Recent content by DualTriode

I received a Fosi P4 on my doorstep a couple of days ago. Hooked it up to the analyzer but had issues with PS HD's in the noise floor. Put the cute little amp in a shielded steel box bonded to the analyzer ground connection, the PS HD's were removed. Yet at 2 v RMS the SINAD was 104.2, 2nd and...

Not really true sine but chopped up re constituted dc. Like Spam is to ham

I worked at the Facility Design and construction department at a large 500 bed hospital and many Medical School Labs and teaching facilities on a 110 acer campus. The three largest electrical loads on site 1) were fans, compressors and motors in general 2) lighting and 3) computers. Most every...

I like to see that NEC code section, The recommended NEC max voltage drops are Fine Print Notes that are not enforceable. (only recommendations.)

Looking at the lower SPL curve in the attached plot and thinking + / - 3dB's, the boost bandwidth is over an octave wide. Not competition loud or audiophile but adds an octave to the bottom end. That could be the bass extension you are looking for.

Enough of your absence of evidence fallacy. if you say something is blatantly false the proof is on you.

Yes I could hear differences for Tubes and Jfets at Elevated line level outputs. My posted measurements do the job well enough. There is also a lack of audibility evidence supporting the no difference of audibility claims between/among Op-Amps. The posted measurements do the job well enough...

My validation is the measurements that I have posted. This afternoon I completed the assembly of a HP-22 PCB purchased from neurochrome. The PCB makes a nice PRE-Amp / OP-Amp test project. https://neurochrome.com/products/hp-22 The volume pot was replaced with bare wire jumpers. The output...

So this my take on all this Op-Amp rolling stuff: Yes much of it is psychological, first comes Denial then Anger ...... Real measurements are important. Speaking of Op-Amps the only place I found numbers that stood out to me was rt Hz kind of sound floor measurements for high gain noise...

https://www.audiosciencereview.com/forum/index.php?threads/amplifier-op-amp-rolling-part-2-video.62412/post-2289504 2nd HD is higher than 3rd HD, 3rd HD is higher than 4th HD ..... This is the common distortion signature for single end triodes and jFets. Stair step distortion.

You can setup the output from the jFet circuit just as you would the output of your CD or RIAA pre-amp. On my bench the jFet output goes to the Benchmark preamp, the listening SPL is set with the Benchmark remote control, the same as with any other input device. Also note that by adjusting the...

Using words that you do not understand except to be demeaning.

As I have said already a couple of times; I am not buying lunch for a room of blind listeners. Plus I do this for fun. I have built and used the "H2 HARMONIC GENERATOR". I have measured the output and can hear the difference particularly with the gain turned up. That was only a half blind test...

In a previous post I posted a link. Here is a more direct illustration of people tuning the distortion profile to change the sound. Yes it is audible, especially as you turn up the gain. We are not speaking of flat top clipping, just honest stair stepping harmonic distortion. This thing is...

After seeing the measurements it is evident to me that the electronics, including the Op-Amps, are innocent. That does not mean that those that roll op-amps should be shunned. They will learn or they won't, that is fine with me. If you want to measure and hear real differences look at the...