Yes, that's what I found. It doesn't indicate volts required for full power output, or voltage to induce clipping. You'll have to experiment to figure out.
Hello
Best than to check with Tango ( distributor ? ) for NP126 data - since these are not cheap items i personally would not dare to assume error but would try to find out what is the true state, if i could.
Regards, Krca
I have written to ISO Tango and asked them to confirm this which I found on the reseller site. I also received a quote to buy direct from the company.
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The Tango NP-126 has 2 primary windings and can be used as Single-ended (SE) to SE, or PP to SE, or SE to PP.
With the 2 primary windings connected in series the NP-126 can be used with tubes which internal resistance is between 10K and 20K. (tubes with lower internal resistance are always possible) When the primary windings are connected in parallel the NP-126 can be used with tubes which internal resistance is between 2K5 and 5K.
———————-
The Tango NP-126 has 2 primary windings and can be used as Single-ended (SE) to SE, or PP to SE, or SE to PP.
With the 2 primary windings connected in series the NP-126 can be used with tubes which internal resistance is between 10K and 20K. (tubes with lower internal resistance are always possible) When the primary windings are connected in parallel the NP-126 can be used with tubes which internal resistance is between 2K5 and 5K.
I think I'm closer on the schematic after working for more on it and getting advice. Also here is a screen shot of the PSUD I am trying to model. I get close to proper voltage. I am guessing at impedance of the used TRIO power transformer and stuff. Also on the schematic removed the 5k resistor at the input to the output transformer as we dropped the voltage on the PSU side before that I think. I drew it in as a resistor with 0 ohms to remind me it used to be there in the Japanese circuit we started with. Tried to draw in the black magic choke stuff based on some emails from the power guru.
Attachments
Update on volume from DAC when using DAC with a pre-amp from guys on the DAC forums who are using pre-amps...
They recommend to send to the pre-amp at 0db from the DAC and let preamp do it.
Also they pointed me to this article on volume control.
https://diyaudio.pl/downloads/digital-vs-analog-volume-control_by_ess.pdf
They recommend to send to the pre-amp at 0db from the DAC and let preamp do it.
Also they pointed me to this article on volume control.
https://diyaudio.pl/downloads/digital-vs-analog-volume-control_by_ess.pdf
You should check how much current draws R1 shunt resistor ( first after the choke ) and see how much power it burns to size it in Watts properly.
PSUD - change the rectifier configuration to full wave - on the picture is half wave ( assuming You are using transformer with Center Tap - also 6X5 rectifier tube is for full wave rectification - as drawn in Your schematic ).
PSUD - change the rectifier configuration to full wave - on the picture is half wave ( assuming You are using transformer with Center Tap - also 6X5 rectifier tube is for full wave rectification - as drawn in Your schematic ).
Tried to put resistor in the lower branch ( 0 Volts ) in PSUD and could not do it.
Try to find Morgan Jones - Valve Amplifiers fourth edition - apart from being a good book there is an extended chapter about chokes - You can buy a book or maybe find it in pdf format for free download. Also Morgan Jones - Building Valve Amplifiers for lot of practical advices.
For the books about building valve amps - there are links at Pette Millett's web site - the major one is Radiotron Designer's Handbook 4th edition, downloadable for free since it is was printed in 1953 - this is one of the reference books.
Try to find Morgan Jones - Valve Amplifiers fourth edition - apart from being a good book there is an extended chapter about chokes - You can buy a book or maybe find it in pdf format for free download. Also Morgan Jones - Building Valve Amplifiers for lot of practical advices.
For the books about building valve amps - there are links at Pette Millett's web site - the major one is Radiotron Designer's Handbook 4th edition, downloadable for free since it is was printed in 1953 - this is one of the reference books.
What is the point of a 0 Ohm resistor?
Do not guess at the resistance of the primary or secondaries of the transformer. Measure them with an ohm meter. Same for the choke.
You do not need to be able to insert a resistor onto the 0V or "ground" rail of the PSU. If you want a resistor on the "+" rail and the "0V" rail, these can be considered as in series and can be represented with one resistor in PSUD.
E.g., two resistors, each 50ohm, equals one 100 ohm resistor.
Look at DHT Rob's guidance on how to use PSUD. (Google that name and PSUD.)
Your primary checks will be voltages at capacitors, not the transformer.
What is a dual coil choke? Can it not be modeled as a single choke with a definite inductance and DC resistance?
You should know the total current draw of your preamp circuit. Use that (current source) as the load on the PSU in PSUD instead of a resistance.
KISS
Do not guess at the resistance of the primary or secondaries of the transformer. Measure them with an ohm meter. Same for the choke.
You do not need to be able to insert a resistor onto the 0V or "ground" rail of the PSU. If you want a resistor on the "+" rail and the "0V" rail, these can be considered as in series and can be represented with one resistor in PSUD.
E.g., two resistors, each 50ohm, equals one 100 ohm resistor.
Look at DHT Rob's guidance on how to use PSUD. (Google that name and PSUD.)
Your primary checks will be voltages at capacitors, not the transformer.
What is a dual coil choke? Can it not be modeled as a single choke with a definite inductance and DC resistance?
You should know the total current draw of your preamp circuit. Use that (current source) as the load on the PSU in PSUD instead of a resistance.
KISS
Hello,
It seems only the old people amongst us have a clue about choke input. They probably remember Allen Wright saying the input choke should be bigger than the power transformer.
Lundahl chokes always behaved very well when used in choke input circuitry and on top of that they are constructed with two identical coils.
Don't tell us now we have bigger caps and we dont need chokes anymore.
Greetings,Eduard
It seems only the old people amongst us have a clue about choke input. They probably remember Allen Wright saying the input choke should be bigger than the power transformer.
Lundahl chokes always behaved very well when used in choke input circuitry and on top of that they are constructed with two identical coils.
Don't tell us now we have bigger caps and we dont need chokes anymore.
Greetings,Eduard
In your preamp, everything you hear is the result of the quality of the transformers.😢
For sure. 👍 and I find power really really is overlooked and makes an audible difference. I learned that building a hi-fi DAC. And then short connections everywhere you can whether it’s traces on a circuit board or wires or anything.
Hi fusion360guy,
I'll agree. The very best thing you could possibly do is find a copy of Morgan Jones "Building Valve Amplifiers", BVA for short. Morgan knows precisely what he is talking about, and comes from a common sense perspective.
Powered speakers are always problematic. The good news is that you can use your design to drive a better solution. Keep in mind your amplifiers are far better located with the rest of your gear. The worst cable to run long distance is the signal feed to the amplifier.
I'll agree. The very best thing you could possibly do is find a copy of Morgan Jones "Building Valve Amplifiers", BVA for short. Morgan knows precisely what he is talking about, and comes from a common sense perspective.
Powered speakers are always problematic. The good news is that you can use your design to drive a better solution. Keep in mind your amplifiers are far better located with the rest of your gear. The worst cable to run long distance is the signal feed to the amplifier.
Thanks @anatech it’s awaiting me in my Apple Books! I love common sense! But find it in short supply! Maybe bedtime reading tonight. I’ve been so busy following up on the advice of all here this weekend! I will eventually build the power amp and speakers! II came to that angle from being a semi pro musician. I retire next May and will have time to build something I could never afford. Same with the Serious pre I hope and Franken DAC I just built.
My cable from DAC to serious pre will be short. But my speakers are on the other side of the room. xLR transformers cheaper than new house 🏡! Especially in post COVID market !
My cable from DAC to serious pre will be short. But my speakers are on the other side of the room. xLR transformers cheaper than new house 🏡! Especially in post COVID market !
Well, it is a big book. I prefer paper.
There is a lot of great information he gives us, so you aren't going to rip through it if you hope to retain anything.
There is a lot of great information he gives us, so you aren't going to rip through it if you hope to retain anything.
Tango np126 core not big enough lacks transperiency. Choke input power supply only way to go, beats any other type of voltage regulation. Use hasimoto choke, beautifull sound beats lundhal hands down and yes they are expensive.
Hi Michael C,
You may prefer this for various reasons. There are solid reasons why electronic voltage regulators were developed, and they were constantly improved over decades and decades. Also, a choke is a choke as long as it has reasonable quality. Leakage factors and series resistance come into play, and higher resistance isn't always a bad thing. Being stuck on one brand doesn't make any sense at all.
So you may say "only way to go", but that is for you alone. The rest of the world moved on a long time ago. Choke input - sure (it has problems you need to be aware of), followed by electronic regulation. The choke attenuates high frequencies effectively, couple that with electronic regulation and you've got something. Resistive input also works well in a pi configuration with a smaller input cap. than most use.
Ahhh, nope! Not even close.
You may prefer this for various reasons. There are solid reasons why electronic voltage regulators were developed, and they were constantly improved over decades and decades. Also, a choke is a choke as long as it has reasonable quality. Leakage factors and series resistance come into play, and higher resistance isn't always a bad thing. Being stuck on one brand doesn't make any sense at all.
So you may say "only way to go", but that is for you alone. The rest of the world moved on a long time ago. Choke input - sure (it has problems you need to be aware of), followed by electronic regulation. The choke attenuates high frequencies effectively, couple that with electronic regulation and you've got something. Resistive input also works well in a pi configuration with a smaller input cap. than most use.