PS-02 and 8x A12's: Should I expect Hum issues?

[Randyman...]

I recently filled up my first Seventh Circle chassis. It has a PS-02, and I was running 4x A12, 2x N72, and 2x J99. The PS02 could not supply ample current, and resulted in hum on the N72's in particular.

Tim offered to "cross-grade" me to a PS03 (with a nice discount, but still not quite free), but I decided to buy a SECOND Seventh Circle Rack, and get a PS-03 with it - and I snagged 2x C84's to get the package discount . Now, I plan on eventually filling up both chassis.

My question - I currenlty have 6x A12's in the old PS02 equipped chassis. I would like to add 2 more A12's, but I am afraid I will run into the same hum issues as before. Do the A12's pull more/less current than the N72 and J99? Am I going to have to replace the PS02 anyway I look at it (and take an out-of-pocket hit)? That is what I am trying to avoid if possible. I was under the initial impression that a PS02 would be fine with 8 modules - but I guess not.

Is there a better arrangement of 8 modules that would work comfotably with an old PS02? Overall, my goal is to have 8x A12, 4x N72, 2x J99, and 2x C84. I'd prefer to keep the 8x A12's in their own rack for ease of identification - but I'm open for suggestions.

Thanks for any pointers. Just trying to save some green, you know! (Tim has seen lots of my green )

[tpryan]

The A12s use less current than any other module, and you shouldn't have troubles with the PS02.

[Randyman...]

Lovely.

Can you list the current draw of each Pre-amp (worst case scenario conditions)? Just curious

Thanks

[Randyman...]

Old-School Bump. I'd love to get the "per module" amperage draws on the different preamps.

I'm still in the process of filling up my two SCA chassis (2 slots left in each chassis). The chassis with the older PS02 power supply has 6x A12's - and I'd like to know which other modules have lower current draws to avoid the PS02 voltage sag and associated hum I experienced previously (see above). I might pop 2 more A12's in there (should be fine since Tim previously indicated the A12 is the lowest-current model), but I might use 2 different modules to fill up the PS02 chassis, and I'd like to use modules that have a lower current draw to avoid taxing the PS02 any more than I have to.

From what I understand, my other PS03 equipped chassis should handle any combination of SCA modules w/o voltage sag and hum, correct?

[tpryan]

The D11 draws about the same as an A12, around 45mA per module. The T15 draws even less at about 25mA. The N72, J99, and especially the C84 draw more.

The PS03 is happy in any load/line condition up to about 1200mA on the load side and down to about 85VAC on the line side. You can mix and match 8 modules in any combination.

[Randyman...]

Thanks for the reply. Do you think the PS02 would have any issues driving 6x A12's and 2x J99's? My other option was 6x A12's and 2x C84's, but I see the C84 has the highest draw. If 6x A12's and 2x J99's are too much for the PS02, I guess I could "Skimp" and go for 2x T15's for "Utility Use", and keep all of the power hungry modules in the PS03 equipped chassis.

Basically - I'm trying to avoid the need to purchase another PS03 and get the most out of my older PS02 equipped chassis by rearranging the modules and carefully selecting my future module purchases. Cash is in short supply over here