MARANTZ 4220 Amp Ajustment procedure

[oldmarantz]

Hi
I picked up this rare little 4220 in a nice shape, all is working now, I need the amp adjustment procedure, the schem use an IC TA7109P (??) for each channel...If you can help...Thanks


http://images3.hiboox.com/vignettes/1408/6b572uxq.jpg (http://www.hiboox.com/lang-fr/image.php?img=6b572uxq.jpg)

[catrafter]

OM,
From the not-so-clear service manual:

Audio adjustment:
Connect a VTVM to the speaker jacks. Apply a 1 KHz, 150mV signal to the CD-4/AUX jacks. Then adjust R719, R720, R721 and R722 so that the power output may be 8W (at 8 ohm load).

R719=Left front
R720=Left rear
R721=Right front
R722=Right rear

Hope this helps.

Tom

[oldmarantz]

Thanks for your help Tom
I think I have to set the volume pot at the maximum and follow your procedure...I will try:yes:

Regards
Dominic

[chauncy]

Hello I am in the process of cleaning and relamping a 4220 right now and am having a bit of a issue with the signal strength meter lamp, can you tell me how it's relamped? Must be on the bottom side of the meter or else I am really missing something....thanks

[catrafter]

Chauncy,
From the parts breakdown in the service manual it looks like there are two bi-pin lamps mounted on a small circuit board right behind the meter. There is one screw that goes in from the back that secures it.
The lamp part number is IN1006302. Time to PM AK member dgwojo for a lamp order. I'm sure he will know what to put in there.

Tom

[chauncy]

Thank you I will have another look tomorrow, I'm already in touch with dave, we are trying to determine if the bi pin lamps are 6v or 8v, nothing written on them.
The fuse lamps are marked 8v does that indicate the other backlighting is also 8v ?...Thanks

[catrafter]

The bi-pin meter lamps are connected to the same transformer winding as the 8v fuse lamps but with a 2ohm series resistor. I'm thinking 6.3 volt bi-pins, but why not get both 6.3 an 8 volt and see which ones match the best?
You're only talking a few bucks.

Tom

[oldmarantz]

I confirm the two bi pin lamps are 6.3 V...

[chauncy]

Ya I know you guys know your chit, there two lamps in the meter(which have yet to find) and four bi pins above the fuse lamps....AM,FM,Quad and stereo lamps...really cant imagine they would be different voltages....Thank You !!

[HAL9000]

Hi
I picked up this rare little 4220 in a nice shape, all is working now, I need the amp adjustment procedure, the schem use an IC TA7109P (??) for each channel...If you can help...Thanks


http://images3.hiboox.com/vignettes/1408/6b572uxq.jpg (http://www.hiboox.com/lang-fr/image.php?img=6b572uxq.jpg)


well yours is in fantastic shape, mine gives smoke :thumbsdn: :no:
i have two, and both are sigarets :smoke:

[oldmarantz]

I Hal
you're right this one is in a beautiful shape, it's my first little Quadradial (I had got before a 4230-4240-4300-4400...) , I realigned the tuner and cleaned all the receiver, bench is perfect 2x20w with less than 0.3% dht, the four 8 W amps set to 8 W...it works perfect!

http://images3.hiboox.com/vignettes/1508/erk2p2uw.jpg (http://www.hiboox.com/lang-fr/image.php?img=erk2p2uw.jpg)

[HAL9000]

I Hal
you're right this one is in a beautiful shape, it's my first little Quadradial (I had got before a 4230-4240-4300-4400...) , I realigned the tuner and cleaned all the receiver, bench is perfect 2x20w with less than 0.3% dht, the four 8 W amps set to 8 W...it works perfect!

http://images3.hiboox.com/vignettes/1508/erk2p2uw.jpg (http://www.hiboox.com/lang-fr/image.php?img=erk2p2uw.jpg)

if they work they sound great!
:thmbsp:

[CDFixer]

Anyone know where to get a good quality service manual for the 4220? By good quality I mean the schematics and such are readable.

cheers Jim

[catrafter]

Jim,
I have always received good stuff from servicemanuals.net, but I haven't seen their scan of this particular one.
http://www.servicemanuals.net/ServiceManual/MARANTZ/4220/pos1/results.aspx

Tom