Hi, I'm new here, and my English is no good, please be nice to me.
I just bought a Pioneer A400X to pair my Warfedale Diamond 9.1. The A400X is in quite good condition, except the selection switch is little loose from the panel. I mean the turning knob is still very tightly secured to the switch, but as a whole, they are little loose from the panel. I'm sure it has no effect to the performance. But just feel not so good when using.
I would like to know how to detach the turning knob from the frong panel/turning switch? I cannot find a screw on the knob. Shall I just PULL IT HARD? Anyone knows?
Plus, I have a user manual of A400X, anyone needs information, just let me know. Cheers.
I just bought a Pioneer A400X to pair my Warfedale Diamond 9.1. The A400X is in quite good condition, except the selection switch is little loose from the panel. I mean the turning knob is still very tightly secured to the switch, but as a whole, they are little loose from the panel. I'm sure it has no effect to the performance. But just feel not so good when using.
I would like to know how to detach the turning knob from the frong panel/turning switch? I cannot find a screw on the knob. Shall I just PULL IT HARD? Anyone knows?
Plus, I have a user manual of A400X, anyone needs information, just let me know. Cheers.
hi mate, what you need to do is pull the knob off the switch which will revel a nut ,just tighten this and jobs done.
Another issue,
I don found the volum potentiometer has a bit of noise on the left channel. I want to clean it, but don't to de-solider it if possible. Will this spary solvent work? http://www.jaycar.co.nz/productView...d2=&pageNumber=&priceMin=&priceMax=&SUBCATID=
I don found the volum potentiometer has a bit of noise on the left channel. I want to clean it, but don't to de-solider it if possible. Will this spary solvent work? http://www.jaycar.co.nz/productView...d2=&pageNumber=&priceMin=&priceMax=&SUBCATID=
Hi Guys,
Yes, Huchiz, that contact cleaner will work.
I need to replace my A400 vol pot & I believe it's the same as the 300 & 400X. Trying to find a replacement.
I see some ID markings on my pot but most are illegible - can you make out what's on yours?
They are ALPS pots & ID starts 02 & ends 063-A
Yes, Huchiz, that contact cleaner will work.
I need to replace my A400 vol pot & I believe it's the same as the 300 & 400X. Trying to find a replacement.
I see some ID markings on my pot but most are illegible - can you make out what's on yours?
They are ALPS pots & ID starts 02 & ends 063-A
It's Pioneer part ACT1077 but that probably will not help a great deal. BTW, it's a linear pot 50K-B1X2 and uses resistors on the PCB to do the log taper.
I'm pulling my A400X out tomorrow to go on ebay so will see if I can see some Alps numbers on it.
I'm pulling my A400X out tomorrow to go on ebay so will see if I can see some Alps numbers on it.
Thanks Rabbitz,
My guess was wrong then - the 300 pot is not the same as the 400 & 400X. Mine is 100K log pot, I believe (but I've been known to be wrong)
If you get a chance to spot the 400X's vol pot markings, that would be excellent
Edit: Jeez, I just looked up the price of this part here http://www.ued.net/catalog/cat_item_idx_2904.html
$38 is a joke, right?
Rabbitz, did you get the part no from a service manual? I only have the schematics for the A400!
My guess was wrong then - the 300 pot is not the same as the 400 & 400X. Mine is 100K log pot, I believe (but I've been known to be wrong)
If you get a chance to spot the 400X's vol pot markings, that would be excellent
Edit: Jeez, I just looked up the price of this part here http://www.ued.net/catalog/cat_item_idx_2904.html
$38 is a joke, right?
Rabbitz, did you get the part no from a service manual? I only have the schematics for the A400!
Hi guys,
That cleaner really works, it kills all the noise. lol
I will open the case again today to lookup the part marking, will post soon.
That cleaner really works, it kills all the noise. lol
I will open the case again today to lookup the part marking, will post soon.
Had a look at the pot today and no more info than that shown on post #6 sorry. There's no Alps identifier on mine except for Alps Japan.
The marking detail came from the A400X service manual and I think there is a reference to it in the schematic.
Not only do these have 2 rows of 4 pins but they also have a leg out the back to ground the pot body as they are mounted on a plastic recess. If a pot is replaced, you have to be sure to ground the pot body.
The marking detail came from the A400X service manual and I think there is a reference to it in the schematic.
Not only do these have 2 rows of 4 pins but they also have a leg out the back to ground the pot body as they are mounted on a plastic recess. If a pot is replaced, you have to be sure to ground the pot body.
$38 isn't a bad price as it would cost more to put a non standard pot in there and get it working.
Thanks rabbitz,
The markings are printed on the opposite side of the pot body to the ALPs Japan markings which are indented.
The reason I say $38 is expensive (apart from being a cheapskate) is that from looking at the pot & opening it up - it is not high quality about a $5 pot if even.
Is your A400X pot the same as in this pic - sounds like it might be?
Just to be clear, the ACT1007 part no is for the pot from the A300 amp?
Edit: BTW, when I took mine apart to try fix it, I discovered what the 4th pin is for - it's another alternate ground pin - so the pot can be used with the 1st 3 pins for operation one way or with 3 last pins for operation another way. I think the difference in operation is got to do with where the knob gives minimum resistance - if you look at how the pot attaches to the front panel there are small two holes on the inside - the lug on the pot can slot into either hole - these twist the pot 90 degrees so the minimum resistance position will now be different by 90 degrees. I hope all this makes sense?
Anyway, just saying this in case somebody could use this to overcome a bad channel on one side of their pots?
The markings are printed on the opposite side of the pot body to the ALPs Japan markings which are indented.
The reason I say $38 is expensive (apart from being a cheapskate) is that from looking at the pot & opening it up - it is not high quality about a $5 pot if even.
Is your A400X pot the same as in this pic - sounds like it might be?
Just to be clear, the ACT1007 part no is for the pot from the A300 amp?
Edit: BTW, when I took mine apart to try fix it, I discovered what the 4th pin is for - it's another alternate ground pin - so the pot can be used with the 1st 3 pins for operation one way or with 3 last pins for operation another way. I think the difference in operation is got to do with where the knob gives minimum resistance - if you look at how the pot attaches to the front panel there are small two holes on the inside - the lug on the pot can slot into either hole - these twist the pot 90 degrees so the minimum resistance position will now be different by 90 degrees. I hope all this makes sense?
Anyway, just saying this in case somebody could use this to overcome a bad channel on one side of their pots?
Attachments
It's also expensive in comparison to this motorised ALPS QUAD pot for $15 : http://www.alltronics.com/cgi-bin/item/27P009/162/Alps-Motor-Driven-Quad-Pot
Attachments
It's a ACT1077 and not ACT1007.
That pic looks the same to me. The 4th pin connects the wiper via a resistor to ground to do the log taper from a linear pot the same as this.
http://sound.westhost.com/project01.htm
If you have a look at the pot schematic you can see the use of pin 4 and the fake law resistor. This is done as it's a linear pot and not a log pot. If a log pot is used, then you would use pins 1,2,3 only and remove the resistors R731, R732. The body of the pot would have to be grounded and can be done via a washer and wire from the threaded area near the pot body to a ground point on the PCB.
That pic looks the same to me. The 4th pin connects the wiper via a resistor to ground to do the log taper from a linear pot the same as this.
http://sound.westhost.com/project01.htm
If you have a look at the pot schematic you can see the use of pin 4 and the fake law resistor. This is done as it's a linear pot and not a log pot. If a log pot is used, then you would use pins 1,2,3 only and remove the resistors R731, R732. The body of the pot would have to be grounded and can be done via a washer and wire from the threaded area near the pot body to a ground point on the PCB.
Attachments
Sorry, yes I mistyped it - still $38 though!
My A400(X) schematic doesn't show any part nos but the circuit is the not the same as yours. R731 & R732 are both 100K & in series with the wiper of the 100K pot.
I can't extract the relevant section from the PDF (It's protected) & it's too big to post here. The relevant section is on page 6 at the far right & schematic is here: http://www.hifiengine.com/manuals/pioneer/a400.shtml
So my observations about the use of pin 4 are in relation to the A400(X) pots only!
Edit: Just noticed that you need to register to get the download from hifiengine so I hosted it on my web stoarge along with pics of the pot here: http://www.4shared.com/dir/9385701/7af7801e/Pioneer_Vol_Control.html
My A400(X) schematic doesn't show any part nos but the circuit is the not the same as yours. R731 & R732 are both 100K & in series with the wiper of the 100K pot.
I can't extract the relevant section from the PDF (It's protected) & it's too big to post here. The relevant section is on page 6 at the far right & schematic is here: http://www.hifiengine.com/manuals/pioneer/a400.shtml
So my observations about the use of pin 4 are in relation to the A400(X) pots only!
Edit: Just noticed that you need to register to get the download from hifiengine so I hosted it on my web stoarge along with pics of the pot here: http://www.4shared.com/dir/9385701/7af7801e/Pioneer_Vol_Control.html
OK, the part no ACT1077 is for the 400(X) pot which is linear and not what is used in the 400. Although if it is physically the same I will be able to use it.
So does anybody have a spare 400 or 400(X) vol/balance pot. I will pay or swap parts for this - some genuine matched Toshiba 2SA1302/2SC3281 power transistors taken from the Pioneer A400 amp?
So does anybody have a spare 400 or 400(X) vol/balance pot. I will pay or swap parts for this - some genuine matched Toshiba 2SA1302/2SC3281 power transistors taken from the Pioneer A400 amp?
Thanks Huchiz
I found something like this pot here but shaft is not D-shaped but round & knurled http://www.ampslab.com/accessories.htm
$25 for 2 - better than the Pioneer price - just need to find out if it will fit?
Anybody interested in 1 of these?
I found something like this pot here but shaft is not D-shaped but round & knurled http://www.ampslab.com/accessories.htm
$25 for 2 - better than the Pioneer price - just need to find out if it will fit?
Anybody interested in 1 of these?
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