dweekie, what is the simplest way to fix sub out

[engtaz Ready for a reference theater Find all posts View Profile Close engtaz]

dweekie,
What is the simplest way to fix sub out on the the Gizmo amp so that the sub out works in conjunction with the volume controls.

Thank you for any and all advice,
engtaz

[dweekie Find all posts View Profile Close dweekie]

Hmm, I don't know, I get a bit lost in the input/sub-out section without some schematics :crazy:. Doug could provide the information you need, or one of the ELT package owners could pop the lid and snap a picture. It's supposed to be a fairly simple fix. Sorry I'm not much help here.

[craigsub Find all posts View Profile Close craigsub]

We are doing a mod for this at AV123's HQ in Colorado.

I will ask if we can post this mod on line.

The guys better say yes. :burgerking:

[engtaz Ready for a reference theater Find all posts View Profile Close engtaz]

I'm a electronic tech so doing the work is not a problem, audio theory is.:D

[alphaiii Find all posts View Profile Close alphaiii]

With the arrival/existance of Gizmo v1.1 up in the air, and no guarantee on being able to swap out the original Gizmo for the updated version, is it possible there will be an option for those of us with the Gizmo v1.0 to get this mod done?

[Down Find all posts View Profile Close Down]

dweekie, I heard from a separate source that you know of the mod for the Gizmo that eliminates distortion caused by a source without a variable output. Is this the same mod? If not, can you enlighten me about this please? I'm interested in how to do it.

[dweekie Find all posts View Profile Close dweekie]

dweekie, I heard from a separate source that you know of the mod for the Gizmo that eliminates distortion caused by a source without a variable output. Is this the same mod? If not, can you enlighten me about this please? I'm interested in how to do it.

Bypassing the input section seemed to alleviate the distortion issues. I basically jumped that section and sent the signal directly to the volume chip. Then it was necessary to tap the signal from the volume chip back to the input section so the subwoofer will work (and track with volume). Taken from the Modded Gizmo thread:

Remove R2, R4, C2, C19, C29, C53


Connect 2.2uf caps below


Connect 10uf caps and wire to the volume chip


That's all that needs to be done to bypass the input section and have subwoofer tracking; the rest of the mods shown in that thread are performance enhancements to improve the sound quality of the amplifier. It's not quite as simple as the unreleased mods by AV123 to fix sub tracking, but if you have distortion issues with your particular amplifer, this may remedy the issue.

[dweekie Find all posts View Profile Close dweekie]

I'm a electronic tech so doing the work is not a problem, audio theory is.:D

The problem is, I think I'm an electronics tech.

I'm a bit weak on both, but I still poke away anyway :poke:

[Down Find all posts View Profile Close Down]

Thanks so much! I'll save that and see if I can get around to doing that one of these weekends.

[engtaz Ready for a reference theater Find all posts View Profile Close engtaz]

Thanks, dweekie
So, unsolder C19 neg and C53 neg leads from printed circuit board.
Jumper U3 pin 22 to C53 neg lead
Jumper U3 pin 23 to C19 neg lead
The jumpers on the back, what are the location names for what your jumpering?
I want to know, will doing the jumpers make the needed change without component replacment or deletion?
In otherwords, can I just run jumper wire and remove legs of component from PCB.
Do you have the schematics.

Thanks,
engtaz

[dweekie Find all posts View Profile Close dweekie]

On the bottom, it is RCA -> 2.2uf cap -> neg holes of C2 and C29. You should be fine running jumper wires. You can try the mod, and if you have more rolloff in the subwoofer than expected, you can increase the value of the caps that attach to C19 and C53. I used 10uf (I think original is 2.2f, but I don't remember exactly).

[engtaz Ready for a reference theater Find all posts View Profile Close engtaz]

RCA pin or shield?

Thanks,
engtaz

[TJEli Find all posts View Profile Close TJEli]

My modded Giz from AV123 will be here on Tuesday. (27th) I will take a look at it when it gets here. I am looking forward to it. My origional Sonic T-amp is a little light trying to power the 525Ms in my office. (its also ugly next to the beautiful Rosewood ELTs)

-Eli

[TJEli Find all posts View Profile Close TJEli]

Well... sorry guys. I have no pics for you. I was told that the Gizmos would be shipping the week of the 19th. Last week I got a tracking number from AV123 on Wednesday. I did get a package from them today but it was just my Ultralinks. No Gizmo.:hissyfit:

To make it worse, the batteries in my T-amp died today in the middle of Dave Matthews "live at Luther college" while I was trying to get some work done.

I'll keep you posted,

-Eli