New Old Amp Day: Quad

Triaxis, Quad Preamp, Stereo Power series, Recto Preamp

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Thaymz
Mark II
Posts: 138
Joined: Wed Apr 20, 2016 6:04 pm

New Old Amp Day: Quad

Post by Thaymz » Sun Jan 05, 2020 6:45 am

A Quad preamp became available local to me at a decent price so I picked it up.

Am very very happy with it so far and It is much better than I thought it would be. It does sound a bit different to my c+ but that is expected as I've not yet run it through the c+ powersmp which I'll test out at a later date. Generally am preferring the lead tone in Channel 1 over Channel 2.

Curiously though, the Channel 1 / Lead 1 has so much gain it is ridiculous. With equivalent settings the Channel 1 has more gain with LD at 3 than Lead 2 does set to 10 and it makes me think this might be modded to a c++ as I've read this can and has been done before. I've only seen this much gain at such low levels on iic++s (referring to metallica's Puppets / Justice notes and a couple videos on youtube.

For any that have done this, is there any indicator, perhaps on the circuit board to confirm? I'll separately email mesa with the serial but not sure they'll have a record.

Or alternatively, have any of the aussie boogieboarders on here had their 240v quad channel 1 modded to a c++, either by Mike B or themselves, and sold it some 10yrs ago (s/n 02145)? The guy it bought from had it for 10yrs and he didn't mention any mods.

In any case, happy days \m/

JD
Donating Member
Posts: 182
Joined: Sat Jun 16, 2007 3:27 pm
Location: Australia

Re: New Old Amp Day: Quad

Post by JD » Wed Jan 08, 2020 10:32 pm

Great preamp i modded channel 1 of one mine to C+ and channel 2 to C++ I still have it though.
Took a while to fill in blanks of the schematics
sounds good to me.
Mesa Boogie Mark 3++ RGX 60W
Axe fx 2
Mesa Boogie Quad Preamp with C+ Mod Ch1 C++ Ch2
Mesa boogie Studio pre with C++ Mod by Mike B
Mesa Boogie Studio pre with C++ Mod

Beer
Bottle Rocket
Posts: 3
Joined: Sun Dec 01, 2019 4:28 pm

Re: New Old Amp Day: Quad

Post by Beer » Sun Jan 12, 2020 6:51 pm

JD wrote:
Wed Jan 08, 2020 10:32 pm
Great preamp i modded channel 1 of one mine to C+ and channel 2 to C++ I still have it though.
Took a while to fill in blanks of the schematics
sounds good to me.
You do the mods yourself? If so do you have a "how to" documented process?

Thaymz
Mark II
Posts: 138
Joined: Wed Apr 20, 2016 6:04 pm

Re: New Old Amp Day: Quad

Post by Thaymz » Mon Jan 13, 2020 5:52 pm

JO - did yours have as much gain as I’m describing which LD set at 3? Just trying to understand if it’s stock or modded.

JD
Donating Member
Posts: 182
Joined: Sat Jun 16, 2007 3:27 pm
Location: Australia

Re: New Old Amp Day: Quad

Post by JD » Tue Jan 14, 2020 1:12 am

The Gain is similar between Ch1 and 2
I know i had to clean the pots with contact cleaner try that.
Mesa Boogie Mark 3++ RGX 60W
Axe fx 2
Mesa Boogie Quad Preamp with C+ Mod Ch1 C++ Ch2
Mesa boogie Studio pre with C++ Mod by Mike B
Mesa Boogie Studio pre with C++ Mod

Thaymz
Mark II
Posts: 138
Joined: Wed Apr 20, 2016 6:04 pm

Re: New Old Amp Day: Quad

Post by Thaymz » Fri Jan 17, 2020 1:00 am

How close would you say the Quad modded to c++ sounded to your c++ head?

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