Old Mesa Boogie Combo

[kafka]

It's an old Mesa Mk I, made in 1977, back when Boogie was making amps on a custom-order basis. These are nice amps. They're not particularly rare, but they're fun and sound great when they're well taken care of. Get some NOS tubes to find out what all the fuss was about back in 1977, when everybody playing fusion had to have one.

[DerekJ]

Originally Posted by EarCandy

Hey all you amp slutz out there-

Trying to find out some info about this old Boogie combo I acquired recently.
Looks to be pretty well used, and has been re-capped and re-tubed.
Has an old Altec 417-8H series 2 speaker in it.
All punch tape labels on the back, there is one above the "speakers" label
next to the speaker plug that has "A1207" on it. Is that a serial number?
Also the bottom of the head has green writing indicating what tubes go in
what socket, along with the pictured circled letters RIS or RLS and what must be a date 8-77.
I don't think this is a re-issue, any information would be appreciated-

Thanks for looking, the pictures are large so they take a little bit to display-

It sounds awesome…..

Sweet amp! Love my Mark II.

[Riccardo]

Congrats, really nice MKI.
It also takes pedals well if you need a larger palette of sounds.

[EarCandy]

I've been playing around with the amp, it really sounds great. Twisting the pots cleaned up the crackling, now they are silent.
To my surprise input 1 and input 2 are completely different in sound and operation. Input 2 is very Fendery, clean, warm and round and very difficult to break up.
With the master down and volume 1 cranked it will break up slightly, very nice and bluesy. Input 1 allows the 2 preamp stages to work together, along with the pull bright and pull boost.
Lots of different crunch flavors can be dialed in, very mid forward sounding like I remember Robbin Ford and Larry Carlton sounding in the 70's.
The tone controls work differently than I'm used to on any other amp, the treble control really makes a huge difference in the sound, and where it sits seems to affect the other EQ controls,
especially bass. mid control doesn't seem to do much. The pull bright (or pull boost-can't remember) seems to defeat the tone controls- Would anyone know if this is correct?
Also, are the 2 jacks (bottom one has "Line" label) on the back an FX loop in/out?
Thanks for the help and input!

[kafka]

Originally Posted by EarCandy

The tone controls work differently than I'm used to on any other amp, the treble control really makes a huge difference in the sound, and where it sits seems to affect the other EQ controls,
especially bass. mid control doesn't seem to do much.

The gain staging inside Boogies is a little weird. The tone knobs have more influence over preamp distortion than in other amps. One lesson I have to remind myself of every now and then on Boogies is to start with the tone knobs all the way down, and then pull them up slowly.

[Riku]

The older boogie tone controls are at the start of the pre-amp section where as most other tone controls (ie Marshall etc) are at the end of the pre-amp. This allows you to vary the amount of signal going through the tubes and allows you to vary which part of the freq spectrum distorts.

[drbob1]

The lower jack is a line out, would the upper one be the reverb footswitch?

[foldback]

As reported, that's a 70's Mark 1, one of my all time favorite sounding amps when it's working right. I love the sound of the presence control on that amp, it's very special.

One of the guitar players in my band in the 70s had one of those. I took it apart and drew a schematic from it. From that I modded dozens of Fender amps (that boogie is a fender amp with an extra gain stage out front and Marshall presence circuit on the back end.

If you unmount the chassis and look inside you may find a date code in there.

That amp launched my love affair with Mesa amps, I currently have 11 including three Dual Rectifier models.

Treat her nice and she will sing beautifully.

Good music to all!

[Ron Vogel]

I'm certain you will find this out on your own eventually, but the first Boogies were modified Fender Princetons. More power from the output section obviously, but circuit is not that far removed from the Princeton. I love the early Boogies, but you really need to crank them!

[mu6gr8]

Originally Posted by EarCandy

To my surprise input 1 and input 2 are completely different in sound and operation. Input 2 is very Fendery, clean, warm and round and very difficult to break up....
The tone controls work differently than I'm used to on any other amp, the treble control really makes a huge difference in the sound, and where it sits seems to affect the other EQ controls,
especially bass. mid control doesn't seem to do much. The pull bright (or pull boost-can't remember) seems to defeat the tone controls- Would anyone know if this is correct?

Here's a link to a Mark 1 Reissue user manual. The two inputs sound different because one of them has an extra gain stage.

http://www.mesaboogie.com/manuals/Mark1%20Reissue.pdf

[seancostello]

Originally Posted by Riku

The older boogie tone controls are at the start of the pre-amp section where as most other tone controls (ie Marshall etc) are at the end of the pre-amp. This allows you to vary the amount of signal going through the tubes and allows you to vary which part of the freq spectrum distorts.

This also makes it hard to get a clear distortion sound w/bass out of an older Boogie combo. Turn up the bass, and you get a flubby distortion. Turn it down, and the distortion clears up, but the overall sound is thin.

I suppose the same can be said about older Fender combos, where the distortion would come from the power amp stage being cranked. And a Boogie w/a graphic EQ section, cranked through a 4x12 cabinet, would probably have plenty of post-distortion bass on tap.

[git45]

Pardon my brash response....but HOLY CRAP THAT's A MARK ONE Whatever condition its in, that's a wonderful tonal investment. Love the grill cloth too!!! If you wanna push the gain on that sucker, pop in a treble booster or a Keeley Katana to get things juicin'

If you dig the Blue Album tone, this is high-gain valhalla.

[Frederik]

Originally Posted by EarCandy

I've been playing around with the amp, it really sounds great. Twisting the pots cleaned up the crackling, now they are silent.
To my surprise input 1 and input 2 are completely different in sound and operation. Input 2 is very Fendery, clean, warm and round and very difficult to break up.
With the master down and volume 1 cranked it will break up slightly, very nice and bluesy. Input 1 allows the 2 preamp stages to work together, along with the pull bright and pull boost.
Lots of different crunch flavors can be dialed in, very mid forward sounding like I remember Robbin Ford and Larry Carlton sounding in the 70's.
The tone controls work differently than I'm used to on any other amp, the treble control really makes a huge difference in the sound, and where it sits seems to affect the other EQ controls,
especially bass. mid control doesn't seem to do much. The pull bright (or pull boost-can't remember) seems to defeat the tone controls- Would anyone know if this is correct?
Also, are the 2 jacks (bottom one has "Line" label) on the back an FX loop in/out?
Thanks for the help and input!

I have the exact same amp from 1977 except mine is 60w only and does not have reverb. Also it originally had the jbl k-120 speaker, but when I bought it i. 2001 it had a celestion vintage 30.

I also have the 2 jacks in the back, one with a black line towards the pot. The pot controls the output level from the slave out. The other jack seems to be a fixed output slave out at 100% output, maybe to directly drive a power amp?

One interesting tone I have found and use most of the time with this amp, on a strat, is the 2 gains around 6-7, treble around 7-8, bass at no more than 3, mid at 7-8, presence knob at the back of the amp on a low setting (really sensitive knob, play a bit with it to find the sweetest spot).

This give a nice srv like tone at low playing volumes. If playing really low volume you can pull the bright knob and turn down presence a bit.

I think mine was modded because it also have an effect loop with its own 12AX7 tube and pot added to it. I have found some interesting sounds (very high gain, more focused) by connecting a straight cable in the effect loop and playing with its knob.

Let us know what tricks you have found with it. It is a nice little amp full of tricks apparently!

[Frederik]

craptastic iPad pictures of mine:

[Frederik]

I forgot, on mine I also have an additional jack next to the speakers for an external mesa boogie switch to activate the gain boost (pull knob) remotely. Not sure if this was modded or original, but the external switch I have is definately genuine mesa.

And on the far right these are the effect loop jacks and pot.

[Frederik]

Oh and yes the pull boost does take out the tone controls, except the presence control at the back. I think this is because the pull switch rewires the available amplification stages to use them as additional gain instead of using them for the tone controls.

Regarding the tone controls having an impact on each other, I am not sure what the proper words are to describe this, but the controls are somehow in a series, treble-bass-mid, and the treble have te most impact on the tone, then bass and mid.

Edit: the Axxxx number is the serial number, A indicates original makr amp, reissues start with an H.