best option for pot/stepped attenuator?

[nub]

Any opinions on best value brand/model for volume controls?

[Grainger49]

From the perspective of pure sonics a stepped attenuator with good resistors is the best.  The single shunt version puts only two precision resistors in the audio path at any given time.

The pot gives you the ability to infinitely vary the volume.  As someone recently posted in the Crack folder that makes a pot a good choice for headphone listening. 

I would use a pot.  It depends on whether a precise volume level is more important than the absolute purity of the audio path.

[nub]

Right   what I am asking for is advice re. brands and models.

[Grainger49]

There is a recent thread in the Crack folder asking about some inexpensive Dact-like stepped attenuators.  The posts have a lot of the information you are asking for.

PJ has some good advice that would make me buy the real Dact attenuators.  Outside that there are the ALPS pots in a number of configurations.  Sadly some might be counterfeit.  If you can find it the ALPS Black Beauty is one of the most sought after.

[jrihs]

I LOVE my GOLDPOINT mini-v!

[nub]

I LOVE my GOLDPOINT mini-v!

edit: nvmd

[corndog71]

I like the 2W PEC pots from Antique Electronic Supply.  Not too expensive.

I've been wanting to get a goldpoint for years but just haven't pulled the trigger yet.

[matthewmckay]

I put an audio note pot in my boutique quickie... it is vastly superior to the alps blue that it replaced.

[jrihs]

DOC recommended the goldpoint mini-v stepped attenuator. It's a fair price for what it is. Sounds wonderfull and feels solid and reliable. Easy to work with, though the post may need trimed depending on your knob choice...worth every penny.

Thanks again Doc!

[adamct]

I realize this is an old thread, but I figured I would revive it, rather than start a new thread. After reading through numerous other threads, it seems that there are several recommendations for volume pots / attenuators.

Roughly in order of their recommendations:

Alps RK27 (Blue Velvet)
PEC
TKD
Goldpoint mini-v

That said, most of the threads on this subject are quite old, and I think the relative values of these options bear revisiting.

The Alps RK27 100 Ohm pots seem to be scarce these days, but I did manage to find one available for just under $17.

I wasn't sure which PEC pot people were recommending. Is it the "Potentiometer, PEC guitar amp, 100K Audio"? If so, those are only $10, which actually means they are now cheaper than the Alps pots. I'd be grateful if someone could confirm that is the right pot, or else guide me to the correct one.

In the older threads, the TKD pots seemed to cost about $40. But unless I am misunderstanding it, they currently cost about $100!    And am I correct that the only current models that would be suitable are the "100K, 2CP-2508" or the "100K, 2CP-2511"? See here: http://www.partsconnexion.com/controls_pot_tkd.html. Betwen those two options, if I want to have more room on the pot at lowe volumes, I assume the 2511 is preferable, since it has the "audio taper"? But do people really think the TKD model is still a worthwhile option, given that it is 10x the cost of the PEC, and only $50 less than the Goldpoint, below?

Goldpoint mini-V standard - $149. Probably the best audio quality, but it is still a stepped attenuator with only 24 steps.

I'd be grateful if someone could weigh in on whether I have identified the correct models, and whether the (a) the TKD is worth the premium over the PEC, (b) whether the TKD is worth getting, when the Goldpoint is (relatively speaking) not that much more, and (c) whether any of this is really likely to result in an audible improvement over the stock pot. For what it's worth, I don't have any problems with the stock pot in terms of functionality, so this is a move I would only make if it had a real audible benefit.

Thanks,
Adam

[corndog71]

I wasn't sure which PEC pot people were recommending. Is it the "Potentiometer, PEC guitar amp, 100K Audio"? If so, those are only $10, which actually means they are now cheaper than the Alps pots. I'd be grateful if someone could confirm that is the right pot, or else guide me to the correct one.

Thanks,
Adam

Yes, that's the correct one.  Although that's a mono pot.  For a stereo version you'll need to go to www.digikey.com and order KKA1041S28-ND  which goes for $25.12

[adamct]

Thanks! I figured that was too cheap to be the right one! Any idea how it compares to the TKD? And have you found that upgrading the volume pot has a noticeable effect on the sound itself (not just an improvement in tracking/channel balance)?

Best regards,
Adam

[corndog71]

I haven't compared them to any stepped attenuators recently but I found the PEC pots to sound better than the cheaper alps pots.  It's not a major change but it should be noticeable.

Stepped attenuators will probably sound better but you're going to pay for it.

[Grainger49]

We need a sticky in Tech Topics that lists the possibilities and good examples of what is available.  This is so very often asked and answered.

Suggestion:  Pots of different constructions, descriptions, advantages and disadvantages.  Stepped attenuators of different configurations, descriptions, advantages and disadvantages.  A link to VoltSecond's stepped attenuator page is a must!

[Jim R.]

Hi Adam,

Yes, the PEC pots are a noticeable upgrade, though not huge and Rob already pointed out the correct one.  They used to be over $30 so they seem to have come down in price since I bought mine.  They are military grade pots and are sealed, which could be an advantage over others depending on your environment, but again, not something to typically worry about.  The TKD pot with the two halves separated by a shield is a very nice pot and in the Crack with it's simple circuit and high-performance and HD-800s should be noticeable, the question, which only you can answer for yourself is is that improvement worth the price.

As far as stepped attenuators go, they can be all over the map, but for a headphone amp, the steps are more often too large for dialing in just the right listening level.  You can deal with this by pre-attenuating the attenuator with some resistors (see "getting more steps) on the goldpoint site).  Then there are the large Khozmo attenuators which have 41 steps, and those with some pre-attenuation could be really nice.  Not sure if those will fit in a standard Crack, but I can check it out for you this weekend.  Also you can change the shunt resistors on those to something like Vishay nude bulk foil resistors and get very good performance from them.  I personally amnot a huge fan of the nichrome surface mount resistors in the standard goldpoints and I'd definitely prefer the alps or PECs over them if I had a choice.  However, you can get the unpopulated 24 position switches from goldpoint and make your own attenuator, in which case you can custom select the resistors for quality and value to perfectly meet your personal needs, though it can be somewhat of a process and the quality of solder joints will be critical.

Personally, I think the PEC in the crack -- perhaps with some high quality pre-attenuation resistors to extend the usable range, is a nice compromise.  Beyond that, the TKD pot with the shielded halves and then a custom or tweaked Khozmo attenuator (if it fits) are potentially an upgrade oover the PEC/TKD.

You certainly have a fleet of quality cans that should let you hear the differences, so I'd encourage experimentation.

Hope this helps,

Jim