Metal Ace Ultimatum mod

The definitive headphone guitar amp.
Ash517
Posts: 15
Joined: Mon Jul 31, 2017 6:14 pm

Metal Ace Ultimatum mod

Postby Ash517 » Sat Nov 04, 2017 3:53 am

https://www.facebook.com/groups/Rockman ... 590521604/

I’m wondering 2 things
1. How this mod sounds
2. If it works on the Guitar Ace

I’m no good at electronics, so I don’t wanna risk the life of my beloved Dunlop Guitar Ace. Anyone here know how removing that jumper affects things? Is it related to the compressor? The poster says it sounds less “choked-down” with the jumper removed, hence the compressor theory.
GEAR:
Rockman Guitar Ace (Dunlop)
Epiphone Les Paul Custom Pro (Alpine White)
Boss Katana 50
Rockman Sustainor 200 Rev 20 (borrowed)
Rockman Instrument Equalizer (borrowed)
Rockman Stereo Chorus (borrowed)
All borrowed gear is from my Dad :D

RockmanCentralBob
Posts: 161
Joined: Fri Feb 06, 2015 2:10 am

Re: Metal Ace Ultimatum mod

Postby RockmanCentralBob » Sat Nov 04, 2017 12:43 pm

I'm not on Facebook so I can't read it.

Ash517
Posts: 15
Joined: Mon Jul 31, 2017 6:14 pm

Re: Metal Ace Ultimatum mod

Postby Ash517 » Sat Nov 04, 2017 1:09 pm

I’ve attached an image of the post with a circle around where the jumper-thinggy was.
You do not have the required permissions to view the files attached to this post.
GEAR:
Rockman Guitar Ace (Dunlop)
Epiphone Les Paul Custom Pro (Alpine White)
Boss Katana 50
Rockman Sustainor 200 Rev 20 (borrowed)
Rockman Instrument Equalizer (borrowed)
Rockman Stereo Chorus (borrowed)
All borrowed gear is from my Dad :D

RockmanCentralBob
Posts: 161
Joined: Fri Feb 06, 2015 2:10 am

Re: Metal Ace Ultimatum mod

Postby RockmanCentralBob » Sun Nov 05, 2017 1:56 pm

Interesting.... I'll have to dig around to see if I have the schematics for the Metal Ace to see what's going on. Based on my understanding of the design of the Ultimatum, I highly doubt if it's doing the same thing. But, it could be that it sounds more like an Ultimatum that it did before the adjustments.

I will say that I take these "it sounds just like..." posts with a grain of salt. I'm guilty of it myself, but I've found that these comparisons are rarely made in an A/B comparison setting. And even then, it's a degree of comparison only.

User avatar
darthoverdrive
Posts: 37
Joined: Tue Mar 25, 2014 1:39 pm
Location: Kansas

Re: Metal Ace Ultimatum mod

Postby darthoverdrive » Mon Nov 06, 2017 8:12 pm

I traced out a Guitar/Metal ACE a few years back, not sure if I posted the schematic on this site. I’ll dig it up if anyone is interested.

The trim pot and the jumper are for the compressor circuit. The trim adjusts the gain of the compressor opamp and removing the jumper removes the compressor from the feedback loop of the input circuit.

Removing the jumper won't hurt the amp but remember to put it back on the correct pins. Placing it on the opposite pins will greatly reduce the output volume.

If you going to adjust the trim pot I'd suggest measuring the ohms first, that way you can always try to get it back to the original setting.