And now I can get on with the enjoyable job of soldering through-hole components on the 4 main PCBs. 😀
Had to stop soldering for today, after finishing the diodes - due to the stress involved with SMD-soldering. 😱
Andy
A very valid point, thimios - thanks.
However, if I measure the SMD component - after resoldering - and it measures true ... then surely it must be OK?
Andy
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Andy, I’m learning from your experience, thanks for your posts.
Have you determined what the problem was with C1002? Was it a bad solder join that caused the low measurement you reported?
Thanks,
Francois
I think the journey is as fun as the end result. I say ths because it's over rather quickly, but the listening can go on for years. I just LOVE to build. Since we are sheltering in place, I'm going to go ahead and get a case, or make one for the M2X, but I have to say, the J2 and the AN are so good, I really could live with these for the rest of my days. I do love tubes too and both have their merit. Perhaps it's time tube pre. 🙂
I also love the Elekit 8600 for the money, I don't think anything beats that little amp. I only wish they did a mono version of the amp, I think Mr. F is leaving a lot on the table, by not exploring the option. I would build it in a heartbeat to get that last little bit out.
@ Andy, when I was going through my own SMD woes, I soldered and un a few times. IMHO, as long as the part tests in spec solder it in and carry on. As long as you didn't cook the part, the diodes can get hurt, I saw it under major magn and replaced the package when I saw a bit of heat damage.
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Yes, Francois, I think it must've been a bad solder joint that caused the low reading. The first solder join must have moved the cap so that the other end was moved, basically, past - rather than on - the other solder pad. So there was nothing really, for the solder that end to 'grab onto'.
When I removed and replaced it, I made sure the cap was centrally positioned, between its solder pads.
However, given thimios's comment, what I will do this morning is re-measure all the components on the Snubber boards - just to make sure they are reading correctly. 🙂
Aah but with me ... the build is not over 'rather quickly'! 😀
But yes, the joy goes on for years and years.
That's good to hear, JT. I measured my diodes with a Peak DCA75 (between the Gate & Source pin holes) - and they all registered as a diode. So I think in my case, they must have survived the soldering operation. 🙂
Andy
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X111?
Am I right in thinking that:
* I solder this in place
* then push a Bourne pot into its top
* adjust the pot to minimise the DC offset
* then pull out the Bourne pot and measure it
* then solder a res with this value into R113?
(Leaving X111 in place but empty.)
If so - that is a very neat trick! 🙂
Thanks,
Andy
Am I right in thinking that:
* I solder this in place
* then push a Bourne pot into its top
* adjust the pot to minimise the DC offset
* then pull out the Bourne pot and measure it
* then solder a res with this value into R113?
(Leaving X111 in place but empty.)
If so - that is a very neat trick! 🙂
Thanks,
Andy
Yup, that's how it's done... I found very little, if any, difference when changing values. The DC was so low it was moot anyway.
JT
Sure, JT - but I am building the 4R version - which has 20v DC rails and substantially different resistor values in the circuit.
So I expect the pot is going to be useful. 🙂
Andy
We probably could have left the pot out of the design as the DC offset never seems to be more than 10mV, typically less. That’s one nice thing about all of the Alpha designs - no adjustments needed.
Hi,
What's the value of the C125 C126 cap (// FB 22k) for the 8R Nirvana ?
I see mention of 5pf, 10pf and 11pf.
The difference in AC simulation is minimal, 10-11pf looks a little better.
Danny
What's the value of the C125 C126 cap (// FB 22k) for the 8R Nirvana ?
I see mention of 5pf, 10pf and 11pf.
The difference in AC simulation is minimal, 10-11pf looks a little better.
Danny
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Yes, Danny, I'd use 10pF. It does not need to be high to pull the loop gain at very high frequencies.
HD
HD
I have a request regarding the output section.
The board has:
* 4 holes in a square - for a Molex vertical connector (X143)
* and then a double hole above and below the Molex holes - for spade terminals (X144 & X145).
In the pics of the AN boards that you built, X, you used a vertical Molex connector (X143).
Am I correct that you either use X143 ... or you use X144+X145?
Whichever you use, the spkr terminal's ground post is connected to ground on the AN PCB (which is X145 or the 2 pins in the Molex connector which are next to X145) - not the ground on the SLB?
Thanks,
Andy
The board has:
* 4 holes in a square - for a Molex vertical connector (X143)
* and then a double hole above and below the Molex holes - for spade terminals (X144 & X145).
In the pics of the AN boards that you built, X, you used a vertical Molex connector (X143).
Am I correct that you either use X143 ... or you use X144+X145?
Whichever you use, the spkr terminal's ground post is connected to ground on the AN PCB (which is X145 or the 2 pins in the Molex connector which are next to X145) - not the ground on the SLB?
Thanks,
Andy
