Hi All,
I'm running out of online resources to find a schematic for a Trio KA-8100. It's a Japanese Trio-Kenwood and the USA equivalent is a Kenwood KA-601...and I have that SM. Problem is, the phono preamp circuitry is different in the Japanese model since it also supports a MC cartridge input. I think the Trio KA-8300 -- next model up -- has the same phono preamp circuit design, so that would work as well. Thanks.
I'm running out of online resources to find a schematic for a Trio KA-8100. It's a Japanese Trio-Kenwood and the USA equivalent is a Kenwood KA-601...and I have that SM. Problem is, the phono preamp circuitry is different in the Japanese model since it also supports a MC cartridge input. I think the Trio KA-8300 -- next model up -- has the same phono preamp circuit design, so that would work as well. Thanks.
Those have 6556 or 5532 pre amps for the phono circuit, I think.
What is your problem?
You can make a circuit with TL072, and similar, do not go super exotic. 5532 also works.
With the parts available, should not be more than an hour on a perforated board.
What is your problem?
You can make a circuit with TL072, and similar, do not go super exotic. 5532 also works.
With the parts available, should not be more than an hour on a perforated board.
The problem is that I need a schematic. That's all I need. I did a full resto on this unit and the volume level for the MC stage -- both channels -- is too low. That suggests I may have used the wrong value resistor somewhere in the circuit, but without a schematic, I won't know where. And no, the phono stage has no op amps...it's all discrete.
Then measure the voltage on the input and output from the stage, before that check supply to that area of the board, should be in 12 to 15V range.
MC and MM outputs were 40 and 100mV range, IIRC, please check.
The stage should boost that to the 400mV to 1V range, same as Tape / CD (please check), and feed the pre amp / selector to main amp section.
Then change the resistor as needed, use a preset if you can, that will allow some adjustment as well.
Spray the selector switch and check for resistance at joints first before doing any of the above.
MC and MM outputs were 40 and 100mV range, IIRC, please check.
The stage should boost that to the 400mV to 1V range, same as Tape / CD (please check), and feed the pre amp / selector to main amp section.
Then change the resistor as needed, use a preset if you can, that will allow some adjustment as well.
Spray the selector switch and check for resistance at joints first before doing any of the above.
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The following link may help. I am from Cali Colombia. And well, these sites here in my country are easy to access. I hope this link will help you. Blessings. http://www.akdatabase.org/AKview/albums/userpics/10007/Kenwood KA-8100,KA-8150 Service Manual.pdf
Moving coil cartridge outputs are between .15mV and 1.5mV. The MM stage is being fed by +/-30Vdc rails, then dropped to around 28Vdc. However, that's the MM stage and I need data for the MC stage. That said, if you really want to help me out, I've included a pic and maybe you can tell me which stage needs a resistor change and which resistors to change.
Attachments
@ARAGONELECTRONICA -- Thank you, but that's for a Kenwood KA-8100, not a Trio KA-8100. They're different.
IT IS COMPLICATED TO FIND THE CHANGES TO EXCITE THIS CM CAPSULE. IN ORIGINAL CIRCUIT. BECAUSE THAT PHONO MODULE IS ONLY FOR MM. YOU MUST MAKE A LOT OF CHANGES. IT IS BETTER TO SWITCH WITH ANOTHER MODULE. OR WITHOUT SWITCHING PHONO 2 CAN WORK WITH A MODULE SEPARATE FROM THE EXISTING ONE. AND MAKE THE CONNECTIONS TO THE SELECTOR BETWEEN PHONO 1 AND PHONO 2. IN THE DESIRED EFFECT, PHONO TWO PROPERLY POWERS THE CM CAPSULE. THE TRUTH I WAS RESEARCHING AND FRIENDS AND ON PAGES, THEY DO NOT PROVIDE TRUTHFUL AND RELIABLE INFORMATION. IN ANY WAY IT IS A PLEASURE TO SERVE. A HUG