MAC - Micro Auto Compressor
Moderator: Joe Malone
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MAC - Micro Auto Compressor
This deserves its own thread.
I've been taking a little look at the pic Joe posted, and I'd like to know if I'm the right track ....
(1) its an opto compressor with program sensitive attack and decay
(2) you WILL need a DINGO to run it, as the actual VCA and bypass relay switch sit on that board.
I've been taking a little look at the pic Joe posted, and I'd like to know if I'm the right track ....
(1) its an opto compressor with program sensitive attack and decay
(2) you WILL need a DINGO to run it, as the actual VCA and bypass relay switch sit on that board.
Chris P
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I do lots of things. I believe eclectic skills are best.
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I do lots of things. I believe eclectic skills are best.
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Yes just think solid state LA2A or LA3A. Attack and release are set by the opto cell type.(1) its an opto compressor with program sensitive attack and decay
Yes you will need a Dingo for the audio path as the MAC PCB is only the sidechain PCB. The bypass relay is on the Dingo as well but you do NOT need the VCA on the dingo as this is a opto compressor. The opto cells sit on the MAC PCB. Makeup gain is provided by the dingo output opamp.(2) you WILL need a DINGO to run it, as the actual VCA and bypass relay switch sit on that board.
The MAC can be easily added to a Dual 99v kit at the fader/trim control point as that runs on +/-24v rails. Trying to work out if it can run with a BAD kit as it is or I will do a 48v rail version PCB that will.
Joe
JLM Audio
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Joe, is there an option to include the DIngo VCA section into the signal chain with the Opto? I´m thinking of a box à la squash-it-to-hell with both Opto and VCA characteristics. Having the possibility to catch transients and then tastefully compress it with an opto is what I pretty often do with 1176 and LA2A. This combination 4x in a tiny 1HE box would be killer
Jens
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Hi Joe,
How close to the Forsell opto sidechain is your comp? Looks like you went with a fullwave rectifier, and only two opamp stages (one 2604). One inverting and one non, each driving a fullwave bridge into the vactrol LEDs?
I was just figuring out how to integrate the Forsell opto with a BabyAnimal mic pre. I'm making a small box for traveling with an mbox mini. I had settled on using the LDR as the shunt R in a U-pad on the output.
Details of the Forsell here: http://www.diyfactory.com/projects/fors ... /ffosc.htm
Thanks!
Brian
How close to the Forsell opto sidechain is your comp? Looks like you went with a fullwave rectifier, and only two opamp stages (one 2604). One inverting and one non, each driving a fullwave bridge into the vactrol LEDs?
I was just figuring out how to integrate the Forsell opto with a BabyAnimal mic pre. I'm making a small box for traveling with an mbox mini. I had settled on using the LDR as the shunt R in a U-pad on the output.
Details of the Forsell here: http://www.diyfactory.com/projects/fors ... /ffosc.htm
Thanks!
Brian
- Joe Malone
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No the VCA is for a separate compressor project. Cannot be used at the same time as the OPTO on the dINgO.Joe, is there an option to include the DIngo VCA section into the signal chain with the Opto? I´m thinking of a box à la squash-it-to-hell with both Opto and VCA characteristics. Having the possibility to catch transients and then tastefully compress it with an opto is what I pretty often do with 1176 and LA2A. This combination 4x in a tiny 1HE box would be killer
MAC kit price will be $80AUD. Parts list here http://www.jlmaudio.com/MAC%20Parts%20Kit.txtJoe, do you have a rough idea of price? Ballpark will do.
And the Mac Link kit $20AUD. Parts list here http://www.jlmaudio.com/MAC%20Link%20Parts%20Kit.txt
No we had an opto comp similar to the Forsell in the works but once the Forsell version came out I decided there was no reason to go down the same track. So went off on a different tangent and experimented with lots of simple opto comps configurations with the aim to be minimum controls for a easy to use tracking compressor along the lines of a LA2A and LA3A which has ended up good enough to be able to use on stereo buss as well with the small MAC link PCB.How close to the Forsell opto sidechain is your comp? Looks like you went with a fullwave rectifier, and only two opamp stages (one 2604). One inverting and one non, each driving a fullwave bridge into the vactrol LEDs?
The ideal for that is the BAD as it has 2 amp stages and would work perfectly. But you can do it in the BA by cutting one track and adding the compression element between the secondary of the input transformer and the +in of the opamp like Manley do in there voxbox.I was just figuring out how to integrate the Forsell opto with a BabyAnimal mic pre. I'm making a small box for traveling with an mbox mini. I had settled on using the LDR as the shunt R in a U-pad on the output.
Circuit for the MAC here http://www.jlmaudio.com/MACSCH.pdf
Joe
JLM Audio
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For those playing along at home, attack is about 3.5 ms, release is about 500 ms for the VTL5C2.Joe Malone wrote:Attack and release are set by the opto cell type
A few more questions when you've got a moment:
(1) The opamps on the DINGO board - I assume they exhibit the same sonic character as they do in BA kits? So far a snappy clean sound you'd look at maybe the hybrids, or for a more textured sound the 99V?
(2) The MAC board includes a path to pin 6 of the IDC connector, which on the DINGO is the cv feed to the 2181 VCA - I assume this actually does nothing as the 2181 isn't fitted.
(3) What's the DINGO/MAC power consumption?
(4) The "Reduction" pot - this is a threshold control right? With the slope determined by the ratio pot?
Thanks
Chris P
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I do lots of things. I believe eclectic skills are best.
---------------------------------------------------------
I do lots of things. I believe eclectic skills are best.
- Joe Malone
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- Posts: 2082
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Yes JLM99v is fat and silky, Hybrid is tight and fast with silky tops in class A, OPA2604A fast and tight. If you lower the +/-rails to 18v you can use NE5532A as well. When using a Dual opamp like OPA2604A or NE5532A the dingo is electronically balanced out while the JLM99v and Hybrid are quasi-balanced out like the BA kits with no output transformer (Audio out on pin 2 only, pin 3 for noise pickup only). But the JLM111DC output transformer can wire into the side of the dingo PCB to give true balanced out for these.1) The opamps on the DINGO board - I assume they exhibit the same sonic character as they do in BA kits? So far a snappy clean sound you'd look at maybe the hybrids, or for a more textured sound the 99V?
Pin 6 is used in the MAC configuration for comp link function and when the ribbon cable from dingo to MAC also continues to MAC link PCB the link function requires no extra wiring.(2) The MAC board includes a path to pin 6 of the IDC connector, which on the DINGO is the cv feed to the 2181 VCA - I assume this actually does nothing as the 2181 isn't fitted.
Totally depends on the opamps used. But an AC/DC power supply can run about 8 dingoes with MAC comps in any configuration. The 3 power wires to each dingo are the only normal wiring that is needed to them.(3) What's the DINGO/MAC power consumption?
Yes just like a LA2A.4) The "Reduction" pot - this is a threshold control right?
The Ratio is normally a 3 position toggle but a 10k rev log pot can be used instead of the switch if fully adjustable ratio is needed.With the slope determined by the ratio pot?
Joe
JLM Audio
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JLM Audio
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