Lyra Delos Settings

Jonathan - Your comments are always full of nuggets ( gold ).
Quick question, with my Marantz 7, it has enough gain ( and dynamics ) for cartridges from about .3 up. I prefer MC's that will run at 47k to avoid loading down and reducing the apparent gain. Odd thing is some MC's such as Denon 103 produce no sound at all, some sort of resonance for cartridges with higher internal impedance.
Do all the Lyra's work ok into 47k ?
What is the maximum capacitance that you feel is appropriate for a 47k load ?
I also use MIT cable extensively but am aware that it is quite capacitive. I've noticed that the more capacitive phono cables are they do timing better - are they acting as a capacitor block on the MC output ? Does this have any negative effect on cartridge performance from your point of view ?
Sorry - a few questions here.

Thanks.

Jonathan,

To answer your questions above...

"The Nordost Heimdall 2 will likewise be one meter long (3.28 feet)? FWIW, 1.2m is more common for bespoke tonearm cable." - Correct, the Nordost Heimball 2 will be 1.2m in length.

"How long would you estimate the signal wiring inside the JMW-9 tonearm to be (including the leads to the junction box)?" - I would estimate about 12.5 inches.

Hi and hope that everyone is doing well:

According to a member of the Phonogram mailing list who recently contacted Harry Weisfeld, the total capacitance for a Classic tonearm with standard tonearm wiring and the standard RCA junction is 143 +/- 2 picofarards (for the arm and box).

He also asked about the Valhalla version, and I am not entirely sure which version Harry's reply addressed. Still, at least 143 can be a starting point.

kind regards, jonathan

I was finally able to set aside some time to put together an electrical model that reflects Agiaccios's particular situation, and start running simulations. Over the next days, I will make a series of posts, one for each capacitance setting on the Uphorik. Today's post will be for the Uphorik's lowest-capacitance setting, 470pF. 23 simulations (a decent amount of work!) were run in order to obtain the results below.

First let me set forth the parameters of the electrical model.
Delos internal resistance is 6.3ohms, coil inductance is 9.5uH.
VPI tonearm internal cable capacitance is 143pF
Since VPI internal resistance and inductance are unknown, I will use values taken from AWG25 50cm zip cable, which are 0.3117uH, 0.106ohm
Tonearm external cable Nordost Heimdall 120cm, capacitance 98.4252pF
Since Nordost resistance and inductance are unknown, I will use values taken from AWG20 120cm, which are 0.748087uH, 0.0798ohm
Phono stage Linn Uphorik capacitance settings 470pF, 1000pF, 1500pF, 2000pF
Phono stage Linn Uphorik resistance settings 31, 37, 42, 53, 70, 100 170, 580, 670, 810, 1000ohms

Today's net capacitance will be 143pF (tonearm) + 98 (Nordost) + 470 (Uphorik minimum setting) = 711pf.

Load__________Peak magnitude_____Peak frequency
1000ohm:_____15.1847dB_____1.8394MHz
810ohm:_____13.8811dB_____1.8356MHz
670ohm:_____12.6458dB_____1.8305MHz
580ohm:_____11.6723dB_____1.8254MHz
170ohm:_____3.1484dB_____1.5957MHz
100ohm:_____0.2680147dB_____944.8883kHz

From 70ohm and lower there is no high-frequency peak, so I changed the table to show at what frequency the response drops to -3dB, which is a standard way of speccing audio components. The small differences in amplitude simply reflect how closely I was able to get to -3dB.

Load____________________Frequency
70ohm:_____-2.9923dB_____1.5423MHz
53ohm:_____-3.0008dB_____1.0860MHz
42ohm:_____-3.0040dB_____825.7936kHz
37ohm:_____-2.9968dB_____719.1689kHz
31ohm:_____-2.9969dB_____602.3495kHz

Below are 3 resistive values that the Uphorik does not have, but in conjunction with a net capacitance of 711pF, would yield a rise of +6dB, +3dB, and +0dB, respectively.

Load resistance for a +6dB rise would be
256ohm:_____6.0009dB_____1.7402MHz

Load resistance for a +3dB rise would be
166ohm:_____2.9907dB_____1.5825MHz

Load resistance for a +0dB rise would be
89.8ohm:_____0.0244404dB_____524.9368kHz

Hope this was of interest. jonathan carr

BTW, the Linn forums have a thread which is for Uphorik users and loading of various cartridges. It treats cartridge loading from Linn's own perspective, which is to load MC cartridges not only resistively (per standard MC phono stage design practice), but capacitively as well (a practice which AFAIK is seldom found on MC phono stages, at least those designed in the US or Japan).

http://forums.linn.co.uk/bb/showthread.php?tid=10332

When defining the resistive load recommendations for the Delos, the assumed maximum load capacitance was 600pF, so I find it interesting to analyze MC cartridge behavior with phono stages that allow significantly higher capacitance values.

kind regards, jonathan carr