doobooloo
Headphoneus Supremus
- Joined
- Nov 3, 2002
- Posts
- 2,544
- Likes
- 11
It was winter, it was cold, it was a cold winter... (giggles)
OK so it's cold outside and I'm sitting here wondering why I have a fantastic sound card (Echo MIA MIDI) that is capable of balanced outputs and I'm only using it as a single ended card, despite my HD580s being terminated to a 5-pin XLR (my choice AND the official standard for dual balanced signals).
And, my sound card, with AD8620 opamps and BlackGates caps, is more than capable of powering my HD580s beautifully (and loud!) in single ended mode without an amp. Balanced technically doubles the power, and should power my phones even more beautifully, but this configuration has that 2% missing from a truly capable amplification and a lossy digital volume control controlled via Windows.
Right now I'm quite content with my GS-1 with SA in single ended mode but I know I can do better by going balanced and going simpler... by building a balanced JISBOS!
So here's my thought. Since quality 4-channel stepped attenuators are rather expensive, I'm going to build a separate passive preamp box (perhaps with multiple selectable inputs/outputs) that can be used with various other future DIY amps, and have a standalone "amp" box with just audio in, and audio out, no volume control. This amp box, of course, will merely be a buffer box as there's enough quality voltage amplification going on at the sound card level.
I'm going to put the four JISBOS boards on a FPE designed sheet acting as a motherboard and heatsink for the output transistors. This board is going to slide into one of those nice extruded aluminum cases, and with nice thick custom panels from FPE for front and back, and I'm good to go.
Progress is going to be slow as I'll have to work little bit by bit but it's surely going to be exciting! I'll post updates as I get preliminary details up... but right now I've only ordered about half the parts needed...
Oh, and power supply recommendations? Since I'm not feeling particularly motivated, I'm thinking of starting off with the +/-15V Elpac power supply that is bundled with the HeadAmp Gilmore Lites, and upgrading to maybe a sigma 22 built in similar fashion later on...
OK so it's cold outside and I'm sitting here wondering why I have a fantastic sound card (Echo MIA MIDI) that is capable of balanced outputs and I'm only using it as a single ended card, despite my HD580s being terminated to a 5-pin XLR (my choice AND the official standard for dual balanced signals).
And, my sound card, with AD8620 opamps and BlackGates caps, is more than capable of powering my HD580s beautifully (and loud!) in single ended mode without an amp. Balanced technically doubles the power, and should power my phones even more beautifully, but this configuration has that 2% missing from a truly capable amplification and a lossy digital volume control controlled via Windows.
Right now I'm quite content with my GS-1 with SA in single ended mode but I know I can do better by going balanced and going simpler... by building a balanced JISBOS!
So here's my thought. Since quality 4-channel stepped attenuators are rather expensive, I'm going to build a separate passive preamp box (perhaps with multiple selectable inputs/outputs) that can be used with various other future DIY amps, and have a standalone "amp" box with just audio in, and audio out, no volume control. This amp box, of course, will merely be a buffer box as there's enough quality voltage amplification going on at the sound card level.
I'm going to put the four JISBOS boards on a FPE designed sheet acting as a motherboard and heatsink for the output transistors. This board is going to slide into one of those nice extruded aluminum cases, and with nice thick custom panels from FPE for front and back, and I'm good to go.
Progress is going to be slow as I'll have to work little bit by bit but it's surely going to be exciting! I'll post updates as I get preliminary details up... but right now I've only ordered about half the parts needed...
Oh, and power supply recommendations? Since I'm not feeling particularly motivated, I'm thinking of starting off with the +/-15V Elpac power supply that is bundled with the HeadAmp Gilmore Lites, and upgrading to maybe a sigma 22 built in similar fashion later on...