Lyra Delos Settings

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

Jonathan,
As a happy owner of the Delos and the VPI Classic, this thread is of great interest to me. However, honestly I do know how to read your findings. Would it be possible to explain "in English" which setting is optimal given these readings? Thank you!

Jonathan - I am an owner of three Kleos cartridges and am having problems with no less than 2 of them in terms of a low-riding suspension . Emails to the Lyra email address go unanswered , could you please email me at newanalyst@me.com to discuss? Thanks

Hi Kinara:

It would be interesting to see what is going on in your tonearm(s), because 2 out of three is highly unusual.

I would be happy to send you an email, to either discuss what may be going on. or set the corrective wheels in action (smile).

Wonder why I haven't seen your emails?

kind regards, jonathan