Recent content by Michael Fidler

What a great job they've done here! I'm really tempted to get one of these. It would be great to make an active version...

It's not too tricky. If you know the algebra that creates the function well enough, you can even make a CSV, XML etc. file with 20 or so points per octave in Excel or LibreCalc that will give the generator amplitude values... If you have all the scripts ready-made from the manufacturer of the...

Thanks for the kind comments! I think you might want a rotary switch if you're adding extra settings like that. The AT91 is in the bottom left hand side of the photo, just above the ground binding post. EDIT - I wouldn't bother with a resistance of 60 ohms, as it only gives a noise voltage of...

Or more likely not enough HF stability to bring full feedback as frequency increases, so the gain doesn't drop down low enough as it approaches maximum possible feedback...

Shipping to AU might be a bit pricey, but if you're happy to source a centre-off switch (or just a normal DPDT if you wish to forgo the open option and just have 'cartridge' and 'short' modes) then I can send you a few bits and pieces such as the board, RCA connector, and some 'B metal'...

I use a custom box I made a while ago that contains an AT91, with a switch on the front that provides short and open options. When you go from the short to the cartridge, the noise floor typically increases by about 6dB. I like to test from 220Hz to 22kHz. Testing from 22Hz with a cartridge...

It's also well worth adding that your typical moving magnet cartridge has a high output impedance, due to inductance, that exacerbates the problem of noise by converting the current noise of the loading resistor and the input amplifier very effectively into considerable amounts of voltage noise...

Regrettably, I would say that +-0.8dB is significantly below the average type of circuitry we might find in a typical cheap receiver. By using 5% capacitors (very low cost C0G SMT devices) and readily available 1% resistors (they don't even have to be thin film types to beat the distortion...

Not yet. I need to do one about current input MC too. I'm just wondering whether I should start it off with a long post containing everything I have to offer up, or a short one with a basic premise/objection and then let everything else I'm considering flow as an organic product of the dialogue...

I sort of knew that, but it's a question that's worth an answer, whether or not made in jest. I'm hoping to improve crosstalk, RIAA accuracy and general magnetic immunity further with SMT MELF layouts. Through-hole metal film resistors actually represent the best value as parts alone in terms...

I don't think I could do that and look myself in the eye, to be honest. I'd really rather offer a fair price for no-nonsense people, who are my target audience after all. At the moment I just ask for details of what people are using and if they're experiencing any issues in the setup, which...

Old colleague pictured above!

New video review on this one: It's a pretty good subjective analysis and also includes audible demonstrations of the noise floor in-situ with a cartridge connected, as well as LF XFEED on groove noise. I'm really dragging my feet on the Spartan 20, to be honest, as it's chaotic enough at the...

I highly doubt that, to be honest. For 78s, you would want a much higher-order filter, with a cutoff frequency slightly below 50Hz, as a lot of the LF disturbances are raised up through the spectrum by the higher relative velocity of the groove. This product would be horribly unsuitable for the...

If you add a third pancake on top and knock them slightly askew, you'll have a super Chebyshev filter (0.01dB ripple works well). Easy to get 0.03dB at 40Hz, -3dB at 24Hz, and -22dB at 10Hz!