Sansui AU-D607X need treble pot and some help

sansuibutch

sansuibutch

Super Member
I made some trade and this came to me in a small bundle a while back. Today I finally had some time so I pulled it out and hooked it to some speakers. Right away I could tell somthing was a miss. The left speakers sounds ok but not much treble. The right channel sounds lifeless besides the treble. When I spin the treble adjustment back and forth the right speaker reacts accordingly but the left speaker has absolutely no change. I pull the unit apart and figure Il give it a good deox. This is where it gets interesting. Right away I notice the treble potentiometer is half missing. Someone deliberately unsoldered half of the pot and my guess would be it's for the left channel. It looks like they broke it apart. Now I'm on the hunt for 2 or 3 of these pots to replace them and hope that will get me a good start. Does anyone have any clue to why someone would do this? It seems if it didn't work properly it would still make more sense to leave it in there to me. Because it definetly doesn't work at all like this for the left channel.20181001_114325.jpg 20181216_180913.jpg 20181216_180943.jpg
 
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So here is the potentiometer in question. I've been looking around and it seems pretty tough to find. Does anyone have any idea where to source these things?20181217_145602.jpg 20181217_145553.jpg
 
AUD101 said:
need to confirm the value used in the AU X711 / AU X911DG - as the pot in the link is for these amps
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Unfortunately this pot P/No 48669000 is 100KΩ x2.

There is one for the AU-X501 - and a few others - also one or two in 'Pot Meters' 'Unknown'

Would be good to know the P/No of the wanted one - but the SM seems hard to find. :(
 
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Too small - you mean shaft too short? - what about taking a Sony one apart and using the track to repair your one?

It might not work - but worth a try don't you think...
 
Hyperion said:
Too small - you mean shaft too short? - what about taking a Sony one apart and using the track to repair your one?
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Yes too short is what I mean. Taking the Sony one apart is an option. The one that pops up when I'm searching is in Warszawa, MAZOWIECKIE. I'm pretty sure that's poland. I'm looking a little closer to home and for the correct one but Idk if that's going to happen. Were most pots in sansuis made to order and only for sansui products?
 
First things first - with the tone control defeated that circuit will have no effect whatsoever on the amplifier. So if there is a problem in that configuration you need to verify that the tone control switch has not been bypassed, or look elsewhere for the left channel problem.

I would expect the flat amp in the D607X to be the same as the D707X, and that in turn to be the same as the D11 II. The tone control pots are 100K. (I've just checked the manuals and the 607mr, 607mrx, and the x07dr and x07kx all use 100K pots). The balance pot is 250K (and a very specific configuration to Sansui). Check the value on the bass control pot and if it is 100K then the pot linked above should be fine as a replacement. I would also check the balance pot since if that has been messed with (e.g. used to replace the treble pot) then that will certainly give some strange behaviour from the amp.

Check this out and let us know how you get on.
 
phonomac said:
First things first - with the tone control defeated that circuit will have no effect whatsoever on the amplifier. So if there is a problem in that configuration you need to verify that the tone control switch has not been bypassed, or look elsewhere for the left channel problem.

I would expect the flat amp in the D607X to be the same as the D707X, and that in turn to be the same as the D11 II. The tone control pots are 100K. (I've just checked the manuals and the 607mr, 607mrx, and the x07dr and x07kx all use 100K pots). The balance pot is 250K (and a very specific configuration to Sansui). Check the value on the bass control pot and if it is 100K then the pot linked above should be fine as a replacement. I would also check the balance pot since if that has been messed with (e.g. used to replace the treble pot) then that will certainly give some strange behaviour from the amp.

Check this out and let us know how you get on.
Click to expand...
Ok with the tone control defeated either bass or treble adjustments have no effect whatsoever. With the tone control activated the bass and treble both do make a difference on the right channel. When I turn the treble up and down it does effect the right channel properly but absolutely nothing in the left channel. I would guess that is because half the treble pot is missing. Bass ,treble, and balance pot are all these identical 250kohm pots like I have pictured. But lookin closely at the solder on the pots it appears the balance pot has never been messed with but the bass and treble pots have definetly been removed at some point in the past. If it did indeed come with 100kohm pots that would make sense but it's weird that all 3 pots have the same number and markings, I mean identical. Seems strange that what I think would be years down the road someone had these 250kohm pots (identical to the balance pot) on hand.
 
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Check the 250K pots carefully. As I said Sansui balance pots have a very specific configuration. One half of each pot track is a pure conductor with zero resistance. When the pot is centred then in to out will measure zero on both channels. When you rotate the pot one way the resistance in one channel will increase, but the other channel stays at zero. Vice-versa when you rotate in the opposite direction. In other words the balance pot only reduces one channel - it does not boost the other channel.

If you have this kind of pot in the tone control circuit then you will really have weird effects when using them. And if all three are normal pots then your balance control isn't working as intended.

And if someone didn't know what they were doing they could have bought these from SansuiPartsShop assuming that it was 'one size fits all'.

Keep us posted on what you find.

ps I wouldn't hesitate to use the 100K pots linked in the post above for your tone controls
 
phonomac said:
Check the 250K pots carefully. As I said Sansui balance pots have a very specific configuration. One half of each pot track is a pure conductor with zero resistance. When the pot is centred then in to out will measure zero on both channels. When you rotate the pot one way the resistance in one channel will increase, but the other channel stays at zero. Vice-versa when you rotate in the opposite direction. In other words the balance pot only reduces one channel - it does not boost the other channel.

If you have this kind of pot in the tone control circuit then you will really have weird effects when using them. And if all three are normal pots then your balance control isn't working as intended.

And if someone didn't know what they were doing they could have bought these from SansuiPartsShop assuming that it was 'one size fits all'.

Keep us posted on what you find.

ps I wouldn't hesitate to use the 100K pots linked in the post above for your tone controls
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It is kind of hard to test this pot with a meter because half of it is gone. So I hooked the amp up without the treble pot. The left channel does not work either with the tone button depressed or not. I'm guessing because the signal takes a route through the pot regardless. Anyway when listening to the right channel, if I turn the bass potentiometer nothing happens from center to counterclockwise. But from center to clockwise the bass increases as expected. When I first hooked this up it did seem to be doing some weird stuff. Low bass on one channel and low treble on the other. The balance pot worked perfect and I can tell that one has never been messed with or replaced. I think your hunch about someone replacing the tone pots with balance pots is dead on. Specially seeing as the tone pots have both been replaced. This would make a lot of sense seeing as only half of the total adjustment makes change in the sound. I guess for the price of the 100kohm pots it's a no brainer. Il try to order these, hopefully the guy selling the one in the link above will have 2. Thank you very much, I will get some 100k pots and install and report back.
 
I tried to order those pots but I don't think sansui parts shop ships to the US. At least I have a part number now and know what I'm looking for. Again thank you very much, I am going to try to hunt down a couple of these.
 
Don't give up. Sansui Parts Shop is a kind of old school website. I've sent Nies (the owner) an email about shipping to the US. I'll get back to you. By the way he has 21 of them.
 
phonomac said:
Don't give up. Sansui Parts Shop is a kind of old school website. I've sent Nies (the owner) an email about shipping to the US. I'll get back to you. By the way he has 21 of them.
Click to expand...

That is beyond awsome that you are going out of your way for me. Thank you very much. I can't even begin to describe how awsome the people are on this sansui page. I'm on a few forums on this site and others but the people in the sansui section are just the nicest most helpfully bunch of people ever. I'm super happy my love for this vintage gear has landed me in this section. BIG THUMBS UP...
 
I've now heard back from Nies, and he does indeed ship worldwide. The process for ordering from Nies is:
  • register on the website (free)
  • add the items you want to your basket
  • checkout (you haven't paid yet)
  • you will receive an automatic order confirmation - do not pay at this point
  • you will then receive another email with confirmed shipping costs (options for insured or uninsured)
  • tell Nies which shipping option you want and ask for a PayPal invoice (assuming that's how you want to pay)
  • pay the invoice and await shipping/delivery of the goods.

It's a bit long-winded but you will get there!

Hope this helps.
 
phonomac said:
I've now heard back from Nies, and he does indeed ship worldwide. The process for ordering from Nies is:
  • register on the website (free)
  • add the items you want to your basket
  • checkout (you haven't paid yet)
  • you will receive an automatic order confirmation - do not pay at this point
  • you will then receive another email with confirmed shipping costs (options for insured or uninsured)
  • tell Nies which shipping option you want and ask for a PayPal invoice (assuming that's how you want to pay)
  • pay the invoice and await shipping/delivery of the goods.

It's a bit long-winded but you will get there!

Hope this helps.
Click to expand...
Thank you very much, I will get on there soon. A few days ago I tried to register and it would not let me pick any other location than the Netherlands. Il try it again and if that's the only option Il just pick it so I can get registered. Thanks again
 
I walked to the mailbox today and the goods have been delivered. I am very excited to get these babies in the unit and give it another shot. I didn't order them that long ago. They were delivered pretty fast considering where they were coming from. Can't wait to get an in. Thank you again Phonomac. Very much appreciated.15489810661681588189119.jpg
 
I ended up getting these installed last night. The bass and treble adjustments work perfect, and the unit sounds great it. One problem is they are longer than the originals by about 1/4 inch. I wish I would of noticed before I installed them. Not really a big deal, shortening them will be easy but bringing the flat the knob slides down on further might be tricky.
 
nosirrah said:
A very good file, and a steady hand will make that easy. Measure with a micrometer or caliper as you go
Click to expand...

I used a small air file to bring the flat part farther up the shaft and then a cut off wheel to get the right length. Obviously this thing was in a big bag and taped off real well, but all went great and they are perfect. Very pleased that it worked and this thing is singing some very nice tunes.
 
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