Linn Asaka : need suggestion

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inertial

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Joined 2004
#1
Hi,

My friend have an old Linn Asaka cartridge with a Thorens turntable and SME "s" arm.
Issue is the correct value for the load in the phono preamp ( a DIY Artur Loesch replica).
Initially we have followed the value reccomended by Linn: 470 ohm.
The sound was good on the mid and high but "anemic" in the bass.
We have tried 1K, 2K,5K but no appreciable difference.
A cartridge expert here in Italy have said that we have to load with much more lower loads.
Very strange but it seems confirmed by listen: with 47 ohm go better,
with 10 ohm better again and with 4,7 ohm (!) the sound is "full":hot:
These comments are reported only from my friend, I do not have listen.
Unfortunately the gain is lowered with such low load and the noise is annoing.
( we have measured the Re of the Asaka and it is 5 ohm)
My question is: what do you think?
Do you have similar or different experience with this Asaka?

Thanks,
Paolo
 
#4
Hi Paolo ,

measuring the asaka with a multimeter is
not good ! Maybe you have damaged the
asaka , because of the foreward voltage
of the multimeter . Thats not good for any
cart , don`t do this because that damages
the cartridge !

Jürgen
 
#5
Thanks for the advisement but this man that "fix"/ re-stylus cartridges
for work, has said that it is a metropolitane legend !😀
If the multimeter is little, the current is very low and it can't damage the voice coil.
I don't know anything about this,I'm a rookie, maybe I am lucky but the Asaka is still in good health🙂

Thanks,
Paolo
 
#8
Actually, it may not be an SME III but my earlier statement still stands as all the S shaped arms that SME made were intended to be used with high compliancy cartridges (as these were most common in those days). You may try adding mass to the headshell (not forgetting to rebalance the arm).
 
#9
Thanks,
I have jet suggested to my friend to sell that S arm and find a decent RB300!

Indeed now I am more interest to know WHY the sound of the asaka change in huge mode when I lower the load.
Maybe because asaka into 5 ohm work in "power" instead of in "voltage" ? 😕

Cheers,
Paolo
 
#10
If the impedance of the asaka is indeed 5 ohms then I would say that a load of 50-100 ohms should be sufficient.The recommended 470 ohms might work on Linn or NAIM phono stages for some reasons.I have never achieved correct balance by loading a MC cartridge with loads more than 20 times its impedance,There might be some exceptions though,and some explanations come to mind.Usually,a too high load will make the cartridge sound thin in the mids and highs,and anaemic/bloated in the bass,especially if the suspension damping is low(among other reasons).The above are more valid when the arm/cartridge matching is correct.In the case of SME III/Asaka,the resonance frequency is propably too high,making things even worse.So,either the SME or the Asaka must go🙂 If I were you,I would send the Asaka out🙂 The Thorens and SME are a nice couple,try to make it work and you won't regret it.
 
#11
Hi panicos,

Thanks for suggestions🙂

Indeed my friend love that Asaka ( not I) and think to swap all the base and arm. I have suggested a Gyrodeck+rb300😀
We will see🙄

About the load, I am interested to the theory behind the Dynavector
PHA 100 and 200. They claims it make the cartridge work in current mode but I am perplex because they have a impedence selector : 3-4
0hm, 10 ohm and 35-40 ohm if I well remember.
This appear to my inexpert eyes as like the cartridge is working in power mode, not current mode....😕

Cheers,
Paolo
 
#12
Hi Paolo,Dynavector phono stages have a circuit that they call "enhanced mode".In this case,the usual input resistor found in all phono stages is by-passed and the phono stage is configured to act as a current amplifier.The cartridge coils then,see an effective short circuit as a load,in theory a better configuration.The impedance selector refers to the cartridge output impedance,and in practice you will see that this "enhanced mode"is more effective on very low impedance cartridges,and not so on higher impedance models.A reason perhaps why,Dynavector cartridges-among others-have low imoedances,around 5-6 ohms.
 
#13
Hi Panicos,

I don't understand: if the input of the PHA 200 is a "short circuit" what
is the use/function of the selector ( 3, 10 or 35 ohms?)😕
My friend has the PHA100 with a extraordinary Dynavector 17Karat mk2 ( internal Re=37 ohms). If you swap the selector on the erroneus
3 ohm position, the sound become a lot dull, closed.
For this reason I have argued that the circuit act as like in "power mode" and not in "current mode"...........just an ipothesis.

Thanks,
Paolo
 
#14
Hi Paolo,I don't remember all things about the PHA100,but if its settings are like the P75,then there are some jumpers you use.One or two of them are connected deprnding on the cartridge's output impedance.I will try yo find some info about the PHA100 and let you know more.
 
#15
Paolo,the PHA100 must be set to the 35-40 ohms position with the Karat.The 3 ohm setting is for cartridges with lower impedance close to 3 ohm.With the selector the PHA100 gives you the facility to match most cartridges according to their output impedance.When you use the correct input setting,the PHA100 will do the rest on its own,i.e to get the maximum current from the Karat and then convert it to a voltage needed to drive a conventional preamp section of the PHA100.This according to Dynavector,recuces distortion of mc cartridges.It is important however to use the correct input impedance setting on the PHA100,otherwise it won't work correctly.
 
#16
Hi Panikos,

Thanks for the help. But in my vision your statement do not explain why:cannotbe:

The cartridge must see a short-circuit in order to work in"current mode" ( ie zero ohms).
If the cartridges see a load equal to his internal resistance it will work in "power mode" IMO.
So this Dynavector PHA IMO works in "power mode".

Maybe you can call it semanthics, but I want only understand if my reasoning is correct🙄

Cheers,
Paolo
 
#17
Paolo,in post 12 that is what I said:There are no input resistors on the PHA100.In the other posts I have just said what Dynavector claim about their design.Are there any jumpers inside the PHA100 like in the P75?If it does,it may also be used as a conventional phono preamp as does the P75.If this is the case,then it has the switches for matching the cartridge correctly in the standard mode.
 
#19
Thanks Panicos,

indeed I don't know about the jumpers.
But it is unimportant because the PHA100 was purchased exactly because it works "different"😀

YNWOAN, yes it is old but still good. Few hours of use and just checked by Torlai ( who professionaly "fix" cartridges).

Cheers,
Paolo
 
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