Mr. Pass...
Greetings Mr. Pass. Love your DIY projects! Thank you for all of your efforts! But I have a simple question for your modulated power supply stage (Zen V.3). It's designed for one channel operation, I understand that part. Don't laugh...were does it go in the circuit? From what I can understand, it goes on the output stage side, but were/what is this +47 volt coming from?
Very simple question for all of you, but not for me...still learning. This is going to be my first DIY amp, and I felt it's better to ask than get a face full of smoke and lightning :>)
Thanks agian
Rino Odorico
Greetings Mr. Pass. Love your DIY projects! Thank you for all of your efforts! But I have a simple question for your modulated power supply stage (Zen V.3). It's designed for one channel operation, I understand that part. Don't laugh...were does it go in the circuit? From what I can understand, it goes on the output stage side, but were/what is this +47 volt coming from?
Very simple question for all of you, but not for me...still learning. This is going to be my first DIY amp, and I felt it's better to ask than get a face full of smoke and lightning :>)
Thanks agian
Rino Odorico
Tazzy,
I think the voltage is just fine and even a bit on the low side judging from Mr Pass:
"Meanwhile, for those of you carving metal in anticipation,
here is a picture and dimensioning of the PC board. It
contains everything for one channel except the unrequlated
power supply at 50 volts @ 2 amps per channel. The
amplifier is designed to draw 100 watts per channel, but can
also easily be set up to draw 67 watts."
The main problem is not the voltage but the power (unless using the 67W draw) available as 300 VA is a bit on the low side according to Mr Pass again:
"We have been using the Plitron 070014201 with is 300 VA
with 18 + 18 V secondaries. It does a good job with one
channel at the 100 watt draw or two channels at 67 watt
draw each. We did run it with two 100 watt channels,
and it worked, but it was hot and buzzed a bit."
Twice 18 is 36 and you are at 35...
All from this thread...
/UrSv
I think the voltage is just fine and even a bit on the low side judging from Mr Pass:
"Meanwhile, for those of you carving metal in anticipation,
here is a picture and dimensioning of the PC board. It
contains everything for one channel except the unrequlated
power supply at 50 volts @ 2 amps per channel. The
amplifier is designed to draw 100 watts per channel, but can
also easily be set up to draw 67 watts."
The main problem is not the voltage but the power (unless using the 67W draw) available as 300 VA is a bit on the low side according to Mr Pass again:
"We have been using the Plitron 070014201 with is 300 VA
with 18 + 18 V secondaries. It does a good job with one
channel at the 100 watt draw or two channels at 67 watt
draw each. We did run it with two 100 watt channels,
and it worked, but it was hot and buzzed a bit."
Twice 18 is 36 and you are at 35...
All from this thread...
/UrSv
Well, read up a little bit on the rectified DC versus the AC and you will find that 35 VAC rectified is close to 35*1.414 VDC which is roughly 50 VDC not deducting the drop in the rectifiers which could be something like 1-3 V depending on set-up.
Using this transformer would be fine for the 67W draw and then using one winding per channel i.e. "separate" power supplies. If using the 100W draw you would need to find another one like it and then you would connect the secondary windings, on each transformer, in parallell for single 35VAC out with one transformer per channel (also separate power supplies).
/UrSv
Using this transformer would be fine for the 67W draw and then using one winding per channel i.e. "separate" power supplies. If using the 100W draw you would need to find another one like it and then you would connect the secondary windings, on each transformer, in parallell for single 35VAC out with one transformer per channel (also separate power supplies).
/UrSv
OK guys, time to step back in time just a little. Does anyone remember how they got full wave rect. back in the old days using tubes?
Tazzy, you can just ground the center tap. Use two diodes with the anodes connected to the x-former output ends and cathodes connected together. The output is the cathodes (+) and ground (-).
Try that. It'll work.
Bruce
Tazzy, you can just ground the center tap. Use two diodes with the anodes connected to the x-former output ends and cathodes connected together. The output is the cathodes (+) and ground (-).
Try that. It'll work.
Bruce
Ok, just so I understand this fully. If I were to build a stereo version of this, I would build 2 Modulated Supplies for Zen. Also this Modulated supply's "In" is from the "Output" of the amp (say the left channel), it then goes through the circuit, and finally to the output (+) terminal of the speaker tap. Correct?
Rino Odorico
Rino Odorico
Zen Regulated power supply.
No.
The drain of the MOSFET is connected to the power supply's voltage rail. The regulator pass MOSFET and its related circuitry regulate the amplifier supply voltage at 40V. The connection between the amplifier output and the gate of the MOSFET allows the regulator to supply a higher regulated voltage dependent upon the magnitude of the output transient. +47 volts in the schematic is the supplied rail voltage.
No.
The drain of the MOSFET is connected to the power supply's voltage rail. The regulator pass MOSFET and its related circuitry regulate the amplifier supply voltage at 40V. The connection between the amplifier output and the gate of the MOSFET allows the regulator to supply a higher regulated voltage dependent upon the magnitude of the output transient. +47 volts in the schematic is the supplied rail voltage.
AHHHH, now I get it!!!
Ok, now I get it! This circuit goes after the power supply (output rail after the filter caps). Then the output of the Regulated circuit connects to amplifier circuit....and viola...done (Power supply-Regulated Circuit - Amplifier Stage).
So am I right in thinking the (-) out of the regulated circuit gets grounded...or does it connect to the (-) out of the speaker output?
Rino Odorico
Ok, now I get it! This circuit goes after the power supply (output rail after the filter caps). Then the output of the Regulated circuit connects to amplifier circuit....and viola...done (Power supply-Regulated Circuit - Amplifier Stage).
So am I right in thinking the (-) out of the regulated circuit gets grounded...or does it connect to the (-) out of the speaker output?
Rino Odorico
Absolute Phase.
The speaker should be connected to the output as shown. This amplifier is configured as a common source amplifier which produces a 180 degree phase shift on the drain when compared to the gate. To keep the absolute phase of the system correct the (-) lead of the speaker is attached to the drain of the amplifier and the (+) lead is attached to ground. The symbols are relative to how many inverting stages you have in the signal path from signal source to the speaker. With an odd number of inverting stages connect as shown. With an even number of inverting stages, the positive lead of the speaker should be attached to the output of the amplifier and the negative lead should be attached to ground. If you were to use the Bride of Zen pre-amp with this amplifier, you would have two inverting stages and would need to switch the polarity of the speaker leads from what is seen on the schematic.
From what I can gather, Mr. Pass believes that keeping the absolute phase is essential if not for many other reasons, just for aesthetics.
The speaker should be connected to the output as shown. This amplifier is configured as a common source amplifier which produces a 180 degree phase shift on the drain when compared to the gate. To keep the absolute phase of the system correct the (-) lead of the speaker is attached to the drain of the amplifier and the (+) lead is attached to ground. The symbols are relative to how many inverting stages you have in the signal path from signal source to the speaker. With an odd number of inverting stages connect as shown. With an even number of inverting stages, the positive lead of the speaker should be attached to the output of the amplifier and the negative lead should be attached to ground. If you were to use the Bride of Zen pre-amp with this amplifier, you would have two inverting stages and would need to switch the polarity of the speaker leads from what is seen on the schematic.
From what I can gather, Mr. Pass believes that keeping the absolute phase is essential if not for many other reasons, just for aesthetics.
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