danielchodges
Member
Hello All!
I am new to the forum, so I am hoping that this is the right spot for this post.
Several years back I was given a Soundcraft 500 by a good friend. I had a small production studio at the time, and used the console to mix through as well as route things to outboard FX and cue mixes etc. When I got the console I replaced the master mix's summing amp with a CAPI 2 channel ACA and Booster, re-capped the master section and most of the input channels. I never got around to re-capping the power supply. I am now building a new studio and have decided to re-work the console entirely. I've done a fair amount of circuit board soldering, recapping and basics of that nature, but I am new to the electronics and the details of their design. I have a great relationship with a tech here in town, however he is booked up months out so I am trying to do as much research as possible and lean on him only when I need to.
The console has 32 input channels (16 mono, 8 stereo), 6 'auxiliary' and 8 'group' busses. It is a 32 input frame, so there is some empty space under the hood. The plan is to use the mono input channels as the "record" and "remix" inputs, the stereo channels as the "monitor section" as if it were a split console. I'll feed my input converters and tape machine primarily from the group buses when recording, and using them as sub groups when mixing.
My plan for the rebuild:
Replace the current soundcraft 'medium console power supply' with a Yamaha PW4000 power supply, re-capped and regulated for 17v +/- rather than the stock 19v +/- rails. I have spoken with a tech about handling the modification and re-capping of the power supply, as it is a bit outside my comfort zone.
Remove existing input amplifier and EQ from mono channels. Install a transformer balanced (312ish?) mic amp, possibly a JLM Baby animal, followed by a mic/line select switch and phase reverse switch. Following the phase reverse will be a CAPI 2 stage line amplifier card. Stage 1 of the card will be balanced at its output and feed a new/reworked insert send, the insert return will go to stage two of this card, and leave unbalanced and feed the existing SC fader routing, pfl and mute facilities.
EQ for mono channels will be handled by outboard eqs, normaled to the inserts at the patch bay. Insert send could be able to be multed if a "direct out" is needed. In order to handle the balanced send/return I will re-work the previous "direct out" jack as the insert send and the "insert" jack as the insert return. Since the insert send will ultimately need to feed the return, I figure I'll go through the patch bay for this.
Install a "fader" bypass switch at each mono input channel. The plan is to measure the resistance of the fader at (around) unity, and put in a toggle switch that on one side is the fader, the other side will be a resistor of equal resistance to the fader at unity gain.
Replace group buses summing amps with CAPI 2 channel ACA cards. Bypass the simple eq in these groups.
I don't plan on altering the stereo input channels much, though the ICs are socketed here so I will likely spend some time listening to a few different ICs. I've already increased the coupling cap values in these. I don't plan to use the EQ and will likely pull the ICs from this section and leave it bypassed. Aux buses will remain as is as well, they also have socketed ICs and I may swap those for BBs.
I won't use the monitor section aside from to monitor the PFL bus and send it to my monitor control.
The plan is to start with two input channels and the power supply, I will start to really figure out what op amps and transformers make the most sense and what I can source. I have a handful of 2520s and 2520 like op amps that I'll use to get things working at first.
I've attached a simple input signal flow drawing that sort of outlines my current thoughts, as well as some of the OG soundcraft schematics/drawings. I'm curious of anyones general input, words of caution or just general advice. Anyone have thoughts on grounding? Venting/heat sync thoughts? I know that its a bit of a large and crazy project, but I am excited to pull up my sleeves, learn some things, and come out with a totally unique and tailored to me console for my new studio.
I am new to the forum, so I am hoping that this is the right spot for this post.
Several years back I was given a Soundcraft 500 by a good friend. I had a small production studio at the time, and used the console to mix through as well as route things to outboard FX and cue mixes etc. When I got the console I replaced the master mix's summing amp with a CAPI 2 channel ACA and Booster, re-capped the master section and most of the input channels. I never got around to re-capping the power supply. I am now building a new studio and have decided to re-work the console entirely. I've done a fair amount of circuit board soldering, recapping and basics of that nature, but I am new to the electronics and the details of their design. I have a great relationship with a tech here in town, however he is booked up months out so I am trying to do as much research as possible and lean on him only when I need to.
The console has 32 input channels (16 mono, 8 stereo), 6 'auxiliary' and 8 'group' busses. It is a 32 input frame, so there is some empty space under the hood. The plan is to use the mono input channels as the "record" and "remix" inputs, the stereo channels as the "monitor section" as if it were a split console. I'll feed my input converters and tape machine primarily from the group buses when recording, and using them as sub groups when mixing.
My plan for the rebuild:
Replace the current soundcraft 'medium console power supply' with a Yamaha PW4000 power supply, re-capped and regulated for 17v +/- rather than the stock 19v +/- rails. I have spoken with a tech about handling the modification and re-capping of the power supply, as it is a bit outside my comfort zone.
Remove existing input amplifier and EQ from mono channels. Install a transformer balanced (312ish?) mic amp, possibly a JLM Baby animal, followed by a mic/line select switch and phase reverse switch. Following the phase reverse will be a CAPI 2 stage line amplifier card. Stage 1 of the card will be balanced at its output and feed a new/reworked insert send, the insert return will go to stage two of this card, and leave unbalanced and feed the existing SC fader routing, pfl and mute facilities.
EQ for mono channels will be handled by outboard eqs, normaled to the inserts at the patch bay. Insert send could be able to be multed if a "direct out" is needed. In order to handle the balanced send/return I will re-work the previous "direct out" jack as the insert send and the "insert" jack as the insert return. Since the insert send will ultimately need to feed the return, I figure I'll go through the patch bay for this.
Install a "fader" bypass switch at each mono input channel. The plan is to measure the resistance of the fader at (around) unity, and put in a toggle switch that on one side is the fader, the other side will be a resistor of equal resistance to the fader at unity gain.
Replace group buses summing amps with CAPI 2 channel ACA cards. Bypass the simple eq in these groups.
I don't plan on altering the stereo input channels much, though the ICs are socketed here so I will likely spend some time listening to a few different ICs. I've already increased the coupling cap values in these. I don't plan to use the EQ and will likely pull the ICs from this section and leave it bypassed. Aux buses will remain as is as well, they also have socketed ICs and I may swap those for BBs.
I won't use the monitor section aside from to monitor the PFL bus and send it to my monitor control.
The plan is to start with two input channels and the power supply, I will start to really figure out what op amps and transformers make the most sense and what I can source. I have a handful of 2520s and 2520 like op amps that I'll use to get things working at first.
I've attached a simple input signal flow drawing that sort of outlines my current thoughts, as well as some of the OG soundcraft schematics/drawings. I'm curious of anyones general input, words of caution or just general advice. Anyone have thoughts on grounding? Venting/heat sync thoughts? I know that its a bit of a large and crazy project, but I am excited to pull up my sleeves, learn some things, and come out with a totally unique and tailored to me console for my new studio.
