Pro Audio Design Forum

I forgot to post the noise measurements:

Noise wideband, flat, unweighted, 1 Hz to 96 kHz: -60 dBu.
Noise 20-20 kHz, A weighted: -95 dBu

Finally, the sound. I listened to a number of my own reference recordings using the Audeze Flagship LCD-5 phones, which are revealing yet quite pure, and using Bob's LCD-5 EQ that has been officially endorsed by Audeze. The EQ is implemented in the digital domain. I matched the Kirkman amp subjectiv...

Measurements description: The Prism Lyra ADC/DAC I use for measurement has a noise shaped noise floor with an HF rise from 50 through 96 kHz, the limit of my measurement, which I take at 192 kHz sampling and Spectraplus software. Frequency response: I use a stepped 1/3 octave tone, which explains th...

I know the DCAO_173 board has long been superceded! But I finally got around to building a headphone amp with one of these and I thought I would report on the performance and sound. Since it keeps on improving, what can you lose getting the next generation! Also important to note that I'm using a ve...

mediatechnology wrote: ↑Wed Jul 12, 2023 12:32 pm

bobkatz wrote: ↑Wed Jul 12, 2023 8:08 am
Do I need to add diode logic in this case to prevent interaction between Sw1 and sw2?

Looks like it will work as drawn.

Perfect. Thanks very much.

I measured the THD of the WE111 transformer. A THD sweep and also 60 Hz at 0 dBu and +10 dBu with 0 series R versus 2k series R Measurements are in the PDFs in here https://crush.digido.com/?u=Mastering_Insert_switcher&p=Kirkwood It's subtle for sure, but maybe not too subtle for me. I'll put it...

Here's a question: SW1 is for the series resistor SW2 is to engage or bypass the transformer I want SW1 to be dependent on SW2. In other words, LED #1 will not light and the "series resistor" will not engage unless the transformer is engaged. So I connect the + side of external switch 1 to...

Regarding the board mod to adapt the flip to being the termination resistor. I might have to give it up because with the relay coils being in series, it looks like RY4 and RY8, which I want to keep, are involved in that series/parallel arrangement. It looks like I would have to do a lot of whacking ...

BTW, the termination resistor idea is meant to linearize the transformer so I might be able to get away without the switchable termination since I'm looking for color.

Hey Bob thanks for dropping in! I'll have to wrap my head around the board mods. Are you sure its possible to actually get color out of a "big iron" 111? Nice to be here, Wayne. Hope you are well. Excellent point. Thanks for the link from DIY audio. I am looking for subtle color, but depe...