Volume Cut for Mono Carts

the thin end of the wedge
dog-dog-dog
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Volume Cut for Mono Carts

Post by dog-dog-dog » 18 Nov 2019 16:13

I spent some weeks modding a GE VRII to fit onto my Garrard AT60, and it sounds wonderful! The only issue is that some of the '50s and '60s mono releases I've been enjoying are so loud, they start to clip even at -10db on my pre-amp.

My setup is enclosed in the top of a gutted Sylvania 4/20 that I've loaded the top to the brim with small modern amps (ART DJ II pre-amp, a Kinter bluetooth to run auxillary digital through, and an Amphony 200 for the final output). I put a small, cheap, volume-cut for sub-woofers in, but I get an unwanted hum that will not go away, even with the buzz-kill box that I installed at the end of the system. Grounding the volume control at the beginning (beore the ART DJ II) seems to do nothing to eliminate the hum. There is no direct spot to put the ground on this little box.

I'm looking a pre-amp under 100 dollars that maintains excellent fidelity at the beginning of the system, is small, and which has a ground.

nat
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Re: Volume Cut for Mono Carts

Post by nat » 18 Nov 2019 23:59

Your system is so idiosyncratic that it is difficult to hypothesize a reason for the hum. You may be on your own here, simply because not many (if any) people have any relevant experience.

dog-dog-dog
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Re: Volume Cut for Mono Carts

Post by dog-dog-dog » 19 Nov 2019 17:06

The hum comes directly from the first, cheap, passive pre-amp. It may straighten out if I put it in the middle of the chain, as I cannot ground it. Removing it immediately removes the hum in the left stereo channel.

Coffee Phil
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Re: Volume Cut for Mono Carts

Post by Coffee Phil » 19 Nov 2019 18:18

Hi dog-dog-dog,

You have two questions here. First the whopping output level from the GE VR cartridge and then the discription of your set-up and how it is causing hum.

I am having trouble getting my head around your system setup but I can comment on the GE VR cartridge.

I have an RPX triple play (older than the VRII). I have it mounted in a knock-off SME headshell and it's output connected to both channels in parallel. From either my stereo stage or my dedicated mono stage the cartridge "sees" a load of ~25 k Ohm. It sounds good to me but it is loud. So far distortion has not been an issue so I just turn the volume down. I'm guessing that the load is not optimum but since the sound to me is quite similar to my Sonus Blue (same designer) I call it good.

Here is a link to literature for the VRII. https://www.vinylengine.com/library/gen ... r-ii.shtml

Sadly they don't explicitly state a recommended load impedance. I get the idea 100 k Ohm is recommended but they also mention one of their phono stages which has ~6.2 k Ohm resistance. I have not seen the schematic of that stage but I get the idea that they are using the 6.2 k load and the inductance of the cartridge as part of the EQ. If you want to be total purest about this you might research the stages which they are recommending and emulate one of them.

Alternatively if you connect your cartridge two each channel of your favorite mm stereo stage with 47 k-Ohm resistors. This will attenuate ~6dB and should give good results. Keep the cable length after the junction short as the impedance is high and cable capacitance will attenuate the highs.

Phil

dog-dog-dog wrote:
18 Nov 2019 16:13
I spent some weeks modding a GE VRII to fit onto my Garrard AT60, and it sounds wonderful! The only issue is that some of the '50s and '60s mono releases I've been enjoying are so loud, they start to clip even at -10db on my pre-amp.

My setup is enclosed in the top of a gutted Sylvania 4/20 that I've loaded the top to the brim with small modern amps (ART DJ II pre-amp, a Kinter bluetooth to run auxillary digital through, and an Amphony 200 for the final output). I put a small, cheap, volume-cut for sub-woofers in, but I get an unwanted hum that will not go away, even with the buzz-kill box that I installed at the end of the system. Grounding the volume control at the beginning (beore the ART DJ II) seems to do nothing to eliminate the hum. There is no direct spot to put the ground on this little box.

I'm looking a pre-amp under 100 dollars that maintains excellent fidelity at the beginning of the system, is small, and which has a ground.

circularvibes
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Re: Volume Cut for Mono Carts

Post by circularvibes » 19 Nov 2019 18:44

You may also be getting more volume and distortion if the stylus is not centered. If it gets too close to one of the poles it will go bonkers. It has much more output than most magnetic carts but should play nicely with cutting the volume. I had this issue when I brought home a Glaser-Steers changer with a VR-II. The 78 tip was crashing into the pole from mishandling.

KentT
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Re: Volume Cut for Mono Carts

Post by KentT » 20 Nov 2019 15:52

The GE VR II and RPX are severely high output cartridges (12 mv or so). Your phono stage is likely being overloaded.

Coffee Phil
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Re: Volume Cut for Mono Carts

Post by Coffee Phil » 20 Nov 2019 18:17

+1 to this! I have to admit to not thinking of it.

First look to see that the stylus is centered and the damping block is in good shape.

If all looks well, don't overlook what Kent T is saying. At present both my stereo and mono phono stages are solid state op-amp designs with decently high supply rails (~ +/- 15 V for the stereo & ~ +/- 8 V for the mono) and they deal with my RPX fine, but I can conceive of some solid state phono stages saying ouch with the mono GE VR cartridges.

Phil
circularvibes wrote:
19 Nov 2019 18:44
You may also be getting more volume and distortion if the stylus is not centered. If it gets too close to one of the poles it will go bonkers. It has much more output than most magnetic carts but should play nicely with cutting the volume. I had this issue when I brought home a Glaser-Steers changer with a VR-II. The 78 tip was crashing into the pole from mishandling.

JoeE SP9
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Re: Volume Cut for Mono Carts

Post by JoeE SP9 » 20 Nov 2019 19:40

Ceramic cartridges generally do not need a phono stage or RIAA equalization. They work best into an input designed for them.

circularvibes
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Re: Volume Cut for Mono Carts

Post by circularvibes » 20 Nov 2019 20:42

JoeE SP9 wrote:
20 Nov 2019 19:40
Ceramic cartridges generally do not need a phono stage or RIAA equalization. They work best into an input designed for them.
I think you may have confused "high output" with "ceramic". We are discussing variable reluctance cartridges here.

JoeE SP9
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Re: Volume Cut for Mono Carts

Post by JoeE SP9 » 20 Nov 2019 21:00

All I can say about VR cartridges is "why bother?". Are they worth the effort? There is a very good reason no one makes them any more.

I feel the same about ceramic cartridges.

circularvibes
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Re: Volume Cut for Mono Carts

Post by circularvibes » 20 Nov 2019 23:29

JoeE SP9 wrote:
20 Nov 2019 21:00
All I can say about VR cartridges is "why bother?". Are they worth the effort? There is a very good reason no one makes them any more.
Some Japanese audiophiles would take exception to your comments. Variable reluctance mono cartidges command prices well above US$300. I enjoy the sound of them for pre-1965 mono records that don't play nice with modern cartridges due to wear, abuse and crappy vinyl. They were used in broadcast so they can't be too bad. In fact, a Japanese company, NEAT, made copies of VRII and RPX carts and those also command high prices. They may not be on par with today's moving coil carts, but most of us can't afford that luxury or the snobbery the hobby can bring with it. No one makes a triple play cartridge today for magnetic inputs but it would be useful to some of us. No setting up separate microgroove and coarse groove carts or styli and less chance of oopses happening with styli change.

JoeE SP9
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Re: Volume Cut for Mono Carts

Post by JoeE SP9 » 21 Nov 2019 15:03

circularvibes wrote:
20 Nov 2019 23:29
JoeE SP9 wrote:
20 Nov 2019 21:00
All I can say about VR cartridges is "why bother?". Are they worth the effort? There is a very good reason no one makes them any more.
Some Japanese audiophiles would take exception to your comments. Variable reluctance mono cartidges command prices well above US$300. I enjoy the sound of them for pre-1965 mono records that don't play nice with modern cartridges due to wear, abuse and crappy vinyl. They were used in broadcast so they can't be too bad. In fact, a Japanese company, NEAT, made copies of VRII and RPX carts and those also command high prices. They may not be on par with today's moving coil carts, but most of us can't afford that luxury or the snobbery the hobby can bring with it. No one makes a triple play cartridge today for magnetic inputs but it would be useful to some of us. No setting up separate microgroove and coarse groove carts or styli and less chance of oopses happening with styli change.
A "triple play" cartridge makes no sense. You do realize 78's and many mono LP's were cut using vertical modulation. Stereo cartridges are totally unsuited for this.

I place a lot of Japanese audiophiles in the camp that buys speaker cables that cost more than a good power amplifier. That's not a compliment.

Were I into playing 78RPM recordings I'd get a Grado mono cartridge with a stylus for 78's. I'd also get one of KAB Electro Acoustics phono preamps. They have multiple Eq settings to accommodate the various Eq curves used before the RIAA standard. It goes without saying I'd also have a TT with variable speeds (71RPM-91RPM) strictly for playing 78's.

I don't understand how using the best cartridge one can afford has anything to do with "snobbery". Even so, there are plenty of very good sounding reasonably priced MM cartridges. Many of the bargain priced AT MM's sound very good regardless of cost.

Yes, I use a $1K+ MC cartridge. So what? It had/has nothing to do with snobbery. It sounds better than anything else I could afford. Why does someone spending more than you or others think is appropriate always called snobbery? It sounds more like jealousy than snobbery.

FWIW: I'm retired and living on a very modest disability pension. I do what many people still do. I save for a couple of months to buy what I want.

Coffee Phil
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Re: Volume Cut for Mono Carts

Post by Coffee Phil » 21 Nov 2019 19:10

Hi JoeE SP9,

I will overlook your dissing VR cartridges even though there are many of us here who own and like them however I do have to call you on spreading misinformation.

You stated that a “triple play cartridge” makes no sense. Triple play means that it will play standard groove 78 records, microgroove Lps, and microgroove 45. To my knowledge there are no contemporary cartridges which do this without changing the stylus assembly. As I own records of all of those formats I see the “sense” in that feature.

You also stated that 78s and many mono Lps were cut using vertical modulation. What we think of as 78s were cut with lateral modulation. Lps as introduced by Columbia in the mid ‘40s were also cut with lateral modulation. Edison Diamond discs were cut with vertical modulation. During the 1920s Edison introduced a Long Playing version of the Diamond disc with a smaller stylus and finer groove pitch however they were not successful and therefore were not made for more than a very short time.

You also stated that stereo cartridges are not suitable for playing vertical cut records. Actually the fact is that ONLY stereo cartridges will play BOTH vertical AND lateral cut records. A “true” mono cartridge needs to be designed for vertical records OR lateral records.

For most of my record playing I use stereo cartridges with a stylus suitable to the record being played. For mono records I sum the channels either in phase for lateral records or out of phase for vertical records.

For LATERAL cut mono records (Lp or 78) I sometimes use my triple play GE RPX, as there is something about the way it sounds which I like.

Phil

JoeE SP9 wrote:
21 Nov 2019 15:03
wrote:
20 Nov 2019 23:29
JoeE SP9 wrote:
20 Nov 2019 21:00
All I can say about VR cartridges is "why bother?". Are they worth the effort? There is a very good reason no one makes them any more.
Some Japanese audiophiles would take exception to your comments. Variable reluctance mono cartidges command prices well above US$300. I enjoy the sound of them for pre-1965 mono records that don't play nice with modern cartridges due to wear, abuse and crappy vinyl. They were used in broadcast so they can't be too bad. In fact, a Japanese company, NEAT, made copies of VRII and RPX carts and those also command high prices. They may not be on par with today's moving coil carts, but most of us can't afford that luxury or the snobbery the hobby can bring with it. No one makes a triple play cartridge today for magnetic inputs but it would be useful to some of us. No setting up separate microgroove and coarse groove carts or styli and less chance of oopses happening with styli change.
A "triple play" cartridge makes no sense. You do realize 78's and many mono LP's were cut using vertical modulation. Stereo cartridges are totally unsuited for this.

I place a lot of Japanese audiophiles in the camp that buys speaker cables that cost more than a good power amplifier. That's not a compliment.

Were I into playing 78RPM recordings I'd get a Grado mono cartridge with a stylus for 78's. I'd also get one of KAB Electro Acoustics phono preamps. They have multiple Eq settings to accommodate the various Eq curves used before the RIAA standard. It goes without saying I'd also have a TT with variable speeds (71RPM-91RPM) strictly for playing 78's.

I don't understand how using the best cartridge one can afford has anything to do with "snobbery". Even so, there are plenty of very good sounding reasonably priced MM cartridges. Many of the bargain priced AT MM's sound very good regardless of cost.

Yes, I use a $1K+ MC cartridge. So what? It had/has nothing to do with snobbery. It sounds better than anything else I could afford. Why does someone spending more than you or others think is appropriate always called snobbery? It sounds more like jealousy than snobbery.

FWIW: I'm retired and living on a very modest disability pension. I do what many people still do. I save for a couple of months to buy what I want.

circularvibes
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Re: Volume Cut for Mono Carts

Post by circularvibes » 21 Nov 2019 19:46

Coffee Phil, I would like to add one piece of info here and have no issue if I am proven wrong. I do believe RCA and Western Electric (possibly a couple more) made transcription cartridges for broadcast that could play lateral and vertical transcriptions by means of a switch on turntable or preamp. I have to assume they are moving coil carts with two windings. I think these carts also might have been the basis of the original and failed attempt at putting 2 channels into one groove in the 1930's by Bell Labs (methinks). The original 2 channel groove was not the 45/45 Wetstrex method but a combination of lateral and vertical modulations. This was long before the twin groove records as well.

Coffee Phil
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Re: Volume Cut for Mono Carts

Post by Coffee Phil » 21 Nov 2019 20:53

Hi circularvibes,

I do believe that what you say is true. I also recall reading of two channel binaural experiments which Bell labs were doing in the thirties. I’m not sure that the failure of this to come to market was technical. This was in the middle of the depression and I’m not sure the demand was there.

I don’t know if the thirties “stereo” was 45/45 degrees as now or one channel vertical and the other lateral. Going from one to the other is vector math. I believe the 45/45 approach was chosen for compatibility between lateral mono and stereo Lps. In fact I believe that the Decca cartridges which many love have vertical and lateral coils and the 45/45 stereo signal is derived via matrixing networks. I am no Decca expert but hopefully a Decca guru will chime in here and clarify this.

Phil
circularvibes wrote:
21 Nov 2019 19:46
Coffee Phil, I would like to add one piece of info here and have no issue if I am proven wrong. I do believe RCA and Western Electric (possibly a couple more) made transcription cartridges for broadcast that could play lateral and vertical transcriptions by means of a switch on turntable or preamp. I have to assume they are moving coil carts with two windings. I think these carts also might have been the basis of the original and failed attempt at putting 2 channels into one groove in the 1930's by Bell Labs (methinks). The original 2 channel groove was not the 45/45 Wetstrex method but a combination of lateral and vertical modulations. This was long before the twin groove records as well.

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