[jamca]

I used a Little-Dot II+ as a preamp for a number of years with my Yamaha M-2, which is a Direct Coupled Amp. The Little-Dot II+ came with the same warning you described, yet it was never an issue in practice.

Most power amps have an in-line capacitor on the inputs that blocks ultra-low frequencies, below what the human ear can hear. A Direct Coupled amp is theoretically capable of passing any frequency from the preamp to the speakers, all the way down to 0Hz, which would be a DC (Direct Current) signal at that point. A normal audio signal is AC (Alternating Current). This is why the cone moves in and out. When a DC (Direct Current) signal is fed to a speaker, the cone will move in, or out, and stay there. This causes the voice coil to heat up despite the speaker not producing any sound. Speakers can be damaged easily if fed significant amounts of Direct Current.

I found that the only time any relevant amount of DC (direct current) was being passed from my Little-Dot into my power amp was right after the Little-Dot was powered on. I mitigated this by always making sure to turn the Little-Dot on first, and give it a short time to warm up before I powered on the power amplifier. Ultimately, no other precaution was necessary.

Oh that is a great and simple explaination!! Really thanks! I have a Yamaha with direct input that bypasses the preamp section of the amp and I was thinking using little dot as buffer zone… perhaps i will try it

 

[mab1376]

I used a Little-Dot II+ as a preamp for a number of years with my Yamaha M-2, which is a Direct Coupled Amp. The Little-Dot II+ came with the same warning you described, yet it was never an issue in practice.

Most power amps have an in-line capacitor on the inputs that blocks ultra-low frequencies, below what the human ear can hear. A Direct Coupled amp is theoretically capable of passing any frequency from the preamp to the speakers, all the way down to 0Hz, which would be a DC (Direct Current) signal at that point. A normal audio signal is AC (Alternating Current). This is why the cone moves in and out. When a DC (Direct Current) signal is fed to a speaker, the cone will move in, or out, and stay there. This causes the voice coil to heat up despite the speaker not producing any sound. Speakers can be damaged easily if fed significant amounts of Direct Current.

I found that the only time any relevant amount of DC (direct current) was being passed from my Little-Dot into my power amp was right after the Little-Dot was powered on. I mitigated this by always making sure to turn the Little-Dot on first, and give it a short time to warm up before I powered on the power amplifier. Ultimately, no other precaution was necessary.

It worked fine for me in front of my Nakamichi SR-4Δ integrated amp, just the Schiit Aegir power amp reported high DC offset and faulted.

High DC offset. Aegir is a DC-coupled amp. Its microprocessor monitors DC levels at the output and adjusts it down to zero. However, it may not be able to correct for high DC from your source (such as a preamp). To clear this fault, turn off the amp, disconnect the RCA cables or XLR cable from the amp, and turn it back on again. If the amp turns on normally, then there may be high DC on the output of your source. Have the source inspected and repaired.

 

[Terozzzz]

Im using dot mk III as preamp for SMSL SP400 headphone amp. DAC is Denafrips ARES II and the soundstage with hifiman ananda is HUGE. Like HD800 level and beyond.
But the imaging is far superior and the detail i mind bending now.
When i use STAX L700 with T1 modded AMP its too out of this world experience.