Just Completed: Kenwood Super 7500!

YESSSS! It's finished (for now), the transformation from a humble KT-7500 into the mighty Super 7500!

The Scoop:
I performed the mods from TIC's section on the KT-7500/7550. Specifically, subsections 1, 3, 4, 7, and the class-A mod, the power supply upgrade, and the passive deemphasis mod. This next is kind of corny, but I think it's cool: I routed the class-A wires & resistors through the former deemphasis switch, so now I can switch the op-amp into and out of class-A. (See the white wires in the "bottom view" photo.)

For Later:
I would like to add a front-mounted headphone jack, taken off the variable outputs. The level knob is already on the front, so why not? Also, I left the stock mains cord, I didn't see a compelling reason to change it (and I couldn't get the grommet out!). And I want to change out the filters at some point.

Here are pictures of the completed tuner:











And of course I pimped out the front face lights!

THANK YOU THANK YOU THANK YOU to Jim'N'Bob of FM Tuner Info!!! Their information was absolutely priceless, and allowed me to transform a nice, but pedestrian tuner into a world-beater.

Nice work. I always enjoy reading posts like this, even though I have never held a soldering iron and probably never will.

I have KT-7500 sitting in my closet that I picked up off CL locally for $20. It is in pretty decent shape- I have several other tuners, so I should probably pass it on to someone who will give it the care it needs...

Thanks. Nice to see someone who has done the mods and report.

Front looks nice too.

Very nice!

Why no fuses? EDIT: Jus' saw the back-mounted fuse holder. Smooth... does it blow that ofter than you need it there?

thefragger said:

Very nice!

Why no fuses? EDIT: Jus' saw the back-mounted fuse holder. Smooth... does it blow that ofter than you need it there?

Click to expand...

Naw, it just gets the fuse off the pcb. This way, there's no 120VAC on the board at all.

And what does the before and after sound like?

I have a KT-7550 that was modded by Jim Rivers. Hands down best tuner I've heard. It has detail that no tuner I've owned has pulled out. I have owned big buck ones, and restored ones as well. My only complaint is it pulls in a station about 25 miles away with some noise, probably due to me only having an omnidirectional antenna.

dew.

Before: good, but not great.

After: Warm. Open. Lush. Spacious. Bottomless bass. Topless treble.

My "reference" tuner is the Hitachi FT-8000, which is extremely neutral and crisp, top to bottom. The Kenwood came in with the same crispness and clarity, but somewhat warmer and fuller through the midrange.

Nice work, that's a purdy tuner. How's the RF performance?

I didn't do any RF mods (except an F connector). I can't really afford to have this aligned if I screw something up... I do want to (eventually) replace the filters with low-loss Muratas.

Very good effort. Thanks for sharing the info and pictures.

I love this board.

Very nice work! Now let me box my 7500 up and...

Scott

Very nice. I had a KT-8007 back in '77 or so. Incredible tuna, never should have sold it.

wow. I wish my KR-5030 looked like that!I want to someday....Soon. It needs a restomod BADLY!!!

Beautiful work! I just bought a KT-7500 in a wooden case from a thrift store. I know it lights up and tunes but I haven't listened to it yet. I can only dream of the quality of work you did.

Nice work!, I know i'm late to reply :scratch2: hahaah!.
On my KT 7500, i have a resistor in R1, (beside the ac points on the board).
Your's have a jumper. Did you change the resistor for a jumper?.
I'm doing the "AC removal" from the board too :thmbsp:

Thanks!