Absolutely, if you wire it as it was suggested with the red and black wires as the primary the blue and brown will have a couple thousand volts on it! Yikes!
You are right, the MULTICOMP PRO VTX-146-050-115Toroidal Transformer, 50 VA, 230V, 2 x 15V https://nl.farnell.com/multicomp/vtx-146-050-115/transformer-50va-2-x-15v/dp/1675058 must be powered by brown and blue
Maybe not “high end” but it’s cheap and does the job and it’s in Europe:
https://www.audiophonics.fr/en/line...rd-lm317-337-tl431-5v-to-37v-15a-p-12221.html
https://www.audiophonics.fr/en/line...rd-lm317-337-tl431-5v-to-37v-15a-p-12221.html
Audiophonics sell good stuff, I ordered before, so thanks, I will defenitely look into it
@wayne
@6L6
This is a question that I thought best addressed to the store... but they referred me to you.
After buying a kit (with parts) last year I've been leaning more and more to building a fully balanced version which naturally requires a second kit.
I was wondering if, after all this time, there were parts substitutions in the store kits that might alter the performance such that the two channels wouldn't be the same... and be of consequence.
You guys aren't putting these kits together (like the Pearl 3 pioneer kits) are you? Even so... thoughts?
@6L6
This is a question that I thought best addressed to the store... but they referred me to you.
After buying a kit (with parts) last year I've been leaning more and more to building a fully balanced version which naturally requires a second kit.
I was wondering if, after all this time, there were parts substitutions in the store kits that might alter the performance such that the two channels wouldn't be the same... and be of consequence.
You guys aren't putting these kits together (like the Pearl 3 pioneer kits) are you? Even so... thoughts?
I finally got around to testing the three boards I built nearly two years ago. The one with MOSFETs works great, and one of the ones with JFETs works fine, too. The other one I got a transistor backwards: Q11. Will it likely be OK if I remove it and resolder it? Or should I plan to replace it?
Also, the DC offset on that board is not stable, unlike the one with the MOSFETs. It fluctuates quite a bit between -3mV and +3mV or so. Is that unusual? Is there somewhere obvious to look for a problem? I'm thinking about adding a cap at the output, just to be on the safe side. What's a reasonable value? 10uF?
Also, the DC offset on that board is not stable, unlike the one with the MOSFETs. It fluctuates quite a bit between -3mV and +3mV or so. Is that unusual? Is there somewhere obvious to look for a problem? I'm thinking about adding a cap at the output, just to be on the safe side. What's a reasonable value? 10uF?
Color me confused... JFETs? MOSFETs? Where? Q8 and Q10? I'm only seeing BJT's there @post #1..
A part can be removed and reused if you are an expert solder slinger and know how to do it without overheating the part or wrecking the PCB. Or you can just chop it out of there and install a new one, whatever.
I wouldn't sweat a few mV of offset, that's practically nothing...
A part can be removed and reused if you are an expert solder slinger and know how to do it without overheating the part or wrecking the PCB. Or you can just chop it out of there and install a new one, whatever.
I wouldn't sweat a few mV of offset, that's practically nothing...
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My bad.
I know that, in principle, I can desolder, etc, parts. But there have been other times when putting a part in the wrong way fried it. What I'm wondering is whether this particular part is likely to have been fried. (If I had an extra, I'd just use it, but I doubt I do.)
I know that, in principle, I can desolder, etc, parts. But there have been other times when putting a part in the wrong way fried it. What I'm wondering is whether this particular part is likely to have been fried. (If I had an extra, I'd just use it, but I doubt I do.)
rikiheck: I overheated the power supply on a headphone amp build last year. Debacle! While checking parts I ran across this site which describes testing MOSFETs, etc. I hope it helps. https://www.wellpcb.com/testing-a-mosfet.html
There are a few test concepts on this page: "Using a measuring meter" (sic.) and a few other tests such as "Testing a MOSFET - Diode Test" and "Testing a MOSFET - Resistance Test." Taken together you can likely get a better understanding of whether your components are working correctly. Also, further down are even more details. Just search for "The following are some of the key steps when performing this test." That seems to be the meat of the article.
William2001's testing method seems: ahhhh, so much easier! I keep forgetting to get one of those!
There are a few test concepts on this page: "Using a measuring meter" (sic.) and a few other tests such as "Testing a MOSFET - Diode Test" and "Testing a MOSFET - Resistance Test." Taken together you can likely get a better understanding of whether your components are working correctly. Also, further down are even more details. Just search for "The following are some of the key steps when performing this test." That seems to be the meat of the article.
William2001's testing method seems: ahhhh, so much easier! I keep forgetting to get one of those!
Hmm. No answer. Odd. If it were me, I would purchase two new kits and sell your previous version in the Swap Meet section, just to be safe.
@bhjazz
oh but I did get an answer... just not here.
you diyaudio chaps are the best!
(someone found a stash of resistors that matched the ones from last year. but the real answer was that the critical semiconductors were still the same and the sound of both channels would be very close in any event.
so... second channel kit is on the way!)
oh but I did get an answer... just not here.
you diyaudio chaps are the best!
(someone found a stash of resistors that matched the ones from last year. but the real answer was that the critical semiconductors were still the same and the sound of both channels would be very close in any event.
so... second channel kit is on the way!)
I’ve been using Wayne’s BA2018 with an Academy Audio Muses volume for some time now and I have been enjoying the sound. In the application note on how to use the Muses with WBA2018 I read it was also possible to use WBA2018 with Academy Audio’s balanced pre amp (https://www.academyaudio.com/isb). Has anyone tried that?
Hey Leeuwarden! The link you provided is for the Academy Audio balanced input board. It is not a balanced preamp by itself. Academy Audio also has a single-ended input board as well. I know that SRMcGee built his BA2018 with the single-ended board, and I am as well (although mine is not yet done 
) The input board(s) just implement the Muses chip for volume and input selection. I would imagine, though, that having the input switching with the Muses system would be better than many mechanical input switches. I say that because I've had some issues with them in a few builds. Your own experience could be different.
) The input board(s) just implement the Muses chip for volume and input selection. I would imagine, though, that having the input switching with the Muses system would be better than many mechanical input switches. I say that because I've had some issues with them in a few builds. Your own experience could be different.