2. analog
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Turntable, where is my bass???

Hi, I've noticed a clearly diminished low frequency output with my analog gear lately but cannot put it in precise timely relation with a particular event since I have mainly been playing newly acquired records during the last few weeks or very old ones that I hadn't heard for years. But now, the familiar records surprised me with a lack of "something" (there was actually one recent change of IC)

The chain of the signal is Transfiguration Spirit III cart -> Well Tempered Reference arm with original wiring sitting on Well Tempered Reference table -> Synergistic Research Tricon analog IC -> Tidal Preos pre-amp.

Possible culprits I can think of:
1 (the one I hope it to be) The SR Tricon is only a few weeks old; before that the dealer had lent me a broken-in demo cable that I was allowed to keep several weeks until my newly ordered one arrived. So could this be a questin of break-in?
2 Could the arm somehow have "deregulated" itself, e.g. in respect of VTA?
3 Resistive load is fixed at 120 Ohm; could I just be growing aware that is the wrong value? Does anyone know the preferred value for the Spirit III ? (I can't experiment changing it myself, but the Tidal guys could fix another value if can tell them which one)

Does someone know of other possible causes that are perhaps subtle first and then just "snap"? It can't be my hearing since I don't notice any change in the digital department.

Thanks for your insight.
Karel
karelfd
karelfd OP
476 posts
 
Thanks to everyone. I actually bought ithe new IC directly from the SR distributor for the Benelux - in Germany it is not even distributed - who is an extremely helpful guy, but since the Tricon is so novel, I'll talk to SR first, see what they think about the Tricon's burn-in period.

If that is not the cause, looks like I'm going to have to roll up my sleeves (sigh, probably started this thread, to have all you good people encourage me)
johnss
584 posts
 
Karelfd,
obtain a Frequency test LP if you do not have one. Play the frequencies at 1Khz first. measure the voltage output from your phono stage or pre amp tape outputs.

Then start playing lower frequency tones and measure the voltage for each. If you are hearing a true drop off in freaq. response, and can confirm it with the voltage meas. then you either have a cart, that is not broken in yet, has a poor low freq. response, or need to tweek the RIAA circuit, to increase the gain where the drop off happens.

Make sure you keep the same time contant by changing out equiv. cap and resistor values.

John
thom_at_galibier_design's avatar
thom_at_galibier_design
729 posts
 
To elaborate on Dcstep's comments, changing damping (either by using a different viscosity or by reducing the contact with the fluid) will have the effect of altering the effective mass of the arm, and hence the bass response.

I would absolutely revisit every setup parameter on your rig. Something has changed (perhaps only the cable), but you won't know if your setup is correct until you re-verify it. Bond with your turntable ;-)

Cheers,
Thom @ Galibier
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