-
Feeling lucky? Check out the AK 24th Anniversary Giveaway thread and join in the fun!
Sansui 1000A vs. Sansui 1000
- Thread starter McBulldog
- Start date
Register to hide this ad
Felvis
Active Member
Oddly, I have been sitting on one of each for years, trying to decide which one to get restored, and by whom. Both have their visual merits and are in good physical condition. I powered up each when each was scored. The 1000 blew a fuse immediately. The 1000A played for a short while and then one tube started to red-plate and died. Never did plug either into a wall socket again.
So.... be careful!
So.... be careful!
Last edited:
Concur on the 1000A. Uses commonly available 7591 for output. The 1000 uses a 25E5 tubes (Top Anode).
For rarity, stick with the 1000. Rebuild it, use it occasionally.
For daily use, stick with the 1000A. Once you get all the leaky Suzuki and elna caps replaced it's in the same class as a FISHER 800-C IMO.
For rarity, stick with the 1000. Rebuild it, use it occasionally.
For daily use, stick with the 1000A. Once you get all the leaky Suzuki and elna caps replaced it's in the same class as a FISHER 800-C IMO.
Here are the details of what the repairman put on the invoice. He gave me the two extra tubes and two baggies filled with the old parts. -
"1000A - Test powers up with no function.
Found failed and disconnected high voltage power supply by others.
Repair power supply and test unit most controls very dirty / intermittent and several failing capacitors.
Replace failed coupling caps at bass control circuit and all electrolytic caps at phono circuit.
Deep clean controls and switches. Replace fuse with proper type. Replace all lamps. Test all features and function ok.
Reassemble and retest, ok.
1 - Fuse 4A SLO USA
2 - Resistor 6.8 OHM 2W metal film
1 - Resistor 2.7R 5W
2 - Diode, 3A. 1KV
2 - Capacitor .01UF 630V Metalized Polyester
2 - Capaccitor .022UF 630V Metalized Polyester
2 - Capacitor 10UF 50V LO-Z HI REL
8 - Capacitor 47UF 50V LO-Z HI REL
2 - Lamp fuse type 8V .25A
3 - Lamp 6.3V .25A screw base"
________________________________
1000 -
Replace blown main fuse and basic test unit ok for service repair broken wiring and mount at AM bar antenna. Fashion insulator for broken plate cap connector.
Deep clean controls, switches, and tube sockets. Test driver tubes ok. Preamp tubes noisey, power tubes weak/failing - replaced.
Troubleshoot and replace many electrolytic capacitors at preamp, power supply, and phono circuits.
Install inrush limiter to preserve original AC power switch.
Test all in / out and function ok except FM Stereo Indicator, and intermittent spot on vol control (works above and below spot with no change in volume.)
1 - Fuse 4A SLO USA
1 - Current inrush limiter 4A 16R
6 - NOS RCA 25E5 4 in use, 2 spare
1 - Tubes Shipping
2 - Selected 12AX7/ECC83 High MU Twin Triode, Spiral Filiment
4 - Capacitor 22UF 25V Axail
8 - Capacitor 33UF 50V LO-Z HI REL
2 - Capacitor 10UF 50V LO-Z HI REL
1 - Resistor 100K OHM 1W
1 - Resistor 18K-3W
2 - Resistor 6.8 OHM 2W Metal Film
2 - Lamp 6.3V .25A Screw Base
"1000A - Test powers up with no function.
Found failed and disconnected high voltage power supply by others.
Repair power supply and test unit most controls very dirty / intermittent and several failing capacitors.
Replace failed coupling caps at bass control circuit and all electrolytic caps at phono circuit.
Deep clean controls and switches. Replace fuse with proper type. Replace all lamps. Test all features and function ok.
Reassemble and retest, ok.
1 - Fuse 4A SLO USA
2 - Resistor 6.8 OHM 2W metal film
1 - Resistor 2.7R 5W
2 - Diode, 3A. 1KV
2 - Capacitor .01UF 630V Metalized Polyester
2 - Capaccitor .022UF 630V Metalized Polyester
2 - Capacitor 10UF 50V LO-Z HI REL
8 - Capacitor 47UF 50V LO-Z HI REL
2 - Lamp fuse type 8V .25A
3 - Lamp 6.3V .25A screw base"
________________________________
1000 -
Replace blown main fuse and basic test unit ok for service repair broken wiring and mount at AM bar antenna. Fashion insulator for broken plate cap connector.
Deep clean controls, switches, and tube sockets. Test driver tubes ok. Preamp tubes noisey, power tubes weak/failing - replaced.
Troubleshoot and replace many electrolytic capacitors at preamp, power supply, and phono circuits.
Install inrush limiter to preserve original AC power switch.
Test all in / out and function ok except FM Stereo Indicator, and intermittent spot on vol control (works above and below spot with no change in volume.)
1 - Fuse 4A SLO USA
1 - Current inrush limiter 4A 16R
6 - NOS RCA 25E5 4 in use, 2 spare
1 - Tubes Shipping
2 - Selected 12AX7/ECC83 High MU Twin Triode, Spiral Filiment
4 - Capacitor 22UF 25V Axail
8 - Capacitor 33UF 50V LO-Z HI REL
2 - Capacitor 10UF 50V LO-Z HI REL
1 - Resistor 100K OHM 1W
1 - Resistor 18K-3W
2 - Resistor 6.8 OHM 2W Metal Film
2 - Lamp 6.3V .25A Screw Base
kvflyer
Super Member
Not to beat the proverbial "dead horse", I too agree with most of what is above. The 1000A would be my choice if I could only keep one. I have both. My 1000A is restored. The 1000 is partially done and back in the "queue". One caveat is that the output tubes on 1000 were originally from a television receiver and can be inexpensive.
I want to keep both of mine!
I want to keep both of mine!
+1. Those grey Japanese oil caps are not well known for reliable operation.
kvflyer
Super Member
And plus two to this. ^^^ Whilst those capacitors were the good choice "back in the day", they are certainly not good for daily use. If they have not failed yet, it's just a matter of time. Do yourself a favor and toss them into the bin.
Having had a couple of those SUZUKI PIO's blow up literally in my face on initial power up on mine back in '09, I replaced them all. SANSUI designed them to run at the ragged edge of the envelope, yes there were wattage wars back in the 60's, with the 1000A being Sansui's last gasp for tube receivers while SS was taking over. Even with the repairs above, they won't last long. They both need a complete overhaul to run reliably and safely.
There is a difference between "repair to working" and "restoration for everyday use". Neither of these units are good candidates for long term use with the repairs that were given them. On the other hand you can now sell them as "working" (but how well and for how long?), possibly recoup your initial costs, and let the next guy restore it or get nickled and dimed as parts die off.
On the 1000A the coupling caps MUST be changed (same value, up to 630v) and some basic improvements done so the 7591's won't crash and burn. (go over to the FISHER Forum and look up the 800-C. It's basically the same topology and most of the "mods to the output's" will work on the 1000A.) Not Hype, personal Experience as I have both a 1000A and 2 800-C's. Leave the grid resistors alone. They are fine for value(200K).
Add;
1.)Screen resistors (100ohm) to minimize opportunities for arcing in the tube.
2.)cathode resistors (10ohm 1/4w) allow you to measure current draw from each tube for biasing AND when a tube goes chernobyl, blows thereby shutting down the tube and protecting the output tranformer.
3.) If it's a SINGLE or DUAL bias pot unit, convert it to quad pots.
4.) rebuild the Voltage doubler circuit
5.) rebuild the bias voltage circuit. (use new sealed Bournes pots)
6.) install CL-70 (2) THERMISTORS between the power cord and the primary side of the Main transformer
7.) Rebuild ALL can caps. with the limited space available, it's best to either gut and stuff, or get custom built cans. Forget CE. None of their caps are rated high enough in voltage.
8.) If you have an early version with the two tall black power resistors between the main transformer and the one pair of output tubes, make sure they aren't cracked, chipped or otherwise compromised. If they are you'll need to get some power resistors. I found the metal chassis mounts work fine but you need to parallel 2 12K to get the 6k value needed. Use 50W and they'll run a bit cooler. Move them to an open area of the chassis that doesn't have the heat load like the back does.
As for the rest of it. The resistors don't take to kindly to movement. These are generally the metal end capped type and they pop the ends. Replace them.
replace all of the electrolytics with 105*C rated caps. The PIO's and old films use modern film caps.
A lot of this also applies to the 1000.
I'd keep both honestly and restore them at leisure. But they won't be easy or cheap. Spread it out and take your time.
There is a difference between "repair to working" and "restoration for everyday use". Neither of these units are good candidates for long term use with the repairs that were given them. On the other hand you can now sell them as "working" (but how well and for how long?), possibly recoup your initial costs, and let the next guy restore it or get nickled and dimed as parts die off.
On the 1000A the coupling caps MUST be changed (same value, up to 630v) and some basic improvements done so the 7591's won't crash and burn. (go over to the FISHER Forum and look up the 800-C. It's basically the same topology and most of the "mods to the output's" will work on the 1000A.) Not Hype, personal Experience as I have both a 1000A and 2 800-C's. Leave the grid resistors alone. They are fine for value(200K).
Add;
1.)Screen resistors (100ohm) to minimize opportunities for arcing in the tube.
2.)cathode resistors (10ohm 1/4w) allow you to measure current draw from each tube for biasing AND when a tube goes chernobyl, blows thereby shutting down the tube and protecting the output tranformer.
3.) If it's a SINGLE or DUAL bias pot unit, convert it to quad pots.
4.) rebuild the Voltage doubler circuit
5.) rebuild the bias voltage circuit. (use new sealed Bournes pots)
6.) install CL-70 (2) THERMISTORS between the power cord and the primary side of the Main transformer
7.) Rebuild ALL can caps. with the limited space available, it's best to either gut and stuff, or get custom built cans. Forget CE. None of their caps are rated high enough in voltage.
8.) If you have an early version with the two tall black power resistors between the main transformer and the one pair of output tubes, make sure they aren't cracked, chipped or otherwise compromised. If they are you'll need to get some power resistors. I found the metal chassis mounts work fine but you need to parallel 2 12K to get the 6k value needed. Use 50W and they'll run a bit cooler. Move them to an open area of the chassis that doesn't have the heat load like the back does.
As for the rest of it. The resistors don't take to kindly to movement. These are generally the metal end capped type and they pop the ends. Replace them.
replace all of the electrolytics with 105*C rated caps. The PIO's and old films use modern film caps.
A lot of this also applies to the 1000.
I'd keep both honestly and restore them at leisure. But they won't be easy or cheap. Spread it out and take your time.
The 1000A that I'm piecing together out of two early units (which apparently went through at least 5 OPTs between them, as one was a service replacement and each unit had one dead OPT) actually blew one of the terminals off the high-voltage grey multicap in the middle of the chassis. These things really have some crap capacitors in them.
kvflyer
Super Member
Correct, horizontal output tube.
jaymanaa
RIP 1961-2018
Hmm, certainly cheap and plentiful.
Rod Beauvex
Look at the tiny bunny...
Why are the OPTs so bad?
They're excellent-sounding OPTs. I think they must get fried when those horrible coupling caps let go...or they're made with undersized wire. Not a pleasant thought.
Pio1980
AK Member
8
Probably easier and cheaper to get 25E5s than the 7591, there's at least an early 1000 that somewhat resembles the SM-80 from which it is descended and a later version that favors the 1000A. I have the early version and a SM-80, there are pix of them in the thread titled " The Sansui sweep tube siblings". The SM-80 is fully functional with almost all of its original caps, the 1000 has been mostly somewhat recapped in the past but has a bad unobtainium loudness control and badly needs a benching for the FM section that I can not perform.
Sent from my SM-N900V using Tapatalk
Probably easier and cheaper to get 25E5s than the 7591, there's at least an early 1000 that somewhat resembles the SM-80 from which it is descended and a later version that favors the 1000A. I have the early version and a SM-80, there are pix of them in the thread titled " The Sansui sweep tube siblings". The SM-80 is fully functional with almost all of its original caps, the 1000 has been mostly somewhat recapped in the past but has a bad unobtainium loudness control and badly needs a benching for the FM section that I can not perform.
Sent from my SM-N900V using Tapatalk
Last edited:
