It doesn't solve the problem then. Which is to have a good quality power supply that attends most audio needs.
There's a moving coil phonostage here on the Forums called "Pearl3".
Moving . Coil . Phonostage .
With 100 microvolts to 400 microvolts of input signal and 70dB of voltage gain (3160X).
Pearl3's power supply is just a MC7815 voltage regulator IC for +15V plus a MC7915 voltage regulator IC for -15V. That's all. Yet those old and forlorn IC regulators manage to attend the needs of a moving coil phonostage. Many dozens of diyAudio members have built Pearl3 and LOVE its sound. LOVE its sound. Measured performance is extremely good too. Search the Forums, you'll find Pearl3 easily.
If there's anything even remotely exotic about Pearl3's power supply, it could be the fact that the transformer and rectifiers and power supply filter capacitors are located in a separate chassis. Two meters away. The high gain amplifier (with decrepit old 7815 / 7915 regulators) is 2 meters away from the transformer's magnetic field, and there are two metal boxes separating them.
Moving . Coil . Phonostage .
With 100 microvolts to 400 microvolts of input signal and 70dB of voltage gain (3160X).
Pearl3's power supply is just a MC7815 voltage regulator IC for +15V plus a MC7915 voltage regulator IC for -15V. That's all. Yet those old and forlorn IC regulators manage to attend the needs of a moving coil phonostage. Many dozens of diyAudio members have built Pearl3 and LOVE its sound. LOVE its sound. Measured performance is extremely good too. Search the Forums, you'll find Pearl3 easily.
If there's anything even remotely exotic about Pearl3's power supply, it could be the fact that the transformer and rectifiers and power supply filter capacitors are located in a separate chassis. Two meters away. The high gain amplifier (with decrepit old 7815 / 7915 regulators) is 2 meters away from the transformer's magnetic field, and there are two metal boxes separating them.
The preamps I am using already have 7X15 regulators on board, one even having 7X18 followed by 7X15. So regulation is not the problem. Noise and impedance are.
About the noise induction I can try and listen if it's audible. The preamps are for MM carts, not MC, so noise interference may be nonexistent.
We'll see.
About the noise induction I can try and listen if it's audible. The preamps are for MM carts, not MC, so noise interference may be nonexistent.
We'll see.
Yes, I'm considering others, after waiting and waiting for a solution to 337 regulators problems here.
LM337 has no issues or else it wouldn't be on the market. The Denoisator is not a standard datasheet application for it.
Then I will use it with no denoisator.
So what's the problem using the 337 on Dantwomey's design?
So what's the problem using the 337 on Dantwomey's design?
It doesn't bring anything compared to stock application with R1/R2. It does seem to offer more LF PSRR with a bypass cap though. But that is also valid with higher value R1 (2.7K-3.3K).
There might be a middle term: you can blunt the denoisator by reducing the gain of the correction. The simplest way to do it would be the addition of an emitter resistor to the transistor.
If the correction is reduced from 30dB to 15~20dB, it will still make useful job, but it should be more stable.
I didn't test it, but it should be done in the real world, because sims are useless for this kind of tweak.
Start with 150 ohm, and see what happens
The same trick can be used with dantwomey's regulator?
Pity it can't be seen on LTspice sim. How will this modified circuit, with the emitter resistor, show it's stable?
dantwomey's regulator should be stable because it has no real gain. The only way to test for stability is to breadboard a prototype
Could you tell me what schematic you followed to make the PCB's. I'm confused. I see 2 transistors on the PCB, I thought there was only one in the schematic.
Got a new transformer(exact same model) and my denoiser(tombos design) becames completely unstable. It starts up normally then after 5 minutes or so the positive rail starts oscillating between 5V and 12.6V. It takes 2-3 minutes before it returns to 11.9V and after a few minutes it starts again. Looks like i gonna have to remove the second transistor and hope it stops like with the negative rail.
Those small signal preamp stages tend to draw a small and relatively steady amount of supply current, so really stiff regulation is not a major need for them. Cleanliness of the supply voltage, even if it slowly drifts a bit with line voltage variation is a more important issue. It certainly does not hurt to use high quality regulation; it will just likely not improve anything sonically.
??
My design of positive rail dienoiser (LM317) is perfectly stable under any conditions, so I don’t know why would you have a stability problem.
However, you don’t seem to be using my design! At your initial post #2945 is picture of some PCB design that has nothing to do with me.
Removed the second transistor and it became stable
Its your design just both positive and negative put onto the same board as cost saving measure. After more tinkering it was the transformer that caused the instability.
Well, no! It can’t be said that PCB you have is my design.
Dienoiser circuit design is by forum member diegomj1973. I have done implementation of that circuit that includes PCB design and components choice. PCB layout can greatly affect circuit stability, as can some critical components choices.
So, you have a design from anyone who has designed that PCB.