cordless drill meet wires, table and clamp. zzzzzzzzzt. zzt, zzt.
Very nice build.
Very nice build.
Built up some Norwood boards.
Sharing pics to help others. Note the flux on the pads prior to soldering. I used MG 8341 paste for reference. Also note that the IC 5002 bevel is on the "top" of the board when looking at the PCB board when the silkscreen is read upright. Both of the IC silscreens are upside-down relative to the PCB board silkscreen per Jim's "notes for builders 2018". That was a bit tricky for me to grasp and I gotta say thanks for @6L6 for helping confirm the correct orientation.
Cleaning the boards with 99% IsoP after all the SMD parts were installed was pretty simple. Be sure to do that before soldering in the two larger components.
The images below include zoomed in shots from a stereo microscope.
Sharing pics to help others. Note the flux on the pads prior to soldering. I used MG 8341 paste for reference. Also note that the IC 5002 bevel is on the "top" of the board when looking at the PCB board when the silkscreen is read upright. Both of the IC silscreens are upside-down relative to the PCB board silkscreen per Jim's "notes for builders 2018". That was a bit tricky for me to grasp and I gotta say thanks for @6L6 for helping confirm the correct orientation.
Cleaning the boards with 99% IsoP after all the SMD parts were installed was pretty simple. Be sure to do that before soldering in the two larger components.
The images below include zoomed in shots from a stereo microscope.
Attachments
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Question on the FETs
The BOM calls for (per channel of course ) 1 each IRFP240 IRFP9240. When I look on digikey they are eol'd and the replacements are listed as:
IRFP240PBF and IRFP9240PBF
Are these safe to use? I know some people do matching is that necessary or should I just buy them and not worry?
Thanks!
The BOM calls for (per channel of course ) 1 each IRFP240 IRFP9240. When I look on digikey they are eol'd and the replacements are listed as:
IRFP240PBF and IRFP9240PBF
Are these safe to use? I know some people do matching is that necessary or should I just buy them and not worry?
Thanks!
Don't worry, these are the new lead free versions, I use them in my amp too, they are perfectly safe - and no matching is needed.
Hey all, I'm still scanning through the thread - its rather lengthy 😉
I know I need 18vac secondaries and, I believe, a combined 400va ish right? I'm leaning towards getting 2 transformers of a lower capacity - for instance ~200va each channel. Does this seem sensible? Transformers I'm looking at:
https://www.antekinc.com/au-2218-200va-18v-transformer/
https://www.antekinc.com/as-3218-300va-18v-transformer/
https://www.hammfg.com/part/1182G18?referer=1026
https://toroid.com/product/rectifier-transformer-p-n-718-182-190va-117-234v-50-60hz-output/ - very close. Curiously expensive compared to the others though
https://toroid.com/product/rectifier-transformer-p-n-732-182-320va-117-234v-50-60hz-output/ - would be over the necessary VA but room to grow?
https://www.antekinc.com/au-4218-400va-18v-transformer/ - would be a single transformer and just wire each secondary coil to the left/right vs dual?
Also on the filter/dc side - what size caps do I want to go with? Should I just take a hammer and get the biggest I can order? I have the rectifier and dc board from @rhthatcher in thread https://www.diyaudio.com/community/...ated-build-guide.241729/page-508#post-7887284 - I have ordered the power supply pcb and rectifiers just gotta figure out the toroid and capacitor sizing!
I know I need 18vac secondaries and, I believe, a combined 400va ish right? I'm leaning towards getting 2 transformers of a lower capacity - for instance ~200va each channel. Does this seem sensible? Transformers I'm looking at:
https://www.antekinc.com/au-2218-200va-18v-transformer/
https://www.antekinc.com/as-3218-300va-18v-transformer/
https://www.hammfg.com/part/1182G18?referer=1026
https://toroid.com/product/rectifier-transformer-p-n-718-182-190va-117-234v-50-60hz-output/ - very close. Curiously expensive compared to the others though
https://toroid.com/product/rectifier-transformer-p-n-732-182-320va-117-234v-50-60hz-output/ - would be over the necessary VA but room to grow?
https://www.antekinc.com/au-4218-400va-18v-transformer/ - would be a single transformer and just wire each secondary coil to the left/right vs dual?
Also on the filter/dc side - what size caps do I want to go with? Should I just take a hammer and get the biggest I can order? I have the rectifier and dc board from @rhthatcher in thread https://www.diyaudio.com/community/...ated-build-guide.241729/page-508#post-7887284 - I have ordered the power supply pcb and rectifiers just gotta figure out the toroid and capacitor sizing!
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Hey all,
More questions 😉
I'm working through the BOMs for the input stages. Are there updated BOMs for the different stages? For instance the Ishikawa toshiba fets seem to have gone bye-bye
2SK170BL Toshiba N-JFET
2SJ74BL Toshiba P-JFET
What would I want to replace them with? Are the ones from https://diyaudiostore.com/products/matched-jfets the replacements I should look to?
I'm planning to build all of the input stages and then try them out. Any advice would be appreciated!
More questions 😉
I'm working through the BOMs for the input stages. Are there updated BOMs for the different stages? For instance the Ishikawa toshiba fets seem to have gone bye-bye
2SK170BL Toshiba N-JFET
2SJ74BL Toshiba P-JFET
What would I want to replace them with? Are the ones from https://diyaudiostore.com/products/matched-jfets the replacements I should look to?
I'm planning to build all of the input stages and then try them out. Any advice would be appreciated!
Ok another important and hopefully not controversial topic 😉
hookup wiring. In theory I could have upwards of 200VA ( the max of the toroids I just ordered ) at 24V so approx 8.3 amps. Assuming this is right, I need approx 18gauge or better.
My OCD says red/black for power, green for ground and probably white/yellow/blue for signal? Is there any "standard" color scheme I should try to follow?
Thoughts? Something like this but in the difference colors?
hookup wiring. In theory I could have upwards of 200VA ( the max of the toroids I just ordered ) at 24V so approx 8.3 amps. Assuming this is right, I need approx 18gauge or better.
My OCD says red/black for power, green for ground and probably white/yellow/blue for signal? Is there any "standard" color scheme I should try to follow?
Thoughts? Something like this but in the difference colors?
Have you watched the YouTube video(s) of any of the talks at Burning Amp Festival 2024?
In particular, have you watched the video of Jim "6L6"s talk? It goes over this material in detail. Worth searching, finding, watching, and digesting. The video(s) will forestall any possible accusations of carelessness or laziness.
In particular, have you watched the video of Jim "6L6"s talk? It goes over this material in detail. Worth searching, finding, watching, and digesting. The video(s) will forestall any possible accusations of carelessness or laziness.
@Mark Johnson & @6L6 are experts with good advice!!!
For reference, I purchased 16Ga BNTECHGO silicon insulated copper stranded wire from Bezo's bookstore in a variety pack of colors. I think you're question about "standard" color scheme is a good one, but you'll get numerous opinions. I'll share what I use, but it's no 'standard', other than I try to be consistent with all the amps I build. Note that I'm in the US, so AC mains is 120V.
AC Mains In:
Live - Black
Neutral - White
Earth Ground - Green
DC Rectified:
Positive Rectified - Red
Negative Rectified - Black
DC Amp Rails:
V+ Positive - Red
V- Negative - Blue
Ground - Black
Chassis Grounds:
Green
Speaker Out:
Positive - Yellow
Negative - Brown
Inputs:
Thin gauge is fine. I've used 28Ga wire, 30Ga wire, and Mogami W2381 primarily.
I'll let the experts chime in on what's probably a "not ideal idea" in my scheme. I'm sorta "wingin'" it.
For reference, I purchased 16Ga BNTECHGO silicon insulated copper stranded wire from Bezo's bookstore in a variety pack of colors. I think you're question about "standard" color scheme is a good one, but you'll get numerous opinions. I'll share what I use, but it's no 'standard', other than I try to be consistent with all the amps I build. Note that I'm in the US, so AC mains is 120V.
AC Mains In:
Live - Black
Neutral - White
Earth Ground - Green
DC Rectified:
Positive Rectified - Red
Negative Rectified - Black
DC Amp Rails:
V+ Positive - Red
V- Negative - Blue
Ground - Black
Chassis Grounds:
Green
Speaker Out:
Positive - Yellow
Negative - Brown
Inputs:
Thin gauge is fine. I've used 28Ga wire, 30Ga wire, and Mogami W2381 primarily.
I'll let the experts chime in on what's probably a "not ideal idea" in my scheme. I'm sorta "wingin'" it.
So towards the end of that video there was a demo of Quasimodo. I checked the parts store and they don't stock it - anyone aware of a place to pick up the pcb / parts as a kit or assembled? I don't mind doing the assembly but a kit would be pretty nice!
A great project to try ordering PCB the first time.
PCBs ordered 😉 Next up a bunch of BOM parts!
Hey all,
Working on my build. Looking at the bom for mountainview and it calls for MV5075C but its out of stock. Thoughts on a replacement? It's out of stock at both digikey and mouser ;( The BOM says not to substitute so not sure what to do. Is it worth hunting around for other suppliers?
Looking on octopart it looks like I may be able to get it from one supplier.
Also curious why that specific led but not out to resurrect old flames!
Working on my build. Looking at the bom for mountainview and it calls for MV5075C but its out of stock. Thoughts on a replacement? It's out of stock at both digikey and mouser ;( The BOM says not to substitute so not sure what to do. Is it worth hunting around for other suppliers?
Looking on octopart it looks like I may be able to get it from one supplier.
Also curious why that specific led but not out to resurrect old flames!