Updated list of e capacitors ... 105c ones including Nichicon BP bipolar for power pcb but stay with Nichicon ES bipolar for preamp pcb to try ensure same SQ if not better especially since any needed recap of these is more accessible.
Power e caps will be already received 125c 15000uf Mundorf to follow Martin Poulin's mod.
SMT polymer ones will be changed to hybrid polymer 125c and 135c ones.
Cheers.
Power e caps will be already received 125c 15000uf Mundorf to follow Martin Poulin's mod.
SMT polymer ones will be changed to hybrid polymer 125c and 135c ones.
Cheers.
Hey everyone, love the thread on this as I have one of these and will be going through it to recap it as well. For those in need, I have the full schematic for this amp. Sadly it isn’t a digital copy, I only have it printed out on large 11x17 sheets and there are like 20 pages. So not sure the best method of getting a good copy onto the site.
Dan
Maybe when I can get some free time I can go down to a kinkos or somewhere with a large bed scanner and put the images on a thumb drive. Then I can email them to a member that would know the appropriate place to put them. I’m guessing just attaching them to the page here they would be lesser quality to make the images not too large.
Dan
Dan
saabracer23
I think even a cell phone photo would be okay quality. I would be very grateful if you could attach them here. it would help me a lot, and not only me
thanks in advance.Hi Dan,
Rest of the pages like the 2nd one which I downloaded and reattached below will already be great !
Exciting time for kav-400xi owners finally after almost 20 yrs !!
Cheers.
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Hi Saabracer23,
With just the phone photo of the preamp schematic, one can see that these unmarked 4x op amps circled in blue are opa604au which I am inclined to remove and have 8 pins socket soldered for easy swap to various newer and latest op amps e.g. stable LME49710 ... should be fun with hope of improved sound quality thanks to your sharing ! 🥳🥳
Await your further sharing of remaining 19 pages for any further mod opportunities and hence mentioned exciting time ! 🙏🙏
Thanks again and cheers !
Oops looks like some of these are 300iL as well. Maybe the 300 and 400 share similarities in the amp section? I have more photos, but they are labeled 300iL. So I’ll post them if you all want to see them. I do see that the amps share many similarities, even in the power supply. But these are what was given for the full schematic.
When I get a chance I’ll do detailed scans and email them to richlol and he said he could post them in the appropriate place.
Dan
When I get a chance I’ll do detailed scans and email them to richlol and he said he could post them in the appropriate place.
Dan
I’m glad they are able to be of use to people. I get lots of help from the folks here and it’s good when I can help. I’ll reach out to you once I’m able to email you some good clear scans.
Dan
Hi Dan,
Tks tks .. this is one of the best share I had seen on previously impossible to find schematic that I see many owners asking over the years and hope not sounding ungrateful but any specifically kav-400ix power board schematic missed ?
I certainly can see its power board top silk screen as well as kav-300il power schematic (slight blurred) that indeed may also be for kav-400xi power schematic but really need to check them out to be sure .. if at all possible.
Thanks again ! 🙏🙏👍👍🥳🥳🍻🍻
Tks tks .. this is one of the best share I had seen on previously impossible to find schematic that I see many owners asking over the years and hope not sounding ungrateful but any specifically kav-400ix power board schematic missed ?
I certainly can see its power board top silk screen as well as kav-300il power schematic (slight blurred) that indeed may also be for kav-400xi power schematic but really need to check them out to be sure .. if at all possible.
Thanks again ! 🙏🙏👍👍🥳🥳🍻🍻
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So I asked my buddy and I’ll double check in my 400xi tomorrow, but I yes, I can say with absolute certainty that the 300il and 400xi use the exact same power board and share the exact same schematic. He said they’re basically the same amp. Which makes sense since both are rated 200w at 8 ohm and 400 at 4 ohm. But do use the power board schematic labeled 300il as it is the same.
Dan
Hi All,
Oops ... hope someone can help advise on some issue upon looking at the schematic nicely provided by Dan
The preamp schematic shows 2x 3300uf 35v capacitors that I had not previously identified and hence not on marked up pcba photos on front panel, preamp and power with marked up capacitor details as shared above
Dumb to question the schematic and hope not sounding ungrateful to doubt but checked thru the photos again for surely big e cap type for large 3300uf capacitance and still cannot find such 2X 3300uf 35v capacitors unless on the underside of the preamp which I had not been able to locate ... can anyone who had recapped advise ?
TIA and cheers,
Oops ... hope someone can help advise on some issue upon looking at the schematic nicely provided by Dan
The preamp schematic shows 2x 3300uf 35v capacitors that I had not previously identified and hence not on marked up pcba photos on front panel, preamp and power with marked up capacitor details as shared above
Dumb to question the schematic and hope not sounding ungrateful to doubt but checked thru the photos again for surely big e cap type for large 3300uf capacitance and still cannot find such 2X 3300uf 35v capacitors unless on the underside of the preamp which I had not been able to locate ... can anyone who had recapped advise ?
TIA and cheers,
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My guess is that they’re on the bottom side of the board. I can take a look at my amp a bit later.
Looking at your photo, the four solder joints circled in red look to be them. See that two are circular and two are square, generally signifying polarized electrolytics are there. Plus they come straight off of the 2 four pinned devices just below them, right above those four wires coming into the board, I’d say those 2 four pinned devices are the two bridge rectifiers. Thus those would be the two caps filtering the two rectifiers. The traces between them tell the same story.
Dan
Looking at your photo, the four solder joints circled in red look to be them. See that two are circular and two are square, generally signifying polarized electrolytics are there. Plus they come straight off of the 2 four pinned devices just below them, right above those four wires coming into the board, I’d say those 2 four pinned devices are the two bridge rectifiers. Thus those would be the two caps filtering the two rectifiers. The traces between them tell the same story.
Dan
Hi Dan,
Thanks again and yes, will be ordering these 2x 3300uf 35v capacitors for C36 and 38 that are certainly not on both the top sides your very clear power board silk screen as well as all the preamp photos from other websites and link. Will be the Panasonic FR for 105c rating, outstanding ESR and endurance as well as small size to avoid any fitting issue especially since I will have 4x Mundorf 15000uf of 35mm diameter when laid on their sides following Martin Poulin's mod vs stock 8x 6800uf Nichicon LS height of 30mm.
My apology for seemingly helpless to check on my own kav-400xi but it is still at the repair shop after the blue led modification and waiting for me to deliver the needed capacitors.
Your schematic are already save a lot of trouble from this realisation and will request them for photos of this underside of the preamp board for these elusive capacitors that had never been mentioned from days and weeks of hours of goggling by repair shops and diyers' photos but your photos will certainly expedite update to the earlier shared capacitors list. This will further help those like myself who started on a blank page but progressed ok due to the generosity of members here like yourself and others with their experience from actual recap/repair/upgrade and/or just accumulated technical knowledge beyond me.
Cheers and indeed you are right on the fun of this thread on how I had progressed
Thanks again and yes, will be ordering these 2x 3300uf 35v capacitors for C36 and 38 that are certainly not on both the top sides your very clear power board silk screen as well as all the preamp photos from other websites and link. Will be the Panasonic FR for 105c rating, outstanding ESR and endurance as well as small size to avoid any fitting issue especially since I will have 4x Mundorf 15000uf of 35mm diameter when laid on their sides following Martin Poulin's mod vs stock 8x 6800uf Nichicon LS height of 30mm.
My apology for seemingly helpless to check on my own kav-400xi but it is still at the repair shop after the blue led modification and waiting for me to deliver the needed capacitors.
Your schematic are already save a lot of trouble from this realisation and will request them for photos of this underside of the preamp board for these elusive capacitors that had never been mentioned from days and weeks of hours of goggling by repair shops and diyers' photos but your photos will certainly expedite update to the earlier shared capacitors list. This will further help those like myself who started on a blank page but progressed ok due to the generosity of members here like yourself and others with their experience from actual recap/repair/upgrade and/or just accumulated technical knowledge beyond me.
Cheers and indeed you are right on the fun of this thread on how I had progressed
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