I'm using the Phonoclone BE with much joy and am happy with it. No particular problems. I know the saying "Don't fix if ...".
Having said that, I'm always looking for areas to improve. Noise could be a little lower, just as sensitivity to RF pickup. This is my current setup, built by the book with a 50VA trafo. Could I improve on the wiring, parts, the case of somewhere else based on experiences of newer iterations?
Ralph
Having said that, I'm always looking for areas to improve. Noise could be a little lower, just as sensitivity to RF pickup. This is my current setup, built by the book with a 50VA trafo. Could I improve on the wiring, parts, the case of somewhere else based on experiences of newer iterations?
Ralph
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Not having build a phonoclone I cannot say if your interpretation will sound nicer, but this philosophy of bringing the rectified half waves (and the very short charging pulses) to remote smoothing caps brings all the pulse currents into the very sensitive areas of the circuitry.woodturner-fran said:I'm sure RJM will step in here, but IIRC, I asked this and was told not to use any smoothing at the Tx, just bring the raw rectified DC to the phonoclone.
I would at least try the compact TINY loop area method to prove it one way or the other.
I consider it very important to keep the transformer secondary and rectifier and first stage smoothing in a very tight loop area configuration and if possible to keep all the interconnections between these three PSU components short.
but this philosophy of bringing the rectified half waves (and the very short charging pulses) to remote smoothing caps brings all the pulse currents into the very sensitive areas of the circuitry.
This is true, but it also put all the resistance (and inductance) of the lead wire between the cap and the diode, which if it does anything improves the filtering and dampens the diode spike. It avoids having, from the point of view of the op-amp, a capacitor sitting a long way from the power pins behind a significant inductance. Anyway trust me it sounds much better without capacitors in the power supply box itself. But you are welcome to do the test yourself.
Richard
Filtering
Hello.
A few months ago I build my last version of Phonoclone I use till now. This is total dual mono. Each opamp on the pre pcb has each own regulators (lm317/337). Second opamp is biased to class A by adding a 2k resistor (supply is 2x15V). Filtering: 70 000uF/25V & 8 inductors 10mH/1A for each channel. I bypassed also schottky (1N5819 1A/40V) in rect by a small cap.
http://img170.imageshack.us/my.php?image=phonoclonee002fs8.jpg
Chassis .... I called it The Tower ...why .... see the pictures:
1. http://img502.imageshack.us/my.php?image=thetower002xp4.jpg
2. http://img517.imageshack.us/my.php?image=thetower003zu9.jpg
Sound for me and friends who listened that version is wonderfull. Bigger, deeper bas, incredible soundstage. High freq are also beatiful. This isn't cheap improovement but I can recommend it for everyone.
Krzysztof
Hello.
A few months ago I build my last version of Phonoclone I use till now. This is total dual mono. Each opamp on the pre pcb has each own regulators (lm317/337). Second opamp is biased to class A by adding a 2k resistor (supply is 2x15V). Filtering: 70 000uF/25V & 8 inductors 10mH/1A for each channel. I bypassed also schottky (1N5819 1A/40V) in rect by a small cap.
http://img170.imageshack.us/my.php?image=phonoclonee002fs8.jpg
Chassis .... I called it The Tower ...why .... see the pictures:
1. http://img502.imageshack.us/my.php?image=thetower002xp4.jpg
2. http://img517.imageshack.us/my.php?image=thetower003zu9.jpg
Sound for me and friends who listened that version is wonderfull. Bigger, deeper bas, incredible soundstage. High freq are also beatiful. This isn't cheap improovement but I can recommend it for everyone.
Krzysztof
Re: Filtering
Wow that's pretty impressive. I just started building mine today and it will be dual mono as well. I got one channel finished and it worked the first time, I can't wait to finish the other channel.
ahaja said:Hello.
A few months ago I build my last version of Phonoclone I use till now. This is total dual mono. Each opamp on the pre pcb has each own regulators (lm317/337). Second opamp is biased to class A by adding a 2k resistor (supply is 2x15V). Filtering: 70 000uF/25V & 8 inductors 10mH/1A for each channel. I bypassed also schottky (1N5819 1A/40V) in rect by a small cap.
http://img170.imageshack.us/my.php?image=phonoclonee002fs8.jpg
Chassis .... I called it The Tower ...why .... see the pictures:
1. http://img502.imageshack.us/my.php?image=thetower002xp4.jpg
2. http://img517.imageshack.us/my.php?image=thetower003zu9.jpg
Sound for me and friends who listened that version is wonderfull. Bigger, deeper bas, incredible soundstage. High freq are also beatiful. This isn't cheap improovement but I can recommend it for everyone.
Krzysztof
Wow that's pretty impressive. I just started building mine today and it will be dual mono as well. I got one channel finished and it worked the first time, I can't wait to finish the other channel.
Zener diodes. Two for each rail. 12V/3W. For each opamp.
Is much better than any LM .... I got these diodes and only resistors for I load (about 70R). V sec from toroid I got 2x16,92V (after rect and filtration).
Here is the calculator: http://www.opamplabs.com/zenerreg.htm . Try it .
Krzysztof
Is much better than any LM .... I got these diodes and only resistors for I load (about 70R). V sec from toroid I got 2x16,92V (after rect and filtration).
Here is the calculator: http://www.opamplabs.com/zenerreg.htm . Try it .
Krzysztof
No, there is no penalty for this since the Phonoclone can drive the pot directly even if it has a relatively low impedance, like 5k or less. The purpose of original gain/buffer stage before the pot would have been to present a very high impedance to the input source device, so as to be compatible with tube tuners and so forth incapable of driving low impedance loads.
Hi Richard, I made another VSPS, because my original was "taken away" from me... I really love the VSPS. Thanks!
I made two inputs this time, switchable with DPDT switch, but everytime I wire with the switch, I get a buzz. With one input hardwired, silent as before.
Any tips on wiring for two inputs, specially grounding route?
I made two inputs this time, switchable with DPDT switch, but everytime I wire with the switch, I get a buzz. With one input hardwired, silent as before.
Any tips on wiring for two inputs, specially grounding route?
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