ART Tube MP Studio and Dual MP Mods

Warning!!!: Art uses VERY small traces that can be easily damaged by improper soldering techniques. Take extra care with these units!
Note: Both Channels of the Dual MP have the same part designations.

Tube MoD: - Replace the tube with a better quality 12AX7 (or 12AT7 for lower gain) tube (mullard, tung-sol, rca, whatever)

- Replace ic's u1 and u2 with 8 pin gold contact ic sockets and change the chips to: OPA2132, opa2134, OPA2107, LT1358, or LME49860NA (My fav)
- Bypass the modded IC's V+ (pins 8) with a .1uf capacitor to ground

Capacitor/resistor MoD:
- Replace c12 and c13 with 100uf 63v bipolar caps
- (Optional) Bypass those caps with 1u film caps
- Replace c14, c15, c17, c18, and c23 with 47u 25v bipolar caps
- (Optional) Bypass those caps with .47u film caps
- Replace c24 and c25 with 10u 50v bipolar caps
- (Optional) Bypass those caps with .1u film caps
        - Option 2 - Instead, Replace those electrolytic caps with a 10uf 5mm spacing film cap (10u = MKS2B051001N00MSSD or MKS2B051001N00JO00). No need to bypass those with smaller film caps.
- Replace c26 with a wire jumper or a 10u 50v bipolar cap. Wire is better.

- Replace R3 and R4 with 10R metal film resistors
- Replace R6 and R7 with 150R metal film resistors
- Replace R36 with a 1k metal film resistor
- Replace R51 with a 20k metal film resistor

Input transformer MoD:
- Add a 600:600 (or any 1:1) input transformer on the input.
- Take out c12 and wire the Tranny input(+) to the pad on the XLR side (Junction of r24 and the xlr jack). Solder the tranny out(+) to the other pad of c12 (Junction of cr9, c14, and r18)
- Take out c13 and wire the Tranny input(-) to the pad on the XLR side (Junction of r25 and the xlr jack). Solder the tranny out(-) to the other pad of c13 (Junction of cr10, c15, and r19)

Output transformer MoD: - Wire in line a 600:600 transformer. Cut or desolder the ribbon cable at JP2(+) and JP3(-). The pcb side is your input to the transformer and the ribbon cable (or output board) is your output.

PSU MoD: - Change the diodes (CR1-7) to Fast (UF) diodes (UF4002 or UF4003)
- Bypass c10, c11, and c21, with .1uf 63v or higher film/ceramic caps

Higher Voltage MoD:
- Replace r56 with a 100k or 150k metal film resistor to provide more voltage to the first gain stage of the tube + reduces noise, lowers gain.

Disclaimer: I encourage people to DIY and I'm here in a informative role.
_______________________________________________________________________________________________________________________________________________ Schematic PDF


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