiers! 

If I have a layer (or two) of a combination of copper and aluminum foil between the transformers and the amp boards, do you think that will be enough, or should I use the TI shield for that, and just use the copper/aluminum for the overall sheilding of the box.

Also does anyone have experience with both the Elma and the Dact? is the Dact switch worth the added cost? With the elma, have people noticed a difference between switching both hot and nuetral, or just hot?

Thanks for all the advice guys.

-West

[gerado]

west, andy,

Is it an assumption that copper is the best shield? I always thought (assumed ) aluminium or nickel were good.

The frequency(wavelength) one is trying to block out must also determine the material used

[AKSA]

Hi West,

I'm pretty sure the DACT uses an ELMA switch, made in Switzerland.  They are high quality switches, very durable, with a nice feel to the action.  I suspect that DACT offer slightly better resistors in their design, but can't be sure....  I'll be guided by others here who might have bought them in the past.

Hope this is helpful, there ain't nuttin' new under the sun!!

Cheers,

Hugh

[curly joe]

Hi West,

No, there was no extra hum, the extra transformer is pretty small and encapsulated as well. My pre has a  slight 50hz hum, but it was there before my mods, it's something I want to work on next time it's apart.

Cheers
CJ

[whubbard]

west, andy,

Is it an assumption that copper is the best shield? I always thought (assumed ) aluminium or nickel were good.

The frequency(wavelength) one is trying to block out must also determine the material used

Yes, that is correct. That is also what makes the TI Shield special. Texas Instruments made the proprietary clad metal so that it would block a bigger spectrum.
I am using the Copper on the basis that many others use for shields. I did look around for more information on what blocks what...but came up fairly empty. It is rare that I will just jump onto a bandwagon like this (I like doing research), but I think the copper will do just fine. Especially when combined with the aluminum, which should block some other frequencies. I don't think I'm going to use the TI shield as it was a bit too expensive. What I am going to do is look into what I should use to shield the transformers in my GK-1. I think that a steel plate, then a copper layer, with some aluminum foil over would sure shield them, but I'm not sure.

Also, I just went ahead and got the DACT selector switch from Kevin at diycable.com. Hopefully it was worth it. At this point it's looking like my GK-1 is going to be as good as it gets (if it weren't for the Swift...)

Curly,
I'm praying to avoid hum, but I have a feeling its something I'm going to have to deal with.

-West

[jules]

I'm pretty sure the DACT uses an ELMA switch, made in Switzerland.

Yes, it looks like that to me too Hugh. As far as resistors go, you get to choose. From Michael Percy you can get Holco or Roderstein [if they haven't run out] but you could just buy use whatever you want if you are DIYing and you could even choose different resistors for the signal and ground sets.  I've used an Elma attenuator and an Elma source select switch here:

http://www.audiocircle.com/index.php?topic=54068.10

but I can't make any comparisons with Hugh's stock rotary as my GK-1 was built the way it is.

Thin copper is fine for RF shielding but thickness counts when it comes to magnetic shielding. Somewhere, sometime, Occam suggested that 10mm of copper only had a ~30% shielding effect on magnetic fields [approximate memory too  ]. Mild steel or stainless steel that has slight magnetic properties,  seem to do the job on magnetic fields. Keep in mind that magnetic fields fall away fairly rapidly so distance is your biggest ally. RF on the other hand doesn't  , so the shielding needs are slightly different.

jules

[whubbard]

Thin copper is fine for RF shielding but thickness counts when it comes to magnetic shielding. Somewhere, sometime, Occam suggested that 10mm of copper only had a ~30% shielding effect on magnetic fields [approximate memory too  ]. Mild steel or stainless steel that has slight magnetic properties,  seem to do the job on magnetic fields. Keep in mind that magnetic fields fall away fairly rapidly so distance is your biggest ally. RF on the other hand doesn't  , so the shielding needs are slightly different.

Jules,
This was basically what I had guessed the properties were, and luckily you were able to pretty much confirm it. I think I will stick with my current design. Copper for the whole box, steel between the path of the transformers and the amp modules.

-West

[kyrill]

from a purists side i would not invite magnetic metals to enter my house of sound

[stvnharr]

Hi West,

I'm pretty sure the DACT uses an ELMA switch, made in Switzerland.  They are high quality switches, very durable, with a nice feel to the action.  I suspect that DACT offer slightly better resistors in their design, but can't be sure....  I'll be guided by others here who might have bought them in the past.

Hope this is helpful, there ain't nuttin' new under the sun!!

Cheers,

Hugh

DACT uses Elma switches and smd resistors.  They are almost exactly the same as Goldpoint, which now uses Elma switches and smd resistors.
Neither DACT nor Goldpoint use the BV switches though.  DACT does give cleaning instructions in case there is switch noise, as there can be with the kind of switches that they use.  DACT is made in Thailand.  GP is made in Colorado now, or at least the company is based there now.