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Which ZMC with a Sumiko Blue Point MC? (Read 9516 times)
Kirk
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Posts: 29
Which ZMC with a Sumiko Blue Point MC?
12/25/21 at 19:57:21
 
Santa thought I was a good boy this year and gifted me some sweet vinyl.  I think I want to step up my vinyl game with a ZMC.  I am not sure which ZMC I need with a Sumiko Blue Point MC?  Specs below:

High Output Moving Coil
Mass & Dimension
6.3g, 11 x 16.9 x 27.8mm (WxHxD)
Stylus
0.3 x 0.7mil Elliptical
Cantilever
Aluminium Pipe
Coils
High-Purity Copper
Internal Impedance
135Ω
Load Impedance
47kΩ
Frequency Response
15Hz – 35kHz
Output Voltage
2.5mV @ 1kHz
Channel Separation
30dB @ 1kHz
Channel Balance
<1dB @ 1kHz
Compliance
12×10-6cm/dyn @ 100Hz
Capacitance
100pF – 200pF
Vertical Tracking Angle
20°
Tracking Force Range
1.8g – 2.2g
Recommended Tracking Force
2.0g
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SE84UFO2, CSP3, ZP3/ZMC2, Klipsch Jubilees, ZLC, Cambridge Audio CXN V2 (Modwright), Rega Planar 3, Ortofon Quintet Blue MC, GR-Research and Decware cables
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Archie
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Posts: 2731
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #1 - 12/25/21 at 23:43:22
 
For a 2.5mV output cart you don't need a ZMC.  I use the ZMC1 with my 0.4mV MC cart and a ZP3.  You're in a bit of a "no man's" land though since it's on the low side, for the ZP3, anyway.  At that output you might need a pre-amp after the phono stage if you don't already have one.
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
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Edsonic
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Posts: 154
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #2 - 12/27/21 at 00:11:34
 
The cartridge info specifies a 47kΩ load impedance, which indicates that it's meant for going into a MM phono preamp (which are [almost] all 47kΩ input). The ZMC2 @10X / 20dB gain (between TT out and phono pre) would present a load of 470 ohms for the 135 ohms DCR of the Sumiko cart. The ZMC1 input would present 117 ohms. No bueno.

There is no phono pre or preamplifier listed in your sig, so we don't quite have the whole picture, here.

A phono pre with 48dB or higher gain would do, but not many MM pre's do that. In the case of a (more typical) MM phono stage with 38-44dB gain, a head amp might be the way to go. Here's one I've come across that I think would do the job well for reasonable money:

https://hagerman-audio-labs.myshopify.com/collections/phono-preamps/products/pic...

Set the gain to 12 dB and input impedance to 47 kohms. You would then have a plentiful ~ 10mV going into the phono preamp from the Sumiko cart.

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Archie
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Posts: 2731
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #3 - 12/27/21 at 00:42:24
 
That's a cool little device that just boosts the signal?  If it's truly transparent then get one for sure.

What does it mean that its output impedance is 300 Ohm though.  If you use it before the ZP3 doesn't it need to be 47k Ohm?
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
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Kirk
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Posts: 29
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #4 - 12/27/21 at 00:51:15
 
This is all great info.  I am learning.  I've been pretty much exclusively streaming, but would like to hear how far I can take vinyl.  I currently have a Schitt Mani https://www.schiit.com/products/mani sitting between the TT and the UFO2.  My vinyl sounds really good, but I am cursed with a desire to push the envelope.
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SE84UFO2, CSP3, ZP3/ZMC2, Klipsch Jubilees, ZLC, Cambridge Audio CXN V2 (Modwright), Rega Planar 3, Ortofon Quintet Blue MC, GR-Research and Decware cables
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Archie
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Posts: 2731
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #5 - 12/27/21 at 00:55:22
 
I don't see what your amp is but when I first contacted Steve about upgrading my system with a ZP3 he told me that my amp was my weak link and that I should upgrade that first.  Be careful though, I ended up dumping my entire system for what I list in my profile!   Wink
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
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Edsonic
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Posts: 154
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #6 - 12/27/21 at 01:07:18
 
Quote:
That's a cool little device that just boosts the signal?  If it's truly transparent then get one for sure.


Yes, it is intended for use in providing gain for both low output and high output MC carts. This can also be useful for some Grado and Soundsimith and other moving iron carts.

I think it's a great option for those with a LOMC who can't yet afford a good step-up transformer, to tide them over in the meantime.

Hagerman seems to have a pretty good reputation and positive commentary and reviews for their SS and tube phono preamps, all at very reasonable prices.

I would think that this separate unit with its own power supply, etc. would be an improvement over the first gain stage of more than a few MM/MC phono preamps out there.

-- The input of the Piccolo2 can be set for different input impedance, including 47kohms. The 300ohm output of the device is going into the 47kohm input of whichever MM phono stage, making for well over the standard minimum 10:1 ratio of input impedance of load (second device) to output impedance of the source plugged into it. For reference, MM carts have much higher output impedance but are still comfortably within the minimum ratio. (E.g., Ortofon 2M Black- 1.2kohm DCR; AT VM520EB- 800ohm DCR, output impedance @ 1,000 Hz- 2.7kohms).
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Kirk
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Posts: 29
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #7 - 12/27/21 at 02:17:52
 
So you guys think a pre-amp (ala CSP3) would be better suited to sit between the UFO and TT?  No SUT needed?  I would like to get the Schitt Mani out of the signal path to simplify if possible.
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SE84UFO2, CSP3, ZP3/ZMC2, Klipsch Jubilees, ZLC, Cambridge Audio CXN V2 (Modwright), Rega Planar 3, Ortofon Quintet Blue MC, GR-Research and Decware cables
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Edsonic
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Posts: 154
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #8 - 12/27/21 at 03:47:55
 
Your SE84UFO2 and Klipschorn make a great combo, and will make full use of the effort and $ to improve elsewhere.

You can't lose the Mani just yet, since it's your phono preamp (and it does have 47kohm input and a 48dB gain setting). The DW CSP3 is a line stage preamplifier, no phono stage within. You would plug the Mani into the CSP3. As it is, you're using a lot of gain in the 84UFO2 if the Mani is plugged straight into it. Though it might sound counterintuitive at first blush, using the CSP3 for most of the gain after the Mani (and lowering the amplifier volume) might result in lower noise overall. Everyone I've come across in these forums who has run phono pre straight into amplifier reports that the sound is much improved by inserting the CSP3 inbetween phono stage and amplifier.*

As funds allow, you would eventually want a cartridge upgrade (preferably a good low output MC (LOMC), and if sticking with Decware, that into a ZMC2 (10X/20dB) or ZMC1 (20X/26dB) step-up transformer, and that plugged into the  ZP3, -> CSP3 -> 84UFO2.

If I could do only one or two items at a time I would get the CSP3 first, because that plays better with the phono pre and amplifier. The LOMC, SUT, and new phono preamp would all have to come essentially at the same time, so that's a wallop to the wallet to save up for.

OTOH, the Mani can accommodate some LOMC's with its 59dB gain H(igh) setting, but there is only one input impedance for LOMC  @ 47 ohms. LOMC's with DCR higher than 5-6 ohms (of which there are many) might not sound at their best into 47 ohms. But there are a number of good and very good LOMC's w/ DCR at 5 0hms and below.

If the cartridge I wanted fit the latter description, then I would get the CSP3 first (for much improved overall gain structure), then the low DCR LOMC cart, then save up for the ZMC + ZP3 to replace the Mani.

*Except for one person, who's name I can't recall. He doesn't use any preamplifier.
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Archie
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #9 - 12/27/21 at 06:14:07
 
While waiting for my ZMC1 several years ago, I was able to use my 0.34mV MC cart with just the ZP3 and CSP3 by cranking the CSP3 to maximum.  In that case I did amplify noise quite a bit but it shows what a CSP3 can do.  With your 2.5mV cart a CSP3 will boost the signal out of the phono pre up to enough voltage to allow the UFO to play at it's maximum potential.  Without a boost your UFO will be hobbled.  I'm not sure what the math on you combination is but with my cart, a 20X boost from my ZMC1 and the 42dB gain from my ZP3, I'm still only about 1 volt out of the ZP3.  My ZMA needs 2 volts for it to reach full potential volume wise so my CSP3 is still very important.

The CSP3 also adds heft to the sound, especially with gain riding.
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
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Arpin
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Put a great stereo
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Posts: 41
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #10 - 01/03/22 at 08:04:27
 
The Schiit Mani has a 48dB mode that is enabled by setting Gain1 to H and Gain2 to L. Try this first. Should solve your entire problem.

And save for a ZP3 or CSP3. Maybe when Steve builds the ZP3 there could be a way to adjust sensitivity slightly lower?
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Exposure Super XV, Exposure CD (original), Rega Planar 3 (1986 - solid silver rewire), Dynavector DV20XH, Neat Acoustics Mystique II, DIY solid silver interconnects, DIY solid copper speaker wire.

Panasonic multibit, Verum, Etymotic, Elac, Pioneer, Schiit
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FalseMetal666
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Posts: 7
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #11 - 03/03/22 at 19:38:08
 
Related to all this:

Does anyone know the approximate overload margin for the ZP3? I'm starting to experiment with step up transformers, and that info would be great as a baseline.
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Arpin
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Posts: 41
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #12 - 03/03/22 at 19:54:24
 
I second this question about overload. I’ve seen Steve say in other threads that putting on a really high output MM makes it sound good. So maybe something like a Rega Exact with a 6.7mV output was what he had in mind?

But if we’re using a 20:1 step up on say a 0.5mV MC. Then what… that would step up the output to 10mV which is double the 5mV biased ZP3.

Maybe someone has tried overshooting the 5mV bias of the ZP3?
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Exposure Super XV, Exposure CD (original), Rega Planar 3 (1986 - solid silver rewire), Dynavector DV20XH, Neat Acoustics Mystique II, DIY solid silver interconnects, DIY solid copper speaker wire.

Panasonic multibit, Verum, Etymotic, Elac, Pioneer, Schiit
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Archie
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Posts: 2731
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #13 - 03/04/22 at 01:07:36
 
Have you done the math?  By the numbers, my .340mV cart with a 20:1 ZMC only makes about 1 volt out of the ZP3.  I think that's far from an overload.  

I was really surprised how low the output from the ZP3 is with a 5mV cart (I seem to recall about 0.5volts) given Steve's amps generally need 2 volts to get to full power.  I've found a preamp essential with my vinyl setup.

I never tried my MM cart with the ZMC but that'd be an interesting test.
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
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Arpin
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Put a great stereo
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Posts: 41
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #14 - 03/04/22 at 06:06:07
 
Wouldn’t a 0.34mV MC with a 20:1 step up (ZMC1) come out to 6.8mV or am I not understanding the math of a step up transformer. I thought the ratio was a voltage ratio and didn’t have anything to do with decibels.

I’m very surprised at the low output you are reporting. Is the 2V output peak output and not RMS?
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Exposure Super XV, Exposure CD (original), Rega Planar 3 (1986 - solid silver rewire), Dynavector DV20XH, Neat Acoustics Mystique II, DIY solid silver interconnects, DIY solid copper speaker wire.

Panasonic multibit, Verum, Etymotic, Elac, Pioneer, Schiit
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Archie
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Posts: 2731
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #15 - 03/04/22 at 06:17:25
 
It's a logarithmic formula.  I haven't worked with the formula for a while but you can search for it on the Internet.  You can probably find it with some examples.  I'm not 100% sure but I think you can use the 20X step up linearly but the 43 dB gain of the ZP3 is calculated logarithmically.

Try this link:  https://www.theabsolutesound.com/articles/taking-the-guesswork-out-of-phonostage...

So, for my 0.34mV cart you'd multiply by 20 and plug that number into the log formula.
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
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Arpin
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Posts: 41
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #16 - 03/04/22 at 16:59:09
 
Right. I’ve been running those formulas and have been able to calculate Steve’s decibel gains that he has posted as well as Schiit and other manufacturers. So I think I am tracking the math (theoretical physics is my background). But yes, I did assume that the 20:1 was a straight voltage multiplier.

I’m still wondering though why you are only getting 1V out on a 5mV cartridge on the ZP3. Your profile says you are using the ZMC1. And you also mentioned that you haven’t tried a high output MM like the Rega Exact. So I’m wondering if the variable loading on the ZMC1 is causing the low output. The ZMC1 on a 0.34mV should step it up to 6.8mV unless the loading dial is directly controlling that step up. 6.8mV should be enough to drive the ZP3 without a preamp and well over the 2V output.

The reason I’m asking is that I’m trying to determine which way to go with the ZP3. I’ve toyed around with just doing the Rega Exact (6.7mV) vs something from say Dynavector or Vandenhul, where I would need to use a step up. If I do another DV-20x (high output - 2.8mV) then I would need to do a pre-amp. I’m really trying to figure out how to avoid doing a ZMC1 plus a pre-amp. I’d prefer one or the other, or none at all (Rega Exact).
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Exposure Super XV, Exposure CD (original), Rega Planar 3 (1986 - solid silver rewire), Dynavector DV20XH, Neat Acoustics Mystique II, DIY solid silver interconnects, DIY solid copper speaker wire.

Panasonic multibit, Verum, Etymotic, Elac, Pioneer, Schiit
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Archie
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Posts: 2731
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #17 - 03/04/22 at 17:49:42
 
I agree with you to the point that with the ZMC1 I am putting 6.8mV into the ZP3.  But when I run the formula NdB = 20 log V1/V2 I get about 1 volt for V1 (V2 is 0.0068 volts) and about 43dB for NdB (ZP3 gain).  Am I doing something wrong?

According to that formula and using my cart and with the ZMC1 I would need about 49 dB gain from a phono stage to reach a 2 volt output.

One more thing.  My CD player puts out 2 volts and when switching between the CD player and TT I have to turn up my CSP3 to match volume levels.  This tells me that my TT side is putting out less than 2 volts.
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
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Edsonic
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Posts: 154
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #18 - 03/05/22 at 00:26:33
 
The ZP3 product page cites a gain of 42dB, which is ~125x, after 26dB (20x) from the SUT. So; .00034V *20*125=  0.85V. [inverse log (42dB/20) = 126;  log126*20= 42dB] Thanks to Archie (thanks, Archie!) periodically re-publishing Steve's gain chart for the CP3, I can recall that 2V-in maxed to 32V-out, and 1V-in maxed at 10V-out. My guess would be ~ 6-7V max out for .85V-in, which would easily overload the input of any amp I know of. Of course that's w/ CP3 turned all the way up, and the ZMA only needs 2V/ full power, so then plenty of room to back off and play the gain dance w/ ZR2, etc.

The 2V standard for a DAC is @ 0dBFS (full scale), meaning the upper limit, all 1's for all the bits, 'No more rooms at the Inn'. The average level (volts) is something less. That said, in the last 10-15 years or so the studio DSP compressors have become highly sophisticated, so they can cut it really close (much less headroom needed) w/ pop music, R&R, R&B, etc. which have limited dynamic range to begin with. More compression = more loudness, and digital compressors can attain more loudness than the old Fairchild analog compressors.
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Archie
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #19 - 03/05/22 at 00:38:32
 
I do have my CSP3 turned up pretty high (I used Steve's chart to make sure I don't overload the ZR2 @ 15V max) but I also have my ZMA turned way down.  I rarely go past 9 o'clock/

I've mentioned before that when I was waiting for my ZMC1, I was still able to use my MC cart by turning the CSP3 WAY up.  This did amplify noise though so the ZMC1 is the way to go regardless.
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
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NormD
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Posts: 243
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #20 - 03/05/22 at 00:45:10
 
I’m running The Voice cartridge from Soundsmith. It is 2.12mv output. I feed it into a ZP3 into my ZTPre into my ZMA. Plenty of volume.
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OPPO Sonica DAC
Technics SL-1200M3D Turntable
SoundSmith The Voice cartridge
JRMedia Center running on a MacMini
Panasonic DP-UB820
Marantz AV8802a Pre/Rotel RMB-1585 Surround
ZTPre & ZMA Stereo
Focal Sopra No. 2 speakers (91 db)
2 Hsu ULS-ULS-15 MK2 Subs
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Archie
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Posts: 2731
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #21 - 03/05/22 at 00:57:03
 
So long as there is a gain stage involved, the ZP3 output is fine.  Without a gain stage it is marginal into the 2V Decware amps.  IMO
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
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Edsonic
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Posts: 154
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #22 - 03/05/22 at 01:29:38
 
Quote:
I was still able to use my MC cart by turning the CSP3 WAY up.  This did amplify noise though so the ZMC1 is the way to go regardless.


That should give you a hint. I know that many here like to play a higher level with the preamp against reduced input level of the amplifier to get that slight saturation effect, described as more fullness, more density (F&D). But, as you experienced, more gain reveals more noise from the source, and resident noise of the preamp. High gain can uncover noise even from good S/N rated gear.

OTOH, increasing amplifier sensitivity, turning it up, while lowering the preamp gain generally results in better 'pop' and 'snap', better apparent transient response. Since you have the ZR2 to provide some heft (from numerous comments, even that w/o using much bass lift), you might try temporarily reversing your current gain ratio, e.g., amp at ~ 80% and preamp lowered accordingly. Then gradually work it back, until you find that 'best of all worlds' setting, a bit more snappy, and still plenty of sonic gravitas. Better 'hit', possibly. Possibly.
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Edsonic
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #23 - 03/05/22 at 01:42:14
 
Quote:
I feed it into a ZP3 into my ZTPre . . . Plenty of volume.


That explains it. The ZTPRE has a bit more 'oomph' than the CSP3.
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Archie
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #24 - 03/05/22 at 02:26:07
 
Edsonic, I'm not sure I understand your point.  The ZMC is needed when using MC versus MM carts.  My post only pointed out that with the massive gain potential of the CSP3 that I could get usable volume out of my MC cart without the 20X boost of the ZMC1.  This all has nothing to do with the relative lack of gain of the ZP3.  I believe that most "typical" amps require only 1 volt to come to full power.  For most MM carts and those amps, the ZP3 would be close enough.  I don't know if there is a difference between gain potential of the ZTPRE and CSP3 but again, that has nothing to do with what I was trying to convey in my posts.

When I was using my NAD phono stage (less gain than the ZP3) and my NAD amp I never noticed a difference between CDs or LPs.  I think that's solely due to the 1V rating of the NAD amp.
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
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Edsonic
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Posts: 154
Re: Which ZMC with a Sumiko Blue Point MC?
Reply #25 - 03/05/22 at 04:33:49
 
Quote:
Does anyone know the approximate overload margin for the ZP3? I'm starting to experiment with step up transformers, and that info would be great as a baseline.


Hi, Metal. "Sorry you had to wait."

Decware doesn't give the spec for that,  a lot of phono preamps don't. But there are still enough who do, so I poked around a bit. The lowest I saw were an Art Pro w/ 40 mV rms (= 56 mV peak) and an entry level Graham Slee at 41 mV. A soundsmith w/ 53 mV, another unit at 60, an ARC phono at 70, and a number of others at ~80, 90, 100, 120 mV. If not given in rms, I assume peak. (Peak/√2=rms; rms*√2=peak). The lower numbers specified @ 1,000 Hz, the higher numbers did not.

What these numbers mean . . .  The CBS test record (most often used) has bands cut at level of 5 cm/sec peak, @1,000 Hz. This is related to the IEC reference cutting level of 5cm/sec RMS = 0 dB. The actual level of recorded sound will of course vary a lot, and can be much higher. The practical limit at 1 kHz is (supposedly) 35cm/sec. For a common 5 mV output from MM carts at this level,  that leaves a 35/5 ratio of 7x (~ 17 dB) of headroom.

Look at this page; http://pspatialaudio.com/max_velo.htm Scroll down to half page, the chart titled 'What Signals Are On Records?' Informative.

So then about SUT situation.  A .5mV MC cart through a 20x / 26dB SUT will have 10mV output. But when a record is playing and some big surge or blast pushes the cart to 6x the test figure, it's now putting out 3mV, after a 20x SUT, now 60mV.

A number of phono preamps spec higher than that, but still . . . I think the usual MO is to use a 10x SUT for .4 mV and above, 20x for   <.4mV cartridges.

I could have said that at the beginning.
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #26 - 03/05/22 at 04:52:18
 
Archie,  I got your point (mostly). I was just taking a sidetrack re gain staging. Inserting unsolicited advice.

Anyway, I think it's great that people arrange their gear and connections and gain structures in completely different ways and, once settled upon and settled in, everybody's happy as a clam.

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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #27 - 03/05/22 at 06:30:00
 
If I can remember to do it, I'll put my MM cart on my TT with my ZMC1 in front of it.  That should give 80mV into my ZP3.  Unless someone here thinks I could damage something.
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #28 - 03/05/22 at 07:41:58
 
Keep in mind, the cartridges are tested at a fairly low level to measure the output, and in practice can have much higher output. If you read the post above about SUT and look at the 'practical limit' of 35cm/sec, a 5mV cart can music peak to 35 mV (7x above test level). The 4mV cart, now at 80mV from the SUT, gets a loud drum blast and the 4x increase makes it 20 cm/sec, so 16mV into the SUT, and then 320mV into the phono preamp.  

In looking at other phono preamps with max input spec, I haven't seen one higher than 56mV @1kHz, or 120mV for all frequencies (occurring at the moment) together. And if that's near the center it could be 5x or 6x greater cm/sec.

Aside that, the 20x SUT steps down the 47,000 ohms of the ZP3 to present 117 ohms to a cartridge with internal resistance of 1,000 ohms. That's a pretty serious load, don't know if that would melt the coils or not. I don't think the cartridge or the phono pre would be happy about any of this. I don't know enough about electromechanical matters to venture a guess as to the potential physical repercussions.
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #29 - 03/05/22 at 17:59:54
 
You know a lot more than I do about this so I won't proceed.  It's obviously safe to go the other way (TT to MC to ZP3) but I'll take the cautions route and not do any unnecessary experimenting.

Thanks

BTW, I just went to the top of this thread and you had given the relevant info in your first post.  It pays to reread these sometimes.
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Technics 1200G TT w/ Ortofon Jubilee MC cart
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #30 - 03/06/22 at 19:28:27
 
I was able to get pretty close to the same answers as Edsonic. I calculated a 128x voltage increase for the 42dB gain of the ZP3. For a 5mV input on the ZP3 we would see about a 0.64V output. If we consider the peaks involved as Edsonic is explaining, then we should expect that the ZP3 is capable of handling upwards of 7x that 0.64V output, which would be 4.48V.

To calculate the effective resistance that the SUP (ZMC) shows to the cartridge, you square the voltage ratio and divide that into the 47,000 ohm resistance of the ZP3. So the ZMC1 will present a 117.5 Ohm load, the ZMC2 will show a 470 Ohm load, and the ZMC3 will show a 326.4 Ohm load.

So if we look at how a 0.5mV MC cartridge behaves, I think it would make sense to shoot for a ZMC2 or ZMC3 depending on the loading that one needs. My feeling is that Steve has probably overbuilt the ZP3 which means it may be able to handle something wild like using a ZMC1 on a 0.5mV MC, but then one has to start paying very close attention to the recommended loading values for that MC. The variable loading capability of the ZMC will help dial in the exact sound, but I’m not really sure how Steve has designed the loading dial to work. But at least it’s there. And he was careful to list the appropriate MC resistance that best works for a given cartridge internal resistance.

So for a Sumiko Blue Point MC, it seemed to me that the most appropriate match was the ZMC3. Thanks Edsonic for helping to dig into the numbers and providing additional insights into vinyl. Very informative.
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #31 - 03/06/22 at 19:52:09
 
I'm completely confused by your analysis.  I've never worried about impedance so long as my carts were in the range.  This particular statement seems to contradict what the ZMC is for:

Quote:
My feeling is that Steve has probably overbuilt the ZP3 which means it may be able to handle something wild like using a ZMC1 on a 0.5mV MC, but then one has to start paying very close attention to the recommended loading values for that MC.


Did you mean 5mV and not 0.5mV?

Assuming that it's me, would you mind explaining how the impedance works at these various stages?
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Technics 1200G TT w/ Ortofon Jubilee MC cart
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #32 - 03/06/22 at 20:56:27
 
Archie

He said "a 0.5mV MC [cart]" - there are no 5mV MC cartridges (there are plenty of 5mV MM carts). Yes, he meant 0.5mV (test output, not max). And he was implying that a .5mV MC cart going through the 20x ZMC1 and becoming 10mV would be a bit on the high side for a MM phono input, which it is, while also saying that the ZP3 could likely handle it.

Quote:
Sumiko Blue Point MC, it seemed to me that the most appropriate match was the ZMC3


Arpin

The OP showed the specs for his Sumiko in his post. It is the high output version, and the spec sheet says " Load Impedance 47kΩ ".  All high output MC carts I've seen have that load requirement, they are designed to go into a MM input.

The LO version is .5mV and load requirement is " >100Ω ", then a SUT could be used.
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #33 - 03/06/22 at 21:13:15
 
Yes, Edsonic got it right. I was talking about a 0.5mV MC. And yes, I also forgot to look at the original post in the thread before I responded. I saw that the Sumiko Blue Point MC H.O. is 2.5mV output. And it would be hard to see how to use any ZMC to best resolve that particular situation. The ZMC2 has a 10x step up on the voltage and a corresponding 10^2 = 100 dividing on the 47,000 Ohms, bringing it down to 470 Ohms.
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #34 - 03/06/22 at 21:47:47
 
I agree that by the specs of the OP, a ZMC should be unnecessary.
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #35 - 03/06/22 at 23:46:57
 
I'm still hung up on the comment that a ZMC1 would not be the right choice for a 0.5mV MC cart.  Could someone explain this?  I use a 0.35mV MC cart with a ZMC1 which isn't far off.  I'm not following the impedance numbers and how they matter.   Embarrassed   I would hope that Steve would detail limits on the component web pages if this were even close to a problem.

And as I've pointed out several times, despite all of this, I don't see any combination that is getting even 1 volt out of the ZP3.  Did Steve design a phono stage that is really suboptimal for his amps?
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
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ZR2 (25th A Mods)
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #36 - 03/07/22 at 00:30:53
 
I can see why the confusion. I think it's a matter of misapplied caution.

Quote:
So if we look at how a 0.5mV MC cartridge behaves, I think it would make sense to shoot for a ZMC2 or ZMC3 depending on the loading that one needs.


One needs to know both the cartridge DCR and the effective impedance presented by the SUT to determine what will work (or not). So then just considering the standard arbitrary 10:1 minimum ratio of line level bridging, the Jubilee cart has DCR of 5Ω, which will go into the 117Ω input of the ZMC1. Giving an impedance ratio of ~23:1. Not even close to loading down the cartridge, almost arguably too light of a load, but no matter, it's definitely not "out of range", either direction.

A .5 mV cart can have any DCR number from 5Ω to 40Ω or more. There is no standard or average DCR for any given .x mV. That is determined by design choice of how thin the coil wire and how many turns.
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #37 - 03/07/22 at 00:50:34
 
Are you referencing the ZMC1 spec of 3 to 25 ohm and the Jubilee spec of internal impedance of 5 ohm?  Where does the 117 ohm ZMC1 input come from?

I was looking through Ortofon's high end MC specs and I think the highest internal impedance I saw was 7 ohms.

I'm asking all of this for my education.  I'm not planning any changes since I own 3 Jubilees and I just had one retipped with a sapphire cantilever.  The tech, Andy Kim, made that call/upgrade on his own.

Quote:
ZMC1

For low output MC cartridges

1:20 ratio for use with 3~25 ohm cartridges.

ZMC2

For high output MC cartridges

1:10 ratio for use with 3~100 ohm cartridges.

ZMC3

For high impedance MC cartridges

1:12 ratio for use with 25~100 ohm cartridges.
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
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ZP3 (25th A Mods)
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #38 - 03/07/22 at 01:33:48
 
Ah yes, 'more different information', more confusion.

"ZMC1: 1:20 ratio for use with 3~25 ohm cartridges"

What that means is that it will work for cartridges with internal resistance (or  DCR) of 3Ω to 25Ω, as you guessed right. The reason why it will work for cartridges in that range of DCR is because the corresponding impedance ratio  - into the 117Ω input of the SUT would be from 39:1 (117/3) to 4.7:1 (117/25). All 'acceptable' Z (impedance) ratios.

Clear as mud, right? That 4.7 ratio looks a bit low, but it's not. Explanation coming. But in the meantime, the ZMC's all have adjustment to vary the actual presented impedance,and so also the impedance ratio. I don't know for sure which direction the adjustment takes, but it's likely on the increase side (higher input impedance). That 25Ω of a particular cart can have the ~ 4:1 ratio, or you can make it (I'm guessing) 10:1 instead, if that sounds better to you. You won't know the exact input impedance of the ZMC, or the exact ratio vs. the cart, but you'll be setting  "the Goldilocks knob" by best perceived sound quality instead of all these formulas I'm pestering everybody with.

As long as the internal impedance or DCR (whichever the manufacturer calls it) of the cart is within the range stated by a particular ZMC, you can't go wrong. (Almost like it was designed that way!)
.

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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #39 - 03/07/22 at 01:58:15
 
Where does the 117ohm value come from?  I don't see it in the specs.

The ZMC directions have you turn up the knob up until the sound doesn't get any louder.  I set and forget but I suppose someone else may hear a difference in sound and tweak around this same setting.
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
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ZP3 (25th A Mods)
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #40 - 03/07/22 at 02:37:03
 
With out any Z (impedance) adjustment available, just the transformers, the turns ratio amplifies the cart voltage by amount of turns ratio. .For 10:1 (20dB); .5 mV * 10 = 5mV. For  8:1 (18 dB); .5mV * 8 = 4 mV. etc.

What also happens is that the 47kΩ at input of the phono pre gets stepped down, by the square of the turns ratio of the SUT. So for a 12:1 ratio SUT; 47,000/12^2 = 326Ω. That is  the Z the cartridge 'sees'. A cart w/ 30Ω DCR into that 326Ω load is an 11:1 impedance ratio. It complies with 10:1 min. 'rule' for line level Z bridging. For a 20:1 SUT - 47,000/400 = 117Ω. --  117/5Ω (Jubilee) gives an impedance ratio of ~23:1.

But this isn't line level, and the rules are different. I've read a pro reviewer say that as low as 3:1 works, with some cart. More often I've seen 5:1 or 8:1 as lowest ratios that can work. 'Conducers are different.' I know that studios have mics w/ 200 ohm output, and many inboard or outboard mic channels w/ 1200 or 1500 ohm inputs, 6:1, 7.5:1 ratios.

Really low Z ratios drag the cart down a bit. I've heard it too, it starts to sound a bit muddy. Even then not a deal breaker, but . .  Carts are very different, some few actually sound good at a low ratio, and many are claimed to sound best at 100:1 or higher.  With those SUT's having pre-set Z dials, they show the effective Z of the transformer. people find the DCR of the cart and set the 50-, 70, 200 ohms, etc. to get different Z ratios.

I understand all that, but you won't get the 'perfect' ratio except by luck (not that it needs to be perfect). The Z potentiometer on the ZMC makes it a lot easier, I imagine, if for no other reason than it almost prohibits over thinking it.

Like we're doing now.
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #41 - 03/07/22 at 06:20:22
 
Well darn.

My apologies to readers suffering this long already, but . . .

I forgot to address another thing a few posts above, re "considering the behavior of a .5mV cartridge." and what SUT to use. What Arpin was referring to was what might happen if that plugged into a 20:1 SUT. And Archie said he was worried because it was "so close" to his .34 mV cart. So I responded in those terms. Sorry Arpin! What a dufus (me). In the first place- Archie, .0005 and .00034 aren't that close. Think 50 and 34, 500 and 340, etc. 50 is 47% more than 34. Back to the other -

Yes, most people having a .5mV MC cart would do the easy math and see the 5mV (same as a MM) obtainable from a 10:1 ratio SUT right away, so that's that. Purchase. In the scenario of somebody with that same cart buying a a 20:1 SUT (found a cheap used one), -and- has a record wherein lies a spot where a 1,000 Hz groove velocity reaches the absolute practical limit for a record  of 35 cm/sec, which for that cart means 3.5 mV , times 20 = 70 mV going into the phono preamp input. Yowsa.

As presented above somewhere, some phono preamp's limit at 1kHz was 56 mV, but I later found one from ARC and also the Chinook, both which could withstand 240mV @ 1,000 Hz. With that info, I can't imagine the ZP3 input limit being any less than 100 mV, on its worst day. Likely a good bit higher.

With that 20:1 SUT the impedance ratio would be 117 divided by the DCR of that cart.

Sorry Arpin!
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #42 - 03/07/22 at 06:48:33
 
Thanks for all that Ed.  It's mostly way past me and that's why I went with Steve's SUT.  It seemed "idiot proof" with the built in adjustment.  It seems to work for my set up so I really don't need to completely understand the why.  Which is good since I don't!
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
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ZR2 (25th A Mods)
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Re: Which ZMC with a Sumiko Blue Point MC?
Reply #43 - 03/07/22 at 07:07:48
 
No sweat, Archie. It was kind of fun, and it forced me to re-check a few things, since I hadn't delved into that for so long. All good.

You are set for life with that rig, and Ortofon, since they keep throwing all these great deals at you. At every stage in your system you've got a mile of head room, even in the whole analog section. Worry free, the Decware way, right?
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