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So let's spiff up an Onkyo TX-4500 MKII receiver

w1jim

w1jim

I can fix it but good...
Subscriber
I scored a very nice Onkyo TX-4500 MKII receiver today. This is fairly sizable; 21" wide - that puts it in the Yamaha CR-2020 width category.

Rated at 65 watts x 2 these are well regarded but certainly didn't sell in the numbers that the big names did.
As a result there isn't much out there in terms of repair notes and nudies.

An interesting feature of this receiver is that it has 3 tape loops but no AUX input. Tape #3 is also labeled "AUX" so I guess that's what they had in mind there.

This one seems to work well, just in need of a vacuuming of the dust, then a deoxit treatment for the switches and pots and then lubricating the pots.

Attached pictures are after the internal cleaning and a recapping of the power supply PCB.

So lets take a look!


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Look at all that room to put in bigger PS caps. I know the Oinks sound good so maybe it is not necessary but those sure look small for such a large unit size-wise.
 
All done!
FInal touches included soaking the knobs and faceplate in soapy water and cleaning with a soft brush. I polished the four (tarnished) screws that hold the dial glass in place on a buffing wheel.
I then recapped the main amp board (along with the power supply PCB). I decided not to recap the other boards. Nothing looked like it was exposed to excess heat so I don't think this was necessary.
Hooked it up to my Klipschorn Forte' speakers and compared it to my Pioneer SX-D7000. Sounds every bit as nice. My gut reaction is that the tuner on this is excellent.


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I have the identical unit, that was interesting!! I do think this model is somewhat under-appreciated though....
 

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Blue Shadow said:
Look at all that room to put in bigger PS caps. I know the Oinks sound good so maybe it is not necessary but those sure look small for such a large unit size-wise.
Click to expand...
The PS caps do look kind of puny in there but they're rated at 12,000 mfd each. That's probably ample for a 65 watt x 2 amplifier.
Other oddities about this is that while they expect you to use the tape loops for AUX inputs it has two phono inputs.
Also the metal casing is finished in (genuine) rosewood vinyl. It would have been so nice to have some real wood instead; guess it wasn't in the budget, but then maybe that isn't so unusual for 1978 when build quality was starting to slip.
Also the tuning knob has a sensor that determines when you are touching it (like the Yamahas) to disable the xtal lock circuitry. There's a switch on the back (L-M-H) to adjust the sensitivity of the touch circuitry.
All-in-all a nice piece of gear - makes me curious about the TX-8500 since I'm a bit of a big receiver junkie.
 
Very nice. I have a TX4500, but not the MKII version. I believe its essentially the same, but your dial is a little different than mine. Do you happen to know what bulbs it uses? A number of mine are burned out, and it makes it look kind of shabby only having part of the dial lit and not all of the function indicator lamps working.
 
I'm fortunate that I didn't have to replace any bulbs but looking in the service manual it states they 6.3 volts / 250 ma. I don't know what kind of base they are.
It's pretty easy to get to them - remove the top cover (6 screws) and then remove the plastic bulb cover (5 screws).
Time to start digging and make that beauty shine!
 
I'm a big fan of vintage Onkyo....both my A-5 integrated and TX-6500MKII were amazing performers....far superior to some of the comparable offerings from more popular names IF you ask me.
 
what a beauty! thanks for your post
As you can tell from my signature I'm already a huge fan of that series. They are the most reliable of all my vintage receivers. here are some pics
http://www.audiokarma.org/forums/showthread.php?t=337596
Yes, very under-rated. They do everything well, and to my ears sound as good as any of the other popular receivers of their day. I bought the 2500 over 30 years ago and did my foolish best to fry it, running 2 sets of 6 ohm speakers wide open at parties, and it is still in use every day.
Some say the tuners and phono section are better than most.
All-in-all, one bitchin' piece of gear!
 
I would expect the tuner to be excellent. This receiver came out after the highly rated, by TAS, T-4055. Onkyo added servo-lock to the lower models, the T-4 and lower receivers and quartz-lock to the high end gear, T-9 and the bigger receivers. Nice feature.

These receivers were a step up from the standard Japanese receivers and we sold them alongside the HK and Lux units.

Since many receivers have a phono, aux and two tapes, this one has two phonos and three tape loops. This is just the addition of that phono and a tape out. Something I would much rather have, the ability to loop a signal, possibly a signal processor. The unit has some kind of dubbing flexibility, doesn't it?
 
IIRC I used an equalizer on the 2500 through a tape input. Just use the button and it would work with other inputs.
The 6500 and 8500 have an input for an external processor.
 
just dave said:
She's a beauty nice job!
Click to expand...
Thanks Dave, I don't think I'm seriously out of bounds here to say that most AKer's respect your definition of beauty :drool:.

BTW, I got this one for free from a guy who I bought a Pioneer from on CL last year.
He remembered I liked this old junk so he gave me a call!
 
Wowee ...

I picked up a oink 3000 my 3rd 3000 matter of fact on 11th.
It was almost as clean as this one and worked right away as well. Of course cleaning and de oxing is standard.
Cool.
Srinath.
 
Still looking for an A-10 dual mono integrated !!!! Or the rare Japan-only Integra N-ii stuff.

Someone mentioned Luxman...I adore Luxman gear.
 
Nice job Jim:thmbsp: Now you got me wishing that I hadn't sent my 4500 to a new home at the Frankfest a few years back.
Hmmm; there is a pristine looking 6500 though right down the street looking for a new home.:scratch2:
 
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