Hey all,
A few years ago I started modifying a Harman Kardon Citation 12 per Nelson Pass’ article. Long story short, life got in the way, had a kid, and I have no time to complete it. Is there anyone in the San Francisco Bay Area willing to complete it for me? Willing to pay for your services.
Thanks!
A few years ago I started modifying a Harman Kardon Citation 12 per Nelson Pass’ article. Long story short, life got in the way, had a kid, and I have no time to complete it. Is there anyone in the San Francisco Bay Area willing to complete it for me? Willing to pay for your services.
Thanks!
oh my goodness
To be very upfront, i would love to debug this with your help, but I do not want you to spend your valuable time helping a novice debug a (most likely) simple problem.
I will post pictures and current status shortly, but feel no pressure to continue.
Both channels. It’s been awhile, but I can’t remember if I made the same mistake on both channels, or the power supply isn’t right.
To be very upfront, i would love to debug this with your help, but I do not want you to spend your valuable time helping a novice debug a (most likely) simple problem.
I will post pictures and current status shortly, but feel no pressure to continue.
Both channels. It’s been awhile, but I can’t remember if I made the same mistake on both channels, or the power supply isn’t right.
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Alright, pushing past my embarrassment, here’s where I’m at.
Purchased a pair of PCBs from Tazzz (Citation 12 complimentary Mosfet version PCB's)
Schematic is also located at that link.
Pulled Q5 and Q6 on one side to see if I could get a better idea of where I went wrong. Pictures attached.
Purchased a pair of PCBs from Tazzz (Citation 12 complimentary Mosfet version PCB's)
Schematic is also located at that link.
Pulled Q5 and Q6 on one side to see if I could get a better idea of where I went wrong. Pictures attached.
Attachments
Now it´s also here.
Where it belongs
https://www.diyaudio.com/forums/att...ary-mosfet-version-pcbs-hk-citation-mf12c-pdf
That said, besides possible "user error", the PCB itself might have some slight quirk, amp will require troubleshooting in any case.
Hi, i have made 2 stereo amp base on Pass MF12C with TAZZZ circuit pcb.
both amps worked fine and i'm still using one and enjoying it.
Now i'm on a third project and have 2 more pcb, but if you look at the pictures, the are not the same silkscreen.
Based search here , i did start to install parts until my first tests, and it did not work....
Found that pcb have different way of positioning 2SA970 and 2SC2705 bipolar transistors.
Unstead of having EBC scheme, they have BCE, and had to exchange pins positions???
corrected the situation.
Now i can apply +Vcc and -Vcc but i have an issue with bias set up, no bias current flows on R21-22.
I'm wandering that if they are two releases of those pcb's
The ones one the left are from TAZZZ with surround white strip.
The one on the right picture is without the white surround, and transistors pinout mix up.
Anyone saw that??
Thanks
both amps worked fine and i'm still using one and enjoying it.
Now i'm on a third project and have 2 more pcb, but if you look at the pictures, the are not the same silkscreen.
Based search here , i did start to install parts until my first tests, and it did not work....
Found that pcb have different way of positioning 2SA970 and 2SC2705 bipolar transistors.
Unstead of having EBC scheme, they have BCE, and had to exchange pins positions???
corrected the situation.
Now i can apply +Vcc and -Vcc but i have an issue with bias set up, no bias current flows on R21-22.
I'm wandering that if they are two releases of those pcb's
The ones one the left are from TAZZZ with surround white strip.
The one on the right picture is without the white surround, and transistors pinout mix up.
Anyone saw that??
Thanks
Attachments
Oh sorry, cant tell a lot, Ive googled for pcb maker and
mme-pcb.com
was one of the first listed, and it was near by my hometown (40km).
They make all the stuff all arround pcb manufacturing, developing and so on.
Ive send them an email if its possible to copy an existing pcb,
they say yes, I say go, and the job was done in only two weeks.
mme-pcb.com
was one of the first listed, and it was near by my hometown (40km).
They make all the stuff all arround pcb manufacturing, developing and so on.
Ive send them an email if its possible to copy an existing pcb,
they say yes, I say go, and the job was done in only two weeks.
Hello "citationfan", do you mean you have MF-12C PCBs on hand? Or you are planning to order from mme-pcb.com. Aren't you?
Is your version Tazzz's first or second as he might have slightly modified the first layout/pattern.
I plan to take two. Would you check regular postage rate shipping to Canada? Thank you.
** I wrote this same message here: https://www.diyaudio.com/community/...mplimentary-mosfet-version-pcbs.236149/page-4
Is your version Tazzz's first or second as he might have slightly modified the first layout/pattern.
I plan to take two. Would you check regular postage rate shipping to Canada? Thank you.
** I wrote this same message here: https://www.diyaudio.com/community/...mplimentary-mosfet-version-pcbs.236149/page-4