GE VR II into normal stereo phono preamp

[alexkorf]

GR VR II, in my experience, likes to see 80-100k Ohm input impedance. Stereo phonostage presents 2x47k Ohm in parallel, or 23.5k Ohm.

It looks like a small 3:1 audio transformer does a good job converting one into the other. I used http://www.conrad.at/ce/de/product/516228/

It works quite well in my system. Subjectively there's less "weight" to the bass compared to a mono phonostage with 80k Ohm loading resistor, but the mids and highs seem a bit clearer.

[richard]

What are you using for needles, Alexey?

[alexkorf]

Pfanstiehl 503-D7. Got a lot of them cheaply and 4th or 5th needle worked quite well. I also have a NOS GE sapphire needle but I just use it as a reference for correct VTA.

[richard]

Aha!

Now, I'm more curious.
So, your Pfanstiehl needles are the .7 mil stereo size, which can be practical for this cartridge (not so practical for the RPX).

Your Pfanstiehl packages should show the city where the needles were made. A few years ago, Pfanstiehl Chemical Co., sold their phono needle business. So, I'm curious about which incarnation of the company made your needles (the buyer is LGK). You may even find an identifying mark that signifies that the needle was actually made by someone else. Brian Clark sent me four LGK-made VR-II needles. Two of these should have never left the factory. I haven't taken a close look at the other two.

I think that we can safely assume that when a stylus is identified as having a .7 mil tip, that it's the size that is claimed. It's when the manufacturer/packager states that it's a 1.0 mil ("genuine mono") size that the needle may be, in fact, a .7 (which was cheaper tip to obtain late in the game). Even GE themselves was selling, exclusively, .7 mil needles for both the RPX and the VR-II. Concentrating the standard pressure of the RPX onto such a small diamond is no kindness to the customer.

[alexkorf]

Richard,

It's an LKG .7 mil stylus. I have 8 or 9, and if I had paid the current ebay going rate for them -- $15 or so plus shipping -- I would have been mightily upset. Only 2 of them are any good, and then the VTA is wrong. If I had no 1 mil sapphire GE stylus as a reference I would have never guessed what they should look like.

I would love to have a 1 mil diamond stylus, but it looks like the post lost it, together with a NOS red GE VR II... It's a pity cause I have a Gray 602C (never used) that I'm aching to try out with a Telefunken or LAWO mic preamp.

[richard]

Alexey,

You've got my attention with your transformer approach. What got you thinking in that direction?

There is something very appealing to me about the variable reluctance principle and its directness and transparency of dynamic response. This characteristic had to be somewhat "reined-in" by the manufacturers for practical reasons.

One curiosity that's had me stumped is hum pickup. My GE cartridges hum into two different stereo preamps. A third preamp, however, gives a much better hum level. I've tried everything my brain can come up with, and have not been able to obtain any improvement. The hum level is "acceptable," but I'm aware that "artifacts" from the hum are mixing into the music (beat frequency effects, etc.). The hum pickup is similar to what I've experienced with the typical Grado stereo cartridge. In other words, radiation from the motor. Yet, the third preamp produces a much more civilized result. These are all transistor products.

I'm wondering about possible deterioration of the Mu-Metal shield. A little research and thought reveals that hum rejection was a problem with these cartridges, and this was acknowledged by GE indirectly: they provided improved shielding for the VR-II vs the RPX, carried the VR-II's shielding concept into their first stereo pickup, and then added a third shield layer for the revision of the stereo design: something was up!

Your thoughts?

[alexkorf]

Richard,

I started toying with GE VR II cartridges quite recently and I think that they are extremely sensitive to load impedance and capacitance. I only have 1 phonostage that I use with all my pickups through a combined switch/MC transformer, so changing load resistor wasn't an option. That leaves a very crude approach of a resistor in series with the pickup, or a transformer. Don't know why but I always think of transformers when faced with impedance matching problems

I had some hum problems too. I removed the metal bit that shorts one of signal clips, the shield and the tonearm, and connected the tonearm ground wire to the phonostage. No more hum! That was really nothing considering everything I tried 10+ years ago trying to stop a Grado from humming (unsuccessfully).

Now that you've got me thinking, it does sound like VR II hums much less into a transformer, compared to a plain resistive load...

[richard]

Alexey wrote,

Don't know why but I always think of transformers when faced with impedance matching problems

Alexey, are you a professional audio person? Transformers are standard in professional, no-bs audio.

I had some hum problems too. I removed the metal bit that shorts one of signal clips, the shield and the tonearm, and connected the tonearm ground wire to the phonostage. No more hum!

I'm very interested in what you just wrote, but I'm not quite following the English. I always connect the arm ground directly to the preamp, and my integral cartridge shields are usually connected to one signal pin, as intended by the manufacturers. My cartridges are usually isolated from the arm by plastic to eliminate ground loops. Are you suggesting that I break the connection of the GE's shield ground from the signal pin and, instead, connect the cartridge shield directly to the arm ground?

Kent: are you listening to this?
Can you dig deeply into your own station engineering notes by your predecessors for any installation/termination stats from actual broadcast practice with these cartridges? Note that we're talking about the ordinary GE pickups here, and not the "professional-inpedance" versions.

Aside:
When Eddie Ciletti did his VR-II test (around 10 years ago, I think), he got a pretty poor response graph. I'm almost certain that Ciletti was not just messing around: he used a "horse's mouth" true industry-standard professional test record. But the cartridge could not have routinely been that bad. I know "the sound," having spent my teenage years with an RPX. Therefore, I have to focus on two other variables as culprits:
- Cartridge loading issues
- Bad stylus

I think that we can nail down the termination issue, especially by going back in time to professional practice. And the needle issue hasn't been widely reported, but I've seen enough asides about this to be certain that bad needles deliver response that's considerably off-spec.

[alexkorf]

I'm very interested in what you just wrote, but I'm not quite following the English. I always connect the arm ground directly to the preamp, and my integral cartridge shields are usually connected to one signal pin, as intended by the manufacturers. My cartridges are usually isolated from the arm by plastic to eliminate ground loops. Are you suggesting that I break the connection of the GE's shield ground from the signal pin and, instead, connect the cartridge shield directly to the arm ground?

I'm very sorry: English is not my first language, I'm 5 years out of practice AND down with a bad cold now

Think we are talking about the same thing. I just removed the stamped metal bit that connects the shield and one of the pins. The cartridge is not isolated from the arm in my installation.

And yes, I moonlighted as a PA technician way back in high school. It was always much easier to just stick a transformer in the signal path instead of trying to figure out why there's a 120V difference between two signal grounds

[richard]

I'm very sorry: English is not my first language, I'm 5 years out of practice AND down with a bad cold now sad

I envy you; your English is much better than my German!

OK, so you're grounding the cartridge shields to the arm, which is grounded to the preamp chassis?
This usually doesn't make a difference to me, but I'm willing to try anything. Most of my cartridges are Stantons, and they're excellent at hum rejection.