2x250 IRS2092 amp build

[hongrn]

Re: 2x250 IRS2092 amp build

Got it. Thanks Neil for your guidance.

Looks fine. However, I'd draw the ground on the mains connector as a chassis ground or earth ground to remind yourself that this this chassis connection should be made separately, either at the input or through a ground loop isolation network. See the figure below, from this RaneNote), or see the discussion for ESP Project04. It's worth reading that RaneNote carefully...

[neildavis]

Re: 2x250 IRS2092 amp build

Can we agree on this? Thanks.
Hong

Looks fine. However, I'd draw the ground on the mains connector as a chassis ground or earth ground to remind yourself that this this chassis connection should be made separately, either at the input or through a ground loop isolation network. See the figure below, from this RaneNote), or see the discussion for ESP Project04. It's worth reading that RaneNote carefully...

[hongrn]

Re: 2x250 IRS2092 amp build

OK... A picture is worth a thousand words, so here are the schematics of a basic PSU using one or 2 bridge rectifiers. Optional components such as bleeders, snubbers omitted for clarity purposes. Can we agree on this? Thanks.

Hong

[1100xxben]

Re: 2x250 IRS2092 amp build

When I finish my Polk redo, I will re-wire to have 8 parallel caps per rail and loose the ground.
Like this one.
Except I'll wire the rectifiers right unlike this one.

You might want to remove or fix that picture. Someone could find that picture and wire it just like the diagram show without realizing the bottom half is wired wrong. They will blow their caps for sure.

[robertcottiers]

Re: 2x250 IRS2092 amp build

When this thread is brought to a conclusion I will calmly check into a rehab facility....:D


Insane in the membrane...

[[email protected]]

Re: 2x250 IRS2092 amp build

When I finish my Polk redo, I will re-wire to have 8 parallel caps per rail and loose the ground.
Like this one.
Except I'll wire the rectifiers right unlike this one.

[Pete Schumacher]

Re: 2x250 IRS2092 amp build

Neil. Its like this but with more caps. And of course dual secondaries vs split like this.

The grounding scheme can be dispensed with completely. These voltages are floating with respect to one another, but there is no need to have the caps meet and connect to ground unless it is to keep the voltages from going too high. The two series caps can be replaced by a single.

Also, this schematic shows the secondary wired as a center tap, not individual windings being full wave rectified. Doing that allows you to get rid of the second rectifier bridge further simplifying the circuit.

I can see why hong is pulling his hair out right now . . . :D

[hongrn]

Re: 2x250 IRS2092 amp build

[[email protected]]

Re: 2x250 IRS2092 amp build

OK, but does the ground for the input connect to earth?

no.
The gnd on the amp is a sum of the minus from one and plus of the other rail.

[neildavis]

Re: 2x250 IRS2092 amp build

Neil, GD goes to earth.

OK, but does the ground for the input connect to earth? The Sure board uses a ground plane that connects the input ground, the output grounds (the speaker "-" connections) and the power ground (the connection labeled "Gnd" on the board). If any of these are connected to earth, then the capacitors that I marked are shorted out and not doing anything. You can verify whether there is a connection between GD and Gnd with an ohmmeter.

Given the symmetry of the PSU, there almost has to be zero volts on that GD line with respect to the Sure Gnd connection, which means there won't be any voltage across the marked capacitors. So even if there wasn't a short, those caps probably aren't doing anything.

[[email protected]]

Re: 2x250 IRS2092 amp build

Neil. Its like this but with more caps. And of course dual secondaries vs split like this.

[[email protected]]

Re: 2x250 IRS2092 amp build

Your right Craig. I'm thinking Integrated tube amp in the future. Just waiting for you to design one.

[[email protected]]

Re: 2x250 IRS2092 amp build

Neil, GD goes to earth.

[neildavis]

Re: 2x250 IRS2092 amp build

Neil,

In this pdf, you wrote "It will work fine, but the middle rows of caps do nothing". I'm not really sure what you meant here, because there's no middle caps, since each rail has only one row of caps. Bottom line, the whole thing has to do with the 2 PSU requirement of the Sure board. I haven't tried it, but I'm tempted to use just one. You built one Sure amp a while back, did you use one or 2 PSUs in your build? Thanks.

Sorry for the confusion. See the two rows of caps with red X's on them in the attachment. These caps might be shorted out, depending on how those "grounds" are connected.

That "2 PSU" requirement verbiage is misleading. The requirement is actually for 2 voltages: plus 65V and minus 65V. You can achieve that with two separate 65V supplies or with a single ±65 supply like the circuit that Pete included in his post. PE should get Sure to revise that data sheet--it is misleading.

PSx.pdf

[hongrn]

Re: 2x250 IRS2092 amp build

By the way, thanks for the warning Craig, but I'm slowly getting there. I'm dragging Lowell along with me as well.

Wait till you get bit by the vacuum tube bug and you run into lots of old text books that used the old school electron current flow instead of the modern "conventional" current flow. Everything is bass akwards. My electronics teacher in high school was a Vietnam vet radio man. He taught us the old military current (Electrons) flows from ground (negative) to the B+. Took me almost the whole first semester of college to get my brain turned around