Hi Jcarr,
I could also ask you for advice to optimal settings my preamp Audiolab 8000PPA for cartridge Lyra Delos, which I right now bought? For me, data for loading mentioned in the Delos-manual and Audiolab-manual are jungles :-). I apologize for this foolishness, but I wish, I had the best setting for my Delos to realize its full potential...it´s my cartridge-dream come true. Thanks in advance and sorry for my imperfect english. Petr.
I have Phono-preamp Audiolab 8000PPA:
specifications and manual for input loading:
http://www.avrevolution.com.au/SiteMedia/w3svc1114/Uploads/Documents/8000%20PPA%20owner%20manual.pdf
I have tonearm Rega RB300:
Cable capacitance 100-150pF
Int.Capacitance 0.002uF
Resistance 0.002 ohms
...and everything on Michell Gyrodec-SE |
Thank you Jonathan Could you please provide the best email address to use ? The one I am using (since there is no contact link on your website) is [email protected] - listed on the instruction manual that comes with the Cart. Best Kinara |
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 |
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 [email protected] to discuss? Thanks |
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! |
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 |
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 |
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 |
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. |
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.
|
Hi Agiaccio: The loading resistance for a low-impedance MC cartridge is related to the values of the capacitances between cartridge and phono stage (plus whatever amount is present at the phono stage input). The general rule of thumb is that, the lower the capacitance value, the higher the resistive loading value can be (which is beneficial for dynamics and resolution).
If you are willing to give me a few days, I could run a set of loading simulations for you. Please be aware that without knowing some of the key capacitance values, a certain amount of guesswork will be involved.
These days you can buy a digital multimeter (DMM) which can easily measure capacitance for not a lot of money, and this would eliminate the guesswork (hint, hint).
The Nordost Heimdall 2 will likewise be one meter long (3.28 feet)? FWIW, 1.2m is more common for bespoke tonearm cable.
How long would you estimate the signal wiring inside the JMW-9 tonearm to be (including the leads to the junction box)?
kind regards, jonathan carr |
Agiacco - you would be best running through all the settings yourself. Although this is tedious you will learn a lot and it is really the only way to find the optimum set up in your system. Even if you found someone with an identical system, if their cartridge allignment or VTA is different then again you may end up with different results.
You may need to adjust VTA or revisit the settings if you alter the VTA to fine tune and double check your conclusions. |
Hi Jonathan,
My tonearm is a VPI JMW-9 Signature tonearm with Valhalla internal cabling and I have no idea what the capacitance is for this cable.
However, the phono cable (1 meter) that runs from the VPI Junction Box (RCA) to the Linn Uphorik phono pre-amp (XLR) will be upgraded to a Nordost Heimdall 2 with a capacitance of 25pF/ft. |
In a way that is the analog dilemma, that there is no real technical Standard. For example, Phonostage A with 100 Ω does not deliver identical sonic results (or even close) compared with Phonostage B with also 100 Ω.
Also huge differences are in the Design of Phonostages, price is no guarantee for real sonic improvements. Indeed, most are more or less same, a bit more that here and less of that there and so on.
Then you have additional different influences (technical & sonic) in Tonearm Leads (silver, copper, different qualities), cabling inside your Arm, Phonocable , the connectors and so on and on. Also the Preamplifier (Phono comes next) has influence to sound...
So, even when you ask precisely and owners from same cartridge will give you advice, finally you can narrow it but you have to find out what matches best in your System. |
Hi Agiaccio: How much capacitance does your tonearm cable have? Also, how much capacitance does the internal wiring inside your tonearm have?
It would be nice if you could disable the capacitance at the phono stage completely, is this possible?
I suspect that you will have better dynamics with the MC gain set to 64dB, but if you have very efficient loudspeakers, you may try 54dB.
kind regards, jonathan |
Will vary with system, but i use resistance 100, 72 dB of gain with my BAT VK-P10 phonostage. I leave the capacitance in the default position.
VTF is set at 1.725
with very little anti-skate |
The ones that your ears like in your system.
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