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Re: MAC Build Thread

Posted: Wed Jun 27, 2012 1:37 pm
by Joe Malone
HI glbaudio
I had a look at the photos you sent.

Did you actually reverse the +/- power as the 100uF caps wouldn’t have bulged unless it had more than 25v across it or reversed voltage?

I can sell you some caps to fix easy but you should be fine to run the PCB’s the way they are for now to see if anything else is damaged once you fix the original power problem or reversed diodes. As the caps will keep working for a couple of months the way they are before they dry out.

You will need to fit the 2 wire links to the Balanced in header to get audio into the comp (See white overlay between 2 sets of pins on BAL INPUT header.)

All other parts should be fine except maybe a opamp if the voltage was actually reversed or went high voltage.

Let me know what you fine when you fix the diodes and add the links to BAL IN and power up again.

Re: MAC Build Thread

Posted: Sat Jul 28, 2012 7:57 am
by glbaudio
Joe Malone wrote:HI glbaudio
I had a look at the photos you sent.

Did you actually reverse the +/- power as the 100uF caps wouldn’t have bulged unless it had more than 25v across it or reversed voltage?

I can sell you some caps to fix easy but you should be fine to run the PCB’s the way they are for now to see if anything else is damaged once you fix the original power problem or reversed diodes. As the caps will keep working for a couple of months the way they are before they dry out.

You will need to fit the 2 wire links to the Balanced in header to get audio into the comp (See white overlay between 2 sets of pins on BAL INPUT header.)

All other parts should be fine except maybe a opamp if the voltage was actually reversed or went high voltage.

Let me know what you fine when you fix the diodes and add the links to BAL IN and power up again.

Sorry for the delay, but I was touring...now i've checked everything (obviusly fixed the diode), one unit was only missing the 2 wire links, and i've changed all the bulged caps in the second unit (i'm now pretty sure i've bulged them with the 48V phantom power due a bad insertion in the rack ON...); now EVERYTHING WORKS!
both units now are correctly trimmed and tested with the oscilloscope.
TNX A LOT for the patience and the support!

Re: MAC Build Thread

Posted: Sat Jul 28, 2012 8:29 am
by Joe Malone
HI glbaudio
Great to hear you got the MAC + INX5 going. Looks like a nice 500 build from the back photo you sent me. 8)

I do not think I have seen a front photo shot of them yet which would be good to put up on this thread if you have time :D

Re: MAC Build Thread

Posted: Wed Jan 02, 2013 9:31 am
by darkironmn07
Hi JLM team,

I recently got a MAC rack compressor kit as a Christmas gift from a friend and was very happy to receive it. I have never put together any kits or done any soldering and I have a very basic understanding of electronics. I got as far as populating both MAC and DINGO PCB boards and soldering everything down, thanks to the very helpful pictures and documentation at the start of this forum, and the part I am stuck on is wiring up the threshold and output pots. I have a x10K pot for the threshold which has 2 sets of the 3 terminals and the 20K push/pull pot for the output. I am also unsure on how to wire up the push/pull section of the pot

If someone could please upload a photo of how these pots should be wired or even a description it would be a massive help.

Thanks

Re: MAC Build Thread

Posted: Thu Jan 03, 2013 11:33 am
by Joe Malone
darkironmn07 wrote:Hi JLM team,

I recently got a MAC rack compressor kit as a Christmas gift from a friend and was very happy to receive it. I have never put together any kits or done any soldering and I have a very basic understanding of electronics. I got as far as populating both MAC and DINGO PCB boards and soldering everything down, thanks to the very helpful pictures and documentation at the start of this forum, and the part I am stuck on is wiring up the threshold and output pots. I have a x10K pot for the threshold which has 2 sets of the 3 terminals and the 20K push/pull pot for the output. I am also unsure on how to wire up the push/pull section of the pot

If someone could please upload a photo of how these pots should be wired or even a description it would be a massive help.

Thanks


Threshold pot wiring
Fold the pot legs 90 degrees with log nose pliers and solder and link as shown below to make a 100k log pot out of the 2 x 200k log pots.
The switch contacts are not used yet so do NOT link like the photo shows.
When we are back to work in a couple of weeks I will put up info on how to use the pull switch for slow attack with 2 x 100uF 50v NP caps that are in the kit already.
Image

Makeup pot wiring
The 2 x 10k rev log pot wired as 20k rev log makeup pot below
Image

Re: MAC Build x8 or x10

Posted: Wed Mar 20, 2013 6:51 am
by dribro
Hi everyone

I was thinking about building more 8 or 10 compressor in a 2 – 3 rack unit. What I’m asking is if it’s possible to do everything with dingo pup’s and the compressor kit, instead of the usual combo.

The one I’ve built is compressor kit+dingo with 2 jlm99 DOA’s and carnhill iron on the output. They sound fantastic.

Yes dingo pup works with MAC kit fine but has no relay bypass feature so you would need to wire a relay to either disconnect the makeup pot and the wiper of the threshold when switched to off/bypass. So probably would be easier to just use the dingo as it takes both DIP and 990 footprint opamps and has the relay bypass.

Aside from the immediate difference in the sound as I plan to use different DOA’s (and as I’m trying to keep costs low too), what is the doa that resemble in sonic characteristics with the jlm99?

DOA = discrete opamp. Or do you mean dual opamp? There is no opamp like the 99v due to the 99v very low gain which normal opamp ICs do not have. Most DIP IC have a gain of over 1000000.

And the mac pcb is available too, or it's only possible to buy the kit version?

Only in kit.

And the power requirements, what toroid do i need, along with the ac/dc kit?

Allow about 100mA per channel not including any meter lamps is a good rule. But total of 10 would usually be about 500 to 600mA max if using led lamp meters like the MAC is designed to use and running into 10k loads.
So a 2 x 22vac to 25vac toroid of 50VA to 80VA would work fine with AC/DC kit.

Re: MAC Build Thread

Posted: Sun Apr 07, 2013 6:27 pm
by ramshackles
Hi

I'm interested in building this comp. I would probably start with one channel and add another one later in the year when more money comes :D

I was wondering what the difference would be between using any of the opamps (hybrid, 99v, 5532, OPA) on the dingo would be to the compressor, and the use of trafo or not??

Re: MAC Build Thread

Posted: Tue Apr 09, 2013 3:56 pm
by conleycd
Hey Joe,

A couple of questions

1) I'm wondering if the MAC compressor kit can be run with just a normal bipolar power supply instead of 48v?
2) Does the MAC and Dingo have to run at +/-24? Can they run at +/- 16?
3) Does the MAC and Dingo have to run at the same voltage? I am gathering so because the dINgO feeds the MAC - correct?

I can run it from a +48v supply (I have one of your Power Stations and could use the 48v rail) but it would be feeding 2 MACs/dINgOs and phantom power for 4 preamps. Would there be sufficient juice? I think the transformer that is powering it is 50VA.

Thanks.

CC

mixup on the overview of the general MAC PCB?

Posted: Sat Dec 21, 2013 9:59 pm
by frans
Looking on the MAC's in the case (page one of the thread), the switches are (top to bottom) ratio, VU, sidechain lowcut on the frontpanel - but on the overview of the general MAC PCB wiring if the blue trimpots/wiring for the pots are on TOP, the switches are (top to bottom) the other way round? So either the text on the front panel is wrong ;-)… the MAC pcb's are upside down in the pictures where they are shown in the case? I think the overview's wrong, huh? Looking at the pictures on the LA500 thread, the switch on the side of the trim pots is ratio and on the side where the VU leads are there's the sidechain locwcut. So.. the overview must be wrong. By the way, the spacing of the switches seems to (from memory :? ) seems to be the same as the spacing on the JLM99MB preamp SWMB PCBs? Want to design my own frontpanel and call it the "koala comp"

Re: mixup on the overview of the general MAC PCB?

Posted: Mon Dec 23, 2013 2:35 pm
by Joe Malone
frans wrote:Looking on the MAC's in the case (page one of the thread), the switches are (top to bottom) ratio, VU, sidechain lowcut on the frontpanel - but on the overview of the general MAC PCB wiring if the blue trimpots/wiring for the pots are on TOP, the switches are (top to bottom) the other way round? So either the text on the front panel is wrong ;-)… the MAC pcb's are upside down in the pictures where they are shown in the case? I think the overview's wrong, huh? Looking at the pictures on the LA500 thread, the switch on the side of the trim pots is ratio and on the side where the VU leads are there's the sidechain locwcut. So.. the overview must be wrong. By the way, the spacing of the switches seems to (from memory :? ) seems to be the same as the spacing on the JLM99MB preamp SWMB PCBs? Want to design my own frontpanel and call it the "koala comp"


Yes the overview with the pen drawn labeling is wrong. The ratio and HPF switch text need to be swapped for it to be correct.

The front panel of the MAC rack comp and the photo of the MAC pcb with trims at top is correct.

The spacing for the 3 toggles is the same as all our 3 toggle PCB's 3 x 6.3mm holes spaced 11.7mm apart.

Re: MAC Build Thread

Posted: Thu Feb 13, 2014 12:30 pm
by scriv
Joe Malone wrote:....When we are back to work in a couple of weeks I will put up info on how to use the pull switch for slow attack with 2 x 100uF 50v NP caps that are in the kit already.


Hi Joe,

I saw mention of "slow attack mode" for the MAC/LA500 on another forum, and then the reference above, but I can't find the documentation on this mod. Can you point me to the details?

Thanks!

Scriv

Re: MAC Build Thread

Posted: Thu Feb 13, 2014 8:12 pm
by frans
Here's the Koala I mentioned three posts earlier :-) knobs are available for guitar pots, but they look nice here, too.

Re: MAC Build Thread

Posted: Tue Feb 18, 2014 10:46 am
by Joe Malone
frans wrote:Here's the Koala I mentioned three posts earlier :-) knobs are available for guitar pots, but they look nice here, too.


Looks great. Please feel free to put the photo up on our JLM audio facebook page.

http://www.facebook.com/jlmaudio1

Re: MAC Build Thread

Posted: Tue Feb 18, 2014 12:08 pm
by Joe Malone
scriv wrote:
Joe Malone wrote:....When we are back to work in a couple of weeks I will put up info on how to use the pull switch for slow attack with 2 x 100uF 50v NP caps that are in the kit already.


Hi Joe,

I saw mention of "slow attack mode" for the MAC/LA500 on another forum, and then the reference above, but I can't find the documentation on this mod. Can you point me to the details?

Thanks!

Scriv


Slow attack mod wiring attached below. Orange wires can go on either way around as cap is non polar.

Re: MAC Build Thread

Posted: Tue Feb 18, 2014 6:06 pm
by frans
Posted it on Facebook. :mrgreen: