Acceptable frequency response, very poor thermal stability, not low distortion. Am I missing something? 😉
Noise with MM cartridge (970R + 425m) is low:
Excuse me for being brief, I am an engineer, and after more than 20 years on various audio forums I became tired of long debates about audio.
Noise with MM cartridge (970R + 425m) is low:
Excuse me for being brief, I am an engineer, and after more than 20 years on various audio forums I became tired of long debates about audio.
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Well the 470µF input cap gives a time constant measured in tens of seconds, and it lacks a bleed resistor... Perhaps 10µF and 100k bleed resistor while upping the 56k input resistor to 100k too?
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Evolution is not yet complete
Three of them go on a journey, ending up in various places around the globe, one discovers North America, one Eastern Europe and our last sailor takes a liking to the Netherlands.
They want to put the finishing touches to their, are already convinced that they bring high-end qualities with them: Single-ended distortion, class A, automatic offset correction and synthetic load (electronic cooling of the virtual 47k !), quasi battery supply. Load-independent up to 10k, secret 5Hz subsonic filter ..!
Now we just have to wait for their travel reports to finalize the last development steps.
Three of them go on a journey, ending up in various places around the globe, one discovers North America, one Eastern Europe and our last sailor takes a liking to the Netherlands.
They want to put the finishing touches to their, are already convinced that they bring high-end qualities with them: Single-ended distortion, class A, automatic offset correction and synthetic load (electronic cooling of the virtual 47k !), quasi battery supply. Load-independent up to 10k, secret 5Hz subsonic filter ..!
Now we just have to wait for their travel reports to finalize the last development steps.
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Emitter resistors are needed to stabilize the bias. Then, the open-loop gain will be too low.
IMO, if you want active EQ in one stage, use an op-amp.
Ed
IMO, if you want active EQ in one stage, use an op-amp.
Ed
CEO meets Haudegen - and both head to the tinkering room
All wishes and ideas are readily taken up by the Evolution. Q1 and Q5, also Q2 and Q6 are thermally linked. OL-Gain is very high - if any (existing) ohmic resistor can convert current into voltage.
tbc
All wishes and ideas are readily taken up by the Evolution. Q1 and Q5, also Q2 and Q6 are thermally linked. OL-Gain is very high - if any (existing) ohmic resistor can convert current into voltage.
tbc
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After detailed consultation with our Feng Shui master, we are removing all 10 Ohm resistors without replacement. 10 ohms is not good, even an odd number of active components would be harmful - so he says. Market analyses have also shown that extremely low-impedance loads must be drivable and a switchable subsonic filter is an absolute must if you want to be noticed on the market at all.
The result is a very extensive power supply unit, a microcontroller-controlled light organ, a dozen clacking subminiature relays ..!
If all else fails, we will go to Prague and consult @PMA. If he can't help us either, we'll fall back on our tried and tested "Letzte Hoffnung" product, a three operational amplifier plagiarism, the old Pro-Ject Audio Phono Box Number 1 Clone.
HBt.
The result is a very extensive power supply unit, a microcontroller-controlled light organ, a dozen clacking subminiature relays ..!
If all else fails, we will go to Prague and consult @PMA. If he can't help us either, we'll fall back on our tried and tested "Letzte Hoffnung" product, a three operational amplifier plagiarism, the old Pro-Ject Audio Phono Box Number 1 Clone.
HBt.
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Yes, that's right, 500mV should already drop.
The problem is:
I only believe thermal problems when the first test setup confirms this warning. It should be possible to keep 45mW thermally within limits by physically coupling it to the input transistor. Otherwise, the emitter resistance must be increased until there is no more significant drfit. I think it will settle between zero and 100 ohms.
But what about all-round performance? Who dares to undertake a comprehensive analysis? The bar is set high, we want to win the challenge in Queensland.
HBt.
Psst.
Three representatives of their species are now going on the journey again, I am waiting for their reports or evolutionary transformations.
