Ortofon A90

[MylesBAstor]

Agreed, and it’s for the exact reason I stated in my first post. Anything above 1K and you are unloading the cartridge so you really aren’t going to hear much change with most cartridges.




You lost me here with your comment that “relative to the 100 ohms, the SS does lose more bass control.” Do you mean above 100 ohms SS loses bass control? As the cartridge edges past the point where it becomes unloaded, the bass will become looser because you have lost your braking action. If you prefer the sound of bass that is not being reproduced optimally with tubes more than SS, I really don’t know what to say.




That sounds like an intelligent statement, but David Wilson’s knowledge extends beyond how to build speakers. I’m not saying he knows more about cartridges than J Carr, I’m just saying he wrote a great article about loading MC cartridges and why it matters.

Let's just say Dave and Jonathan are acquainted with each other. When I was out in UT years ago, Dave had Jonathan build him a one off Parnassus that was supposed to be ruler flat

 

[bblue]

This has me curious and confused... With the ASR Basis I tried it at 100 ohms and didn't care for it. 100 ohms didn't work well with the Boulder 1008 I had on loan either. Everything was bleached out. I settled on 48 ohm for about a year but experimented a bit with the impedance settings in the ASR a couple of weeks ago and found that 57 ohms was the trick.

This is pretty consistent with my findings.

The DC resistance of the A90 is 4 ohms, so maximum load should start at around 40 ohms. Then increase slowly from there to get a proper HF balance with good LF damping. I was at 51 ohms for awhile which is the flattest with my preamp (Pass XP-15 SS), compared to 88k and 192k masters of the same album. When an album is a little too dull at this setting, I bump it up to 71 ohms, which is a significant jump with a rising high end. I also fine tune VTA during this cycle to match the general character and detail of the digitals.

I can't imagine using this cartridge at loads over 100 ohms unless your system somehow benefits by the extended HF. The cartridge sure isn't flat at those settings, unless something in the preamp is loading it further!

I too adjust VTA for each record unless it's just for background. Using an ET2 LT arm. Very easy to do and hear on this setup.

--Bill

 

[pbthal]

Hi, I have just acquired a new a90, it is mounted on a Terminator linear arm and has about 12 hours on it. Love the sound but am noticing a rumble when the tonearm fluctuates up or down in the least. On perfectly flat records there is no issue but almost no records are perfectly flat. Yes I could clamp but I am moving away from clamping, has anyone else experienced this?

 

[TheAudioAssociation]

Hi, I have just acquired a new a90, it is mounted on a Terminator linear arm and has about 12 hours on it. Love the sound but am noticing a rumble when the tonearm fluctuates up or down in the least. On perfectly flat records there is no issue but almost no records are perfectly flat. Yes I could clamp but I am moving away from clamping, has anyone else experienced this?

I have to say I have not experienced this type of behavior with the A90. Is it safe to assume The you have all of the settings within the ballpark range? (VTA, VTF, SRA, Azimuth, etc?)

 

[pbthal]

VTA looks right to me, about level, VTF is 2.2, SRA, don;t have a microscope as of yet but using my lighted 7x lense it looks allright, azimuth is level across the plane of the LP tho I have not done any measurements for crosstalk to verify.

I can make an audio sample this evening along

 

[TheAudioAssociation]

It would be interesting to hear the rumble that you speak of..... Thanks!

 

[HBA]

I am using an Audio Note Step Up S5 adjusted to the A90's internal impedance ( 4 ohms ) connect to an AN M5 Phono ( MM ) + Rega Rp10 ( RB 2000 tonearm ) and the sound that came from this combination is OUTSTANDING...the A90 is very sensible to any small adjustment...by my experience the best is to combine it with a proper Step Up ( high quality one )

 

[ack]

Welcome!

 

[HBA]

Thanks ....

 

[wbass]

Anyone still using the A90 here in 2022? I saw reports on a separate thread that it's hard to get re-tipped, or that Ortofon doesn't do it.

 

[jtinn]

Anyone still using the A90 here in 2022? I saw reports on a separate thread that it's hard to get re-tipped, or that Ortofon doesn't do it.

I know many A90 users who are all enjoying their cartridge. You are getting bad information. Ortofon stands behind every cartridge they make with excellent customer service. It might be wise to avoid getting info like that from anyone other than the manufacturer themselves.

Great cartridge.