Pro Audio Design Forum

From the best I can reconstruct, I didn't filter the drain resistor feeds separately, but used something like 10 ohm R between 3 terminal regulator and preamp +/- V rails.*** On these rails I had one 1000uF electrolytic each and several .1uF ceramic discs by the ICs. Noise coming in the preamp from ...

Another observation about phono preamp design... While you are looking wide band, The RIAA EQ will roll off and understate THD measurements in preamp measurements. Back in the day I rolled my own two-tone (19-20kHz) IMD analyzer that i found very revealing for phono preamp design, since the 19 and 2...

I want to experiment with the technique of transcribing LPs with flat preamplification and performing hiss, click and pop removal in DSP prior to application of DSP-based RIAA de-emphasis. People have reported good results doing it this way since the surface defects which cause clicks, ticks and po...

While this doesn't strictly count as entropy, some puke hacked my website again,,, now here's something maybe there should be a law against... while it's hard to get to the pukes on some distant continent. Glad to see these kids working on their computer skills but come on... Do something productive...

Not to quibble but there is no (RxC) LPF on that input, while there is a transformer in series that is in fact a BPF. The RxC shunt across the input is dialing in the transformer transfer function, one of Deane's (RIP) rigorous engineering practices. The inductor(s) in his opamp input LTP went a lon...

I hate being a digital tout, but if you can get a many bit DAC and the ability to tweak the sine wave look up table, you could correct the linearity of the DAC which is probably already pretty good. This quickly gets into a chicken/egg thing with how do you measure the DAC linearity to tweak it. I'm...

Well speaking of things fixed or at least returned to an orderly state, I hope I am not premature in declaring victory over my cookie monster. My access to this forum seems rock solid now for more than a day. My advice to other safari users is that deleted cookies, may need to be deleted more than o...

Thanks for the update John. John forgot to mention that problem with persistent cookies... computer nonsense is a given.. running a BB may be a PIA but PCI compliance for credit card security is like Sisyphus rolling the rock up the hill. At the moment I am getting pinged for two compliance vulnera...

It's been a while since I updated the constant race toward disorder that my house and equipment are on. New things that broke. 1- curtain pull string on living room window used every day. 2-counter spring on heavy washing machine door 3- intermittent push buttons on my coffee roaster 4- one basketba...

RIP... him and RAP JR edit- in the back of my head I am thinking about mixed technology where a micro driving DPOTs could get the osc loop dialed in just to the edge of amplitude stability, so the dynamic range of the leveling loop can be necked back to almost nil... but we are chasing the echos of ...