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Sansui 1000A, too much maintenance if don't listen to FM?

Old Guy8

Old Guy8

Cliff & Cleo
Subscriber
I picked up a Sansui 1000a from trowling garage sales in the spring. Owner said he had not used in 20-25 years. He bought it in Okinawa in '66. Said it was too much mainenance for him.
I bought it without powering up, from AK advice. Looks in good condition, with I suspect mostly original tubes. Have wanted to try tube sound. I'm unsure how much warmth is enough or too much, for me. I assume if your reading this, warm is your preferance. I previously asked advice in Sansui thread. Advice there said it is worth rebuilding. I'm sure it is.

Main question is: I'm trying to decide if it is a good fit for me. For what I listen to and speakers I have. I have to make that decision, but would like advice. Can you help? Is a tube integrated amp a better option? Or a tube power amp fed from the Rogue? I know lot of choices.
Budget: Not sure of cost to have 1000a rebuilt. A ballpark idea without any outside cosmetics work? How reliable are 1000a rebuilds?
Been advised, it runs very warm. Needs to run without cover or with drawing cooling fans. This extraneous to my questions.

Here there is only couple stations that FM broadcast jazz and blues. Not interested in other local offerings. Don't see me useing the tuner much. Too far from Chicago for their stations.
I listen to a variety of music. Mainly jazz but also blues, folk, rock (not much heavy), classical, light opera, musicals.
Equipment I have: Valhala LP12, NAD 546 CD player, Rogue Sphinx hybrid amp (Mullard NOS 12au7 pre tubes and class D power section), stacked ADS L880 speakers for 4 ohm load. Likely keep this together. (Sansui only has 8 and 16 ohm taps.)
Equipment for Sanui system: Choice of Thorens 165, lab400, Denon DP37F TT's, various Sony CD players, Pioneer TX7500 tuner, stacked NLA Advents (in series 16 ohm load), Moded Ohm C2 (6 or 8 ohm load) and Boston Accoustics A100 speakers to choose from. In future, will add a DAC, streaming music.
 
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1000a's typically will need a full recap in order to work properly. Other than quick testing, I wouldn't run one at all, before one. The chances of taking out one of the desirable, and very hard to replace, output transformers, is too great. They are a very nice, powerful, tube receiver, with great transformers. Years ago, sometimes they were gutted for their iron for DYI projects, they are that good.

It has been my experience, and I've owned a couple, that a full recap, at minimum, will be necessary, no real way around it. The paper and especially the oil caps, are going to be mostly bad. In mine, it was about 80%. The can electrolytics can be much more reliable, but why cheap out when you are already going to have to change most all of the caps anyway.

If you do it yourself, parts will probably be in the $100-$150, possibly a bit more, range. If you have someone do it, it will be much more, as it's quite labor intensive. Once recapped, the receiver has a pretty neutral sound, not nearly as bass heavy (or "tubey") as you would think. Very pleasant and fatigue free actually.
 
I'd honestly try to trade it for a rebuilt amp or something. The 1000A is a pain to work on and you will NEED it rebuilt--1000As are famous for blowing transformers. If you're not going to even use the radio part, it just seems like you'd be better off with something simpler.
 
I'd sell or trade it. Actually I'd just sell it in order to be able to get exactly what I want. If you want to stop by sometime you can listen to my KT 88 integrated. I might have my Maggie back by then as well. As much as I'd like to have some Sansui tubes I have no need for a receiver being in the same radio wasteland that you are.
 
I've owned a 1000A for years. Right now it is hooked up in the shop to a pair of B&W speakers and it sounds really good. But like everyone is saying, the receiver will have to be recapped if you are planning on using it. I'm using Electro Harmonix 7591 output tubes in mine as I don't think NOS Westinghouse or RCA's sound any better and certainly not for the price they are selling for.
 
Think of it as a good investment in great sonics and having something worth the $

Transformers only fail from bad caps, and otherwise will last.

To save $ you could diy , one cap at a time so nothing gets mixed up! Take lot's of detailed pics beforehand , and maybe a great winter's project. You can use the old cap leads to attach the new ones to make it easier. Lot's of threads on AK if you google also.
 
As a 1000A owner for almost 10 years, and having rebuilt it myself as the 1st receiver I've ever done, I will say it is quite daunting to look at underneath. But look at a FISHER 800C underneath and you'll see basically the same circuits, but in a deeper chassis so it isn't so squeezed together. The main reason it runs HOT is the placement of the VOLTAGE Dropping RESISTORS for the FM section and the placement of the tubes between the transformers.

I did a couple of things to mine to cool it down.
1.) cut down the "fence" between the front and back so it's only between the Main power Transformer and the MPX.
2.) Placed Silver colored aluminum HVAC Seam tape on the transformers sides facing the tubes (reflects a fair amount of heat back into the air from the tubes.
3.) Replaced those TOWER Voltage Dropping resistors next to the Main Transformer with Aluminum housing 50W resistors mounted on the fence (1 section) and the back of the Dial cover panel. (2 sections).

It runs cool enough, about 135*F(cover on) to allow the cover on it while running although I leave it off for the tube glow. It doesn't run any hotter than my FISHER 800c's now.

Just be advised that the Phono preamp board is SOLID STATE. The 2sd381 transistors are Germanium, so don't get heavy handed with a heat source near them.

Otherwise it's a pleasureable unit to run, and listen to. Everyone has a FISHER 500C/800C. How many actually have a Sansui 1000A that will givethe Fisher a good run for it's money and in some instances blow the FISHER's socks off. I have 2 800c's (1 in a console) and don't get that much use from them. I do have the 1000A in my room next to the bed, so I can listen to NPR Jazz stations at night. It hasn't hiccuped in the almost 10 years I've had it after I rebuilt it. It's utterly reliable. I did have a NEW Tungsol 7591a suffer an Infant Mortality incident after 50 hours on it, but it was the tubes fault not the Sansui's. A Cathode and screen resistor and it was back up and playing.
 
Thank you to all of you for comments and experiences with 1000a's. Early on, I decided not to power it up, without rebuilding it, from AK advice. A friend gave me a Variable transformer, so I could slowly start it, if I was inclined to. So far I have not. Don't see point of taking risk, if going to rebuild. If decide to sell, might do so to prove it works.
I was on the fence, when I started this post. Guess I still am. I look at the 19 tubes and tuner that won't likely get used much. I see a complicated device. It is 50 years old has issues due to age. On the plus side. Initial low price. So add the (?) hundreds to rebuild. May still be economical compared to new or lightly used modern tube integrateds. When I compare, just for instance, to a Rogue Cronos tube integrated I see a much simpler device with easy tube biasing. It is also well out of my budget, new or used. I have a Rogue Sphinx, so fancy thier products.
Like I say, still on fence. Thanks again for all your thoughtful advice. Once again, members here are the best.
 
larryderouin said:
As a 1000A owner for almost 10 years, and having rebuilt it myself as the 1st receiver I've ever done, I will say it is quite daunting to look at underneath. But look at a FISHER 800C underneath and you'll see basically the same circuits, but in a deeper chassis so it isn't so squeezed together. The main reason it runs HOT is the placement of the VOLTAGE Dropping RESISTORS for the FM section and the placement of the tubes between the transformers.

I did a couple of things to mine to cool it down.
1.) cut down the "fence" between the front and back so it's only between the Main power Transformer and the MPX.
2.) Placed Silver colored aluminum HVAC Seam tape on the transformers sides facing the tubes (reflects a fair amount of heat back into the air from the tubes.
3.) Replaced those TOWER Voltage Dropping resistors next to the Main Transformer with Aluminum housing 50W resistors mounted on the fence (1 section) and the back of the Dial cover panel. (2 sections).

It runs cool enough, about 135*F(cover on) to allow the cover on it while running although I leave it off for the tube glow. It doesn't run any hotter than my FISHER 800c's now.

Just be advised that the Phono preamp board is SOLID STATE. The 2sd381 transistors are Germanium, so don't get heavy handed with a heat source near them.

Otherwise it's a pleasureable unit to run, and listen to. Everyone has a FISHER 500C/800C. How many actually have a Sansui 1000A that will givethe Fisher a good run for it's money and in some instances blow the FISHER's socks off. I have 2 800c's (1 in a console) and don't get that much use from them. I do have the 1000A in my room next to the bed, so I can listen to NPR Jazz stations at night. It hasn't hiccuped in the almost 10 years I've had it after I rebuilt it. It's utterly reliable. I did have a NEW Tungsol 7591a suffer an Infant Mortality incident after 50 hours on it, but it was the tubes fault not the Sansui's. A Cathode and screen resistor and it was back up and playing.
Click to expand...
Larry, Thanks for the background on your rebuild. I have read a little on a thread where you advised someone on their 1000a rebuild recently. That would be beyond my strengths. Don't have the patience and skills, myself.
 
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I just completed one for a neighbor, it took all day.The caps cost $75.I did it the easiest way, by clipping the caps at the terminals and leaving the old wire in place.I was concerned with breaking a tube socket pin,or terminal strip, as the wires were wound pretty tight on all of the connections.
 
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You don't really have to worry about the tubes (maybe they can be removed and saved) or parts in the Tuner Section
so in effect it can be used like an integrated amp!
 
Shadowdog,
If removing tuner tubes works without causing issues, that is an option. Only one station I might listen to here.
thanks.
 
I thought it was OK. Perfectly serviceable. Many say it's the weak spot of the amp and to use a phono preamp. I never did so I can't speak to it.
 
There is a SANSUI A-604 input transformer for MM cartridges that have less than 2mV. output, however I don't know if that makes it compatible with the lower output MC cartridges as I think these need a different load resistance (and maybe EQ?). :idea:

Mark T. :music:
 
Old Guy8 said:
Shadowdog,
If removing tuner tubes works without causing issues, that is an option. Only one station I might listen to here.
thanks.
Click to expand...

I don't know about the Sansui 1000A, but with my Pioneer SX82 receiver, I found that when the tuner section was switched out, the extra voltage was applied to the integrated amp circui! This pushed that part of the amp harder that I feel comfortable with, even though it was part of the design.

If you plan on excluding the tuner permanently, I would check that this doesn't happen to the Sansui. If it does, you should be able to make a plan to drop the voltage going to the rest of the amp.

If you only listen to one FM station, get your programming from the riches of web radio.
 
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