I wonder if my Cascade is getting sufficient cooling. The fronts of the chassis are running at over 105 F. Is that hotter than you would expect? Here are some details.
In all the videos I’ve seen of the Cascade, it is racked on separate shelves rather than being stacked. In one video you mentioned that you can measure the difference between racking and stacking but cannot hear any difference between racking and stacking.
Currently, I have my cascade stacked. I’ve noticed that analog and power chassis front surfaces measure between 105 and 110 F. The director chassis measures between 100 and 105 F. Ambient temperature in the room is 76 F.
The Cascade has 1 inch of space on each side and 5 inches overhead, in the cabinet it is in.
Are these temperatures what you expect from the Cascade? I like the stacked look, but I’m thinking of adding spacers between the chassis’ just to help with cooling. Do you think that would be a good idea?
I would not be worried about these temperatures Dan. Electronic lifespan will be increased if it runs cooler, but you are not in any risk around 100F. The worry would be if the cabinet was sealed or if this was an amplifier that procured a lot more heat. The parts are rated for much higher temps!
The ambience temperature range in my listening room is 82-84 F when the air-conditioning is not switched on. And I usually listens to the system without air-conditioning. I have been running in the Cascade DAC continuously for 1.5 weeks now. The Cascade Powerbase gets pretty warm when stand alone on an open platform. The Cascade analog converter and DD units, stacked together on another platform, get only slightly warm to the touch. The Powerbase gets even warmer when stacked at the bottom of the other 2 chassis. I have not measured the surface temperatures of the chassis, but i am concerned with the elevated temperature of the Powerbase, especially when stacked together with the other chassis. My previous Reference Powerbase ran even hotter than the Cascade Powerbase without stacking them. I think in the long run I would not stack the Powerbase unit, if this could affect the life span of the Cascade!
Still experimenting with the different placements of the 3 chassis of the Cascade. Another setup is putting the Digital Director chassis separately, which may be the best because the DD is supposed to be the “noisiest”
That is the Stillpoints Component Stand with Ultra 6 footers fitted. I am trying out this stand.
The wooden platforms I made them by gluing four pieces of solid bamboo chopping boards from IKEA. Weighs more than 13 kg each platform
How much higher temps, mine runs even hotter when I tested extended playing at 90 I was passing 130 on the front of the powerbase the rest of the system was around 110.
Note I had to step away as 80 on the cascade is simply WAY tooo loud for me, but curious why is peak 106?
The Cascade Converter has the highest power dissipation of all the boxes in the Cascade DAC system. It is designed to run perfectly up to a case temperature of 140F (60C) past that it will still function but you may lose some performance. For the longest lifespan try to keep the case temperature below 122F (50C). Lower than that will have a negligible effect on lifespan. If its case temperature is regularly above 122F (50C) you may want to increase circulation around the chassis, take it out of the sun, turn it off when unused or add some air conditioning.
The reason that the Cascade can run a higher case temperature without shortening its lifespan is using capacitors with low volatility electrolyte and having conduction cooling for all power producing components (they are not cooled through internal convection meaning they are at a temperature slightly above the case temperature). If we were using internal convection the components would be running far above the external case temperature.
The volume control in the Cascade DAC operates by reducing the output of the DACs passively (in the analog domain without a buffer or amplifier) when set below “100”, while keeping the output impedance at exactly 75 Ohms. This is not due to any amplifier or buffer, it is a design feature of the passive attenuator itself. At “100” the Cascade does not attenuate, the DACs full power is available at the outputs but it still has a 75 Ohm output impedance. For settings of “101-106” the Cascade applies gain in the digital domain before conversion (the analog inputs also switch from a +0dB buffer setting to a +6dB buffer setting). Since the Cascades maximum output voltage of about 3.5 volts RMS is above the input sensitivity of the vast majority of power amplifiers, the majority of amplifiers will clip long before the DAC runs out of signal headroom. The extra 6dB of gain available above “100” is intended for quiet recordings that were not recorded with sufficient gain. A common example would be “A Nightingale Sang in Berkeley Square” performed by Harry Connick Jr.
All of the Cascades attenuation settings, “0-99”, are close to lossless. They closely approach the theoretical noise floor and distortion produced by a 75 Ohm resistor at room temperature. This residual noise is called thermal noise. In fact, you can’t get below this noise level unless you lower the true output impedance (parallel more DAC modules for example), reduce the bandwidth (eg. apply a low pass filter), or lower the temperature of the system by a large amount (eg. cryo-cool the system). The only way to reasonably increase the performance is to reduce the gain of the amplifier itself, then increase the volume setting. This is an available option of our 500 series amplifiers.
Typical audio volume controls don’t come close to this level of performance. This is because of parasitic effects, such as the winding wire resistance in a transformer volume control, or the variable impedance (usually high) of a potentiometer based volume control. Even most “stepped attenuators” are essentially potentiometers with discrete steps and have a variable output impedance (usually high) with each setting. Active volume controls are usually much worse by combining loss (eg. a potentiometer) with gain (eg. an OpAmp).
