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Topic: Mesa Boogie Mark 1 early 1975 |
Ken Fox
From:
Nashville GA USA
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Posted 9 Aug 2017 4:49 pm |
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By special request I am bringing serial #121 back to life. This is a rare model with reverb and no mid control. Also no graphic EQ section. From what I have found on the net only a handful were made with reverb.
All early 1975 transformers and choke. Altec speaker. Contacted Mesa and they were stumped, had no recall if seeing one quite like it.
Got it up and running this afternoon. Carlos Santa, Black Magic Woman amp for sure
Did a filter cap job, one bad preamp rube, one bad screen grid resistor and a new reverb transformer.
Going give a good checkout tomorrow and make aschemetic by hand of the amp.
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 9 Aug 2017 8:31 pm
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Ken,
Would the schematic for that amp be different that this one?
Mesa/Boogie Mark I
Preamp (11kb)
Poweramp (16kb)
Mark IA (90kb)
Mark IB (52kb)
Mark I Reissue preamp (40kb)
Mark I Reissue poweramp (43kb)
http://www.tubefreak.com/fschema.htm
_________________
Franklin D10, Telonics (E9)True Tone(C6) pickups, Fender Steel King , Evans (FET 500LV), Nashville 400, Quilter MicroBlock 45 amp's, Telonics FP100 volume pedal, PodXT(effects only), Boss RV3(delay & reverb),Steel Guitar Black Box,Bill Lawrence cables, Walker Seat,Peterson Flip Tuner, IVL Steel Rider, IK Multimedia IRig Pro DUO for recording. |
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Josh Braun
From:
Minneapolis, Minnesota, USA
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Posted 10 Aug 2017 5:04 am
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| Awesome - I'm a huge Mesa fan! |
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Ken Fox
From:
Nashville GA USA
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Posted 10 Aug 2017 6:59 am
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Seen all those schematics. I will blueprint the amp. Even Mesa did not have a schematic, as so few were built like this. Will be easy to draw up a schematic for it. Power supply and preamp are very similar to the existing schematics. Will just have to draw in the reverb section and a few other tweaks,
Last edited by Ken Fox on 11 Aug 2017 3:36 pm; edited 1 time in total |
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Tom Gorr
From:
Three Hills, Alberta
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Posted 10 Aug 2017 8:40 pm
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Nice!
Please give more details on the Altec.. also how it sounds clean and dirty |
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Ken Fox
From:
Nashville GA USA
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Posted 11 Aug 2017 6:27 am
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| From what I have gathered the Altec was the early first choice speaker for these amps. He also has the original extension cabinet. Oddly the original speaker was reconed to 4 ohms in the main amp. Verified with a true impedance meter. |
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Brint Hannay
From:
Maryland, USA
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Posted 11 Aug 2017 10:08 pm
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I had an original "Boogie"--no "Mark" anything. The terminology when I ordered it was that it was a "Boogie Hun-Rev" ( hundred-watt, w/reverb), with graphic EQ, and Altec 12. The only option I didn't go for was the hardwood cabinet with cane grill "cloth". I went with the cream-colored Tolex.
I lived in San Francisco in 1975, and ordered it direct from Mesa/Boogie, which was the only way to get one in '75. I picked it up at Prune Music in Mill Valley, CA, the only retail outlet in the country (or the world!) at that time to pick one up. I loved it, and it was my pride and joy, until it was stolen from my car in about 1980.
I have the original schematic that came with that amp, if it might be helpful. |
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Ken Fox
From:
Nashville GA USA
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Posted 12 Aug 2017 6:03 am
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Wow, that is great info. Learning more with each post. A copy of the schematic would be awesome. If you can scan and email that I would be every so grateful. I started checking it against the earliest schematic I could find and there are small differences for certain.
Email:
info@foxvintageamps.com |
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Ken Fox
From:
Nashville GA USA
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Posted 13 Aug 2017 10:01 am
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| Thanks for the schematic. I started drawing out the amp last week and I can tell this is either right on or very, very close to the amp. I will get back to my shop in Ray City tomorrow and start checking it closer |
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Lefty
From:
Grayson, Ga.
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Posted 14 Aug 2017 11:45 am
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The speaker is like the one in my 1-15 model (only a 12). Mine has reverb but no EQ. It does have the 60/100 watt switch so I believe it to be a IIb.
Great sound, but you need a buddy to help load it.
Lefty |
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Jerry Korkki
From:
Arizona, USA
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Posted 14 Aug 2017 9:12 pm
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| Never seen a mk1 with reverb. Bought a 60w mk2b in '80. I thought I sounded like a new guitar player. Still have it and it makes me sound like a newer guitar player. A few years back, got a 60/100w '79 mk2a that sounds even better, just weighs a lot more. I'm a Boogie man for sure. In many ways it's a heavy little amp. And from my experience, great customer service as well. |
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Ken Fox
From:
Nashville GA USA
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Posted 16 Aug 2017 3:43 am
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| Got it back together. Old reverb tank was causing lots of problems. Temporarily checked it with a long Fender tank and it was awesome! Got a new short tank coming for it. What a sweet amp! Making me a new Boogie fan for sure. |
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Jerry Korkki
From:
Arizona, USA
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Posted 21 Aug 2017 5:07 pm
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| Ken, you might look for a solid wire going from the back of I think the master volume pot to the chassis. Both of my amps had some issues breaking up at volume when I added a little more bass. I replaced the solid wire with braided and problem solved. I always use another single 12" cab with my setup (I like low end) and these things sound outstanding. |
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Steven Paris
From:
Los Angeles
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Posted 21 Aug 2017 11:30 pm
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Just curious why you changed the reverb transformer. Never heard of one going bad---???
_________________
Emmons & Peavey |
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Ken Fox
From:
Nashville GA USA
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Posted 22 Aug 2017 4:45 am
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| Open primary winding on the reverb transformer. Seen that a few times as well in Fendet amps. The reverb drive tube gets it plate voltage thru that winding and it was most definitely off |
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Paul Honeycutt
From:
Colorado, USA
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Posted 27 Aug 2017 11:03 am
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That has to be an early Boogie, having no mid control. They were originally hot rodded Princetons, which had no Middle control, so that's it's linage.
I have a reissue hardwood cab MK I with no pull pots or graphic EQ, but has a "Tweed" setting on the power switch. I have a vintage Altec in it. It's a bit different, but pretty close in sound to the originals with some simple mods.
Glad to see that you're restoring that Boogie! |
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Paul Honeycutt
From:
Colorado, USA
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Posted 27 Aug 2017 11:05 am
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| A quick question. Once you get it done, is there any noise at idle? My RI has a lot of hissy noise, but once you play you don't notice it, but I'm trying to figure out if it's tubes, drifting resistors or filter caps as I'm selling it. |
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Ken Fox
From:
Nashville GA USA
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Posted 27 Aug 2017 11:48 am
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| Amp is very quiet at idle |
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Paul Honeycutt
From:
Colorado, USA
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Posted 30 Aug 2017 2:15 pm
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| Thanks, Ken. I think my plate resistors are the culprit, but I'm going to start with tube replacements. |
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