Paris head amp

PT914 · « **on:** 9 Feb 2008, 08:21 am »

Hi,

I have had the Paris head amp for a month and I am just delighted with its silence. No hum, just a very black background. It replaced a Naim 52 pre amp that I was using to power a Naim head amp. I was using the tape out from the 52 pre amp and connecting that to the GK-1R. The Naim setup had a hiss back ground and was just a little better than my CD-Dac set up. With the Paris setup, the vinyl setup has a blacker background than the CD. The Paris is right next to the Linn LP12 with a Archiv and I am running a five foot DIY interconnect. Very impressive sound stage for a Linn. Now that I have a base line I can start tweaking the Paris head amp. Great product Hugh.

Cheers,
Philip

andyr · « **Reply #1 on:** 9 Feb 2008, 12:04 pm »

Quote from: PT914 on 9 Feb 2008, 08:21 am

Hi,

I have had the Paris head amp for a month and I am just delighted with its silence. No hum, just a very black background. It replaced a Naim 52 pre amp that I was using to power a Naim head amp. I was using the tape out from the 52 pre amp and connecting that to the GK-1R. The Naim setup had a hiss back ground and was just a little better than my CD-Dac set up. With the Paris setup, the vinyl setup has a blacker background than the CD. The Paris is right next to the Linn LP12 with a Archiv and I am running a five foot DIY interconnect. Very impressive sound stage for a Linn. Now that I have a base line I can start tweaking the Paris head amp. Great product Hugh.

Cheers,
Philip

Hi Philip,

I have a "Paris" also ... quiet, absolutely! - and lightning fast!

Are you feeding it into the phono stage of your GK-1R? Strange, though, how there's "different strokes for different folks"! Our esteemed colleague SuperMart prefers his tube head amp (designed by a Melbourne fella in the 1970s - and renovated" in the 2000s) to my Paris ... but I can't stand the tube hiss!

Then again, he is English!

What tweaks are you thinking of ... I think I just implemented the standard PCB as supplied by Hugh, although I did put some filter caps across the battery supply?

You said you have an LP12 ... you might be interested in a CF-composite subchassis that I make for it - see a review here:
http://www.audioasylum.com/audio/vinyl/messages/68/687191.html

As risabet says, it is a major upgrade to the LP12, due to the fact that the armboard can be bolted to the subchassis (because it doesn't suffer the vibration problems of the stock pressed-steel subchassis). Boltng the armboard to the subchassis enables the stylus to pick up more low level information from the grooves, which was previously lost by the "lossy" connection provided by the 3 little armboard screws.

Regards,

Andy

AKSA · « **Reply #2 on:** 9 Feb 2008, 12:24 pm »

Thanks Philip, Andy,

I should rush to explain that it was not named after a famous for being famous heiress of dubious thoughtfulness, but rather after Ry Cooder's famous 'Paris Texas' album which I absolutely adore........

The Paris uses a novel concept (which may not be original, very little actually is, though I've not seen it elsewhere) called 'reflexive ground loading', which references both input and output directly to ground and uses a current source to isolate the power source. This results in very low noise, and with a floating ground from a battery source, there can be no ground loops either. Care must still be taken with the interconnects, of course, but by and large this is the quietest way to do it, and I'm still scratching my head about why others have not done it this way.

Cheers,

Hugh

kyrill · « **Reply #3 on:** 9 Feb 2008, 01:01 pm »

will future options include a cross feed design?
I am absolutely convinced this will enhance the real life (high end) experience

PT914 · « **Reply #4 on:** 9 Feb 2008, 08:44 pm »

Hi Andy,

Yes I am feeding the Paris head amp into to the phono section of the GK-1R. The tweak I'm thinking of is replacing the 2.2 uF output cap in the Paris head amp with a Mundorf cap. It's a big replacement, luckily I have yet to make an enclosure for the head amp. I haven't done anything to the phono section in the GK-1R.

I heard about that LP12 modification, but am presently building a stand for a Teres turntable that I have had in boxes for a while. Need to finish the stand and setup the Teres.

Cheers,
Philip

andyr · « **Reply #5 on:** 9 Feb 2008, 10:16 pm »

Quote from: PT914 on 9 Feb 2008, 08:44 pm

Yes I am feeding the Paris head amp into to the phono section of the GK-1R. The tweak I'm thinking of is replacing the 2.2 uF output cap in the Paris head amp with a Mundorf cap. It's a big replacement, luckily I have yet to make an enclosure for the head amp.

Cheers,

Philip

Hi Philip,

After reading your post, I took Paris's top off and had a look at her.

These are the tweaks I did:
* I used 2x100uF plus 4x47uF BG stds across the battery supply
* I used 2x1uF BG 'Ns' in Ian's "Super-E" configuration for the output cap. These are tiny and fit on the PCB with no trouble.

To handle cartridge loading, I have a second (parallel) pair of input RCAs for "loaded" RCA plugs.

Regards,

Andy

PT914 · « **Reply #6 on:** 10 Feb 2008, 12:12 am »

Hi Andy,

Having a pair of RCAs for cartridge loading is an excellent idea. I have not played with cartridge loading yet, still have the stock 180 in place.

I'll also throw some caps at the battery supply. The box to house the Paris is growing.

Thanks,
Philip

andyr · « **Reply #7 on:** 10 Feb 2008, 12:43 am »

Quote from: PT914 on 10 Feb 2008, 12:12 am

Hi Andy,

The box to house the Paris is growing.

Thanks,
Philip

Well, my pair of 6v 5AH batteries requires a lot more real estate than the PCB - even if it does have filter caps attached - so I suggest that will define the size of the box required!

Regards,

Andy

andyr · « **Reply #8 on:** 10 Feb 2008, 12:53 am »

Quote from: AKSA on 9 Feb 2008, 12:24 pm

The Paris uses a novel concept (which may not be original, very little actually is, though I've not seen it elsewhere) called 'reflexive ground loading', which references both input and output directly to ground and uses a current source to isolate the power source. This results in very low noise, and with a floating ground from a battery source, there can be no ground loops either. Care must still be taken with the interconnects, of course, but by and large this is the quietest way to do it, and I'm still scratching my head about why others have not done it this way.

Cheers,

Hugh

Hugh, is it feasible to take just the phono portion of a GK-1M/R source-select PCB plus the Paris PCB to make up a complete MC phono stage which is battery powered ... either +/-6v or +/12v?

I'm happy to make one up if you'd like me to see how it sounds.

Maybe the phono part would need some slight rearrangement to include this " 'reflexive ground loading' (which references both input and output directly to ground and uses a current source to isolate the power source)"?

Regards,

Andy

PT914 · « **Reply #9 on:** 12 Feb 2008, 08:18 am »

Hi Andy or anyone with a Paris,

You might want to try and change the 1.5 uF MMK caps at C3 and C2 in the Paris Head amp for a higher value and confirm what I hear. I replaced the 1.5 uF with 4.7 uF Axon caps. These are metalized polypropylene caps that I had left over from a Slim Device project. I did a few things to the power supply and the change of these caps are, from what I can figure out, responsible for tightening the bass and clear the mids.

I first changed the power cap to a BG, the only one I had left over was a 4700 uF. I mounted this large cap off the board and connected it to the board with cat5 wire. No change in sound. I then replaced the wire between the board and battery with 20.5 ga Cardas wires and connected the 4700 uF BG cap to the board with the same wire. I solder the wire directly to the board where the original 3300 uF cap was, right in the center. Removed the power pins, don't like soldering to pins, just a pain. Anyway that made room for bigger caps at C3 and C2 which I replace with the 4.7 Axons. Now the sound was much better. I can't image changing the wire or removing the pins was responsible for the better sound that I heard. Maybe my hearing memory has gone, but I'm sure enjoying the music now.

I haven't change the output cap yet.

Cheers,
Philip

andyr · « **Reply #10 on:** 12 Feb 2008, 08:23 am »

Quote from: PT914 on 12 Feb 2008, 08:18 am

Hi Andy or anyone with a Paris,

You might want to try and change the 1.5 uF MMK caps at C3 and C2 in the Paris Head amp for a higher value and confirm what I hear. I replaced the 1.5 uF with 4.7 uF Axon caps. These are metalized polypropylene caps that I had left over from a Slim Device project. I did a few things to the power supply and the change of these caps are, from what I can figure out, responsible for tightening the bass and clear the mids.

Cheers,
Philip

Hi Philip,

Interesting thought but sorry ... I am currently halfway through upgrading my 6 monoblocks from AKSA N+s to LFs (and putting them in a nice new - much neater! - case) so won't be able to get round to this for many weeks.

Regards,

Andy

Dan Kolton · « **Reply #11 on:** 23 Feb 2009, 04:06 am »

Hugh,
Is this head amp currently available? What is the price?

AKSA · « **Reply #12 on:** 23 Feb 2009, 08:18 am »

Yes, Dan,

It's not on the website at this stage (ulp!) but it's available for $US210 plus shipping, which is pretty cheap, around $35 for Express Post.

Cheers,

Hugh

Tim · « **Reply #13 on:** 24 Feb 2009, 08:43 am »

Can anyone post a pic of the Paris to satisfy my curiosity

cheers,

Tim

andyr · « **Reply #14 on:** 28 Feb 2009, 03:48 am »

Quote from: Tim on 24 Feb 2009, 08:43 am

Can anyone post a pic of the Paris to satisfy my curiosity

cheers,

Tim

Hi Tim,

Can't figure out how to post pics directly but here are some shots of my "Paris".

http://www.audiocircle.com/index.php?action=gallery;area=browse;album=487&pos=18

That's the first of 4 ... scroll through. The actrual PCB is dwarfed by the 2 6v gel cells!

Regards,

Andy

Seano · « **Reply #15 on:** 1 Mar 2009, 09:28 pm »

andyr · « **Reply #16 on:** 1 Mar 2009, 09:30 pm »

Quote from: Seano on 1 Mar 2009, 09:28 pm

OK, OK ... tell me the secret, then!

Regards,

Andy

whubbard · « **Reply #17 on:** 1 Mar 2009, 09:44 pm »

[ img]http://www.audiocircle.com/image.php?id=18475[/img]
remove the space after the [

To find the proper link right click on the photo and click properties, or inspect element. It will be different by browser.
Thats the easiet way to find the link.

-West

andyr · « **Reply #18 on:** 1 Mar 2009, 09:50 pm »

Quote from: whubbard on 1 Mar 2009, 09:44 pm

[ img]http://www.audiocircle.com/image.php?id=18475[/img]
remove the space after the [

To find the proper link right click on the photo and click properties, or inspect element. It will be different by browser.
Thats the easiet way to find the link.

-West

Thanks, West - I'll try it sometime. But you need to have the pic already in the gallery, right? I can't upload a pic from my PC's hard drive (like I can when posting on Audio Asylum)?

Regards,

Andy

whubbard · « **Reply #19 on:** 1 Mar 2009, 10:05 pm »

I'm unsure about that, but I do believe so.

I host all my photos on my own server, so I don't really have this issue.
Since the photos have a direct URL link, I just use it.

-West