I used these in rebuilding my SWTPC Tiger .01s; I would have preferred a single pot but the price is reasonable and the build quality and 'feel' is good. They are compact and a easy replacement for old comp pots, though the shaft diameter is smaller than many original parts
I can't say I heard a difference in quality. It's not the optimum configuration like a ladder attenuator would be, but it should be a definite improvement over the original composition pots, just as a metal film replacing a carbon comp resistor would be. I'd definitely consider using them again in future upgrades and projects even though the number of steps is somewhat limited.
I installed a ladder attenuator in a friend's tube preamp to replace the really old carbon volume and balance pots. There was a noticeable improvement in detail and clarity; it sounds better than my Hafler SE100 JFET preamp.
Too bad there aren't bulk foil resistor pots in this form factor, but no doubt they'd be extremely expensive.
Damon Hill,there is one bulk foil resistor stepped attenuator made by Glasshouse.
Take a look on the Hifi Collective website which has numerous types of stepped attenuators.The bulk foil version uses Charcroft 0.01% tolerance resistors and costs an eyewatering £1250!
Take a look on the Hifi Collective website which has numerous types of stepped attenuators.The bulk foil version uses Charcroft 0.01% tolerance resistors and costs an eyewatering £1250!
Membrane pots are probably the modern way to go: they are a re-born re-invention of more than 70yrs ago, but their advantages are still compelling. Not for extreme positional accuracy, but for low noise, durability and toughness in difficult environments.
https://www.google.com/search?q="+m...i=A15vVZisMYSwsQHV34GIDQ&ved=0CCMQsAQ#imgrc=_
https://www.google.com/search?q="+m...i=A15vVZisMYSwsQHV34GIDQ&ved=0CCMQsAQ#imgrc=_
Pots become noisy when they are asked to pass DC. Curiously, many audio designers send a little DC into their pots and then complain that they become noisy. As always in audio, get the circuit right and then worry about components.
Having found that pots are 'noisy', those same people then replace them with switched attenuators - only to find that they get clicks. The solution (as for the pots) is to add coupling caps so no DC reaches the pot/switch. Once the circuit is right, it doesn't really matter how you implement your variable potential divider network.
"Once the circuit is right, it doesn't really matter how you implement your variable potential divider network."
I use transformers, no caps. Still no DC on potential divider. The pot wasn't noisy and the stepped attenuator doesn't click (the stepper motor does make noise). That said, in terms of sound quality there was no contest when I replaced an Alps pot with a stepped attenuator. This was in a line stage with a balanced shunt type attenuator.
I use transformers, no caps. Still no DC on potential divider. The pot wasn't noisy and the stepped attenuator doesn't click (the stepper motor does make noise). That said, in terms of sound quality there was no contest when I replaced an Alps pot with a stepped attenuator. This was in a line stage with a balanced shunt type attenuator.
If you put a pot on a distortion analyzer and listen to the residual, you will hear the same scratchiness, with only AC on the pot. The scratchiness is always there, but the AC signal masks it, whereas DC does not.
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