Marantz SR9000G Recap

[MBuras]

Sooooo.....my next project is a really odd duck, the Marantz SR9000G. Very little information available on this unit but appears it might have only been sold in Germany in 1979 or 1981 depending on the information source. Definitely confirmed it has a variable voltage switch on the back so might support the claim of an international unit. Apparently puts out 130WPC so that definitely attracted me to it but I understand the 1980's styling isn't for everyone.

It's a little beat up with dings in the wood case and missing the grill which I figure I'll never find as it's an odd size. Will wait to decide on refurbishing the fake wood case until I listen to the finished project. Should be worth it but don't want to invest the time/effort/money until I know for sure.

Test on DBT and no shorts. Connected my test speakers and the unit works but is very scratchy with volume and balance adjustments. No surprise given the dirty condition inside and out. Starting with a good cleaning and then mapping out the boards for cap replacements along with a few resistors. This unit actually uses some fairly modern transistors so none of the old SC458's or similar to replace.

Here are a few before pictures of the outside. I'll document the boards as I move forward.

 

[rBuckner]

I had a guy in town ask me if I wanted to buy his a few years back. I wasn't interested in it at the time - hopefully I didn't make a mistake! It should be an interesting journey for you Mike.

 

[Captain581]

You'll find that model lauded fairly highly on a site title 'My Favourite Receivers' - Chris, the author, ranks the SR9000G as one of his favourite receivers and provides some information here. I think you'll enjoy that 'odd duck!'

 

[MBuras]

Seems like forever since I started this post but only been a week or so. Just been busy doing other stuff but finally had a chance to dig in on this monster.

A few construction notes first.

• No wonder this receiver has a cabinet that's integral to the unit. The steel subframe is very thin and just sections screwed together. There's not a lot of stability on it's own outside the case.
• The amp takes up a large portion of the middle section with a massive heatsink and uses modular connectors just like the late 1970's Marantz units (2265B, etc). Makes pulling it out and working on it a breeze.
• The other boards are held in by a series of brackets which aren't very sturdy. And instead of screws most of them use these cheap plastic pins that have a back section like a wall anchor. Put the pin into the back section and it spreads out and grabs hold....kind of.
• There is less of everything compared to the 1970's Marantz receivers. All boards except for the amp are smaller with less components. A few more IC's and a few places where caps, especially on the PLL board, seemed to be an afterthought.

Overall I see what people are talking about when they say construction started going downhill in the late 1970's/early 1980's but I'll reserve a final opinion on that until I hear it when complete.

First up was the power supply, P800, as well as the main filter caps mounted behind the board. It's best to do it all at once.


Nothing overly special here. All the bigger resistors got new KOA Speer parts of similar values. Kept all transistors and diodes except for the big 2SD313 at Q809 (the big heatsink). Those always get a good workout and best to freshen it up. All electrolytics were replaced with similar values in the Nichicon UPW series. I normally like to replace the relay as part of normal service but on researching this one (also used in a few Pioneer models) I found out there is no modern replacement. So it got a good cleaning, reassembled and reinstalled.

The really strange part about this power board is all the "missing"components. They're not actually missing but why they chose to use this board I'll never understand. And adding to that mystery is there's a power daughter board, P850, connected to the front of the receiver. That daughter board received 3 new electrolytics. All UPW series (one is under the board).


Errors found on these boards:

• C815 is listed in the service manual as 100uf/16v but is actually 220uf/16v
• C855 is listed in the service manual as 220uf/35v but is actually 100uf/25v

 

[rBuckner]

Maybe the p/s board is also used in another unit that does get the other parts? One of the boards in our newest line of products at work is built 5 different ways for various models.

 

[MBuras]

It's very likely they used this power board in another unit. Guess I mistakenly assumed the top of the line unit would use the most components thus filling up the board.

Anyway, now moving on to the tone amp board. There's not a lot to this board very much unlike some of the earlier Marantz models. Most of the tasks handled by the IC's I guess. My replacements here consisted entirely of capacitors of both the ceramic and film variety.



All the original 4.7uf/50v polar electrolytics (CE01/02 input, CE23/24 output, CE05/06 purpose?) were replaced with WIMA films. All ceramics (CE03/04, CE07/08, CE21/22) were replaced with same value Kemet C0G MLCC's. And that leaves us with CE09-CE20 which are very small (coupling?) films. While I might not normally replace these films the quality seemed dubious to me just from appearance. Almost a translucent/glow in the dark green and very thin, even more so than other Marantz films in the tone amp section.


So out they went and in went Kemet films in their place. Just the right size lead spacing and perfect body size for the space.

Other than not listing any voltages for the ceramic capacitors in the parts listing (I used 100v - plenty enough and make sure to order 5mm lead space for drop in fit) there were not errors noted in that section. I did just notice on the schematic that CE06 is incorrectly marked as 3.3uf. Typo and the parts listing section is accurate at 4.7uf.

My thought process on this board was to make any improvements in quality of components possible. Can't hurt the sound and definitely might improve it. We'll see once I get the amp board finished.

 

[MBuras]

A little delay in this follow up post as I took a little break to relax and visit the north woods of Wisconsin and Upper Michigan. Great weather and beautiful scenery!

On to the P700 main amp board. It's easy to pull out and work on with 3 modular plugs and 6 screws connecting it to the receiver. Here's the before shot.


And the outputs are tucked in behind the board


The C701/702 input filters were 4.7uf electrolytics. I tried to squeeze in some Panasonic polypropylene films but there's just not much room and had to settle for WIMA films which were also a tight squeeze due to their large base footprint.

All ceramics were replaced with modern C0G types. I always try to order the 5mm lead spacing which makes for easier replacement. These were not required but just what I wanted.

All the remaining electrolytics were replaced with similar value Nichicon UPW's making sure to get the closest lead spacing and checking width for proper fit.

All the small films were replaced with fresh WIMA films of similar value. These were not required but they were similar to the films noted on the preamp and I felt comfortable replacing them.

All big resistors (1/2 watt & up) were replaced to get smaller packages thus creating more cooling space. The only ones I couldn't replace were the emitter resistors as they are a radial variety and I couldn't find anything with similar specs. I usually like to replace these as I've seen them break down over time but settled for testing them and they came in right on spec.

All of the trimmers were replaced with Bourns single turn units. At $1.60 a piece it just makes for easier adjustments later on.

And the two MV-13 epoxy varistors each received 2 x 4148 diodes in series as a standard replacement.

All transistors were left as is. Many oddballs in the bunch that were hard to track down and they were all working fine. The outputs were removed, cleaned, and reinstalled with new thermal grease.

Unfortunately I forgot to take a pic of the finished board so all you get is this crummy pic from the top through the opening where the screen should be. Not much to see other than the Bourns trimmers.

 

[MBuras]

And last up is the large combo board that takes up the whole right side. It includes the AM & FM tuners as well as the phono section and input selector. No pics on this one because it's just a mass of cables and wires running everywhere. A great example of the sloppy work later on at Marantz.

All of the caps in the tuner sections were replaced with similar value newer caps with anything under 3.3uf getting film. A few notes on these sections:

• C301 is a listing error in the manual. shows 50v/0.47uf but is actually 50v/4.7uf
• C304 does not have polarity marked on the board so be careful when removing and replacing this one
• C305/307 are both 1uf bipolar electrolytics. If not replacing them with film make sure you do not order polar electrolytics
• C319/320 are both a listing error in the manual. Both show 50v/0.47uf but are actually 50v/4.7uf

There are only a few caps in the phono section.

• C401/402 were low leakage 3.3uf electrolytics. They were replaced with WIMA films.
• C405/406 were 10v/47uf polar electrolytics and were replaced with 16v/47uf Nichicon UES series non-polar electrolytics
• C415/416 were low leakage 4.7uf electrolytics. They were replaced with WIMA films.

I did order the usual Kemet radial replacements for the ceramic capacitors in this section but realized once I was in there the stock ones were axial varieties. Never seen this before and didn't note it when cataloging everything. My bad. Might be able to stretch the leads on the radial replacements but didn't bother for now.

 

[MBuras]

Well this one is all done for now. Put it back together, made the usual adjustments and testing it on my primary two channel setup.

I did the basic output clipping test using a 1khz signal and 8-ohm dummy loads. Receiver is spec'd at 130wpc RMS. I achieved clipping at 160 on the right an 158 on the left. And let me tell you I'll likely never use most of that. Hooked up to my Axiom M80 towers the volume is extremely full and loud at just over 1/4 volume. A few more notches up to about 10 o'clock and the neighbors can likely hear it through closed windows!

I will agree with those that choose to bad mouth this vintage of Marantz receiver. There is plenty not to like about the build quality. Frame is thin and cheap. Pots have a very light and cheap feel when moving them. Volume adjustment is incremented instead of smooth. And of course it looks like the 1980's. That said the sound is absolutely incredible. I'm no expert like many on these boards but I can say that at least on FM and Aux this receiver bests my Marantz 2285 and Marantz 2325. Just pure, raw power and a very nice soundstage. Bass for miles and yet the highs are very well defined. FM reception is the best of any vintage Marantz or Pioneer receiver I've ever owned. Definitely more listening in the weeks ahead.

Here's a pic of the front all cleaned up. Now I just need to decide if I want to fix up the wood case. It's integral to the design and covered in cheap, peeling vinyl. Maybe a candidate for veneering or a custom case. We'll see.

 

[BeerLegs]

A little delay in this follow up post as I took a little break to relax and visit the north woods of Wisconsin and Upper Michigan. Great weather and beautiful scenery!
View attachment 794750

Hijack. I just spent 4 days up in the Northwoods last weekend -Tuesday for a much needed getaway also. I spent two nights in Minocqua and two nights at Garmisch.

 

[MBuras]

Nice! I stopped at Minocqua Brewing for lunch on Tuesday afternoon on my way down from Marquette. Great drives on two lane blacktop up there.

 

[MBuras]

It's been a while but thought I would share a pic of the finished project. Convinced a contractor I work with to get his amish cabinet guy to veneer the case, stain it and cut a new grille. It turned out better than I could have ever hoped. She's whole again.



-Mike

 

[Captain581]

What a beauty! I'm gratified to see this thing looking so good, back in action and not rotting in some landfill site. Does the sound still stand up in your opinion after having listened for a while now? Still besting your 2325?

 

[Lavane]

very nice!

 

[MBuras]

Does the sound still stand up in your opinion after having listened for a while now? Still besting your 2325?

Interesting question and one I can't quite answer at the moment. This receiver has been out of the rotation since November and I haven't listened to my 2325 since before that even. I'll throw some music at it this weekend and see if I still like it.

 

[MBuras]

So here's the short answer. Marantz 2325 wins.

Here's the long answer. The simple test was playing side one of Fleetwood Mac's Rumors vinyl. NAD533 table with Ortofon 2M blue cartridge. Axiom M80v2 towers [95db sensitivity]. Both the 2325 and SR9000G are fully recapped and restored. And of course I have to disclaim I'm not a critical listener by trade or hobby. Just know what I like.

SR9000G
First thing I noticed is the nice open soundstage. Good instrument separation. The mids and highs are most noticeable. They are neutral and pleasant. Not at all distracting or harsh. Bass is noticeably not present or impactful. Too much bass tone adjustment turns it a little muddy. Using loudness control is better but almost too powerful. Too hard to fine tune to my overall liking. Also the phono section has less gain than earlier Marantz receivers and amps so volume needs to be turned up too high for the same levels and this allows too many vinyl artifacts to be heard. Overall not bad. Powerful but not refined enough.

2325
First thing I noticed on this was the full sound. Much better all around even without the tone controls engaged. The bass and mids were perfect as is but the highs were just a tad too bright and harsh. Engaging tone controls and moving the treble down a notch from center was the perfect solution. Despite having a more full sound the soundstage was not as nice as the SR9000G. Just lacking a little definition but not enough so that most people (my wife) would notice. This receiver is definitely more pleasing overall and thus the winner.

All this said I still love my SR9000G and I picked it up at the right price so I'll probably keep it, at least for now. I have a hard time letting go of some equipment. Then again don't we all?

 

[Captain581]

Interesting and articulate read Mr. B. - nice you took the time to write that. I'm sure it will be enjoyed by all AK readers that discover it.

I had no presuppositions as to what you'd prefer, but I'm just a tiny bit surprised the 2325 won. Chris seemed to really like it on his 'My Favorite Receivers' site, and only mentioned other Marantz products in his 'More Favorites' page. Noticeably absent were any 22xx, 22xxB or 23xx models - bit of a surprise.

Long live the 2325.

 

[MBuras]

Well I certainly don't consider myself to be the final voice on the matter. Everyone has their own experiences they bring to the table. I think my takeaway from the experience is not to automatically dismiss any piece of equipment made after the golden age in the 1970's. The SR9000G is still a strong receiver and worth picking up at the right price.

 

[DJbreakDAbnk]

What price would you say is a good one? Looking at one for just under 3 Ben Franks and guy says the tuner isn’t working. Thinking repair might add up quick. Any help appreciated.

 

[MBuras]

Specific pricing discussion is banned outside the Dollars & Sense forum but I’d say generally at the price you quoted it should be in excellent cosmetic condition and full working order. Many unobtainable replacement parts in this receiver.