I just got a MC for my TT and now need a SUT. How do I design the one that will fit my system best? My phono pre is a DIY Hagerman octal Coronet with 43db gain and the new cart is the Denon DL-110.
Have you hooked everything up and there just isn't enough gain? I haven't actually come across anyone using a SUT with a DL-110. A step-up ratio of 1:5 would be all you'd need.
jeff
jeff
Yes, you'd typically need a SUT with a low output MC, but a Denon DL-110 is a high output MC, with the same loading as a MM cartridge (47k ohms).
Why not just try it as is?
jeff
Why not just try it as is?
jeff
Hi,
DL110 output is only 1.6mV. With a 43dB phono, the output coming out of the phono preamp will be 226 mV. May not be enough (a typical CD player is 2 V)!
At 1:5 (14dB) SUT transformer, the total output will be 1.13 V. At 1:10 (20dB) SUT, the output will be 2.26 volts (close to a CD player output).
I believe that if you are looking for an SUT, I will shoot for a 1:10 (for 2.26 V output) or a 1:8 (for a 1.79 V output).
A Cinemag CMQEE-3440 has a 1:10 setting (as well as 1:20) and the price is right.
DL110 output is only 1.6mV. With a 43dB phono, the output coming out of the phono preamp will be 226 mV. May not be enough (a typical CD player is 2 V)!
At 1:5 (14dB) SUT transformer, the total output will be 1.13 V. At 1:10 (20dB) SUT, the output will be 2.26 volts (close to a CD player output).
I believe that if you are looking for an SUT, I will shoot for a 1:10 (for 2.26 V output) or a 1:8 (for a 1.79 V output).
A Cinemag CMQEE-3440 has a 1:10 setting (as well as 1:20) and the price is right.
It's not rocket science 😉
First you determine the gain that is available in SUT and the gain you need.
In case of the AT-33, output is 0,3mV
So with a gain of x16 (1:16 or 24dB) you get 4,8mV. Which should be acceptable for most MM inputs...
Next, you have to see if the loading is in the right ballpark.
Output impedance of the AT-33PTG/II is 10 Ohm.
Acceptable loading would be 10 times higher, so at least 100 Ohm.
(some cartridge manufacturers will state 5 times to be enough)
Now with a little help from one of the fine VE calculators:
https://www.vinylengine.com/cartridge_d ... pUpLoading
You now know that a 1:16 SUT loaded with 47k will present the cartridge with 184 Ohm.
If you want to experiment a bit, you can add a resistor in parallel of the input of the SUT to vary the loading.
You could do that after the SUT, but I don't recommend that, not all transformers respond well to other than 47k loading.
First you determine the gain that is available in SUT and the gain you need.
In case of the AT-33, output is 0,3mV
So with a gain of x16 (1:16 or 24dB) you get 4,8mV. Which should be acceptable for most MM inputs...
Next, you have to see if the loading is in the right ballpark.
Output impedance of the AT-33PTG/II is 10 Ohm.
Acceptable loading would be 10 times higher, so at least 100 Ohm.
(some cartridge manufacturers will state 5 times to be enough)
Now with a little help from one of the fine VE calculators:
https://www.vinylengine.com/cartridge_d ... pUpLoading
You now know that a 1:16 SUT loaded with 47k will present the cartridge with 184 Ohm.
If you want to experiment a bit, you can add a resistor in parallel of the input of the SUT to vary the loading.
You could do that after the SUT, but I don't recommend that, not all transformers respond well to other than 47k loading.
Some time ago a friend of mine gave me these two SUTs. Now that I am moved and setting up my TT I'll give them a try but I can't find anything about them on the net.
I also think the current MM cart and my Phonepre have low output. I have to turn the volume up two or three notches when I switch from CD to TT.
I also think the current MM cart and my Phonepre have low output. I have to turn the volume up two or three notches when I switch from CD to TT.
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Thanks Jeff.
I can't sell off the Coronet as it was my first audio build besides speakers. I might try to figure out how to increase the gain on the Coronet though.
Wow an amazing version of the Cornet. Not only octal based, but point to point wired. A labour of love.
Please do not use 10:1 step up ratio with your Denon 110. That would be stupid. A cartridge with 1.6mV output at 3.45, or 5 cm/sec (toss a coin which different manufacturers use), will produce over 7mV on common music peak recorded levels of 20 cm/sec. 70mV, after a 1:10 sut, would not be pleasant for any phono stage.
Tell us what your preamp is and we can give some advice about best way forward, noting that what Jeff said is correct. What you have described is probably in the order of 6dB difference in level, not the 20dB that a 1:10 sut would provide.
Brilliant Cornet build.
Cheers
Grant
Please do not use 10:1 step up ratio with your Denon 110. That would be stupid. A cartridge with 1.6mV output at 3.45, or 5 cm/sec (toss a coin which different manufacturers use), will produce over 7mV on common music peak recorded levels of 20 cm/sec. 70mV, after a 1:10 sut, would not be pleasant for any phono stage.
Tell us what your preamp is and we can give some advice about best way forward, noting that what Jeff said is correct. What you have described is probably in the order of 6dB difference in level, not the 20dB that a 1:10 sut would provide.
Brilliant Cornet build.
Cheers
Grant
Hi
Figured these 2 bits of info would explain what I have said better:
CD:
"The standard CD-player output voltage is 2V RMS, with units varying between 1.74V on the low side (the Audio Research DAC1) and a whopping 7.2V on the high side (the Theta DS Pro Basic). Most CD players and processors put out between 2.2V and 3.5V. Note that this value is the highest RMS output voltage possible from the player—there's no digital signal greater in amplitude than 0dBFS (see the "Decibels" sidebar)."
LP:
"07-27-2003 6:23pm
Ok, I found this in a book I bought a few years ago called "The LP is Back!" It contains a reprint of an article from Stereophile vol. 1 no. 8 by J. Gordon Holt.
It says that the maximum recording level is a peak recorded velocity of about 20 cm/sec. At this level it has reached the velocity at which the sylus travels through the inner grooves, where this linear motion is the slowest. Beyond this the groove swings become so sharp that the stylus tends to ride over them rather following them.
The inner grooves are about 40 cm in circumfrence, times 33 1/3 rpm divided by 60 seconds is about 20 cm/sec.
If a cartridge puts out 1 mV at 5 cm/sec then it follows that it probably puts out 4 mV at 20cm/sec. I say probably because I don't know if this is a linear relationship, but I assume that it is.
Now I'm going out on a limb as I haven't found anything to back me up on this. If I also assume that that the record cutter is going to cut it at a maximum level that will leave some headroom, say at 3/4 of maximum, then at 15 cm/sec I should get somewhere around 3 mV during loud passages. I'm going with that until I hear from somebody other than me who actually knows what's going on.
BTW the book was put out in 1999 by Audio Amateur/ Old Colony Sound Lab and has a bunch of good stuff in it."
Quote marks because I stole them off the interweb.
Cheers
Grant
Figured these 2 bits of info would explain what I have said better:
CD:
"The standard CD-player output voltage is 2V RMS, with units varying between 1.74V on the low side (the Audio Research DAC1) and a whopping 7.2V on the high side (the Theta DS Pro Basic). Most CD players and processors put out between 2.2V and 3.5V. Note that this value is the highest RMS output voltage possible from the player—there's no digital signal greater in amplitude than 0dBFS (see the "Decibels" sidebar)."
LP:
"07-27-2003 6:23pm
Ok, I found this in a book I bought a few years ago called "The LP is Back!" It contains a reprint of an article from Stereophile vol. 1 no. 8 by J. Gordon Holt.
It says that the maximum recording level is a peak recorded velocity of about 20 cm/sec. At this level it has reached the velocity at which the sylus travels through the inner grooves, where this linear motion is the slowest. Beyond this the groove swings become so sharp that the stylus tends to ride over them rather following them.
The inner grooves are about 40 cm in circumfrence, times 33 1/3 rpm divided by 60 seconds is about 20 cm/sec.
If a cartridge puts out 1 mV at 5 cm/sec then it follows that it probably puts out 4 mV at 20cm/sec. I say probably because I don't know if this is a linear relationship, but I assume that it is.
Now I'm going out on a limb as I haven't found anything to back me up on this. If I also assume that that the record cutter is going to cut it at a maximum level that will leave some headroom, say at 3/4 of maximum, then at 15 cm/sec I should get somewhere around 3 mV during loud passages. I'm going with that until I hear from somebody other than me who actually knows what's going on.
BTW the book was put out in 1999 by Audio Amateur/ Old Colony Sound Lab and has a bunch of good stuff in it."
Quote marks because I stole them off the interweb.
Cheers
Grant
A CD is "cut" at Maximum level because, why not?
An LP is almost never cut at maximum level because the grooves would collide; or the TPI set so low you'd only get 10 minutes per side.
FWIW: get one of the Disco DJ market 12" Singles. I have a cut of "Oh What A Night" which is easily twice as loud as any other disk in the house. At <7 minutes per side it is not a Good Buy. But it sure kicks butt.
An LP is almost never cut at maximum level because the grooves would collide; or the TPI set so low you'd only get 10 minutes per side.
FWIW: get one of the Disco DJ market 12" Singles. I have a cut of "Oh What A Night" which is easily twice as loud as any other disk in the house. At <7 minutes per side it is not a Good Buy. But it sure kicks butt.
Why not? Because Redbook was specified never, ever to touch the maximum recording level, back when the brick wall digital filters would ring if you did. So the idea was to record the peaks at -6db, knowing that there would still be 90db of dynamic range available, which isn’t possible to use anyway because no recording venue has 0db backgrounds and all microphones have some self noise, very good ones having 15-20db.
Anyway, if you were supposed to record with peaks at -6dbfs, you’d need to have a strong output stage to not clip if it were full scale, and since other sources of the day put out 500mV or so, 2V max output would give 500mV at specified recoding levels, being the equal of everything else.
/diversion
To the original question, as already mentioned, a DL-110 won’t need a SUT, and if you did, It would be something very small like 1:5.
I’m on my 2nd DL-110, I wore out the first, used it with normal-gain preamps and loved every minute.
Anyway, if you were supposed to record with peaks at -6dbfs, you’d need to have a strong output stage to not clip if it were full scale, and since other sources of the day put out 500mV or so, 2V max output would give 500mV at specified recoding levels, being the equal of everything else.
/diversion
To the original question, as already mentioned, a DL-110 won’t need a SUT, and if you did, It would be something very small like 1:5.
I’m on my 2nd DL-110, I wore out the first, used it with normal-gain preamps and loved every minute.
Yes, 1:5. I realize what I have done in my calculation...cart -> SUT -> phono preamp, not cart phono preamp then SUT 🙂.
..... for a total of 8 mV to the input of the 43 dB phono!
I also own a Cornet (II) and use 1:10 for 0.8 mV Cart (Benz Ace).
I also own a Cornet (II) and use 1:10 for 0.8 mV Cart (Benz Ace).
Interesting specs for the DL110:
Denon DL-110 Phono Cartridge Specifications
- Type: Moving coil
- Output voltage: 1.6mV
- Frequency response: 20Hz-45kHz
- Recommended load impedance: over 47k ohms
- Channel balance @ 1kHz: Within 1db
- Channel separation @ 1kHz: > 25dB
- Stylus tip: Special elliptical solid diamond with 0.1 x 0.2 mm rectangular cross section
- Compliance: 8 x 10-6 cm/dyne
- Recommended tracking force: 1.8mN +/- 3mN (1.8g +/- 0.3g)
- Color: Red
- Weight: 4.8 g
I myself would pad down the CD input by 6dB, if I wanted to make levels a little bit closer, provided there were no noise issues with the cartridge direct into the Cornet.
Cheers
Grant
Denon DL-110 Phono Cartridge Specifications
- Type: Moving coil
- Output voltage: 1.6mV
- Frequency response: 20Hz-45kHz
- Recommended load impedance: over 47k ohms
- Channel balance @ 1kHz: Within 1db
- Channel separation @ 1kHz: > 25dB
- Stylus tip: Special elliptical solid diamond with 0.1 x 0.2 mm rectangular cross section
- Compliance: 8 x 10-6 cm/dyne
- Recommended tracking force: 1.8mN +/- 3mN (1.8g +/- 0.3g)
- Color: Red
- Weight: 4.8 g
I myself would pad down the CD input by 6dB, if I wanted to make levels a little bit closer, provided there were no noise issues with the cartridge direct into the Cornet.
Cheers
Grant
Thanks guys. Great discussion but I had to read it a number of time until it all sunk in. The difference in volume does not bother i just mentioned it for reference and I am just now finishing my preamp that has a mechanical volume control controlling two TVCs.
I'm going to install the Denon and give it a test drive for a while before I make a decision.
The other question is can i increase the gain in the phone pre?
I'm going to install the Denon and give it a test drive for a while before I make a decision.
The other question is can i increase the gain in the phone pre?
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