New Old Amp Day: Quad

[Thaymz]

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]

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.

 

[Beer]

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]

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]

The Gain is similar between Ch1 and 2
I know i had to clean the pots with contact cleaner try that.

 

[Thaymz]

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

 

[JD]

From memory it sounds very close.

 

[Thaymz]

I'm really digging the quad pre. I recently recorded this riff to see how it recorded and if translated as well on the mic as it does in person. The riff itself is nothing special. I just wanted a combination of chords and palm mutes for the purpose of the tone demonstration.

https://www.youtube.com/watch?v=qJ2gVJDEnGU

Signal chain:
- EBMM JP6 (Bridge position / Evo pickup)
- Quad Pre
- JP2c Poweramp
- 2x12 Mesa Recto horizontal cab
- SM57
- Quartet into Logic, no post processing.

This was using Lead 1 with LD at 4 which has way more gain than I've experienced with other Mark series.

 

[JD]

Sounds Great

 

[Markedman]

I just bought a quad 50/50 set-up myself. It just shipped out today and will take a week or so to get here if the post office doesn't lose it. Other than a Coli C+, this is about every Boogie that I've wanted, I've owned.


edit; or so I thought! MF'er never sent the pre amp! I paid for it on Reverb.com and he claims he "doesn't know what happened to it" so I initiated a refund.

 

[Thaymz]

I’ve recorded a couple more clips. This is such an excellent preamp. It doesn’t have the compression you’d find in a newer mark. I’m generally using lead 2 which sounds very close to the mark IV when pull fat and pull bright are engaged set to mid gain. This clip is of the lead 1 or (iic+ circuit).

https://youtu.be/h-XD84n2vV0

Same signal chain as before.

Markedman, did you end up receiving yours?

 

[Marshall_SLX]

Great tone mate... matches bang on... you are right tho your unit does sound pretty gainy... is it on 4 there? I have mine on 7 but ive also got my vol on 7... sounds a bit less tallica but i find the tone more razor sharp that way... mines been modded for higher gain on ch 1 and sounds very similar to yours... when it was stock theres no way it could sound that gainy on ch 1.... have you found out if it was modded?

 

[Marshall_SLX]

Ohh i see you're in Aust... same mate... is this the Quad pre that was on ebay 3 weeks ago sold for $760? Or the one at better music $1195? When my unit was stock lead 2 had 1/3 more gain than lead 1... since modding (BJ amps in Bris)... lead 1 has a touch more gain than lead 2... lead 2 sounds fuller and much more authoritive... big improvement all round... does your unit have the master volume difference? That is ch1 master on 4 is same vol as ch2 master on 10... mine was like this stock (ive heard theyre all like this stock) very annoying... i also had this fixed so both masters are level matched... now its a great unit

 

[Thaymz]

Great tone mate... matches bang on... you are right tho your unit does sound pretty gainy... is it on 4 there? I have mine on 7 but ive also got my vol on 7... sounds a bit less tallica but i find the tone more razor sharp that way... mines been modded for higher gain on ch 1 and sounds very similar to yours... when it was stock theres no way it could sound that gainy on ch 1.... have you found out if it was modded?

Thanks man. Yeah it's on 4 there. Although all pull functions engaged and fairly extreme GEQ which adds to the signal going through. I opened it up and saw the original sign offs from 1990 from the techs but didn't see anything to suggest a ch1 mod as far as signature markings etc. That said, tonally... it seems there's more gain than would be in a stock version.

My "stock" settings for a mark are:

vol 1: 8
T: 8
B: 2
M: 4
LD: 8

I deviate from this on the quad lead 1 cause there's so much gain and to have something a bit more scooped, and the mark IV which I run Lead Gain (vol 1 equivalent) at 9.

 

[Thaymz]

Ohh i see you're in Aust... same mate... is this the Quad pre that was on ebay 3 weeks ago sold for $760? Or the one at better music $1195? When my unit was stock lead 2 had 1/3 more gain than lead 1... since modding (BJ amps in Bris)... lead 1 has a touch more gain than lead 2... lead 2 sounds fuller and much more authoritive... big improvement all round... does your unit have the master volume difference? That is ch1 master on 4 is same vol as ch2 master on 10... mine was like this stock (ive heard theyre all like this stock) very annoying... i also had this fixed so both masters are level matched... now its a great unit

I'm in melbourne. Was neither of these, I got mine from ebay in Dec from a local sale. Was listed at a good price and bought it fairly quickly. The one of reverb had quite a few holes drilled into the back of the chassis and the recent ebay listing was a tad rusty. Both issues are cosmetic and unless internals were modified it doesn't really matter. Both of those were at a good price in my opinion given you get a mark iic and iii preamp and rhythm / lead in each. I have amp heads so I didn't need to spend more on a poweramp, so that's where it can get expensive really quickly.

My Lead Drive on 4 on Lead 1 is equivalent to about 8-10 on Lead 2. The masters are fairly different. With LM on about 5 on both channels I run Channel 1 master at 2 and Channel 2 Master at 5.5. At these settings they are level.

 

[Marshall_SLX]

Interesting about the gain on your Quad... ive seen so many different descriptions on Quads now... mine was pretty average before modding... undergained on lead 1 yet noisey... lots of gain on lead 2 but very thin and still noisey... now i like it alot... i also thought the GEQs on it had way less range than my mkiii but again since modding its much better... your stock mk settings mirror mine for the most part except i go 7 and 7 for lead gain and vol 1... treble 9... pull bright vol... pull shift treb...pull deep master... pull bright lead master.... thats for mkiii

 

[Amimaster]

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/

It has been years I didn't power-up my quad (No time, also Strategy 500 being too loud for playing it at home) but for what I remember there was a HUGE unbalance on both gain and volumes between the two channels, and I noticed the same thing on my quad. By fiddling with volumes and gains I managed to somewhat enstablish a "volume hierarchy" between channels (clean/chrunch/lead/solo), but yes, the channel 1 was way louder than the 2. Maybe I got a modded quad too? I bought it when I was 18 and I didn't know anything about this kind of amps .

 

[Markedman]

Boogie designed the Quad with the channel volume difference, I don't know the reason but it has to have one. Anyway, here's a schematic.

http://www.kobra.hr/Schematics/Mesa%20Boogie/s-main.gif

 

[Marshall_SLX]

Im no expert but i believe this is where the volume difference is from (theres also that other 220k on ch2 but i dont know about it)... and you cant simply just replace ch2 220k resistor with a 22k or ch2 becomes unusable noisy and unstable due to the different circuitry that occurs before that resistor in ch2... i had mine level balanced which required lowering ch1 vol and raising ch2 vol enough to match it... but you cant straight up raise ch2 to the same vol... also it changes the tone somewhat... ch1 loses a bit of its C+ likeness and sounds more like a mkiii unfortunately it is less round and liquid on leads and clean however it is now better for Metallica rhy tones... ch2 is greatly improved bolder bigger tone and way tighter yet deeper bass... best description i can give on mine is now ch1 lead sounds like and justice for all and ch2 lead sounds like puppets... i love it some definitely would not like the ch1 changes... if Dream Theater is your thing don't do it you need ch1 to stay how it is for that.

 

[Markedman]

You sound like an expert anyway, thanks for the advice.