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9090DB Recap

MIJ_Pioneer

Super Member
After enjoying my 7070 for a while, the 9090 has always been on the list. Well, one fell in my lap! This one is 10/10 cosmetically. It had (has) an issue with the Dolby board. I picked it up in hopes that I could defeat the Dolby board issue, applied all the known fixes, and still couldn't get it 100%. With that said it has been bypassed. I know I know, it should be fixed but after three full days of attention it was time to throw in the towel on that board. I've got my eye out for a replacement one of these days.

My thread on the Dolby board if anyone is interested: https://audiokarma.org/forums/index.php?threads/9090db-dolby-board-help.917332/

It sounds amazing. Has that beautiful strong bass that separates Sansui from the rest.

BOM:

505-MKP2-.068/100/5 | 1
505-MKP2C024701C00JS | 2
505-MKS20.47/63/5 | 3
505-MKS21.0/63/5 | 20
505-MKS2-2.2/63/10A | 13
505-MKS23.3/63/5 | 4
505-MKS2-4.7/50/10 | 2
512-1N5252B | 10
512-KSA1220AYS | 5
512-KSC2690AYS | 5
647-UEP1E470MED | 1
647-UEP2A4R7MED | 3
647-UKL1E101KPDANA | 1
647-UKL1E470KEDANA | 2
647-UKL1J100KED | 30
647-UPW1E101MED1TD | 5
647-UPW1E471MPD6 | 4
647-UPW1H100MDD1TA | 2
647-UPW1H221MPD | 2
647-UPW1J101MPD6 | 3
647-UPW1J221MPD | 3
647-UPW1J471MHD | 2
647-UPW1V221MPD6 | 4
647-UPW1V471MPD | 2
647-UPW1V4R7MDD | 3
647-UPW2A100MED1TA | 1
647-UPW2A101MHD | 2
647-UPW2A102MHD | 1
647-UPW2A221MHD | 2
647-UPW2A330MPD6TD | 1
647-UPW2A331MHD | 2
647-UPW2A471MHD | 1
652-3296P-1-502LF | 2
652-3386H-1-101LF | 2
660-MF1/2DCT52R10R0F | 2
660-MF1/2DCT52R1500F | 4
660-MF1/2DCT52R1800F | 3
660-MF1/2DCT52R3921F | 2
660-MF1/2DCT52R4R75F | 11
667-ECQ-E1475KFA | 3
71-RN60D18R0F | 2
MOSX1/2CT52R1R0J | 3
MOSX1/2CT52R4R7J | 2
MY3-02-DC24 | 1

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F2655 Dolby NR Circuit Board (sucks)

* note probably can use for the 10uf 16v instead of low leakage UKL

Electrolytic Caps
C-605 100uF 6.3V E.C 4mm 647-UPW1E101MED1TD 25v
C-09 10uF 16V E.C 5mm 647-UKL1J100KED 63v
C-10 10uF 16V E.C 5mm 647-UKL1J100KED 63v
C-11 10uF 16V E.C 4mm 647-UKL1J100KED 63v
C-12 10uF 16V E.C 4mm 647-UKL1J100KED 63v
C-13 10uF 16V E.C 4mm 647-UKL1J100KED 63v
C-14 10uF 16V E.C 4mm 647-UKL1J100KED 63v
C-15 10uF 16V E.C 4mm 647-UKL1J100KED 63v
C-16 10uF 16V E.C 7mm 647-UKL1J100KED 63v
C-19 10uF 16V E.C 4mm 647-UKL1J100KED 63v
C-20 10uF 16V E.C 4mm 647-UKL1J100KED 63v
C-21 10uF 16V E.C 4mm 647-UKL1J100KED 63v
C-22 10uF 16V E.C 3mm 647-UKL1J100KED 63v
C-29 10uF 16V E.C 4mm 647-UKL1J100KED 63v
C-30 10uF 16V E.C 4mm 647-UKL1J100KED 63v
C-35 10uF 16V E.C 647-UKL1J100KED 63v
C-38 10uF 16V E.C 4mm 647-UKL1J100KED 63v
C-606 100uF 16V E.C 5mm 647-UPW1E101MED1TD 25v
C-01 47uF 16V E.C 3mm / 6mm 647-UPW1V4R7MDD 35v
C-02 47uF 16V E.C 3mm / 6mm 647-UPW1V4R7MDD 35v
C-41 1uF / Audio 50V E.C 2.5mm / 5mm 505-MKS21.0/63/5 63v
C-42 1uF / Audio 50V E.C 2.5mm / 5mm 505-MKS21.0/63/5 63v
C-608 1uF / Audio 50V E.C 2.5mm / 4mm 505-MKS21.0/63/5 63v
C-36 10uF / Audio 25V E.C 5mm / Audio 647-UKL1J100KED 63v
C-37 10uF / Audio 25V E.C 5mm / Audio 647-UKL1J100KED 63v

Some important speaker selector switch cleaning

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F2617 Mic Amp Circuit Board

Electrolytic Caps
C-03 2.2uF / Audio 50V E.C 8mm 505-MKS2-2.2/63/10A
C-04 2.2uF / Audio 50V E.C 8mm 505-MKS2-2.2/63/10A
C-06 47uF 6.3V E.C 4mm 647-UPW1V4R7MDD 35v
C-07 1uF / Audio 50V E.C 4.5mm 505-MKS21.0/63/5
C-09 220uF 50V E.C 5mm 647-UPW1J221MPD 63v
C-10 4.7uF 25V E.C 7mm 505-MKS2-4.7/50/10
Tantalum Caps
C-01 0.068uF 25V T.C 4mm 505-MKP2-.068/100/5 100v
 
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F2624 Driver Circuit Board

*
I did not replace any transistors. Can always come back and revisit. TR01 - 04 are matched C1400. I compared the HFE to a 1845 and the 1845 has half the hfe. I put the original back in.

Electrolytic Caps
C-01 0.47 50V E.C 2mm / Low Noise 505-MKS20.47/63/5 63v
C-02 0.47 50V E.C 2mm / Low Noise 505-MKS20.47/63/5 63v
C-05 470uF/16V/5LS 6.3V E.C 4mm 647-UPW1V471MPD 35v
C-06 470uF/16V/5LS 6.3V E.C 4mm 647-UPW1V471MPD 35v
C-07 330uF/100V/7.5LS 63V E.C 7mm 647-UPW2A331MHD 100v
C-08 330uF/100V/7.5LS 63V E.C 7mm 647-UPW2A331MHD 100v
C-09 100uF/50V/5LS 25V E.C 4mm 647-UPW1J101MPD6 63v
C-10 100uF/50V/5LS 25V E.C 4mm 647-UPW1J101MPD6 63v

VR1: 4.7k Ohm: 652-3296P-1-502LF 5K Ohm Multi Turn
VR2: 4.7k Ohm: 652-3296P-1-502LF 5K Ohm Multi Turn
VR3: 100 Ohm: 652-3386H-1-101LF 100 Ohm Single Turn
VR4: 100 Ohm: 652-3386H-1-101LF 100 Ohm Single Turn

Diodes
D-05 340120 VD1212 2 X 512-1N4148 in series Fairchild 2 X 1N4148
D-06 340120 VD1212 2 X 512-1N4148 in series
ZD-01 316070 EQA01-24R 512-1N5252B Fairchild 1N5252B
ZD-02 316070 EQA01-24R

R-33 180 ohm Fuse R. 594-MBB02070C1800FCT
R-34 180 ohm Fuse R. 594-MBB02070C1800FCT
R-35 4.7 ohm Fuse R. 594-MBB02070C4708FCT
R-36 4.7 ohm Fuse R. 594-MBB02070C4708FCT
R-39 10ohm Fuse R. 594-MBB02070C1009FCT
R-40 10 ohm Fuse R. 594-MBB02070C1009FCT
R-41 150 ohm Fuse R. 594-MBB02070C1500FCT
R-42 150 ohm Fuse R. 594-MBB02070C1500FCT
R-43 150 ohm Fuse R. 594-MBB02070C1500FCT
R-44 150 ohm Fuse R. 594-MBB02070C1500FCT
R-47 4.7 ohm Fuse R. 594-MBB02070C4708FCT
R-48 4.7 ohm Fuse R. 594-MBB02070C4708FCT
R-49 4.7 ohm Fuse R. 594-MBB02070C4708FCT
R-50 4.7 ohm Fuse R. 594-MBB02070C4708FCT
R36: 4.7 Ohm 1/4 watt: 660-MF1/2DCT52R4R75F 4.75 Ohm 1/2 watt 594-MBB02070C4708FCT
R37: 3.9k Ohm 1/2 watt: 660-MF1/2DCT52R3921F 3.92k Ohm 1/2 watt 594-MBB02070C3901FC1
 
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F2656 Power Supply Board

Electrolytic Caps
C-03 1000uF 80V E.C 12mm 647-UPW2A102MHD 100v
C-04 470uF 80V E.C 10mm 647-UPW2A471MHD 100v
C-05 100uF 80V E.C 7mm 647-UPW2A101MHD 100v
C-06 100uF 80V E.C 7mm 647-UPW2A101MHD 100v
C-09 220uF 80V E.C 7mm 647-UPW2A221MHD 100v
C-10 220uF 63V E.C 7mm 647-UPW2A221MHD 100v
C-11 10uF 50V E.C 3mm 647-UPW2A100MED1TA 100v
C-14 4.7uF / B.P 80V E.C 4mm 647-UEP2A4R7MED 100v
C-15 4.7uF / B.P 80V E.C 4mm 647-UEP2A4R7MED 100v
C-16 4.7uF / B.P 80V E.C 4mm 647-UEP2A4R7MED 100v

R-27 4.7 ohm. 594-MBB02070C4708FCT
R-28 4.7 ohm. 594-MBB02070C4708FCT
R-30 1 ohm Fuse R. 660-MOSX1/2CT52R1R0J
R-31 1 ohm Fuse R. 660-MOSX1/2CT52R1R0J
R-32 1 ohm Fuse R. 660-MOSX1/2CT52R1R0J

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F2657 Power Relay Circuit Board

Electrolytic Caps
C-03 470uF 6.3V E.C 5mm 647-UPW1E471MPD6 25v
C-04 1uF 50V E.C 3.5mm 505-MKS21.0/63/5 63v
C-06 1uF 50V E.C 5mm 505-MKS21.0/63/5 63v
C-07 1uF 50V E.C 5mm 505-MKS21.0/63/5 63v
C-08 1uF 50V E.C 5mm 505-MKS21.0/63/5 63v
C-02 220uF 50V E.C 7mm 647-UPW1J221MPD 63v
C-01 33uF 50V E.C 5mm 647-UPW2A330MPD6TD 100v
C-05 47uF / Bi Polar 6.3V E.C 4mm 647-UEP1E470MED 25v

Resistors
R-15 201101 100 ohm 1W M.R. 660-MOS1C100J
R-16 201101 100 ohm 1W M.R. KOA MOS1C100J
R-25 203100 4.7 ohm 1/2W Fuse R 660-MOSX1/2CT52R4R7J
R-26 203100 4.7 ohm 1/2W Fuse R. MOSX1/2CT52R4R7J

Relay
RL01 Omron MY3-02-DC24
 
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F2544 Tone Control Circuit Board

Electrolytic Caps
C-09 100uF 6.3V E.C 6mm 647-UPW1E101MED1TD 25v
C-10 100uF 6.3V E.C 6mm 647-UPW1E101MED1TD 25v
C-33 220uF 16v E.C 5mm 647-UPW1V221MPD6 50v
C-34 220uF 6.3V E.C 5mm 647-UPW1V221MPD6 50v
C-601 470uF 6.3V E.C 7mm 647-UPW1E471MPD6 25v
C-602 220uF 50V E.C 7mm 647-UPW1J221MPD 63v
C-05 10uF / Audio 25V E.C 5mm 647-UKL1J100KED 63v
C-06 10uF / Audio 25V E.C 5mm 647-UKL1J100KED 63v
C-31 10uF / Audio 25V E.C 4mm 647-UKL1J100KED 63v
C-32 10uF / Audio 25V E.C 4mm 647-UKL1J100KED 63v
C-01 1uF / Audio 50V E.C 3.5mm 505-MKS21.0/63/5 63v
C-02 1uF / Audio 50V E.C 3.5mm 505-MKS21.0/63/5 63v
C-27 2.2uF / Audio 50V E.C 4mm 505-MKS2-2.2/63/10A 63v
C-28 2.2uF / Audio 50V E.C 4mm 505-MKS2-2.2/63/10A 63v

Also replaced the two C1313 transistors with KSC1845

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F2653 Equalizer Circuit Board

Electrolytic Caps
C-602 1uF / Audio 50V E.C 3mm 505-MKS21.0/63/5 63v
C-19 2.2uF / Audio 50V E.C 3mm 505-MKS2-2.2/63/10A 63v
C-20 2.2uF / Audio 50V E.C 3mm 505-MKS2-2.2/63/10A 63v
C-11 220uF 6.3V E.C 5mm 647-UPW1V221MPD6 35v
C-12 220uF 6.3V E.C 5mm 647-UPW1V221MPD6 35v
C-07 470uF 50V E.C 7mm 647-UPW1J471MHD 63v
C-08 470uF 50V E.C 7mm 647-UPW1J471MHD 63v
Tantalum Caps
C-03 3.3uF 35V T.C 4mm 505-MKS2-2.2/63/10A 63v
C-04 3.3uF 35V T.C 505-MKS2-2.2/63/10A 63v
 
Replaced the micas and regreased the outputs:

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F-2619 Power Supply RF Section Board

S.M. ID Sansui p/n Capacitance Volt. Type L.Space Mouser p/n Voltage
Electrolytic Caps
C-01 100uF 35V E.C 5mm 647-UPW1J101MPD6 63v
C-02 220uF 16v E.C 5mm 647-UPW1H221MPD 50v
C-03 10uF 25v E.C 2.5mm 647-UPW1H100MDD1TA 50v
C-04 470uF 10v E.C 5mm 647-UPW1E471MPD6 25v
C-05 470uF 16v E.C 5mm 647-UPW1E471MPD6 25v

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F-2549 AM / FM Tuner Board

Electrolytic Caps
C-80 47uF 6.3V E.C 2mm / 2.5mm 647-UKL1E470KEDANA 25v
C-24 10uF 16V E.C 2mm 647-UKL1J100KED 50v
C-49 10uF 16V E.C 2mm 647-UKL1J100KED 50v
C-50 10uF 16V E.C 2mm 647-UKL1J100KED 50v
C-72 10uF 16V E.C 2mm 647-UKL1J100KED 50v
C-71 100uF 16V E.C 5mm 647-UKL1E101KPDANA 25v
C-85 47uF 16V E.C 3.5mm 647-UKL1E470KEDANA 25v
C-42 220uF 16V E.C 5mm 647-UPW1H221MPD 50v
C-69 4.7uF 25V E.C 2mm 505-MKS2-4.7/50/10 50v
C-70 3.3uF 50V E.C 2mm 505-MKS23.3/63/5 63v
C-40 1uF 50V E.C 2mm / Low Noise 505-MKS21.0/63/5 63v
C-55 1uF 50V E.C 2mm / Low Noise 505-MKS21.0/63/5 63v
C-56 1uF 50V E.C 2mm / Low Noise 505-MKS21.0/63/5 63v
C-79 1uF 50V E.C 2mm / Low Noise 505-MKS21.0/63/5 63v
C-48 3.3uF 50V E.C 2.5mm / Low Noise 505-MKS23.3/63/5 63v
C-46 0.47 50V E.C 2mm / Low Noise 505-MKS20.47/63/5 63v
 
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Filter caps:

Kemet 13,000uf 100v - ALS70A133KE100
Ring Terminals: 165302
4.7k bleeder resistor: ERG-3SJ472A
* Screws and washers do not come with filter caps!

Not photoed:

F2654 Push Switch Circuit Board

Electrolytic Caps
C-07 10uF 16V E.C 2mm 647-UPW1H100MDD1TA 50v
Ceramic Caps
C-05 0.047uF 50V C.C 7mm 505-MKP2C024701C00JS 63v
C-06 0.047uF 50V C.C 7mm 505-MKP2C024701C00JS 63v

M704 Tune Meters Closure

Electrolytic Caps
C-0u 100uF 6.3V E.C 647-UPW1E101MED1TD 25v

F2623 Filter Circuit Board

Electrolytic Caps
C-05 2.2uF / Audio 50V E.C 5mm 505-MKS2-2.2/63/10A
C-06 2.2uF / Audio 50V E.C 5mm 505-MKS2-2.2/63/10A

Bias setting * Note the schematic is wrong for the bias pots to trim. Also I was getting slightly diffrent readings in mA when a fuse with either in or not in on the other channel not being biased. I stuck with the manual at the end and left the fuse in the other channel during final adjustment (I knew I was in the ballpark of a few mA).

20200605_134145.jpg 20200605_135655.jpg

BOM I used,

Here is how I bypassed the Dolby board:

20200605_135556.jpg






And here she is getting her first session of playing! Installed ice blue LEDs and wired the tuning needle to be on at all times.

20200605_155411.jpg 20200605_155552.jpg 20200605_155600.jpg 20200605_155626.jpg
 
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View attachment 1889010 View attachment 1889011 View attachment 1889012

Filter caps:

Kemet 13,000uf 100v - ALS70A133KE100
Ring Terminals: 165302
4.7k bleeder resistor: ERG-3SJ472A
* Screws and washers do not come with filter caps!

Not photoed:

F2654 Push Switch Circuit Board

Electrolytic Caps
C-07 10uF 16V E.C 2mm 647-UPW1H100MDD1TA 50v
Ceramic Caps
C-05 0.047uF 50V C.C 7mm 505-MKP2C024701C00JS 63v
C-06 0.047uF 50V C.C 7mm 505-MKP2C024701C00JS 63v

M704 Tune Meters Closure

Electrolytic Caps
C-0u 100uF 6.3V E.C 647-UPW1E101MED1TD 25v

F2623 Filter Circuit Board

Electrolytic Caps
C-05 2.2uF / Audio 50V E.C 5mm 505-MKS2-2.2/63/10A
C-06 2.2uF / Audio 50V E.C 5mm 505-MKS2-2.2/63/10A

Bias setting * Note the schematic is wrong for the bias pots to trim. Also I was getting slightly diffrent readings in mA when a fuse with either in or not in on the other channel not being biased. I stuck with the manual at the end and left the fuse in the other channel during final adjustment (I knew I was in the ballpark of a few mA).

View attachment 1889016 View attachment 1889018

BOM I used,

Here is how I bypassed the Dolby board:

View attachment 1889017






And here she is getting her first session of playing! Installed ice blue LEDs and wired the tuning needle to be on at all times.

View attachment 1889019 View attachment 1889020 View attachment 1889021 View attachment 1889022
Awesome job Brother! You're just overlooking something on the Dolby board but it's really hard to pinpoint sometimes. Heck, unless you're using a Tape Deck, it's not used anyways. Enjoy the awesome music!
 
Looks like a ton of work... very nicely done. Bet is sounds like a Sansui.

Meaning = Badass.

Thank you - surprisingly it was a decent amount of work. Even using my new Hakko solder sucker it still took a long time. Filter caps were tricky. It sounds fantastic! Got that warm Sansui mojo going on.

Awesome job Brother! You're just overlooking something on the Dolby board but it's really hard to pinpoint sometimes. Heck, unless you're using a Tape Deck, it's not used anyways. Enjoy the awesome music!

Thanks! If you remember you were a huge help when I first ventured into Sansui land and picked up a 7070. This unit was surprisingly similar, especially the driver board. I'll pick up the Dolby board again sooner or later, just needed a break from it. Doing just fine without it :)

That's the sound of Sansui! :rockon::music:

20200605-211514.jpg
 
Just curious how it compares to the 7070? From what I have read the 9090 is a 7070 with more of everything if that makes sense. Would love to hear some more impressions from a 7070 listener after you have spent some time with it.
 
Good question. Remember this is a DB version. Compared to the 9090 non DB they look very similar on the outside the internal circuitry is very different, particularly the output transistors. I haven't read recently the differences of the two and if people say they sound different or not, but there has to be some sort of difference.

Edit - the 7070 seems to have a npn/pnp transistor setup like the 9090db just from a quick look I did on my old 7070 thread. I haven't checked the manuals though. Maybe they are not so different after all? I believe the 9090 is all one type of output transistor. The driver board on the 9090db seems to be identical to the 7070 (very cool).

I haven't A/B'ed them but was cranking the 9090db all night. The 9090db seems to be a click less warmer and trades it for a less coloured more precise sound. The difference is subtle, both have that unique Sansui sound. Both seem to let you push/remove highs and lows much farther than the Pioneers I am used to. 9090db winning in terms of clarity and "hi-fi", and the 7070 winning in its own right of smooth warm mojo tone. If you are happy with the power of the 7070 honestly it's a perfect sweet spot.

The 9090db is really a treat. It reminds me of the au-717 a bit because of how quiet and precise it is. Gotta be careful with loud volume, loudness and the the bass pot if you're using fragile speakers (was playing them on BW bookshelf speakers). It really pushes through the lows with power and ease. It also runs cool at idle and low volume but as soon as you start pushing power the heatsink gets very hot. Lots of outputs on a small heatsink.
 
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Lots of nice useful pictures revealing a nice restore, nicely documented. :thumbsup:

However, I am quite surprised to see only the 4 trimmers on the driver board have been changed, several others being missed - any reason for that?
 
Lots of nice useful pictures revealing a nice restore, nicely documented. :thumbsup:

However, I am quite surprised to see only the 4 trimmers on the driver board have been changed, several others being missed - any reason for that?

In some aspect I had to build this list from information across many threads. There was no one clean recap list - from my searching the trimmers other than the driver board never came up and therefore overlooked. Other than the Dolby board and the Dolby FM trimmers near the tuning gang, the is the one for regulating the RF board voltage and the tuning meters right? Going off memory here.
 
I'm not that familiar with the 9090DB, but certainly the ones you mention probably don't need to be set particularly finely, or are not in a 'used' part of the receiver (Dolby FM?). I suppose I only mentioned it because it is my habit to change all trimmers. :)
As far as the trimmers on the 9090DB/8080DB/QRX9001/7070 which all use the F-2624 driver board, those 4 trimmers are the critical ones, especially the BIAS trimmers for obvious reasons. The only other trimmer that "takes any heat" would be for the voltage adjustment on the RF (tuner) Power supply (12.5v) in the 9090DB/8080DB, but I have never had any trouble with those. There is little "strain" on them. The trimmers for the power meters never break a sweat either. That of course is if there have never been any "catastrophic" blowouts in those circuits, and/or have spent their lives in harsh or damp conditions. That style of shielded trimmer holds up very well under normal circumstances. BUT like any trimmer pot, they have a limited cycle (number of turns) lifespan. Even the Bourns cermet trimmers are only good for a certain amount of turns (cycles) and is in the datasheet(s). I cringe every time I see someone squirting D5 in an "original" trimmer, and working it "several times" to clean them. They get dangerously close to their "cycle" lifespan limit. As always though, when in doubt, throw it out. You never know how many times one may have been cycled previously, especially a unit that has been previously "serviced".
 
Just curious how it compares to the 7070? From what I have read the 9090 is a 7070 with more of everything if that makes sense. Would love to hear some more impressions from a 7070 listener after you have spent some time with it.
The 7070/8080DB/9090DB use a push-pull output stage with PNP/NPN output transistors. The 8080/9090 (non-DB) use a quasi-complimentary output with all NPN output transistors. There is a bit of difference in the sound, but the Sansui engineers designed the circuits very well so the difference is subtle. Using all NPN transistors makes for a bit less expensive price point of the units. Quasi-complimentary were designed that way because early on, PNP transistors were a bit more expensive to produce. But over time the technology improved along with materials and processes which closed the price gap considerably.Now there is only a small difference in price. Just look on Mouser (or your favorite supply) and you'll notice the differences between PNP and NPN are usually less than a dollar now for output transistors.
 
Great job as always. This model has lot's of quirks and inconstancies, it's quite a project to restore.

Gonna be nit-picky for a sec here - the tuner/Dolby power supply, I like to bump those 270 Ohm resistors to 7W and get them away from the board. Some people even do a 25W mounted one. I've seen that board break in half, or have most of the traces missing from the heat those resistors put off.
 
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