The traditional potentiometer is implemented with an electrical contact that slides over a resistive layer.
Relay switched stepped attenuator.
A high end good and costly alternative is the rotary switch.
No it is a relay switched stepped attenuator posted by 13th duke of wymbourne on august 31 2020 at 12 46 27.
Compared to a potentiometer they give you essentially perfect channel matching and near unmeasurable distortion.
The design represents a audio preamplifier of top class sonic quality in a compact and affordable implementation.
In fact i put together a couple of pcbs with 30 step 2db attenuators nearly fifteen years ago although for various reasons i never matched these up with a preamplifier and i ended up raiding the boards for parts.
We purchased a number of these and were surprised to find that all had design problems that were limiting their perfomance.
Relay switched attenuator was the ultimate solution.
The benefits of a relay switched stepped attenuator for volume are clear.
If you are serious about great sound quality and already have adequate signal amplitude enjoy a passive preamp in your system such as a superior sounding goldpoint sa1 sa2 or sa4.
However some preamps with relay stepped attenuators confuse you with buttons and screens.
δ1 delta 1 is a high end stereo stepped attenuator implemented in a r 2r resistor laddertopology.
Each section consists of a dpdt slide switch and three 1 4 w 1 tolerance metal film resistors whose values are chosen to obtain the desired amount of attenuation.
Its ir remote control provides convenience over solutions with stepped attenuator rotary switches.
The sealed relays will maintain contact quality over a practically endless lifetime.
A program to analyse your own switched attenuator circuit design of any topology.
That was due to the sequence of switching of the relays.
That created an instant spike in volume.
Posted by kal rubinson r on august 31 2020 at 16 59 03 in reply to.
Relay controlled attenuators in theory switch controlled and relay controlled resistor dividers can provide near perfect performance.
In most cases the impedances were too high to achieve our required noise specifications.
The attenuator consists simply of 10 resistive π attenuator sections such as the one shown here.
An example of a well known audio grade potmeter is the alps blue.
For example when going from 31 5db to 32db there was an instant in which the relays that were performing the attenuation had switched off but the single relay that would attenuate the signal by 32db had not yet turned on.
In the passive preamp i used for several years the volume control.
It uses high quality miniature latching relays and precision discrete resistors to achieve a level of performance unattainable with conventional potentiometers or mechanical switch based rotary stepped attenuators.
