I thought Brits only ignored work done in the US in this case it was done right across the channel.
There is no evidence the Altoids used by the rebel colonials anywhere near the performance of the Duraglit tins in Blighty and the loyal colonies!!
As a reference, my Duraglit battery special will be LOT easier to get to its theoretical/simmed performance. If you have the bits, you can knock it up in a morning and get SOTA performance immediately.
I did this circa 1980 when I had the full monty, B&K true RMS with band-limiting filters, zillion weightings, Spectrum Analyser bla bla ...syn08 said:
The 280pV/rt(Hz) in my MicBuilders doc is measured with a resistor as source. (The WW article was rather sloppily edited by the magazine but the stuff in my doc is pukka) There's also a 1/3 8ve plot in a real life MC vinyl system.
From Wayne and H&H, I'm fairly confident ZTX851/951 outperform Ye Olde Unobtainium Hitachi etc stuff.
Actually for the transistors I tested in 1980, the distortion is exactly as predicted. I'd assumed the THD profile would be similar to a LTP but did a full analysis when I got some 'unbelievable' figures.Scott Wurcer said:
On my circuit with the floating 1V5 battery, THD is ALL from the common base i/p and drops much faster with level compared to eg a LTP. I asked Hans to do a THD sim with level of my improved JC wonky virtual earth to see if it behaves similarly.
Well actually IT IS! But the transconduction constant is small.
With my electrodynamic guru hat on ... A MC cartridge gives voltage e = Bl v where v is velocity. B: flux l : length of wire in the flux
Bl : transconduction constant which is also the sensitivity of the cartridge
If you put current through the cartridge, you generate a force f = Bl i
If you short out the cartridge, the stylus sees a max. mechanical resistance (Bl)^2 / Rdc
MMs are more complicated cos the inductance and are much less efficient than MCs. But even in the most efficient MCs, (the bigger Ortofons) the electromagnetic damping is a tiny fraction of the tracking weight.
I know. You hear no music. You talk.
The Hitachis have more hfe when you care about input impedance. We had that over and over again.
The Hitachis have more hfe when you care about input impedance. We had that over and over again.
Sorry, I'm not sure I follow what/how you did/mean. Are you saying ZTX851/951 are in production since 1980? Hmmm...
Tachyons are possible but how how do we cross the line where time stands still. A classic singularity.
One way is paralleling lesser devices like BC337-40 and BC237-40.
The Hfe remains the same, does not matter how much you parallel, but voltage noise goes down.
The Hfe remains the same, does not matter how much you parallel, but voltage noise goes down.
More than 10dB better noise & THD. 🙂
If I take your circuit, throw bits out, change the values of some others and end up with more than 10dB better noise & THD, I think I'm entitled to say I understand it better than you. 😀
Read my MicBuilders article on Bonsai's website.
That's another advantage of my Duraglit battery special. Zilch switch on thump.
I got letters from Wireless World readers who built my circuit and thought it wasn't working cos no thump, NO EXTRA NOISE/HISS even ... So they turned up the volume and THEN lowered the cartridge & blew up their speakers. 😀
And the current noise goes up in the same ratio as the voltage noise goes down. No cigar.
For MC cartridges current noise does not matter much. Only when you want to make a Phono amp that does as well for MC and MM with the same input stage J-Fets have an appeal. 1/F corner is higher though. OK, weighting helps on the subjective side.