Recent content by phonomac

The -3dB frequency of the 47uF with the 3.6k of R21 is 0.94 Hz, call it 1Hz for simplicity. At twice that frequency (ie around 2Hz) the response will be approximately -1dB and at 5 Hz it will be - 0.2dB. If you now replace the 47uF with 4.7uF these frequencies rise by a factor of 10, so -3dB at...

As shown its function is to reduce the DC gain of the control amp, With S10 set to defeat the tone controls R28 is shorted out and the feedback loop goes from the collector junctions of Q5, 6 via R20 acting as a voltage divider with R21 to define the gain. The capacitor (if ideal) will have...

Better not let the Lenco crowd see that :D

So do I. That still doesn't make you right. The AT33 Mono has a 10Hz compliance of 12 -14 cu (measured) with a mass of 6.9 gm. In a tonearm of 12 gm effective mass (the popular way to describe the result of moment of inertia) that places the resonance at 9 - 11 Hz, which most people would be...

Do you actually know how to read and understand specifications?

Garrard 401

!40V required for the neon lamp in the strobe - no other purpose and no effect on drive/control..

Thank you for that, seems to be working fine so far.

Why do I have to keep logging in every time i visit the site? It happens even when I re-visit having been logged in (and tagged to be kept logged in) 2 hours earlier. I have no problems with log-in status being retained on other forums. Any help will be very welcome.

All electronic parts for an SP-15 are most certainly NOT available. The MN6042 has been unobtainable for at least 8 years - I bought the last two genuine ones at that time. FidelisAanalog does produce a modern FPGA substitute. The most likely cause of running like a jet turbine is dry joints on...

I just need to point out that the analysis in the B&K paper is fundamentally flawed. The conclusion was that a low mass arm with damping was better than two other medium mass arms without damping. Unless the conditions for testing are the same (ie all damped or all undamped) you cannot draw a...

No, the NJM devices are a very good match for the C3519/A1386. Similar fT and capacitance, and with better Ic/hFE linearity.

Nice work there, well done.

Rega R200 - made by Acos in Japan and based on the Acos Lustre tonearm. Bias is adjusted by toothed belt which tends to break when old, apart from that a good medium mass tonearm.

I think there are two possible culprits here, both related to the fact that the indicator lamps are driven by ac voltage (not one of Sansui's smarter decisions!). The easier one to fix is to look at the wiring which runs from the control amp board to the indicator board and see if you can...