Industrial
New member
I have a Delta 66 A/D/A converter in my home studio. When performing some distortion tests recently on all of my studio equipment (I wanted to see what kind of harmonics was generated as I passed the signal through various preamps and my mixers and such).... I noticed that the Delta 66 A/D/A produces very low level harmonics (-113dB) that are nearly-equi amplitude and obviously infinite in bandwidth. Granted, these harmonics are quite low level.... but I suspect, that it is well within the sensitivity range of hearing, since I noticed the noise floor was much lower than the harmonics... yet I could still hear the thermal noise quite easily... which means I must be able to hear the harmonics.
I know it must be (?) the Delta converter because I bypassed all my equipment, and just ran the signal from the delta output back into the input and re-recorded it in ACID and then did another spectral analysis.
I used a sine wave test signal... so obviously in theory... you'd want to get only the fundamental frequency with zero harmonics... but in reality.... of course,... running a sine wave through your mixer or any preamp on the market (yes, even the best of them) will produce fair amounts of harmonics. If you've never done this.... try it... it's an interesting and quick test you can run whenever you get a new piece of equipment...
I am wondering if anyone has more experience on these matters. Is this effect common on all types of converters, even the really expensive ones (I've been looking to upgrade to some more serious digital gear, I have a very analogue studio right now...). ??
Also, theoretically.... maybe it's not the A/D/A converter itself.. The wires theselves (my audio patch cable) have a minute capacitance and resistance as does the patch cable connecting the delta break-out box to the PCI card.... this cable capacitance and resistance actually acts as a filter and so maybe I'm filtering the sine wave just a teensy tinsy bit... so maybe thats where my harmonics are coming from... I still think its the A/D/A converter. Anyone have any input or experience? Thanks
I know it must be (?) the Delta converter because I bypassed all my equipment, and just ran the signal from the delta output back into the input and re-recorded it in ACID and then did another spectral analysis.
I used a sine wave test signal... so obviously in theory... you'd want to get only the fundamental frequency with zero harmonics... but in reality.... of course,... running a sine wave through your mixer or any preamp on the market (yes, even the best of them) will produce fair amounts of harmonics. If you've never done this.... try it... it's an interesting and quick test you can run whenever you get a new piece of equipment...
I am wondering if anyone has more experience on these matters. Is this effect common on all types of converters, even the really expensive ones (I've been looking to upgrade to some more serious digital gear, I have a very analogue studio right now...). ??
Also, theoretically.... maybe it's not the A/D/A converter itself.. The wires theselves (my audio patch cable) have a minute capacitance and resistance as does the patch cable connecting the delta break-out box to the PCI card.... this cable capacitance and resistance actually acts as a filter and so maybe I'm filtering the sine wave just a teensy tinsy bit... so maybe thats where my harmonics are coming from... I still think its the A/D/A converter. Anyone have any input or experience? Thanks