PSU for Harrison TV3 sidecar project?

[skeptic12]

Hi

I am helping a friend put 14-16 channels of a TV3 into a smaller frame that he built.  I've gotten it working with the huge old brown PSU that powered the the old 32 channel (plus groups, master etc).  I've gotten it working with mics going in and output from the transformer multitrack out.

What are the options for a more modern PSU that could supply +/- 18v and 48v for these that is smaller (and quieter!) than the monolith that powered the full desk?

What's the best way to calculate current draw for a set of modules like this?


Thanks in advance

 

[Rob Flinn]

Did you try using a meter to measure the current draw ?

 

[abbey road d enfer]

Hi

I am helping a friend put 14-16 channels of a TV3 into a smaller frame that he built.  I've gotten it working with the huge old brown PSU that powered the the old 32 channel (plus groups, master etc).  I've gotten it working with mics going in and output from the transformer multitrack out.

What are the options for a more modern PSU that could supply +/- 18v and 48v for these that is smaller (and quieter!) than the monolith that powered the full desk?

What's the best way to calculate current draw for a set of modules like this?


Thanks in advance

First, as Robb suggests, you need to evaluate the current draw on each rail.
In order to do that, you may try to measure the voltage drop across the limiting resistors, if any.
If not, you can have a rough idea in identifying and counting the opamp sections in the module.
If you have a schemo, it's even easier.
Then you have the choice of a fully linear PSU, a full smps solution, or a hybrid smps+linear regulators.
My favourite solution is a hybrid based on 24V smps followed by linear regulators (LM317/337) for the +/-18Vrails, and for phantom a 48V smps followed by a LC filter.
The Meanwell RS series offers models in 15, 25, 50W that are adustable. I adjust them to about 21-22V in order to not exceed the power dissipation limit of the linear regs.

 

[Bo Deadly]

First, as Robb suggests, you need to evaluate the current draw on each rail.
In order to do that, you may try to measure the voltage drop across the limiting resistors, if any.
If not, you can have a rough idea in identifying and counting the opamp sections in the module.
If you have a schemo, it's even easier.
Then you have the choice of a fully linear PSU, a full smps solution, or a hybrid smps+linear regulators.
My favourite solution is a hybrid based on 24V smps followed by linear regulators (LM317/337) for the +/-18Vrails, and for phantom a 48V smps followed by a LC filter.
The Meanwell RS series offers models in 15, 25, 50W that are adustable. I adjust them to about 21-22V in order to not exceed the power dissipation limit of the linear regs.

+1

But there are a lot of rules about using SMPS.

 

[Andre bratten]

I have a TV3 console. The entire thing pulls around 12 amps. If these are pulled from a tv3 made for Swedish broadcast with RF resistant transformer less mic pre design, I would go for 15 volts as that is the power requirements in the manual. If these are with Jensen xfrms I would go for 18.. Blue dog makes some good psus you could use, they are 17.5 volts, but that makes no difference in the real world. If interested I can measure what 24 channels are pulling and give you the numbers. Note, all my channels are with original Harris quads, if yours are swapped with others then the power requirements would be different.. I would strongly recommend to use 4605-like quads as the circuitry around these operational amplifiers are tailored for these.. Best André Bratten