Parallel Resistive Loading

[derek92994]

Thanks Marco. I'm finding the sweet spot is between 24k and 32k for the AT440Mla/TD 160 super. I am using 220pf as my Cambridge Audio Phono pre is set at that and does not allow adjustment without internal modification.

However when I run the Ortofon OM10 (soon to be an OM20), I find that 220pf and 47k are optimal. That is also on a different turntable (Thorens TD 165).

 

[marcok]

Derek ,
you could use a test record with sine waves and the VU meters of a cassette deck
and adjust the frequency response of your systems as flat as possible .
Ciao
Marco

 

[derek92994]

Derek ,
you could use a test record with sine waves and the VU meters of a cassette deck
and adjust the frequency response of your systems as flat as possible .
Ciao
Marco

That would be the next step. I also have a scope program on my computer. I know my TD 160 Super is slightly fast with its rotational speed but the TD 165 is right on. This would affect the measurements I would assume?

 

[laatsch55]

How?

 

[derek92994]

How?

If the pitch was not correct maybe. I am not sure how a test record works, never used one.

 

[laatsch55]

How would the pitch affect frequency response?

 

[derek92994]

How would the pitch affect frequency response?

I have no idea.

The only reason I have used the software scope on the computer was to set correct speed of cassette decks. The speed changes the frequency, I try to get it as close to 3khz as possible.

 

[laatsch55]

Think of what happens when you speed up the sample frequency reproduction......you also increase the sample frequency....think Alvin the Chopmunk...no bass left in that voice
..

 

[laatsch55]

A good example was a commercial for the Fire HD tablet that Reggie Miller threw in the air, as they slowed his voice down, the bass increased dramatically....

 

[derek92994]

Ok cool, so the turntable doesn't have to be dead on speed. Its going to cost me $500+ to get a project speed box to fix the problem, although it doesn't bother me as its only slightly out. A/C Motor. I don't have a strobe or speed calibration record either. Maybe one day. Could also be the motor run capacitor, its 35 years old. 0.15uf 400 volt

 

[laatsch55]

To get the correct response, yes it does have to be CLOSE to the correct speed. Any speed variation ABOVE the recorded speed or below the recorded speed will affect the response curve.....it has to...

 

[derek92994]

To get the correct response, yes it does have to be CLOSE to the correct speed. Any speed variation ABOVE the recorded speed or below the recorded speed will affect the response curve.....it has to...

One example I heard was this guy ran his speed box at 33.0 instead of 33.3 to achieve the correct speed on a thorens and it is very common that they run slightly above speed due to the A/C motor. I have been listening to mine for 12 years like that, its not fast enough to be annoying. I would like to fix it but don't really want to pull the 160 apart, its very fragile with that arm, and expensive. I may do it one day though.

 

[laatsch55]

I hear ya D2, just keepin it real...

 

[laatsch55]

My Denon had speed control, and anything out of the correct speed didn't sound " right"....

 

[derek92994]

I'll get a test record one day, replace the motor run capacitor and get down to adjusting.

I just shelled out $200 australian for a genuine Ortofon OM20 stylus after experiencing LPgear's shitty generic OM20 Stylus, fuck it was terrible, it sounded worse than the OM10. They didn't respond to my email so I will never do business with them again. The OM20 is for the TD 165, a step above the OM10. The 651p phono stage really brought the OM10 back to life but it lacks inner groove tracking, and inner groove distortion plain sucks. The OM20 will improve on that plus more to boot.

 

[laatsch55]

LP gear is a bust then?

 

[derek92994]

My Denon had speed control, and anything out of the correct speed didn't sound " right"....

I don't mind hearing examples of the slight speed increase when comparing to a different source vs the 160, its not that bad. In my mind slowness is worse than slight speed increase. But being so particular about the setup and having it right will drive me to make some changes, when time and money permits.

I'm more tolerant to a slight speed increase variation than decrease, slowness drives me nuts.

 

[derek92994]

LP gear is a bust then?

Yeah fuck them, they once sent me a 440MLa stylus with a bent cantilever, then they sell me that crappy generic OM20 which they claim to be "improved" over the genuine, and at a much lower price. Also when they replaced the 440MLa stylus, I got around 250 hours out of it, way below spec, and makes me suspicious that it was used before I got it.

I sourced my last 440 replacement stylus from an australian company, we are talking a $200+ stylus here.

 

[laatsch55]

Damn D2, that does suck

 

[derek92994]

Damn D2, that does suck

Such is life. Despite all that I'm happy with the current 440 and pre amp combo with some loading adjustments. Am looking forward to receiving the genuine OM20 later this week.