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Volume Control On PAS-3

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Posted on May 31, 2008 at 21:00:19
byoung334@gmail.com
Audiophile

Posts: 18
Location: southeast
Joined: December 18, 2007
I have a PAS-3 and I am interested in replacing the volume control. I get very little change in volume until I get to the 12:30 position. Then it changes considerably. I notice that the wiring on the stock volume control looks un-conventional. I have an ALPS 250K pot. can I use it? How will I wire it up?

 

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RE: Volume Control On PAS-3, posted on June 1, 2008 at 05:56:00
Flyquail56
Audiophile

Posts: 570
Joined: February 5, 2002
The condition you are describing is due to the design of the loudness contour. Remove the loudness switch from the circuit, and you may be pleasantly surprised. Disconnect the 0.1 capacitor and the wire that are soldered to the volume pot loudness tap, which is the one opposite the other three.

Most Alps pots are very good, and would be a worthwhile replacement for the original. Not knowing which type of Alps pot you have, I can't tell you how to connect it. Also, if it has a loudness tap like the original, it will exhibit the same problem with non-linear operation if the loudness circuit is retained. Hope this helps.

Mike

 

RE: Volume Control On PAS-3, posted on June 1, 2008 at 06:43:50
byoung334@gmail.com
Audiophile

Posts: 18
Location: southeast
Joined: December 18, 2007
Mike I have a linear pot it has 2 sets of 3 taps (stereo)

 

RE: Volume Control On PAS-3, posted on June 1, 2008 at 14:29:19
DaWoofer
Audiophile

Posts: 180
Joined: October 26, 2004
Left right and ground. Or right left ground, I dont think it matter. I installed an ALPS 250k pot two weeks ago and it made a great difference.

 

RE: A Linear taper pot is incorrect., posted on June 1, 2008 at 20:14:40
Bill Thomas
Industry Professional

Posts: 1394
Location: Southern USA
Joined: January 3, 2004
The proper potentiometer should be a log taper pot.

Hope this helps.

Bill

 

RE: Volume Control On PAS-3, posted on June 5, 2008 at 17:20:53
B+
Audiophile

Posts: 65
Location: New Jersey
Joined: September 19, 2002
If you want to keep the loudness control and speed a little money, try the Noble# 64756 250k pot (with loudness tap)at this site:

http://www.partsconnexion.com/catalog/controlsswitches.html

It requires some wiring modifications since it uses PC board pins, but it was well worth it. The volume on my PAS-3 is now smooth and linear.

Mario

 

RE: Volume Control On PAS-3, posted on June 8, 2008 at 06:26:46
byoung334


 
Mike, wow, what a difference. I de-soldered the 2 wires and the .1 caps from the loudness taps on the volume control. Now I am able to listen at 8 to 10 o'clock settings. I plan to install my Alps volume control next. Thanks for the reccomendation.

 

RE: Volume Control On PAS-3, posted on June 8, 2008 at 13:09:13
byoung334@gmail.com
Audiophile

Posts: 18
Location: southeast
Joined: December 18, 2007
Well I installed the Alps volume control this morning after removing the loudness control circuit from the original volume control. The Alps give me much better progressive increase in volume.

 

RE: Volume Control On PAS-3, posted on June 8, 2008 at 14:16:06
Flyquail56
Audiophile

Posts: 570
Joined: February 5, 2002
Glad to hear that it worked for you! I see that you also installed the new Alps pot. Your volume problems should be behind you now :-).

Mike

 

RE: Volume Control On PAS-3, posted on July 6, 2008 at 20:23:13
mpena93
Audiophile

Posts: 1
Location: South Texas
Joined: July 6, 2008
First let me tell you how helpful this site is for persons trying to keep these old Dynacos running. I purchased a set of ST70 and a PAS 3 preamp and I have had them sitting on a shelf not knowing what to do with them. The amplifier is in stock condition but I have no real intentions to put it on full time service, the PAS 3 however was a different story. I almost got rid of it because I hated the sound until I started reading you forums. I bypassed the tone controls and also removed the volume contour switch from the system and it has made a huge difference. I have several questions but will leave for another post. Thanks again to everyone.

 

RE: Volume Control On PAS-3, posted on July 22, 2008 at 12:38:24
tubtub
Audiophile

Posts: 181
Location: US
Joined: June 5, 2007
When removing the loudness taps, there are 2 resistors that go to the volume pot, do I remove those too or leave them intact. I removed them and now there is no sound; can't remember where they were at to reconnect.

 

Volume Control On PAS-3, posted on June 11, 2009 at 07:40:44
dinatiz@alice.it
Audiophile

Posts: 22
Location: Alba Adriatica
Joined: June 8, 2009
Hi,

where is the procedure to de-soldered the 2 wires and the .1 caps from the loudness taps on the volume control?

Best regards

Tiziano Di Natale

 

RE: Volume Control On PAS-3, posted on June 11, 2009 at 11:41:14
dinatiz


 
Thank you very much

Tomorrow i want try.

Best Regards

Tiziano DI Natale

 

RE: Volume Control On PAS-3, posted on June 11, 2009 at 11:46:58
GP49
Audiophile

Posts: 382
Location: No Cal
Joined: April 21, 2009
To disable the loudness function, all you need to do is disconnect everything from the fourth terminal (the one that is not bunched in with the other three) on both the front and rear sections of the volume control. You can just tape off the wires and let them hang, it's not necessary to remove them.

Or you might figure out some other way to use the switch. With minor rewiring it can be configured into a mono switch that will blend the two channels together without any contacts interrupting the signal path; you can then disconnect the factory blend switch, which does interpose several contacts.
GP49

 

RE: Volume Control On PAS-3, posted on July 17, 2016 at 06:02:47
brian.py
Audiophile

Posts: 2
Location: Hong Kong Island
Joined: July 17, 2016
Hi can you show my how to remove loudness control and install the Alps pot? I have a 250k Alps pot with 6 lugs. Thanks in advance.

 

RE: Volume Control On PAS-3, posted on May 30, 2017 at 08:38:45
Audio Pete
Manufacturer

Posts: 53
Location: Long Island,NY
Joined: May 22, 2015
Did the same with mine. I didn't like the orig. pot. action either. So, I disconnected the Loudness (which I don't use) and installed an ALPS Blue Velvet 250kA. What a huge difference! Very smooth action and resolution.
They are making Blue Velvet pots. with a fourth terminal now if you prefer.

 

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