[Luigi]

Im looking to upgrade a tube/gainclone integrated amp with a new pot.

Anyone know who makes these, how they sound, and where they can be obtained in Australia or the US?

They are meant to be very competitive with stepped attenuators, if you read the thread:

http://www.diyhifisupply.com/diyhs_dact_switches.htm

Luigi

[EchiDna]

well you could but direct from diyhifisupply in HK... they are a reputed and safe supplier - I've bought from them a few times without any hassle.

GL

[Panelhead]

Im looking to upgrade a tube/gainclone integrated amp with a new pot.

  I prefer carbon pots over stepped attenuators. These PEC pots have less imprint on sonics than any tried in my system.
  The stereo units are special order, this is why they are so expensive. No company purchases them in real quantities and resells them. Maybe the military orders them.
  If you can deal with it, the mono pots are available from DigiKey. The linear are less than 8.00, and the log taper are 9.35 or so.
  The matching was an issue for me. They really do range more like +/- 5 percent. This is excessive for both loading and tracking.. Purchased seven 25K log taper pots and was able to match them up as 3 pairs that are closer than 0.5 percent.
  My problem with the stereo pots is for a 100K pot one channel might measure 105K and the other 96K. This is well within the specs. This difference should be audible.
  I am used to using mono pots, prefer to stereo. Once matched for total resistance, the tracking has been excellent in the two pair used so far.

                         George

http://www.diyhifisupply.com/diyhs_dact_switches.htm

Luigi

[JoshK]

Are these pots stackable?  Can you take them apart and put them together so that multiple channels are being used?

I am looking for decent pots that you can stack for 6-8 channels.  I plan to law fake them using Rod Elliot's scheme, so linear taper is best.  Anyone got any ideas?  If cheap enough I don't mind buying a bunch of them to match a group.

[Panelhead]

Are these pots stackable?  Can you take them apart and put them together so that multiple channels are being used?

I am looking for decent pots that you can stack for 6-8 channels.  I plan to law fake them using Rod Elliot's scheme, so linear taper is best.  Anyone got any ideas?  If cheap enough I don't mind buying a bunch of them to match a group.

  Do not think they are stackable. But saw them locally for 7.50 for alll values of linear taper today. MCM lists them cheaper still in the catalog that arrived today.
  Locally would be my pick, I could match them up in the store.
  I do not understand the log faking. It is supposed to provide better tracking. But these pots track real well in log taper. Are there other advantages?
  The changing input impedance of the log faking circuit more than offsets the advantage of improved tracking. This changes the loading on the source components feeding the pots.

                               George

[Occam]

Panelhead - good find on the NTE 2watt pots at MCM!

The pots under discussion are the PEC 2watt MIL Style RV4 (series K) in single gang and MIL Style 2RV7 (series KK) dual gang from Precision Electronic Components in Canada
http://www.precisionelectronics.com/Product%20Specs.htm

They can be found in single gang at Digikey -
http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?Ref=318605&Row=302566&Site=US

These mil spec pots are also manufactured by others, as the military used to like multiple sources -
http://www.potentiometers.com/select_mil.cfm?session_num=2005031711383063

I don't know of any sources of the dual gang other than PEC or State Electronics directly, and they tend to require a substantial order.

An explanation of Log Law faking, using linear pots can be found here -
http://sound.westhost.com/project01.htm
The major problem with loglaw faking of linear potentiometers is that dual ganged linear pots tend not to track well with each at low volumes unless they are made to very exacting stadards. [at low volumes the shunt leg of the pot is so low that it totally dominates when in parallel with the law faking resistor, and hence any mismatch causes a large imbalance. At higher volumes, the law faking resistor itself dominates that parallel resistance....]

[randytsuch]

There has been a lot of discussion of this pot at diyaudio.  Go search there for info on it.
There was an attempted group buy, that ended up not happening.

Randy