It does have three test pads located at the end of its shunt section towards the audio section where you can tap +10V/0/-10V regulated DC.
To get as high as +/-18V that will be just raw DC (has ripple and follows the mains level play at a ratio) found between its reservoir capacitors corresponding pins and ground.
Unless a higher voltage transformer will be used and a Vref modification with added Zener or drop resistor will be applied.
To get as high as +/-18V that will be just raw DC (has ripple and follows the mains level play at a ratio) found between its reservoir capacitors corresponding pins and ground.
Unless a higher voltage transformer will be used and a Vref modification with added Zener or drop resistor will be applied.
Hi, I'm almost finished with my DCB1 build and have just tried it with power. I get almost perfect measurements with voltage rails being 9.82V on pluss side 9.84V on minus side, offset is 0.5 and 0.6 mV steady. However over R set resistors I get about 1.7V on minus side but only about 1.55V on pluss side.
Should I consider this good enough?
Should I consider this good enough?
Its normal as the NMOS and PMOS have Vgs differences resulting to somewhat different Vdrop over the plus and minus side Rset resistors. Its a rather small current bias difference not able to unbalance the MOSFETS transconductance enough between sides. They are big semiconductors with rigid curves at this almost turn on current range considering their maximum ability.
In fewer words your build behaves super fine in all the DC aspects you measured.
In fewer words your build behaves super fine in all the DC aspects you measured.
Hello Salas.
I am planning to replace volume pot to muses72323.
https://nw-electric.way-nifty.com/blog/files/muses72323vol_r11e59b9ee8b7afe59bb3.pdf
I am wondering if I can bypass input 22uf cap
and output 10uf cap.
I will bypass opamp.
I am planning to replace volume pot to muses72323.
https://nw-electric.way-nifty.com/blog/files/muses72323vol_r11e59b9ee8b7afe59bb3.pdf
I am wondering if I can bypass input 22uf cap
and output 10uf cap.
I will bypass opamp.
See Meldano's 72323 application for example, I think he does not use coupling capacitors? A thing to keep in mind is DCB1 will not stop sources DC offset if let through or DC produced in the electronic volume implementation due to chip offsets or failure.
I guess when you will get a specific 72323 volume board first thing is to see with a multimeter if there is some inherent DC on the chip's in/out pins before any coupling capacitors.
I guess when you will get a specific 72323 volume board first thing is to see with a multimeter if there is some inherent DC on the chip's in/out pins before any coupling capacitors.
There is a sequence of things and in this very hobby/technical field it is important to know some basics and especially so because we deal with invisible matters. Possibly damaging or even dangerous matters.
If you don’t know how to measure DC with a DMM then you have missed some steps. IMO you should first know how to measure and what the implications are of DC offset voltage. Building a device may be a bridge too far at this time.
I know we are living in youtube tutorial times but please start with the basics.
If you don’t know how to measure DC with a DMM then you have missed some steps. IMO you should first know how to measure and what the implications are of DC offset voltage. Building a device may be a bridge too far at this time.
I know we are living in youtube tutorial times but please start with the basics.
In post #2,728 schematic as linked, measure DCV by probing pins 27,22,11,6 vs ground. Red test lead to pins one by one, black always at ground. If zero volt or very few mV in all cases it means your chip does not produce dangerous offsets of its own so the capacitors are only there to block external offsets. From sources or active parts. For JFET input type OP-AMP there are no series capacitors on pins 11,6 in Muses Datasheet (page -7-) for instance.
Cant wrap my head around grounding
As far as I understand the safety ground or aka earth ground must be connected as close as possible to the socket to prevent one killing themselves.
Theres also chassis ground that makes chassis to act as a shield.
I live in a somewhat old house where all sockets have 2 terminals and are missing earth wire the yellow green one. Even if I do mount earth ground to chassis it will not guarantee that my son will not have a stepfather.
Ive looked at numerous photos of dcb1 layouts and did not see chassis ground connected to the pcb where trafo center tap is connected.
How should it be actually done?
If theres no earth ground, should I connect trafo safety fround and chassis ground to center tap?
As far as I understand the safety ground or aka earth ground must be connected as close as possible to the socket to prevent one killing themselves.
Theres also chassis ground that makes chassis to act as a shield.
I live in a somewhat old house where all sockets have 2 terminals and are missing earth wire the yellow green one. Even if I do mount earth ground to chassis it will not guarantee that my son will not have a stepfather.
Ive looked at numerous photos of dcb1 layouts and did not see chassis ground connected to the pcb where trafo center tap is connected.
How should it be actually done?
If theres no earth ground, should I connect trafo safety fround and chassis ground to center tap?
Keep it insulated in this circumstance. If the volume pot will be in distance from the front panel use a plastic extension rod. Only connect signal ground to chassis if the pot has to be mounted in a way that its metal parts will be conductive to chassis and/or knob. With a wire from the third pin of the volume pot (as we face it).
Salas, to paraphrase, are you suggesting it to keep ungrounded? Basically every part must be not in contact with chassis? The extension rod is made of metal and the joint is also made of metal. I think I will have to wrap pot with teflon tape and check for continuity.
And let's say once I move to a flat with modern installation, I should hook up the third safety ground pin to the chassis and that is all, right?
Sorry, I want to be sure and this language barrier does not help.
And let's say once I move to a flat with modern installation, I should hook up the third safety ground pin to the chassis and that is all, right?
Sorry, I want to be sure and this language barrier does not help.
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