I'm a bit confused about how a pot is actually wired up to the audiosector kit. According to Brian's userguide, the pot's wiper simply goes to "IN" on the board. So do the other resistors (220R, 20K) still remain on the input? This is different to National's schematic which shows just a 10K pot and 1K resistor.
Also, I've got the choice of either a log 10K or a log 50K pot. Which would be a better choice? My inputs will only be computer soundcard, USB DAC, or iPod.
Thanks.
Also, I've got the choice of either a log 10K or a log 50K pot. Which would be a better choice? My inputs will only be computer soundcard, USB DAC, or iPod.
Thanks.
The pot connects to IN and SG on the board, don't worry about other components there, they stay where they are.
You can use either of the pots you have, I would probably go with 50K.
Attached is a pot connection diagram.
Don't use a search function, it's a waste of time.
You can use either of the pots you have, I would probably go with 50K.
Attached is a pot connection diagram.
Don't use a search function, it's a waste of time.
Attachments
I was expecting some flak about using the search, because having used it I know there are a lot of posts about gainclone pots. Unfortunately I couldn't find a definitive answer to the specific questions I've raised.
Thanks to everyone for your help with this, especially Peter. I'm sure I won't be the only one to benefit from these informative replies.
Thanks to everyone for your help with this, especially Peter. I'm sure I won't be the only one to benefit from these informative replies.
Although the title is not totally fitting, this guide was pretty good
http://www.tocos.com/guideline and precautions.pdf
So for a simple three-terminal, single pot, Terminal 3 is signal input, Terminal 2 (the wiper) goes to the amp's input and Terminal 1 goes to ground?
http://www.tocos.com/guideline and precautions.pdf
So for a simple three-terminal, single pot, Terminal 3 is signal input, Terminal 2 (the wiper) goes to the amp's input and Terminal 1 goes to ground?
Peter Daniel said:The pot connects to IN and SG on the board, don't worry about other components there, they stay where they are.
........
I hate to ask but what are pins 1 and 5 for? I have the same Noble pot and really do like it but I have always been curious what the extra pins were for.
CarlosT said:Does Terminal 1 have to go to ground?
Yes
troystg said:I hate to ask but what are pins 1 and 5 for? I have the same Noble pot and really do like it but I have always been curious what the extra pins were for.
On the pots I had those pins were not connected. But maybe in some versions they are used for 'loudness' control.
Peter:
I also aspire to be an artist like you
So back on the subject of pots...does adding a pot as a volume control on an inverting GC not mess with the gain of the amp? In other words since the pot is connected inline to the inverting input as is the feedback loop, does this not add resistance to the R1 side of the gain formula (R2 /R1) and in a variable way? How far back from the inverting input pin does one need to consider these resistances?
I also aspire to be an artist like you
So back on the subject of pots...does adding a pot as a volume control on an inverting GC not mess with the gain of the amp? In other words since the pot is connected inline to the inverting input as is the feedback loop, does this not add resistance to the R1 side of the gain formula (R2 /R1) and in a variable way? How far back from the inverting input pin does one need to consider these resistances?
Those issues have been pretty well explained here: http://www.diyaudio.com/forums/showthread.php?postid=164564#post164564
Very interesting...so adding a linear pot affects volume AND gain at the same time thereby taking more of a non-linear look.
Of course this post goes back to 2003...great find, Peter...you're much better than the Search function which is broken for me according to some here
One statement that he made did not make sense though. Is the pot not in effect IN SERIES with the normal input pin resistor R1 (in my case R1 is 10Kohm)? I'm using a 25Kohm linear pot.
Of course this post goes back to 2003...great find, Peter...you're much better than the Search function which is broken for me according to some here
One statement that he made did not make sense though. Is the pot not in effect IN SERIES with the normal input pin resistor R1 (in my case R1 is 10Kohm)? I'm using a 25Kohm linear pot.
Peter Daniel said:25k linear pot may not provide proper regulation range, even 100k pot didn't work really well here.
I'm sorry but isn't this basically about working out Av= - R2/R1 figuring in all of the resistances (pots, resistive "Y"s, R1...so forth in series) back to the chassis input jack? Where's the voodoo?
The assumption is that there will be more resistances besides the pot so there will always be some basic fixed floor value to R1 regardless of pot wiper position.
Please excuse my ignorance about electronics, too, Peter...I'm a quick learner but I am just learning I appreciate your responsiveness versus other more jaded members here.
I'm not sure about technical aspects here, but when I tried linear pot it didn't work well, I much better preferred 50k log.
BTW, you asked about inverting clones. My early amps where actually inverting designs, including the one in this review: http://www.6moons.com/audioreviews/audiooasis/audiozone.html
I was using 50k log pots there.
BTW, you asked about inverting clones. My early amps where actually inverting designs, including the one in this review: http://www.6moons.com/audioreviews/audiooasis/audiozone.html
I was using 50k log pots there.
Funny thing is that in the overall parts list, these pots are right up there in the unit cost scale and I'm buying on the cheap end...Precision pots through Digikey...some pay a lot more for Alps and Noble and others.
I've also seen wooden knobs to go with these pots in the $500 range so there...there's esoteric for you
http://www.referenceaudiomods.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=NOB_C37_C
I've also seen wooden knobs to go with these pots in the $500 range so there...there's esoteric for you
http://www.referenceaudiomods.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=NOB_C37_C
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