Triplanar RCA out to Balanced out for MP-1

Convention for a balanced connection:

Pin-1: shield (balanced signal ground)
Pin-2: positive signal
Pin-3: negative signal

You have two options:

1. Run single ended into your balanced system as stated the posts above:

Pin-1: jumper to Pin-3 (connect RCA ground to balanced ground)
Pin-2: connect your positive RCA wire
Pin-3: connect your negative RCA wire

2. Create a balanced connection. This has been the subject of heated discussion over the past 12 months. From your perspective, you could care less. I'd try to take this approach.

Pin-1: find a tonearm chassis ground point and connect it to pin-1.
Pin-2: connect to your positive RCA wire (as above)
Pin-3: connect to your negative RCA wire (as above)

Comments on running balanced on the Atma-Sphere site:

http://www.atma-sphere.com/support/se.html

Strictly speaking, Ralph mentions only line level sources in detail in the first paragraph - assuming your tonearm manufacturer will wire your tonearm cable for you. The same principles apply from a wiring perspective for a tonearm - save the discussion on whether or not a cartridge is balanced or floating single ended. For your purposes, you don't care. It's the sound you're after, so wire up in balanced mode and have at it.

Cheers,
Thom @ Galibier

Hi Raul,

By "finding" something, I was referring to establishing electrical continuity between pin-1 and the metal on the tonearm.

If you're lucky and the tonearm cable has a shield which has electrical continuity to the tonearm's body, all is well. I think this is what you're assuming, and in most cases it should be the situation you'll encounter.

Tonearm cables are almost always shielded. Still, I would verify electrical continuity with the tonearm's body just to make sure.

An alternative would be to use the ground wire for this purpose - splitting it into a "Y" to run to the pin-1 of both left and right connector.

Cheers,
Thom @ Galibier

Hi Bill,

Contact me through the contact button on my website. I'll get with Frank on your DPS.

He and I will hook up at the Rocky Mountain Audiofest in 3 weeks (drop on by suite 1130 if you're attending).

I haven't spoken with Frank in a few weeks, but typically he leaves early for the Rocky Mountain Audiofest in order to take in some of our beautiful Autumn weather.

I can't make any commitments, but there's an outside shot that I could "encourage" him to pack your repaired arm in his suitcase.

Cheers,
Thom @ Galibier

Hi Raul,

Yes, I was trying to keep my answer general (not specific to the Triplanar) to help expand on the good advice you gave.

With respect to the Triplanar, I have not opened up the junction box that is positioned 2/3 of the length down the tonearm interconnect. This is where the wire separates into left and right channels.

Someone told me that you can pick up the chassis ground from inside this box (to connect to pin-1). Someone else said that only (+) and (-) (pins 2 and 3) are accessible inside this small box.

I'll make a point of checking this in the next few days (swamped at the moment).

Cheers,
Thom @ Galibier

Triplanars come in two basic terminations:

1. Hardwired from cartrdige lead to connectors (either RCA or XLR).

In this configuration about 2.5 feet of cable runs inside a single braided sheath between the tonearm and a small rectangular box. This sheath carries both channels. The other side of the box feeds two braided cables - one for each channel, terminated in either RCA's or XLR's.

The question I was addressing is what's inside of this box - is there access to the tonearm's chassis ground.

As I mentioned earlier, any wire that connects you to the tonearm's metal components will do (for a pin-1 connection), but it's obviously preferable for there to be a cable shield which is tied to the tonearm - to run this to pin-1.

2. Hardwired from cartridge lead to a junction box with female RCA's - requiring an extra set of interconnects to run to your phono stage. This is *not* recommended because (a) you have an extra connection which degrades the sound, and (b) the Discoverey Cable Tri uses is outstanding.

Cheers,
Thom @ Galibier

Hi Cousinbilly, all ...

Well, I just received delivery of my Atma-Sphere MP-1, and made the balanced conversion on my Tri-Planar tonearm yesterday.

I documented the process with photos and procedural hints in this web page in the Tri-Planar section of my website:

http://www.galibierdesign.com/prd_triplanar_xlr_build.html

The photographic quality is only o.k., but it gets the point across.

Note, that since the ground is common to both channels, you need solder pin-1 to the braided shield connection in only one channel.

I opted to solder the pin-1 connections in both channels and risk a ground loop. My reasoning was, that I could recover gracefully by lifting the connection to one of the shield connections inside the black junction box.

Inside the junction box, you'll find three wires soldered together: (a) the black ground wire used for single ended operation (b) and two yellow wires - with one going to the shield of each channel.

Strictly speaking, you don't have to open up the black junction box to do this job. You can clip off the black ground wire flush with the outside of the box and be done with it (or, alternatively leave it hanging free).

I tidied up the installation and made it more reversible by pulling the black ground wire back into the junction box, coiling it up, and tucking it into the box.

As an aside, your MP-1 will sound a bit soft (Ralph calls it "dead") for the first 20 hours, so don't let this alarm you.

I was a bit surprised that any metal film resistor (Caddock upgrade) along with Teflon capacitor (V-cap upgrade) could start out life sounding soft.

Ralph tells me that while many Caddocks have the characteristic "tizzy" signature common to metal films, these particular Caddocks do not.

Enough about the MP-1, this thread is about conversion of the Tri-Planar for balanced operation. Back to our regularly scheduled programming ...

Cheers,
Thom @ Galibier

Hi Tim,

Well, I know where the MP-1 is going to end up - having lived with one for 3 days in my home away from home, at the Rocky Mountain Audiofest in October. The only new component in the system was the Classic Audio T-3 (field coil) speakers.

About 36 hours into the break-in (see below for my accelerated process), my guess would be that you and Ralph are dead-on about the 120 hour number.

Break-in is normally an asymptotic process - with the first quarter or so yielding the vast majority of the change, but with subtle yet significant improvements occurring over the remaining period.

I think it's inappropriate for a manufacturer/dealer to "review" a component that we carry, as our motives should be treated as suspect. You need to be wary of false prophets ... and false profits ;-)

At the same time however, I think it's safe to say that the bulk of manufacturers and dealers inhabiting this forum are motivated by their vision of musical reproduction. While we may occasionally step over the line of propriety, it comes from a passionate desire to spread our individual view of the gospel.

I am comfortable however in talking about the break-in process of the MP-1, and a good deal of this can be generalized about the break-in of other components.

It's important to remember that the system profile of an owner purchasing an MP-1 or other expensive product is that they're likely to have a highly resolving system. They will set the bar quite high for any "stranger" introduced into their system. Because of this, injecting an un-broken in component into their signal chain is likely to result in initial ambivalence - assuming the remainder of their system is reasonably optimized and fully broken in.

On Tuesday night, I began my interconnect re-wiring project - converting a single ended interconnect to an XLR terminated output in order to run my see-dee player through the balanced inputs.

This allowed me to accelerate the burn-in process by employing a burn-in track along with my Hagerman inverse RIAA circuit. This handy device drops the signal by 40dB and puts an inverse RIAA equalization on the signal as well. It allows you to run a CD player signal through your phono stage, and if you like, to listen to tunes.

I ran the burn-in signal through the phono stage as follows:

CD player --> Hagerman Inverse RIAA --> Phono input --> Preamp Main Out --> Power amps

A few explanatory and cautionary notes are in order (Ralph can comment if I've missed anything obvious):

1. The 40dB drop of the Hagerman inverse RIAA is fine for an MM level phono stage. Dropping a 2 Volt CD signal by 40dB will result in a 20mv output feeding the phono stage. This is about 4-5 times the normal MM cartridge output - well within the overload margin of any competently designed MM phono stage. The MP-1's overload spec is 250 mV, BTW so your o.k. running it here as well.

2. With the MP-1's 60dB of phono stage gain, the resulting output would be VERY loud if you were to play this signal through your loudspeakers, so beware.

3. When burning in as above, remove any loading resistors from the phono stage. They might unnecessarily challenge your CD player. It's safest to present a 47K input impedance to your CD player.

4. Be sure that the phono source is selected.

5. The amplifiers do not have to be powered on. They will show their grid resistor load pair (100K) to the preamp output, so current flows through the system without the power amps being powered on.

This first 36 hour period has resulted in substantial changes to / improvements in the MP-1's character. With the Christmas rush and such, I did not take an intermediate checkpoint between the 6 and 36 hour point.

At 36 hours, the top end really began to open up - to the point where (when plugging my analog rig back in), I started to think about loading resistors. For the first 5-6 hours, my XV-1s was running wide open (47K load) and still sounded closed in. Now, we're approaching where they'll end up - needing a load somewhere in the 50-150 ohm range.

Whether it's the V-Caps, the Caddocks, the wire, or everything isn't all that relevant to me, but the character of the break-in reminds me of a cartridge I'd like to have back in my quiver some day - the Ortofon SPU Royal-N.

This cartridge had a break-in process that many do, but to an extreme. It took a while for this cartridge to connect the dots and to speak with a single voice. A point in time arrived (about 24-30 hours in) where the frequency bands no longer seemed disjointed, the cartridge sang with a single voice and the magic flowed.

I've heard the break in process of V-caps described as a cyclical series of improvements and disappointments, before everything gels into a coherent sonic whole. This (connecting the dots) may well be what these individuals are describing.

Well, at 36 hours (last night's checkpoint) the dots are beginning to connect - like hands outstretched which are trying to touch each other. They're not quite there yet, but it's tantalizingly close. I'm noticing a slight suckout in the midrange. The bass is extraordinary - both in power and more importantly in texture - being extremely tactile and "fleshy" which is a direct result of the top end filling in (bass texture comes from extended treble).

I'll report back next week ...

Cheers,
Thom @ Galibier

Hi Tpsonic,

I feel a bit uncomfortable talking about the MP-1 in a "review" context, since I sell Atma-Sphere, but in the next 10-14 days, I'll set up an Atma-Sphere section on my forum and I'll comment about it in detail over there.

I think break-in is a legitimate topic to cover here, and I'd be interested to hear the experiences of owners of the Essential and the Doshi as far as break-in is concerned.

I'm about 450 hours into the process, and I still sense subtle changes having occurred since my last checkpoint.

I'd agree that in some systems, one could be convinced that break-in is complete at about 120 hours. It's at about this point that the MP-1 becomes very enjoyable, but It's very clear to me that it's still changing and improving like a fine wine.

The first 20 hours were shut in and dead sounding as previously reported, and from hours 20 through 100, the MP-1 swung back and forth over the "neutral" line from sounding restrained to slightly agressive.

This "swinging" is not all that unusual a break-in phenomenon.

In the 120 hour range, the MP-1 begins to show its pedigree.

There's a fairly good review of the MP-1 over here:

http://www.soundstage.com/revequip/atmasphere_mp1iii.htm

The reviewer likens the break-in process to one of a flower blooming, but the sad part of it is, that as much as he fell in love with it, he was not experiencing an MP-1 in full bloom if he thought he was done at 120 hours.

200 hours brought further refinement. At that point, I began traveling 4 days/week, so my subsequent timeline has been in in approximately 120 hour chunks as I continued to avail myself of the Hagerman inverse RIAA and a burn-in CD.

With my next "visit" home (the 320 hour point), solidity of presentation, subtlety, and nuance continued to improve, and I was getting more than hints of what this unit is capable of.

In my current "visit" home, I'm at the 450 hour point and I sense some subtle yet significant improvements since last week - all the normal things you'd expect - improvements in delicacy, space presentation, base solidity and harmonic development, etc.

I'm not prepared to say that we're done yet. I'll spend considerable time this weekend bonding with it while I work on some turntable builds. I'm very interested in hearing how it changes over the next 50 hours (continuing to run the Hagerman inverse RIAA through it while not listening).

If I were a betting man, I'd say that as good as it sounds now, we're not quite done yet. I get a sense of an asymptotic process going on here.

As an aside, cartridge loading (XV-1s) is in the 50-70 ohm range. This is within the range I'd expect. While most of my experience with the XV-1s has been in the 100-150 ohm range, this was when employing step-up transformers, so all bets are off. I've heard for example, extremely musical implementations of the XV-1s where it has been loaded as low as 35 ohms.

I'll file an update at the end of the weekend or early next week.

Cheers,
Thom @ Galibier