The black band on a red diiode is the equivalent of the silver band on a black diode.
Not sure what you are looking at with the double lines. Double lines is usually the symbol for capacitors.
A diode on a pcb is usually represented by an offset single line in a rectangle or a triangle with a single line at the pointed end of the triangle.
Post a picture of your board.
Not sure what you are looking at with the double lines. Double lines is usually the symbol for capacitors.
A diode on a pcb is usually represented by an offset single line in a rectangle or a triangle with a single line at the pointed end of the triangle.
Post a picture of your board.
Thank you, I got it right, I was just venting ;-} PCBs give me gas and some of these parts are tweezers small. Resistors half the size of even Xicons, yikes. It's been more than 20 years since I worked a PCB and never low voltage.I'm a point-to-point kind of guy. The last pre-amp I built, the only board was stuffed by John Broskie. 😆
Looking forward though to having a Nelson Pass design for 1/100th of the price.
You have the orientation correct. Band on the part with the band on the board.
Those diodes are pretty little!
Those diodes are pretty little!
I see that these are 8 pin and not 10pin. Which holes would you not use with these?
Maybe a confusing EC2 photo. EA2 are 10 pin. Surely because a lot have been used in our builds. Originally NEC now KEMET.
Attachments
All parts on deck except the LED which I'll wire in once the boards are in the case. One of you guys was very hot on the Clarity Caps so, liking the color and the price, I went with them. I had experience with them maybe 20 years ago when they were yellow and first came to these shores. Didn't like'm in an 2A3 Amp I built then, too much clarity, not enough music, so we'll see.
Have to decide between a PEC KKA 100k or Audio Note 50k I have on hand. Not a big fan of either but they're certainly better sounding than the dreadful no-escape-from Blue Alps. I have a Goldpoint V24 in my current pre-amp (pic above) which I judge, after the circuit and then the power supply, the most impactful of all "upgrades" for sound quality one can make. Maybe if this experiment works out I'll get one but for now, it's the parts bin.
Next: machine the case.
Have to decide between a PEC KKA 100k or Audio Note 50k I have on hand. Not a big fan of either but they're certainly better sounding than the dreadful no-escape-from Blue Alps. I have a Goldpoint V24 in my current pre-amp (pic above) which I judge, after the circuit and then the power supply, the most impactful of all "upgrades" for sound quality one can make. Maybe if this experiment works out I'll get one but for now, it's the parts bin.
Next: machine the case.
About those Wima Caps PN BC2077-ND....
MKPs, non-directional, right?
I had an e-mail today to let me know something called the ACA Mini parts were in stock and I looked up the thread. Mr. Pass makes the point that one must take care to get the polarity of the Wima Caps right. Are those Wimas a different animal?
MKPs, non-directional, right?
I had an e-mail today to let me know something called the ACA Mini parts were in stock and I looked up the thread. Mr. Pass makes the point that one must take care to get the polarity of the Wima Caps right. Are those Wimas a different animal?
Sorry to report that the perfect enclosure for size and price ($14.95) just can't be properly machined. I used every type of drill bit, a punch, and gave a lot of thought to Dremeling out the back panel then using a metal overlay but no joy. The metal is just too thin.
Pity, I thought the circuit called for a bit of whimsy.
Pity, I thought the circuit called for a bit of whimsy.
If you could somehow support the metal, it might work. I was thinking a piece of wood on the inside, though it would have to be supported somehow. What if you had a piece front and back (on the inside) with short pieces kind of bracing the two sides up against the metal?
I have a B1 the same board as in post 5026 above. I lost the L channel the other day and after a process of elimination found it was the B1.
I can see nothing obvious that has happened. I have measured the volatages of the SK170s which are as follows :-
D= Drain G= gate etc
Q200 D= 24v
G= 11.2v
S= 12.2v
Q201 D=24v
G= 0v
S= 0v
Q100 D=24v
G=11.2v
S=12.2v
Q101 D=12.2v
G= 0v
S=0v
I can't seem to find any troubleshooting figures for checking the fets, nor voltages at the resistor junctions etc. Does anyone know if the above readings are correct or where I might find the info.
I can see nothing obvious that has happened. I have measured the volatages of the SK170s which are as follows :-
D= Drain G= gate etc
Q200 D= 24v
G= 11.2v
S= 12.2v
Q201 D=24v
G= 0v
S= 0v
Q100 D=24v
G=11.2v
S=12.2v
Q101 D=12.2v
G= 0v
S=0v
I can't seem to find any troubleshooting figures for checking the fets, nor voltages at the resistor junctions etc. Does anyone know if the above readings are correct or where I might find the info.
Q200 S and Q201 D are connected together so they should have the same voltage. Measurement error?
The measurements are correct. I have some SK170s. Should I swap out Q201 and see if that is faulty?
yes, 3times 24V is too much, should not happen........
look for a bad soldering point /connection at q201.
look for a bad soldering point /connection at q201.
Q200 source and Q201 drain are connected so their voltage should be the same.
If 24V is at Q200 source and Q201 drain, then replacing Q201 would be a good idea.
If 24V is at Q200 source and Q201 drain, then replacing Q201 would be a good idea.
All fixed. Q201 had a dodgy solder joint, not sure which one so I reflowed all 3. Voltages are now correct. I also did all the other fets. Good job it was a simple fix as the fets I have are SK117 🙂 not 170s. Odd in that I build it years ago and used it for about a year with an F2 and then shelved it for many years and brought it out again to pair with an ACA. It was fine for weeks and then.......but that is sometimes how it goes.
My links to the diyaudio store for the B1 PCB Kit are no longer working and a search of the store, nada. afew people have expressed an interest. Got a working link?
