Mesa Boogie Stiletto Schematic

bls31401 · Post by **bls31401** » 27 Jan 2011, 06:28

Does anybody have the schematic for a Mesa/Boogie Stiletto amp(whether it's an Ace or Deuce is irrelevant)?Because I just can't manage to find either of these amps.

Although it's probably only given out to "certified" techs and servicers,I'm just curious if anyone wants to share it.

blackbunny · Post by **blackbunny** » 28 Jan 2011, 05:07

Here's the 'factory' schematic set for the Deuce.

Unfortunately, Mesa schematics usually don't match the production amps very closely.

I would check the 5U4GB rectifier tubes first, and then the outer power tube pair.
A faulty switching relay is also fairly common, in the output tube area.

What kind of problems are you having? Or are you trying to clone one?

bls31401 · Post by **bls31401** » 28 Jan 2011, 05:34

blackbunny wrote:Here's the 'factory' schematic set for the Deuce.

Unfortunately, Mesa schematics usually don't match the production amps very closely.

I would check the 5U4GB rectifier tubes first, and then the outer power tube pair.
A faulty switching relay is also fairly common, in the output tube area.

What kind of problems are you having? Or are you trying to clone one?

WOW,thanks black bunny

And yeah,I'm thinkin' of cloning one.And on top of that,I was just curious how the curcuit was different from the dual rectifiers...Because the main difference I heard(besides this one having EL34s) was the lack of low-end....(I thought of maybe modding one)

blackbunny · Post by **blackbunny** » 28 Jan 2011, 06:10

bls31401 wrote:And yeah,I'm thinkin' of cloning one.And on top of that,I was just curious how the curcuit was different from the dual rectifiers...Because the main difference I heard(besides this one having EL34s) was the lack of low-end....(I thought of maybe modding one)

Yep, it's very bright and crunchy...maybe Mesa would say it's sharp as a blade?

The preamp circuitry has kinda Marshall Plexi-ish clean mode, JCM800-ish crunch mode and SLO-ish high gain modes.

The RectumFryers have more gain and more smoothing capacitors to "round off" the top end fizz.

bls31401 · Post by **bls31401** » 28 Jan 2011, 06:23

blackbunny wrote:
bls31401 wrote:And yeah,I'm thinkin' of cloning one.And on top of that,I was just curious how the curcuit was different from the dual rectifiers...Because the main difference I heard(besides this one having EL34s) was the lack of low-end....(I thought of maybe modding one)
Yep, it's very bright and crunchy...maybe Mesa would say it's sharp as a blade?

The preamp circuitry has kinda Marshall Plexi-ish clean mode, JCM800-ish crunch mode and SLO-ish high gain modes.

The RectumFryers have more gain and more smoothing capacitors to "round off" the top end fizz.

Yeah,they have a certain type of liquid and "enveloping" sort of gain....You gotta' love those marshall pre-amp tones.

But the only thing I like about the rectifiers more than the stilettos is that thick low-end(which is probably helped by the bigger rectifier cabs).

bancika · Post by **bancika** » 28 Jan 2011, 11:37

I wouldn't rely on mesa schematic for purpose of cloning, they are usually full of intentional mistakes. Correct enough to cover repair work, but not enough to clone.

blackbunny · Post by **blackbunny** » 28 Jan 2011, 13:52

bancika wrote:I wouldn't rely on mesa schematic for purpose of cloning, they are usually full of intentional mistakes. Correct enough to cover repair work, but not enough to clone.

+1.

You can use the Mesa diagram as a guide; analyse each stage and compare it with schematics of Recto's, SLO, Bogner or whatever other amps you like the sound of. That should help keep the trial-and-error and debugging to a minimum.

bls31401 · Post by **bls31401** » 28 Jan 2011, 20:37

blackbunny wrote:
bancika wrote:I wouldn't rely on mesa schematic for purpose of cloning, they are usually full of intentional mistakes. Correct enough to cover repair work, but not enough to clone.
+1.

You can use the Mesa diagram as a guide; analyse each stage and compare it with schematics of Recto's, SLO, Bogner or whatever other amps you like the sound of. That should help keep the trial-and-error and debugging to a minimum.

Alright,thanks everybody for the suggestions!

okgb · Post by **okgb** » 09 Feb 2011, 23:40

Just curious to see it , but can anyone point out some examples of mistakes
on boogie schematics ?

okgb · Post by **okgb** » 12 Feb 2011, 14:30

No one ?
an obvious example or two ?

I'm curious what to look for or
if they mistake the same things all the time
if there's examples of it

blackbunny · Post by **blackbunny** » 13 Feb 2011, 06:13

okgb wrote:Just curious to see it , but can anyone point out some examples of mistakes
on boogie schematics ?

I have found some errors and discrepancies in Mesa Schematics while repairing Mesa amps over the last 20 years,
although I couldn't say whether they are intentional or not.

Mesa schematics usually take around 3 years to be released to authorised techs after the product is launched.
This is fairly common among manufacturers, probably to give them time to launch the product, get a profile in the marketplace, get favourable reviews, sell as many amps as possible before the cloners and competitors copy them, etc.

The schematic that is released can be obsolete already due to the manufacturer making changes after the product launch to fix design problems (following user and service tech feedback), respond to endorsee requests for gain or tonal changes, add extra features or even just to claim it's a new, updated model.

When servicing a Mesa amp, it's fairly common to find a couple of preamp plate resistors, cathode bypass caps, interstage resistors and/or caps that are different from the schematic. If these are among the components that have failed, the tech must analyse that part of the circuit and make a judgement as to what values to use for the repair - or contact Mesa support, if they are an authorised tech / repairer.

I have seen apparent errors or typo's in the switching matrix of early Nomad and Dual Recto amplifers, switching circuits of the V-Twin pedal, and gain stage, FX loop and reverb send circuits of Mk2C and Mk3 amps.

If you are building a clone from a Mesa schematic, you should be aware that the schematic will not represent the current models, and you should be prepared to spend time de-bugging and analysing the amp stages, and you might find that the switching does not work as it should.

okgb · Post by **okgb** » 13 Feb 2011, 15:52

Not planning anything myself , but
i guess spotting odd values shouldn't be too hard
[ with the above advice of comparison as well as knowledge ]
and you're right , one should be prepared to tweak anyway

jhelm_waterw · Post by **jhelm_waterw** » 23 Oct 2011, 15:25

blackbunny wrote:Here's the 'factory' schematic set for the Deuce.

Thanks totally for this schem.
The other guitarist in my band is having issues with the lead channel being way too noisy (we have 2 so we have a baseline)
So... guess who is the lucky bastard who gets to fix it???
Yep... me.

ansil · Post by **ansil** » 23 Nov 2011, 14:35

as far as intentional mistakes i have worked on numerous boogies mostly dual and triple recs. there are consistently Hodge podged on which cap they put in there. i understand plus and minus 20 percent theres not that much difference between 470p and 560p but 560p and .001uf consistently subbed out. .068 instead of .047uf. .047uf instead of .02. and lets not forget the awesome mislabeled resistors the 150k as a 220k no where near the color code. power resistors no where near the values more like +/- 50% and the presence control on the triple rec doesn't go anywhere close to the schematics i have found online. if i still have it i will gladly scan in the revised schematic that we spent a week re doing.

but i still think a well built Marshall sounds better than the stiletto, however thats my unbiased opinion and i only played one once.