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Stunning Pioneer SA-8900II Amplifier Repair & Review

Come along as I repair and review the Pioneer SA-8900II, one of the most visually and sonically beautiful amplifiers I’ve had the pleasure of working on.

Welcome back everyone and my sincere thanks for your patience as I’ve worked through hundreds of repairs and been hanging out to write about more wonderful classic hi-fi equipment. I found a good one here in the drop-dead gorgeous Pioneer SA-8900II integrated amplifier though, so I hope you enjoy it 😊

Spoiler alert: The SA-8900II is one of the best-sounding integrated amplifiers I’ve heard, and regulars will know I’ve heard and worked on most of the great integrated amplifiers from the golden era.

Pioneer SA-8900II
Here she is, the gorgeous Pioneer SA-8900II, as she arrived in the workshop.

There are really only a few series of hi-fi equipment that I get really excited about and this series of silver Pioneer gear from the late ’70s is most definitely one of them. There’s just something about the lack of artifice or pretence and the ‘let’s get down to business’ feel of the gear that I like. Equipment like the Pioneer Spec 2, Pioneer SA-9800, Pioneer SX-1250 and Pioneer CT-F1250 really does put a smile on my face, and yours too I hope!

Pioneer SPEC-2
The beautiful and powerful Pioneer Spec 2 power amplifier, repaired, serviced and very much in need of a story. She’s coming back for an overhaul soon.
Pioneer SX-1250
Gorgeous Pioneer SX-1250 receiver I repaired years ago. I just love this thing.
Pioneer CT-F1250
One of my favourite cassette decks, this one was repaired for her original owner in 2020 I think. Story on this one coming soon too!

I grew up with Pioneer hi-fi equipment. My late Dad owned a wonderful but modest Pioneer hi-fi from 1970 and that’s the system I started on, recording many cassette tapes whilst listening to my favourite tunes on 96FM, probably to DJ and Liquid Audio customer Steve Gordon! I played records on Dad’s PL-12 and pulled the whole system to pieces whilst Mum and Dad were out. Sorry guys!

Features

The beautiful Pioneer SA-8900II is a Japanese market-only amplifier, but it can be found elsewhere in the world as the Pioneer SA-9500II. Hopefully that helps if you like what you see here.

Less well-known than her more famous Pioneer SA-9800 brother, the SA-8900II is nevertheless typical of high-quality Japanese amplifiers from the mid to late ’70s. By that, I mean it is superbly well-built, generously appointed in terms of features and specifications and really performs flawlessly in its intended role.

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This is the better-known Pioneer SA-9800, a slightly newer and more powerful version of the SA-8900II. It’s also a beautiful amplifier, but actually not quite as well-made as the older SA-8900II. Still, a wonderful amplifier though, with that classic styling Pioneer became famous for.

Some of my favourite features of the Pioneer SA-8900II are the superb headphone amplifier, fully adjustable capacitive and resistive loadings for the two phono inputs, discrete phono preamplifier and full dual mono amplifier design. The best feature though is its sound quality.

In typical Pioneer style, the SA-8900II isn’t as fancy as some of Accuphase or Sansui’s offerings. There are no multiple paralleled FETs in the phono preamp for example and so it won’t perform quite as well in this regard. What you do have though is a simple, reliable, well-executed design that just sounds good anyway, no fancy parts required. It’s also much easier to repair if/when it fails.

Unfortunately, the same cannot be said for the output devices. Pioneer used NEC output devices in the unusual and no longer available XM-20 device package. Replacing these is painful and only fakes are available now, meaning surgery is needed to graft in a set of different devices, in a different package.

XM 20
The unusual XM-20 semiconductor package of the 2SB618/2SD588 complementary pair used in the SA-8900II.

Before you tell me you found NOS XM-20 devices on eBay, let me confirm that those devices from Shenzen, China are not real NEC devices. Let’s hope these don’t fail!

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The design and layout of the Pioneer SA-8900II make it a pleasure to work on. Note the dual mono design, with a transformer, diode bridge and two filter capacitors per channel. There’s a third diode bridge and power supply for the preamp stuff. Note also the metal ALPS switches, ALPS ‘Blue Velvet’ volume potentiometer, Elna capacitors and lovely extruded aluminium heatsinks.

Aesthetically, Pioneer has always done its own thing and I appreciate that. They developed their own unique look and feel and the knobs and switches are a big part of it. They continued that tradition through to their more modern gear in the 1980s and ’90s. Also, I have to mention the gun-metal ‘Hammerite’ paint finish on the case, just gorgeous.

Check out the Audio-Database for more about the wonderful Pioneer SA-8900II.

Pioneer SA-8900II Specifications

Courtesy of HiFi Engine

Power output: 80 watts per channel into 8Ω (stereo)

Frequency response: 5Hz to 50kHz

Input sensitivity: 2.5mV (MM), 150mV (line)

Signal to noise ratio: 75dB (MM), 95dB (line)

Output: 150mV (line), 1V (Pre out)

Speaker load impedance: 4Ω to 16Ω

Dimensions: 420 x 150 x 376mm

Weight: 16.2kg

Year: 1976

Problems

This almost pristine Pioneer SA-8900II came to me via her lovely new owner who’d recently purchased her directly from Japan. He has a collection of some of the very best hi-fi equipment ever made (you won’t believe what he has) and let’s just say he also has a good ear. This SA-8900II was sold to him with a couple of issues and my goal was to resolve those rather than completely overhaul the amplifier in this first stage of work.

The main issues included:

  • Audible distortion
  • Incorrectly set standing current or ‘bias’
  • When the tone circuit was activated, the output dropped by about 20dB in the right channel
  • Dry joints, loose fasteners
  • Signs someone tried to resolve issues before me, presumably in Japan

Anyway, the situation was definitely not ideal so I was keen to crack into this one. One of the very best things about this SA-8900II though is that it is essentially 100% original. Despite someone trying to resolve this problem previously, they thankfully hadn’t shotgunned everything and this lovely amplifier is pretty much in the condition she came from the factory, plus a little dirt.

As always, you can watch a video about this repair over on our YouTube channel:

Service & Repair

As always with a job like this, we start with data collection through functional testing and measurement and then progress through cleaning, servicing and residual fault tracing and rectification, then lastly adjustment and bench testing. At that point, I send the owner a report and invoice for the work completed, recommendations for further/future work and we go from there.

I’ll make the point that there are no miracles here at Liquid Audio, just a logic-based, scientific approach to fault-finding and equipment improvement. Be wary of any claims of miracles, wherever they may originate!

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After a bit of routine cleaning and service, I wanted to check the quiescent current draw in both channels as the power consumption of the amplifier seemed low. These are the values I measured and, whilst they are reasonably symmetrical, they are also roughly half of what they should be. Whoever set these values set them incorrectly.
Pioneer SA-8900
Further investigation also revealed problems with the tone circuit. Time to remove all the knobs and front panel to gain further access inside. It’s worth noting that literally every fastener was loose. Someone had been in here before me looking to resolve this fault. They hadn’t been able to, nor had they tightened everything back up!
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The saving grace here is that this lovely piece of Japanese engineering is easy to work on. Here, I’ve removed the tone board for further work.
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I re-flowed a few joints and could see someone had been here before me. I then decided to remove and deeply service this tone control to eliminate it as a culprit. BTW, if you don’t know, you won’t find beautiful metal ALPS switches in most modern amplifiers. Know why..? Too expensive. Note to self: don’t drink the residue in this glass like you did the last time after you cleaned the desoldering gun… 🤦‍♂️
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I use a special process/tools to get boards like this REALLY clean. Honestly, I never see boards cleaner than those I’ve cleaned myself. For me, this is a really important part of the bigger process and one that’s almost never done. I also removed and tested the transistors in the affected channel to ensure they were OK.
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Nice board, typically well laid out by Pioneer, with silk-screen traces printed on top to make fault finding easier. I had this board in and out a couple of times to test each step of the repair. I’ve replaced four capacitors already, including one that was dead.
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Here, I’ve replaced the others I wanted to replace and reinstalled the board. The remaining low-leakage Elnas are perfect and the amplifier is now repaired.
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The underside of the amplifier. Note the main filter capacitors are bypassed by film capacitors, this makes a very real sonic difference. I cleaned the mainboard after replacing a couple of parts and re-flowing various joints.
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That’s more like in terms of standing or quiescent current, what we call bias. This is typically measured as shown here, with two meters, measuring the voltage drop across in this case a string or two emitter resistors per channel. We then replicate the process across the other two emitters to verify they read the same, +/- a millivolt or two. I’ve also had a couple of people ask me about my Fluke 27s. Let me just say that they are truly great, industrial-grade multimeters and I love ’em!
Pioneer SA-8900
I replaced a couple of other dead caps in the power supply with premium film types for good measure – see if you can spot them.
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I deep cleaned the knobs (LOL), toggles and fascia of course. Doesn’t she look a million bucks now?!

Results

In a nutshell – fantastic! I mean, she’s repaired and running perfectly, she looks much cleaner and sounds absolutely fantastic. There’s a lot to be happy with here, for everyone involved.

Pioneer SA-8900
Seriously, just look at this thing. Don’t you want one too..?
Pioneer SA-8900

I had a long chat with her owner and this amplifier will come back for further overhaul work at a later time, once he’s had a good chance to listen to her in one of his many systems. Seriously, you wouldn’t believe what this guy owns.

Performance

So I know what you’re wanting to know. How do the Pioneer SA-8900II and Pioneer SA9500II compare with other contemporary amplifiers that people with a grand or two to spend might be considering? Very, very well.

I’ll come straight out and say it: this Pioneer SA-8900II is easily one of the best-sounding integrated amplifiers I’ve heard and worked on. I’ve recently repaired and listened to the Accuphase E-301, Accuphase E-303, Sansui AU-X1, Accuphase E-202, Sansui AU-819/AU-D707 and Technics SU-V8, all somewhat comparable. The Pioneer SA-8900II keeps up with all of them.

I’d say that the Sansui AU-X1, a story on that resto coming soon, is a better-sounding amplifier. But then it’s one of if not the greatest classic integrated amplifiers ever made. The Accuphase E-303 and E-303X would almost certainly beat it, and I marginally prefer the SA-8900II over the SA-9800, so if you want really good bang-per-buck, the SA-8900II or SA-9500II are excellent choices.

Compared to current equipment, well I recently serviced a Marantz PM-8004 KI Pearl Lite and the Pioneer crushes it. I believe the current version of this is the roughly $3000 AUD Marantz PM-8006 and it will be a similar story there I think, too. The Marantz looks lovely of course, but it’s plasticky. I don’t care either way really but it may help you make an informed decision and my readers need this information.

But Mike, it doesn’t have gold-plated RCA connectors, detachable power cable or accept banana plugs..?!

Someone, soon

Nope, and fancy that, it sounds amazing, so there’s that!

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The Bottom Line

If you want a vintage-looking, wonderful sounding, fully featured integrated amplifier that won’t break the bank, I think it’s fair to say that, along with many other great choices, the excellent Pioneer SA-8900II or Pioneer SA-9500II should be on your shortlist.

As always, thanks for visiting, and for taking the time to read and share your thoughts. If you enjoyed this article, please like, share and subscribe.

If this article has helped or you’ve just enjoyed it, you are most welcome to make a donation or shout me a drink via the donate button in the footer.

If you like me to look at your wonderful vintage Pioneer amplifier, I’d be happy to. Enquiries via the contact page.

Pioneer SA-8900II / SA-9500II Integrated Amplifier

$1000 - $2500 AUD
9.4

Build Quality

8.5/10

Features

10.0/10

Sound Quality

9.0/10

Servicability

10.0/10

Bang-per-buck

9.5/10

Pros

  • Superb build and serviceability
  • Stunning sound quality
  • Wonderful feature-set
  • Fantastic phono preamplifier
  • Tape loops, filters woo hoo!

Cons

  • The SA-8900II is 100V only, no biggie

12 thoughts on “Stunning Pioneer SA-8900II Amplifier Repair & Review”

  1. As always Mike your stories read like a Robert Ludlum thriller, excitement at every paragraph! I am an absolute Jazz piano nut but know very little about the gear (Accuphase E202) that I use to deliver heaven to my ears, your write-ups fill in the missing piece (peace?) for me! Keep it up Mike, brilliant reading!

    1. Hi John, you are too kind, the main thing for me is that people like you are enjoying the articles! Thanks also for the kind donation, very much appreciated, though not necessary.

  2. Mike,

    When this amp comes back for an overhaul, how much improvement in sound would there be or is the goal long term reliablility?

    1. Hi Mike, the goal is to achieve both, through strategic parts replacement, general maintenance and attention to areas that are likely to enhance reliability and performance. She’s significantly better sonically after this first visit, but that’s not surprising given the issues noted.

  3. Another fine article MIke! I really dug that oh so shiny after cleaning pic of the greener TC circuit board. It just screams “ready for action”.

  4. I am so glad I found this website. I own a 10 year old Musical Fidelity headphone amplifier that I love and which still works flawlessly (the interior looks brand new as does the exterior) as well as a similar aged Rego Apollo-R CD player that also works flawlessly. I have had to replace the transport in the Rega twice in the years that I have owned it but to be honest that is close to the limit of my non-existent skills. The thought of replacing caps and other bits and pieces on these multi-layer boards is where I draw the line. So I am glad this equipment will have a place to be serviced so it can give me decades more service. I love the sound of this combo and do not want to buy anything new as I am afraid I will be disappointed compared to what I have.

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