best option for pot/stepped attenuator?
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Grainger49
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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.
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.
what I am asking for is advice re. brands and models.Grainger49
New member
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.
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.
matthewmckay
New member
I put an audio note pot in my boutique quickie... it is vastly superior to the alps blue that it replaced.
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
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
Grainger49
New member
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!
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!
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
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
Thanks, Jim. That is a very helpful (and complete) response. My DAC has a very strong output signal (even on the low setting), so I suspect you are right that the stepped attenuators would not be a good choice for me. I certainly don't have the patience to create a custom Goldpoint.
The means I need to decide between the PRC and the TKD. I'll think it over this weekend. I appreciate your help.
Best regards,
Adam
The means I need to decide between the PRC and the TKD. I'll think it over this weekend. I appreciate your help.
Best regards,
Adam
Adam,
I can tell you that both are very nice -- the TKD is a bit more transparent, and some of the PECs tend to be a bit scratchy at the low endof their range. To get the best out of each though, I'd strongly recommend looking at the "getting more steps" tutorial on the goldpoint site -- this applies to non-stepped attenuators too and it will let you get far more usable (and also put the pot in the region where it sounds it's best) simply by adding 4 resistors -- 2 to each channel.
Once my Crack is rebuilt I'm going to do this after making some measurements with my source (2v standard dac output level.) Yes, the pots sound best when they are at normal listening levels somewhere around 12:00 and worst at their extremes.
-- Jim
I can tell you that both are very nice -- the TKD is a bit more transparent, and some of the PECs tend to be a bit scratchy at the low endof their range. To get the best out of each though, I'd strongly recommend looking at the "getting more steps" tutorial on the goldpoint site -- this applies to non-stepped attenuators too and it will let you get far more usable (and also put the pot in the region where it sounds it's best) simply by adding 4 resistors -- 2 to each channel.
Once my Crack is rebuilt I'm going to do this after making some measurements with my source (2v standard dac output level.) Yes, the pots sound best when they are at normal listening levels somewhere around 12:00 and worst at their extremes.
-- Jim
Not to be a fly in the ointment on this, but IMO, the pot is of relatively minor importance once you get into the 'good' pot category. I'm sure many will disagree with that hypothesis, but if you want to absolutely sleep ok at night in regards to the pot, I would go with stepped resistor, and build it yourself.
I think the fish is better fried from a 'holistic' approach. In other words, you may be better served by addressing your cabling/wire in addition to your pot. For example, I have realized MUCH more benefit from focusing on my interconnects. Just a suggestion. I do agree with the TKD choice over the Alps. YMMV.
I think the fish is better fried from a 'holistic' approach. In other words, you may be better served by addressing your cabling/wire in addition to your pot. For example, I have realized MUCH more benefit from focusing on my interconnects. Just a suggestion. I do agree with the TKD choice over the Alps. YMMV.
[email protected]
New member
Don't forget the Khozmo attenuater. 48 steps give you more than enough volume choices.
http://www.bottlehead.com/smf/index.php/topic,2336.0.html
http://www.bottlehead.com/smf/index.php/topic,2336.0.html
Not to disagree with Eric, but I've tried all kinds of volume controls -- beyond pots) and I still think the best one is none at all. In other words, it's always a compromise -- basically, pots suck, but they are a necessary fact of life (in some form or another unless you go with a very good digital control using an advanced and well-executed adithering algorithm.
This can be fantastic, but as good as they are, they also make me nervous as if for some reason your digital link loses sync, your amp will most likely blast you and your speakers at full volume white noise. Of course thee ways around this too, but more circuitry and probably just another thing to rob the amp/system of it's absolute "purity".
We're now starting to see more direct from digital to amp systems -- amps that take a digital spdif or usb input and with everything done in the digital domain and then what one could call a "power dac" for the output. Right now these things tend to be ultra expensive or only so-so in performance -- certainly not the claims of perfect audio that some people make about them. And of course if you want to use an analog front end, well, you'll have to turn it into bits before you listen to it anyway, and what's the point of that?
-- Jim
This can be fantastic, but as good as they are, they also make me nervous as if for some reason your digital link loses sync, your amp will most likely blast you and your speakers at full volume white noise. Of course thee ways around this too, but more circuitry and probably just another thing to rob the amp/system of it's absolute "purity".
We're now starting to see more direct from digital to amp systems -- amps that take a digital spdif or usb input and with everything done in the digital domain and then what one could call a "power dac" for the output. Right now these things tend to be ultra expensive or only so-so in performance -- certainly not the claims of perfect audio that some people make about them. And of course if you want to use an analog front end, well, you'll have to turn it into bits before you listen to it anyway, and what's the point of that?
-- Jim
