MarkIII top. Not as it was..

I just found this forum, and I hope this is posted on the right place.
I used to be the very happy owner of a MarkIII top. I still have the amp but I am not happy.

It is of the first year MarkIII’s that were made, or so I am told. The local Boogie guru told me that this was easy seen by some letters that are uses on the amp- -Letracet ore something.. 1982 I believe he said.. It’s a long time ago.

Anyway. I started to get a bit of noise, as I have had before, and decided to get it checked and get new tubes. It has been just like this before, and after a checkup it has always come back as the same wonderful amp.
This time I found out there was a problem with getting tubes. The ones I used was not available anymore. The right tubes were not possible to get anymore, but the TADtubes should be fine I was told. I have now tried some different tubes and.. well the noise is gone, and so are the magic. It sounds just like any other sh%&tamp..
The clean-chanel is not as bad as the lead-chanel witch I cannot describe here without breaking the forum rules..

Note: The amp-guy knows his work, so it’s not at Bias thing or something like that. He says there is nothing wrong with the amp, so my guess is that it needs the “right” tubes(?)

Maybe some of you have experience, and can help me out?

Hi,
sorry to hear about your noisy amp... you can figure out which MK III it is by looking on the back. The serial number will help. the first run of mark III's started somewhere around 14,500 to 15,000. Look for a mark on the chassis above the power cord. you might have a black dot, black stripe or no mark at all. The early ones were from 1985. you should find this on your chassis. 1982 puts it into the mark IIB range. Are all the knobs on the front pull pots? you have any pictures? You still can have a tube problem even with new tubes. maybe a microphonic tube is the problem. did you isolate the amp to make sure the noise is from the amp? and not a cable, or guitar or cabinet?

welcome to the board, and hopefully it gets taken care of

scott

Sounds like your amp needs a cap job.

but Tubes do make a huge difference, i would recormed not putting to much trust in your guitar tech since your amp came back sounding like s... get some winged C tubes or go hunting on ebay for sylvania 415 str`s the are the ones that make the mark III shine the most.

Thanks.
Yes, i might have to try find som other to check it out. The guitars sound fine on my old Acustic amp, and on my friends new AC15, so i guess its the amp.
If i shuld discribe the sound in one word i would say Anemic..

The apm is build on the Mark2Bchassi (i belive) and has Presence, and Reverb on the back.

Just had a look on the back of the amp. There is no color or mark, but the number is 15980.
You guys just helped me not to give this ting up. Thanks!

I have spent some time on this excellent forum since the first post, and I have learned a lot. So thanks!
It took some time, but at last, I have taken some pictures.






I get the impression that this is a model, referred to as an "Export model" ?



I did not expect the “dot-marking” to be done with a pen.. I expect this is the X, and the signature of Mr Bendelli ?



X62-162318


And this should solve the question about when it is made :wink:


The difference in the letters on "PULL R2" are what i referred to in the not very well written first post. As I understand it, this amp is made om Mk2 chassis and the letters are added when it ended up as a Mk3.

If someone can tell me more about it, that would be great.


Tha amp is better now. I still have tubes from TAD, that I am not completely happy with, but I want to get the right stuff the next time, so I am still reading about that. :wink: It seems to me that the 6L6 tubes from TAD works ok. The amp's got back its balls. So i have thought about trying to change the preamp tubes first, but then again, might as well take the lot..

I get the impression that Doug at Dougstubes is the man?

Thanks again for this exelent forum. :wink:

You do understand that the graphic EQ is disabled on both channels, with its front panel toggle switch in the middle position. :?:

I would also suggest bringing down the presence control to "3" or lower.

What gave the impression that i didnt know how to turn on the EQ?

In the 19years I have had this amp the presence have been in every position, but used to end up around 6-7.

Hey!
For info:
Your amp is from 1985. The written numbers are 10/85. It's the first run of the MKIII's
The faceplates from the early III's are leftovers from the IIC's, and the letters pull R2 are not engraved as the rest. The chassis is MKIII all the way, the layout on III's are slightly different than the II's, You will see this if you pull the chassis out and look at the tube and plugs layout. The front is the same as MKII's
About tubes, I would double check the preamp tubes if you got TAD's, there are some different types of the ECC83's and they sound different. The ones with partnumber RT001 sounds great, I had some with partnumber RT030, which did not sound great for my taste. There are others as well, but those two is the only ones I have tested.
About Powertubes. Sylvania STR415 (can be branded MESA STR415) or STR387 sounds BEST (no discussions needed)

Good luck

Was it the TAD power tubes that you got? The TAD 6L6WGC-STR is really a 5881 in disguise (read WGC) and only puts out about 17 watts at idle. It is a rock/blues tube as apposed to the much more venerable Sylvania 6L6GC-STR415/387. 5881 tubes definitely do not have that "Boogie Magic" for me - that put out a much more hotrodded Marshall sound. If you can't source Sylvania's quickly or cheaply, get some off the shelf matched Ruby 6L6GC-MSTR which is a excellent copy of the single getter late Sylvania, or the Winged C's which is the premium choice.

Reinhard said:

What gave the impression that i didnt know how to turn on the EQ?

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Your front panel picture.

Reinhard said:

In the 19years I have had this amp the presence have been in every position, but used to end up around 6-7.

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In the 24 years that I have owned Mark series Boogies, I have not heard the need to turn the presence above 5. Especially on a Mark III, if I use EVM-12L speakers. To each their own, though. 8)

Thanks guys.

The power tubes I have now are the 6L6GC. When I wrote first post I had the WGC's. With the GC_STR i have now there is power enough. In the preamp I have TAD's RT080, in the first,RT008, in 2,3,4, and the RT 001 in 5. From the knowledge in this forum I have the Impression that the first I should do is try to change the first and the last of theese.

For powertubes, I'm still not shure. Some say TungSol, and most say wingedC, but I think I will get some new preamptubes first.

And after that I might even turn down the precense. :wink:

Reinhard said:

Some say TungSol

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Just so you know, the TungSol 6L6 is also a short-bottle 6L6 that is designed around the 5881 as well. It is kind of hybridized though, giving closer to the power output of the 6L6GC's plate structure and the ruggedized build of a 5881 without the low power (though I haven't used them personally, I'd imagine the tone would be more "flat" sounding like a 5881 instead of boomy and compressed like a 6L6).

Preamp tubes are going to let you fine tune the mess out of your amps tone. While $$$ may buy you better tone, country of origin is going to let you know alot of how the tube is going to sound. It is going to take some good research and sourcing to find out what suits you best at the right price. I could rattle on for hours about preamp tubes...

I've posted before , with no successful conclusion
I have an early no strip mkIII , screened rythm II , simulclass , eq
Recorded examples from the 80's are good how I remember it , nice texture
good sustain , hadn't used it much for a while since I bought it new and gigged it
in the 80s/90's at best now , it sounds o.k. the decay of distorted notes sputters out a little
like a mediorcre fuzz box [ that's exaggeratted ] leaving the clean note sustaining a little longer
best I got it sounding was comparing it to a friend's mkIIC+ , but next time I fire it up it isn't
something I'd ever buy , just blah , & nothing , no nice texture , no nice sustain .

I did all the mkIII+ mods and recaped the psu , played with different tube combo's but that got confusing
nothing that instantly made it great , maybe better , but not the thing where you play for hrs before you
realize it because you're digging the vibe .

Suggested good sound tube combinations ?

Reinhard said:

I have spent some time on this excellent forum since the first post ...

I did not expect the “dot-marking” to be done with a pen.. I expect this is the X, and the signature of Mr Bendelli ?

...

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Are in the States or overseas? I only ask because I am not sure which of the power settings you are actually using for this amp. More to the point, if there is some gem of infomration could could give me based upon which settings works the best, if you are in the States, and you deal with the variance in voltage from time to time based upon the places you play (I have a meter and see anything from 112V to 124V in several of the clubs in Northern Cal.

Thanks in advance.

Dennis

@okgb. I also have recordings done with this amp in the mid 90's, and in the recordings it sounds like I remember it.

@jpdennis. I’m located in Norway. I was quite exited when I read about the possibility that it might have to do with the variance in voltage, and quite disappointed when I measured it and found it to be what it was supposed to, but with no sound improvement.

I have finally found a matched pair of 7581A Sylvania Philips Ecg that a am told was made in the 80’s. After searching and reading around here it seems like this could be what I need.
So I think that this time I am going to do everything possible to get it right.

I have been reading a lot about preamp tubes in many treads, and I’ve got good advice from a couple of good people but there are many opinions on what preamp tubes to search for.
Many people write about what tubes they get their tone from, but not so often what kind of sound, or music they use the amp for.

Another thing I have not been able to find out is this: Most of those who have found their tone use a mix of different tubes. If I remember correctly, the 12ax7’s that Mesa sold in the late 80’s and early 90’s were the same for all 5. Or was there one that was for P1, and one for the rest? What kind of tube did they mainly use to put the MESA stamp on? Not very important but interesting.

I need to find out what I should bee looking for.

SonicProvocateur said:

While $$$ may buy you better tone, country of origin is going to let you know alot of how the tube is going to sound. It is going to take some good research and sourcing to find out what suits you best at the right price. I could rattle on for hours about preamp tubes...

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Please do. :wink:

The tone I miss the most is the High energy R1- It could make a Fender twin flush as I remember it. and the posibillity do just about everything.

Cap Job: I understand that this might be something I need.

Anything else I might have to think about?