the home of the turntable

Have I Fried my Fidelity Research Moving Coil Cartridge?

the thin end of the wedge

Re: Have I Fried my Fidelity Research Moving Coil Cartridge?

Postby ronaka » 17 Mar 2012 23:28

MR F wrote:You could replace the phono plugs, but the continuity problem could be in the cables themselves. You could de-solder the DIN and attach a new set of cables.


I think you were right. After I "fixed" the connectors neither channel works now. I can't get any kind of consistent DC resistance reading when I measure the cable end to end. Strongly suspect it is "pooched", and am now looking to buy a new cable. This one looks like it should work:

http://www.ultimatecables.com/zencart/index.php?main_page=product_info&cPath=66_67_71&products_id=192
ronaka
member
 
Posts: 71
Joined: 23 Aug 2011 20:12
Location: Canada

Re: Have I Fried my Fidelity Research Moving Coil Cartridge?

Postby MR F » 18 Mar 2012 01:16

Yeah, that looks right (and not too terribly priced as far as tonearm cables go).

Can you give me some general impressions of that cartridge? I intend to send mine off to Soundsmith when I save up the money, hopefully it is not beyond repair:

Image

Ugly :(
MR F
member
 
Posts: 74
Joined: 02 Feb 2012 01:10

United States of America

Re: Have I Fried my Fidelity Research Moving Coil Cartridge?

Postby josephazannieri » 18 Mar 2012 03:20

Yo ronaka:

I had exactly the same thing happen with my G707 arm. After about 20 years, the cable went bad. I wound up purchasing a cablke from Ultimate Cables. My little adventure is detailed here:

viewtopic.php?f=18&t=41274

The cable was not horrifyingly expensive, AND, there was no shipping charge. All I paid was 80 bucks. If I have gone to the auction site, I would have paid a hundred and a half, and they would have charged me additional for shipping.

The only issue was that the new plug was really TIGHT, and I wound up pushing the tonearm base up while installing it, so I had to revise the VTA and all the alignment factors to get back to the way it was. It did take them a while, about a week, to get it to me. Held up several days in Canadian customs. But not a problem. I remember waiting 3 weeks for Allied Radio in Chicago to get me my pair of EV 12TRX-B's in 1973.

The Ultimate Cable is a good solution. Just make sure you get the one for the Grace G707 arm, which has the male DIN/Cardas plug end.

And good luck from the old guy who bought one,

Joe Z.
josephazannieri
contributor
 
Posts: 2149
Images: 0
Joined: 20 Apr 2008 06:01
Location: Norwalk,Ohio,USA

United States of America

Re: Have I Fried my Fidelity Research Moving Coil Cartridge?

Postby ronaka » 18 Mar 2012 06:15

MR F wrote:Can you give me some general impressions of that cartridge? I intend to send mine off to Soundsmith when I save up the money, hopefully it is not beyond repair.


It is a good cartridge and was well rated by the Audio Critic if you were ever a follower of their stuff. They were designed by Isamu Ikeda. The company went under in the mid 80's, but the designer still seems to be around and is making custom cartridges in Japan. See this link:

http://www.audionautes.com/Altriprodotti/ikeda/ikeda_eng.htm

I recall it was one of the first cartridges to use silver wire for the coils and a line contact low radius diamond. Although from your photo that part is toast now. I paid just over $200 for it in about 1980. Apparently they later sold for up to $600 or so as the supply dried up.

My cantilever got bent but I was able to bend it back and it still played. Peter Lederman at Soundsmith rebuilt it with a ruby cantilever and the mid priced diamond. It sounded OK, but perhaps lost a little output. It took almost 6 months as I recall so it was hard to remember or compare sound before to after. Also my rebend of the cantilever had it off in sound before I sent it in.

The output is quite low at 0.14 uV and apparently the matching transformer was the Fidelity Research FRT-3. I have a one page test and review of the cartridge that I could send you if you want to PM me with an e-mail address. The frequency response is quite impressive with only a very gradual drop in output starting at about 500 Hz and ending up about 1 dB low at 20K. Balance is excellent, and separation rages from 20 dB at low frequencies to about 26 dB at 20K.

As far whether it is repairable, Peter Lederman should be able to tell you once he sees it. My cantilever was right angled too, but yours does look a little rough. I would guess the real issue is whether or not there is damage in the coil area, as the cantilever of course is replaced.

I believe the cartridge is in the Library section here if you want the specs.

Hope that helps some,
ronaka
member
 
Posts: 71
Joined: 23 Aug 2011 20:12
Location: Canada

Re: Have I Fried my Fidelity Research Moving Coil Cartridge?

Postby ronaka » 18 Mar 2012 06:35

josephazannieri wrote:Yo ronaka:

I had exactly the same thing happen with my G707 arm. After about 20 years, the cable went bad. I wound up purchasing a cablke from Ultimate Cables. The only issue was that the new plug was really TIGHT, and I wound up pushing the tonearm base up while installing it, so I had to revise the VTA and all the alignment factors to get back to the way it was. The Ultimate Cable is a good solution. Just make sure you get the one for the Grace G707 arm, which has the male DIN/Cardas plug end.


Joe Z., thanks for the comments and tips. I'm in Canada so I will not have the customs issue. I have sent an e-mail off to them to have them confirm which part number has the male DIN plug for the Grace G-707.

I read your thread and my cable seems to be suffering from the same issues. For resistance I got anywhere from open to 300 ohms, 120 ohms, and 20 ohms was the very best I got and only intermittently in one channel. No steady reading, so there has to be breaks in the cable.

I have one question for you. This arm is on a Rega Planar turntable and the cable must make a sharp right angle turn after it comes out the bottom of the plinth. Do you think this standard cable is flexible enough to make the turn? I see they make another cable with a right angle connector but it is double the price at $160.
ronaka
member
 
Posts: 71
Joined: 23 Aug 2011 20:12
Location: Canada

Re: Have I Fried my Fidelity Research Moving Coil Cartridge?

Postby josephazannieri » 18 Mar 2012 17:35

Yo ronaka:

Back when I had the Grace arm mounted on my Thorens TD-150, I made it work by taking the cable and using a cable clamp and doing a turn and clamping the cable to the sprung chassis. However, I was required to cut a hole in the cardboard turntable bottom to allow for the normal motion of the chassis, since the sprung chassis has to be free, and the cable was hitting the cardboard turntable bottom.

I made the room by raising the turntable by using those Audio-Technica absorption feet, but this was with the stock Grace cable, which is somewhat more flexible than the Ultimate cable. I currently have the G707 mounted on a Garrard 301, which has a plinth that is almost 5 inches high, and even this is a little tight. You can make the Ultimate cable turn 360 degrees in about an inch and a half diameter, but that is not an easy turn. Depending on how much space you have under your turntable you might be able to make it work, but your G707, if I remember from the installation on the Thorens, will probably extend some distance below the chassis. You could talk to Ultimate and see if they think you will need a right angle plug for that installation. I think you can improvise it if you are not joined at the hip to having a turntable with an absolutely stock appearance.

You can probably get it done by raising the turntable off the shelf, and just letting the cable come out a hole in the bottom. My Thorens has a hole in the bottom for the cable (Linn Basik LXV arm) to come out, and it is raised on 3/4 inch plywood and hangar bolts to give about an inch and a half additional clearance between the bottom of the 3/4 inch plywood and the shelf. (actually a small paving block for mass filtration to eliminate acoustic feedback) I will send pictures, but you will need to PM me with your Email, since I have trouble getting VE to take my images.

And good luck from the old improviser, who never looks stock anymore,

Joe Z.
josephazannieri
contributor
 
Posts: 2149
Images: 0
Joined: 20 Apr 2008 06:01
Location: Norwalk,Ohio,USA

United States of America

Re: Have I Fried my Fidelity Research Moving Coil Cartridge?

Postby ronaka » 18 Mar 2012 18:29

Joe Z., I measured up the turntable and I have about 2" of space from the face of the female DIN to the counter top. That radius would work out to about a 4" diameter circle. The cable simply comes out a hole in the bottom of the plinth, makes a right turn, and there is a bit of a clamp that screws back into the bottom of the plinth as a strain relief. Based on your 1 1/2" estimate of a 360 turn I should be OK. However in my case it also has to include the male DIN connector so I will loose some with that.

If it does not work, I will have to design some standoff for the turntable feet. I've never thought the rubber ones on the Rega were soft enough in any case, so it probably is not a bad idea. I will PM you with a e-mail address as I would still like to see the pics of what you have done.

One more question. Does the Ultimate cable use twisted pair shielding like in this link? I'm presuming that as it does not seem to be side by side coaxial arrangement. I understand the twisted design may be more suitable for moving coil cartridges.

http://www.canare.com/UploadedDocuments/Cat11_p35.pdf

Thanks for the help in this.
ronaka
member
 
Posts: 71
Joined: 23 Aug 2011 20:12
Location: Canada

Re: Have I Fried my Fidelity Research Moving Coil Cartridge?

Postby josephazannieri » 21 Mar 2012 02:47

Yo ronaka:

I have not taken my Ultimate Cable apart, but I did look at it closely and unscrew the covers off the RCA plugs. It appears that there are 3 white cables inside a flexible fishnet exterior. Looking at the end, it appears that one of the white cables emerges from the end and the ground wire comes out of it. The other 2 white cables emerge and they go to one RCA plug each. On the way to the RCA plugs, they are covered with what looks like black heat shrink. I was reluctant to disassemble the cables any further because I like them, and I paid $80.00 for them, and I am not going to mess them up.

But, unscrewing the the RCA cable ends, I discovered what looks like conventional 2-conductor shielded microphone cable, with both conductors connected to the center pin of the RCA plug. I did not see any kind of unconventional "star" wiring.

Hope that description helps! Best I could do, given my refusal to cut open the cable.

And good luck from the that lazy, cowardly old guy,

Joe Z.
josephazannieri
contributor
 
Posts: 2149
Images: 0
Joined: 20 Apr 2008 06:01
Location: Norwalk,Ohio,USA

United States of America

Re: Have I Fried my Fidelity Research Moving Coil Cartridge?

Postby ronaka » 21 Mar 2012 15:11

Joe Z., thanks for the response. I ordered the same cables, and had a good chat with Carl Barbieri who does the Ultimate cables. He used to own a Grace G-707 so I'm pretty confident he will deliver a good cable. He says that not only did Grace reverse the male and female, but also changed the pinout on the DIN cable. But, I did forget to ask him about the design of the cable. I'm sure it will work.

I also got the photos of your system. Very interesting. I'm thinking of making a 1" MDF sub plinth to screw to the bottom of my Rega Planar 2 plinth. I will then attach the three Rega feet to the 1" MDF. It should give me an extra 1" of room to allow the cable to make the 90 deg. turn. Also the extra mass should be helpful. Thought about getting a piece of scrap granite from a counter top company, but I have no way to work with that stuff. Also thought of Corion, but I am suspecting I would not likely find it in a suitable color.
ronaka
member
 
Posts: 71
Joined: 23 Aug 2011 20:12
Location: Canada

Re: Have I Fried my Fidelity Research Moving Coil Cartridge?

Postby davidsrsb » 21 Mar 2012 16:30

Isn't this circuit the W. Marshall Leach design?
davidsrsb
senior member
 
Posts: 604
Images: 22
Joined: 09 Nov 2009 17:00
Location: Kuala Lumpur

Malaysia

Re: Have I Fried my Fidelity Research Moving Coil Cartridge?

Postby ronaka » 21 Mar 2012 20:08

davidsrsb wrote:Isn't this circuit the W. Marshall Leach design?


Yes, it is very similar. I gather there are/were some hard feelings about Marcof using the design. But, from what I can see Leach never patented it either. The Leach article where he described the circuit is at the link below.

http://users.ece.gatech.edu/~mleach/headamp/
ronaka
member
 
Posts: 71
Joined: 23 Aug 2011 20:12
Location: Canada

Re: Have I Fried my Fidelity Research Moving Coil Cartridge?

Postby davidsrsb » 22 Mar 2012 09:02

At one time I did a redesign of that circuit to use 3V battery supply. 2x AA batteries is far more economic than PP3 9V and should give no problems with headroom for a MC booster.
davidsrsb
senior member
 
Posts: 604
Images: 22
Joined: 09 Nov 2009 17:00
Location: Kuala Lumpur

Malaysia

Re: Have I Fried my Fidelity Research Moving Coil Cartridge?

Postby ronaka » 03 Apr 2012 23:11

Just an update. I got my cable today from Ultimate Cables, and my cartridge is NOT FRIED! I'm happy about that. The problem is now obvious and was a bad cable. There were some issues getting the cable that you should be aware of if considering dealing with Ultimate Cables. I'll let you form your own conclusions. See this thread. My posts are right near the current end.

http://www.stereo.net.au/forums/index.php?/topic/31422-my-experience-with-ultimate-cables-ebay-name-carlsc/page__hl__%20carl%20%20barbieri%20%20ultimate%20%20cables
ronaka
member
 
Posts: 71
Joined: 23 Aug 2011 20:12
Location: Canada

Re: Have I Fried my Fidelity Research Moving Coil Cartridge?

Postby Alec124c41 » 04 Apr 2012 03:14

Ultimate cables do a nice job.

Cheers,
Alec
Keep them spinning.
User avatar
Alec124c41
senior member
 
Posts: 13326
Images: 53
Joined: 28 Oct 2002 04:24
Location: Toronto, Canada

Canada

PreviousNext

Return to Cartridges and Preamps


Design and Content © Vinyl Engine 2002-2013

faq | site policy | advertising | hifiengine