I have tested all my other JFETs in-circuit now. They're mostly all working, which is great! Like I said before, I will test them for THD when driven with a sound card, to see the possible effect of different gfs.
If I were to draw a conclusion from the data I've collected so far, I would state that VGSoff has to be around -5,0V or lower and IDSS has to be 3,0mA or higher. Maybe that will help future builders to pick some parts from the bin and save the expensive K170's for some more demanding projects
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All JFETs were tested with a DCA75.
If I were to draw a conclusion from the data I've collected so far, I would state that VGSoff has to be around -5,0V or lower and IDSS has to be 3,0mA or higher. Maybe that will help future builders to pick some parts from the bin and save the expensive K170's for some more demanding projects
.All JFETs were tested with a DCA75.
Attachments
Speaking of supplies. What about this 120W linear supply customized for 24V? Any benefit to using these instead. I bought 2 v1.6 kits and intend to only use them as balanced monoblocks. And the pair of the liner supplies could be an upgrade.
120W DC Linear Regulated Power Supply DC Output 5V 9v 12v 15v 24V Can be choose | eBay
120W DC Linear Regulated Power Supply DC Output 5V 9v 12v 15v 24V Can be choose | eBay
But is that reading 120 W at 5 V ?
Can you confirm that 120 W is available at 24 V . I have found very deceptive advertisements on eBay when trying to purchase linear power supplies they would often give several voltages 5v, 9v, 12v, 15v, 24v, but Bragg the wattage output at its highest rating but lowest voltage and not tell you that part of the information . Example 5 volts @ 120 W, 10 V @ 60 W, 24 V @ 22 W.
My Best Buy I could find online delivered free charge on Amazon prime was $59 each Toroidal transformers, model: WE-200VA, 120V input, 18V Dual Output, from a online called “Wingo Store”. I bought circuit boards Universal Power Supply from DIY audio store to build dual monoblock power supplies for my mono block amp camp amp. I will up the output of the transformer to 600VA because I want to use it on the F5-turbo. It’s too expensive to keep building power supplies for every amplifier so I want to build one power supply and just change voltage taps for different amplifiers keep the power supplies external.
If you or somebody purchases that linear power supply let us know if the power ratings are truly 120 W at 24 V it appears to be a good deal if that’s true.
Can you confirm that 120 W is available at 24 V . I have found very deceptive advertisements on eBay when trying to purchase linear power supplies they would often give several voltages 5v, 9v, 12v, 15v, 24v, but Bragg the wattage output at its highest rating but lowest voltage and not tell you that part of the information . Example 5 volts @ 120 W, 10 V @ 60 W, 24 V @ 22 W.
My Best Buy I could find online delivered free charge on Amazon prime was $59 each Toroidal transformers, model: WE-200VA, 120V input, 18V Dual Output, from a online called “Wingo Store”. I bought circuit boards Universal Power Supply from DIY audio store to build dual monoblock power supplies for my mono block amp camp amp. I will up the output of the transformer to 600VA because I want to use it on the F5-turbo. It’s too expensive to keep building power supplies for every amplifier so I want to build one power supply and just change voltage taps for different amplifiers keep the power supplies external.
If you or somebody purchases that linear power supply let us know if the power ratings are truly 120 W at 24 V it appears to be a good deal if that’s true.
Noticed also that even though it says there is a 120 volt model that the only specs given are for the 220 volt model. I did not spend much time looking for the 120 volt model: For reasons ThermalAlchemy pointed out. It *might do 120 watts at five volts. Expect it runs out of current pretty quickly as the output voltage increases.
In the meantime - don't hear anything but silence between tracks with the Meanwell supplies. Using an active crossover and have my ACA's driving heil AMT's (Balanced in from the crossover output). Awe inspiring is a good way to describe what we hear from these amps!
In the meantime - don't hear anything but silence between tracks with the Meanwell supplies. Using an active crossover and have my ACA's driving heil AMT's (Balanced in from the crossover output). Awe inspiring is a good way to describe what we hear from these amps!
Right, they don’t specify the current output at 25v, it probably as you mentioned drops. This one actually specified 24v 5A but more than double the cost.
150VA DC24V @5A Low Noise LPS HI-END Linear Power Supply for Audio PSU | eBay
Hi everyone - first time poster here (and brand new to DIY).
I have a v1.6 amp on order and I'm wondering if it'll work with my current speakers, Audio Physic Sitaras.
http://www.audiophysic.de/download/sitara/sitara_hifinews_07_2009.pdf
My worry is that the amp's specs only mention 8 ohm impedence, but the Sitaras are 4 ohm. Will I potentially damage either the amp or the speakers by hooking them up together?
Thanks in advance for your input!
I have a v1.6 amp on order and I'm wondering if it'll work with my current speakers, Audio Physic Sitaras.
http://www.audiophysic.de/download/sitara/sitara_hifinews_07_2009.pdf
My worry is that the amp's specs only mention 8 ohm impedence, but the Sitaras are 4 ohm. Will I potentially damage either the amp or the speakers by hooking them up together?
Thanks in advance for your input!
Nominal 4Ω. That is the paralleled woofers. What is really important is the flatness of the impedance (i could not quickly find a graph) as the ACA has a relatively high outout impedance and end FR of the system will have the impedance convolved into that.
You can only hook it up and listen to see if you have any issues with the pairing.
dave
Mine drive 4 ohm speakers just fine. I looked at your link. Nice looking and efficient.. Have fun!
Another power supply question need guidance
Another power supply question need guidance.
Good afternoon all, since I’m new to this hobby only build three headphone amplifier is by Peter millet, And one Amp Camp Amp my first power amplifier. Last year I was gifted a couple hundred new old stock tubes and did not know what to do with them that is what got me into this hobby . I would like to build my first tube tube rectifier power supply for my ACA. I looked at the forum thread on tubes and the thread on power supplies in my eyes just glazed over with all the complexity and not exactly finding what I’m looking for. Can someone with more experience and greater knowledge guide me to some threads on 24 V tube rectify power supply construction . I built a 24 V power supply my first one using DIYaudio universal power supply circuit board with a toroidal transformer I was very satisfied with this build and want to step it up a notch and learn more especially since I have a bunch of new free old stock rectifier tube‘s . Guidance greatly appreciated I’ve become extremely addicted and want to learn more .
Another power supply question need guidance.
Good afternoon all, since I’m new to this hobby only build three headphone amplifier is by Peter millet, And one Amp Camp Amp my first power amplifier. Last year I was gifted a couple hundred new old stock tubes and did not know what to do with them that is what got me into this hobby . I would like to build my first tube tube rectifier power supply for my ACA. I looked at the forum thread on tubes and the thread on power supplies in my eyes just glazed over with all the complexity and not exactly finding what I’m looking for. Can someone with more experience and greater knowledge guide me to some threads on 24 V tube rectify power supply construction . I built a 24 V power supply my first one using DIYaudio universal power supply circuit board with a toroidal transformer I was very satisfied with this build and want to step it up a notch and learn more especially since I have a bunch of new free old stock rectifier tube‘s . Guidance greatly appreciated I’ve become extremely addicted and want to learn more .
I was driving my Dynaudios with 3W single-ended class A valve amplifier with great success - they produced amazing sound, very pleasant and enjoyable with a great amount of detail and unbelievable extension, top and bottom; dynamics and volume levels were more than enough even for a medium-size room. The speakers are 4 ohms of 86dB/W sensitivity, but they do have a flat impedance curve across a full audio range... which is also quite important.
Increasing the voltage above 24V is not going to improve ACA drive capability much (of a 4 ohms speaker); you need to increase the quiescent current above 1.4A.... so, if you are a brave DIY-er and the heatsink dissipation is supported with few fans here and there, reduce the R1&R2 and R3&R4 proportionally, while keeping an eye on total permissible Q1 and Q2 die dissipation. The voltages at R8 and R15 will also change... but, as I said, you can experiment and see what happens.
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That's not something I would recommend. It's not the voltage but the amperage. Your average power tube amp tube rectifier is made for high voltage, low current. Low powered as it is, the ACA requires low voltage, high current. Finding a tube that can deliver over 1A of current - and into 10,000uF of capacitance - well good luck with that.
If you do want to build a linear power supply - stick with solid state rectifiers. If you want to make it interesting, put some chokes in there.
Did you put power supply on the board? What are those four ss thingies? Schottky diods?