Potting and mods to phono cartridges

[norman]

AT95 CARTRIDGE IS DISCONTINUED

 

For anyone interested in trying a potted AT95 cartridge experiment, I bought another (AT95E) today for $45 (bargained down from their asking $59) from JB Hi-Fi, possibly the last one in Canberra, and I was told that Audio Technica has discontinued this cartridge and no more will be available. My suggestion - get in quickly if you want to grab one or two and experiment on them. The replacement does not have the magic screw and body hole for the plastic body that makes it removable and the cartridge innards accessible.

 

I am loving the sound of the <$50 EX stylus (the red one), but fear not I am hunting for another higher grade stylus to use.....

Edited September 30, 2019 by norman

[norman]

So, here is the promised modded and potted AT95 picture to prove the modding has happened. The story so far in order:

 

Lip balm potted to eliminate coil vibration;

Top cover Araldited on for rigidity;

Stylus upgraded to EX specification;

Stylus carrier cut away (not sure if this has made any real difference, but what the heck?)

 

For a potential investment of $45 for the cartridge and $49 for the stylus, its unbelievable. The detail is tremendous, the midrange and treble are really good, and the bass has slam. My jaw dropped just this afternoon when I played XTC's "Senses Working Overtime" off "Waxworks - Some Singles 1977-1982" album, a 1980s thin pressing I have had since new - kick drums like they sound in a studio with real thump, bass guitar with presence and authority, and the rest of it all nice and uncluttered. My suggestion - invest under a hundred bucks, pot the cartridge and prepared to be amazed. I'm still thinking about a better stylus, but that might wait as it hasn't yet broken in so its final sound hasn't yet been revealed..... And I'm only listening on vintage KEF Concertos that I have modified the crossovers in, with a reasonably powerful NAD C370 amp and my old Technics SL-D2. Oh, and now a Pro-Ject S phono pre-amp which I like better than my NAD PPe2 (a $75 steal this morning - get one!).

 

Edit - more music - Stanley Clarke - Rocks Pebbles and Sand - incredible and clear at high volume, possibly better defined and lower extension of bass then the (also still not run-in) Ortofon 2M Blue, also Stanley on the eponymous album, particularly "Spanish Phases for Strings and Bass" and my favorite "Lopsy Lu" featuring possibly the best drummer to ever draw breath (Tony Williams if you are guessing). Punch, speed power and wonderful. And naysayers notwithstanding, later model KEF Concertos with a properly modified crossover and a high current amp are fantastic, don't be fooled by the cr@p you read on the web about these wonderful vintage speakers.

 

And here's the visual proof:

 

 

 

 

Edited October 1, 2019 by norman

[norman]

And, for my next trick, I have bent the cantilever of the AT95EX stylus I cut back, lucky it was only $45. I am definitely not cutting back the stylus assembly when I buy a fine line or nude stylus, I've learned my lesson. I don''t think it actually made any difference to the sonics anyway. Back to the standard green for a while....

Edited October 2, 2019 by norman

[magical]

On 23/09/2019 at 7:29 AM, norman said:

I have decided to upgrade my Audio Technica AT95 cartridge. I have ordered an upgrade stylus, and I have a possibly stupid idea that potting the internals with wax or epoxy will add a bit of sonic magic maybe by stopping coil vibrations. There is a hole closed with a screw on top that allows access to the cartrige insides. Has anyone done this and if so, do you have any guidance? My final step will be to make a wood body. Any ideas would be appreciated.

Sure, play arround with it, but just buy a better cartridge. The AT 95 was reasonable mid hifi buy hifi standards, it waa never high end. Rember this was the time Koetsu, Kisiki, Ortofon, Van DenHul and others ruled the roost.

Good fun to play with but the at95 that came with my Rega with Jelco arm (ordinary) stays in it's box.

 

[magical]

On 30/09/2019 at 5:49 AM, georgesgiralt said:

Hello,

What would you think about Shea butter to fill the cart ? It is low temperature melting and very hard when cold. So may seal better ?

 

Love it. 

 

I use lard. 

 

[norman]

I have potted a second AT95 cartridge, and here are some photos to prove it:

1. Looking into the stylus cavity:

 

2. The generator removed from the top cover showing the screw (with Locktite) and the screw hole where the wax goes in:

 

3: Potted with wax, cooling off. The wax needs to be scraped off level, and the case cleaned off with lighter fluid to allow the glue in the next step to adhere properly. The wax was injected in with a syringe, and you have to work quickly:

 

4: The top cover has been Araldited (5 minute clear version) back onto the generator, and the screw put back in to align everything before the epoxy sets. I believe this affects the sound in a positive manner, and is an easy alternative to fitting a wooden body (that adds another $70+ which is a bit much to add cost wise to a $45 AT95 generator in my opinion):

 

5. Finished job waiting to be mounted. I have fitted another EX stylus (.03 x .07) which sounds great. I'm not going to nude this one as it makes it too easy to bend the cantilever by accident, and also stops the use of a protector when the cartridge is swapped out. Now it needs 30 hours or so to run in.....

 

This is an easy and great sounding mod. All up my cost was <$100 (including the genuine AT EX stylus) and it sounds terrific, belying its humble origins.

 

Remember, the AT95 is now end-of-life and won't be available new anymore so if you want to try this, be quick. It's replacement doesn't seem to allow for the potting mod.

 

Cheers.

 

 

Edited October 9, 2019 by norman

[norman]

On 24/09/2019 at 9:00 PM, nkoulban said:

I have now added a JICO hyper-elliptical stylus, cut away the excess plastic and epoxied the AT95 body into another wood body.  This combo sounds detailed and organic at the same time and has the lowest surface noise of any of my carts.  I have also loaded it with resistors to smooth out the sound a bit more.  A brilliant cart that I love to bits.

Hi nkoulban - Can you advise what to do to "load it with resistors" - I am guessing you make up a stereo cable with female RCAs at one end, then the resistors in series, and then male RCAs at the other end, and just plug it into the cable run before the pre-amp.

 

If this is the case, what values do you suggest for the resistors?

 

I'm still umming and ahhing about spending $155 on a hyper elliptical - is it really audibly better than the $45 maroon EX elliptical?

 

Cheers, Norm

[nkoulban]

42 minutes ago, norman said:

Hi nkoulban - Can you advise what to do to "load it with resistors" - I am guessing you make up a stereo cable with female RCAs at one end, then the resistors in series, and then male RCAs at the other end, and just plug it into the cable run before the pre-amp.

 

If this is the case, what values do you suggest for the resistors?

 

I'm still umming and ahhing about spending $155 on a hyper elliptical - is it really audibly better than the $45 maroon EX elliptical?

 

Cheers, Norm

I have compared it to EX like elliptical (The LP Gear ATN95SE with a  .0003 x .0007 inch radii) and  JICO hyper elliptical is clearly better as well as reducing surface noise.  I purchased quality RCAs from Jaycar and soldered in resistors (loaded at 36K Ohm using 150K Ohm).  Also refer to this link for more info on how to do this.... http://daveyw.edsstuff.org/vinyl/loading/

 

[norman]

6 minutes ago, nkoulban said:

I have compared it to EX like elliptical (The LP Gear ATN95SE with a  .0003 x .0007 inch radii) and  JICO hyper elliptical is clearly better as well as reducing surface noise.  I purchased quality RCAs from Jaycar and soldered in resistors (loaded at 36K Ohm using 150K Ohm).  Also refer to this link for more info on how to do this.... http://daveyw.edsstuff.org/vinyl/loading/

 

Hey nkoulban - many thanks for your advice, it's much appreciated. I will follow the link and give the resistors a go before I buy a hyper elliptical stylus.

 

I just yesterday bought a swag of Neutrik-family RCAs (Yongshen brand, same plugs as Rean, another Neutrik brand) from Swamp Industries here in Canberra to make up some cables, as I jagged a roll of 80 meters of really great low capacitance OFC cable from Gumtree for forty bucks last week. I will report back when done.

 

Cheers, Norm

[norman]

Just made up a couple of cartridge loading resistors. Owing to me buying 150 ohm rather than 150k ohm resistors (oops) I couldn't do the 36k loading. I ratted my parts stash and found some 100k ohm resistors and made up a pair of 32k ohm loading resistors instead.

 

Results so far (on a not yet run in but potted) AT95EX - better than without, not so edgy upper-biased, but just a little shy in the treble for my tastes now. I think  the "proper" 36k ohm or 40k ohm resistance will sound better, so off to Jaycar again tomorrow to buy the correct 150k ohm resistors, as well as some other values.

 

I also tried the Ortofon 2M Blue at 32k and it sounded much better, losing the icy top edge and it is really lovely now - tight but deep bass, mice mids, and well balanced treble, extended but no longer harsh.  I might save up for a 2M Bronze or Black based on this experiment, it's that much of a change.

 

Edited October 11, 2019 by norman

[norman]

So I have now bought the right value resistors, made up a few sets, and the 39K ohm value seems best so far for the potted AT95EX, which is still breaking in.

Recommend others try this if you have a cartridge to tame - its easy and cheap - $11 for 2 Y female to male connectors, $2 for 2 RCA plugs, and $0.50 for 10 resistors of a specific value. Great stuff.

Edited October 12, 2019 by norman

[georgesgiralt]

Hello !

I've just discovered that the new AT-VM95 series can be potted ! There is a screw to remove the plastic upper body. and open a hole to put the wax in. But this screw is concealed under the little sticker showing the cartridge reference.

So all is not lost if you cant find some of the previous AT models....

 

[norman]

Great discovery, as it's supposed to be a heap better than the old AT 95 out of the box.... Cheers, Norm