I am so excited to see this schematic. Can I see the rest of service manual, I need it to repair my burnt 300il. And do you know what is the bias value for this amp.
Hi, would this for kav-300i works as I Dan mentioned just having the schematics in printed A3 papers and not manual ? For your reference while awaiting for Dan to advise actual of course 🙏
https://www.diyaudio.com/community/threads/krell-kav-300i-information.313933/
Cheers.
Richard
https://www.diyaudio.com/community/threads/krell-kav-300i-information.313933/
Cheers.
Richard
Attachments
Hi Xman,
Oops .. beyond my knowledge unfortunately.
Happened to read it when looking same biasing and dc adjustment for kav-400xi and never found equivalent one .. forwarded the same to my repair shop and hope he knows what to do with some nice repair equipment seen there.
Cheers.
Oops .. beyond my knowledge unfortunately.
Happened to read it when looking same biasing and dc adjustment for kav-400xi and never found equivalent one .. forwarded the same to my repair shop and hope he knows what to do with some nice repair equipment seen there.
Cheers.
Last edited:
Sorry xman2005, I searched over every inch of every page I have and I see no biasing procedure at all. I would think the 300i would be different to the 300iL or 400xi as yes, different amp. I can’t make any promises, but let me see if I can get it. The guy I got this from clearly has access to Krell’s goodies.
Dan
Dan
Hi Dan,
I have to ask my repair man but he did advised that his usual sources of digikey, mouser etc. does not have suitable blue ones and it was aliexpress for Chinese ones unfortunately but we all know that RS component for example just get parts and brand them under their name.
I meant to ask also but priority on getting all the listed caps as I also wish for spare since nvr know when it will fails 😅
Tba 🙏
Cheers.
I have to ask my repair man but he did advised that his usual sources of digikey, mouser etc. does not have suitable blue ones and it was aliexpress for Chinese ones unfortunately but we all know that RS component for example just get parts and brand them under their name.
I meant to ask also but priority on getting all the listed caps as I also wish for spare since nvr know when it will fails 😅
Tba 🙏
Cheers.
I have the 300IL. I have increase the filter caps to 8200uF kemet ones because they are long life (supposed to last 15000hrs).
I also bypass the speaker fuses. Don't see the need for them.
Replace the speaker posts with better ones and also the wires.
First of all, thank you so much, Dan.
I can assume that the 400xi power amp board is a bridged version of the 300. ie two 300s in the same channel. the input of one is connected to the positive half-wave of the signal and the other to the negative half-wave. Their circuits are identical.
Unfortunately in this way their speakers outputs cannot be connected to ground. i didn't know and burned one channel. So be careful guys.
Last edited:
Hi, I bought the neutrik nc3faa1 to replace rusty one which shorts pin #1 to shell after misreading an owner having hum who resolved it by shorting pin#1 to shell and that engrg change was made by Krell.
My repair shop advised that pin #1 is NOT shorted to shell and I had bought nc3faa instead.
Any one has information on the right replacement part for seemingly 3 sets of 4x rca connectors from the mounting screws ?
TIA
My repair shop advised that pin #1 is NOT shorted to shell and I had bought nc3faa instead.
Any one has information on the right replacement part for seemingly 3 sets of 4x rca connectors from the mounting screws ?
TIA
Bought some cheap fan controllers as well as quietest available but expensive Noctua 120mm LS fan for the ample space in the chassis to alleviate the heat related earlier failure in nice hot tropical island of Singapore while already on 105 to 125c for new caps except for the 85c Nichicon ES bipolar for preamp input ac coupling.
Just found this amazing item on AliExpress. Check it out! SG$1.86 15%OFF | Single 12V 0.8A DC PWM 2-3 Wire Fan Temperature Control Speed Controller Chassis Computer Noise Reduction Module NTC B 50K 3950
https://a.aliexpress.com/_mtuSDQI
Just found this amazing item on AliExpress. Check it out! SG$2.33 8%OFF | DC 12V 5A PWM PC CPU Fan Temperature Control Speed Controller Board Speed Controller Temperature Probe Buzzle
https://a.aliexpress.com/_mML5X18
Decided to go with the one with beeper which is quite cool as it alerts you that it is indeed working as well as if the fan fails.
However, had not decided if I will install cheap ac-12vdc transformer to power the modules+fans and tap needed input voltage to the Krell front switch for the convenience but with concern on the detrimental effect of inteference, leakages etc. on SQ with such shared input voltage arrangement.
Just found this amazing item on AliExpress. Check it out! SG$5.42 33%OFF | 1PCS AC-DC Mini Converter AC 1A 5W 220V to DC 3.3V 5V 9V 12V 15V 24V Power Supply Module
https://a.aliexpress.com/_mMrUfMK
Alternatively, just a dc socket modded to the chassis will allow me or next owner to simply plug in commonly available 12vdc adaptor or least detrimental ones to be powered separately from the krell to have no major concern on SQ else all these efforts (and $) go down the drain.
Opinion pls ? 🙏🙏
Just found this amazing item on AliExpress. Check it out! SG$1.86 15%OFF | Single 12V 0.8A DC PWM 2-3 Wire Fan Temperature Control Speed Controller Chassis Computer Noise Reduction Module NTC B 50K 3950
https://a.aliexpress.com/_mtuSDQI
Just found this amazing item on AliExpress. Check it out! SG$2.33 8%OFF | DC 12V 5A PWM PC CPU Fan Temperature Control Speed Controller Board Speed Controller Temperature Probe Buzzle
https://a.aliexpress.com/_mML5X18
Decided to go with the one with beeper which is quite cool as it alerts you that it is indeed working as well as if the fan fails.
However, had not decided if I will install cheap ac-12vdc transformer to power the modules+fans and tap needed input voltage to the Krell front switch for the convenience but with concern on the detrimental effect of inteference, leakages etc. on SQ with such shared input voltage arrangement.
Just found this amazing item on AliExpress. Check it out! SG$5.42 33%OFF | 1PCS AC-DC Mini Converter AC 1A 5W 220V to DC 3.3V 5V 9V 12V 15V 24V Power Supply Module
https://a.aliexpress.com/_mMrUfMK
Alternatively, just a dc socket modded to the chassis will allow me or next owner to simply plug in commonly available 12vdc adaptor or least detrimental ones to be powered separately from the krell to have no major concern on SQ else all these efforts (and $) go down the drain.
Opinion pls ? 🙏🙏
Attachments
Last edited:
Hi, mystery of the missing 2x 3300uf 35v solved with rarely available back view of the preamp pcba from local Singapore community 😅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.
Exactly as I had thought, right off of the bridge rectifiers.
Which fuses are you referring to? The ones for the main voltage rails? They are 10 amp. Is that what you were looking for?
Dan
Hi Dan,
Yes yes yes ! 🙏🙏
I can now order these agc 10 fuses to prepare before repair man returns end of this week to start the recap.
Btw, stereophile review mentioned replacement of 3A fuse here and I hence also more confused as it seems to the ones for speaker output that are marked agc 8 and that they should be 8A ones ?
https://www.stereophile.com/content/krell-kav-400xi-integrated-amplifier-measurements
Cheers ! 🙏🙏
Yes yes yes ! 🙏🙏
I can now order these agc 10 fuses to prepare before repair man returns end of this week to start the recap.
Btw, stereophile review mentioned replacement of 3A fuse here and I hence also more confused as it seems to the ones for speaker output that are marked agc 8 and that they should be 8A ones ?
https://www.stereophile.com/content/krell-kav-400xi-integrated-amplifier-measurements
Cheers ! 🙏🙏
Last edited:
Oops .. looks like I have to give up getting new internal fuses that I had hoped to replace as they are probably oxidised to some degrees 🥲
Despite Dan's help on knowing needing 10A rating, there are just too many versions of voltage, breaking current, slow/fast/time delay etc. types to know what to order especially since photos element14, digikey, mouser etc. specifically mentioned that their photos are not representative of actual while I can see actual one most likely to be time delay type at >>50v as shown on Dan's provided schematic and they are not cheap 😰
Please do advise if you are aware of actual part # to order.
TIA and cheers.
Despite Dan's help on knowing needing 10A rating, there are just too many versions of voltage, breaking current, slow/fast/time delay etc. types to know what to order especially since photos element14, digikey, mouser etc. specifically mentioned that their photos are not representative of actual while I can see actual one most likely to be time delay type at >>50v as shown on Dan's provided schematic and they are not cheap 😰
Please do advise if you are aware of actual part # to order.
TIA and cheers.
Last edited:
Hey escksu,
Thanks again and just noted that you are also from our little red dot of Singapore ! 🥳
Unfortunately, I have no capability to do the recap and relying on external repair shop/man to so, including mentioned polishing of the old fuses .. hence hoping to simply get new ones if at all possible 🙏
Cheers.
Thanks again and just noted that you are also from our little red dot of Singapore ! 🥳
Unfortunately, I have no capability to do the recap and relying on external repair shop/man to so, including mentioned polishing of the old fuses .. hence hoping to simply get new ones if at all possible 🙏
Cheers.