Search results

I can’t see the pictures of the amp. Though by the sounds of the amp there isn’t a lot left of it. I suppose contacting Mesa is a fairly logical choice for parts though they might be more expensive. What about John Kelly, does he have stock of Boogie parts? Maybe he might take on your amp if...

That’s interesting that several Mark 1 amps have had post production factory mods. This is the Boogie forum, there should be a lot of circuit info on the Mark 1 amps and MB should be cool with it. Regards Mark

The volume 1 should not be operating when you are plugged into input 2. This diagram best illustrates this. Mark 1 reissue preamp circuit Regards Mark

With regard to 12AX7 versus the Fetron. The diodes in first and second stage are there only for the Fetron. The diodes clamp the voltage at the cathode at 0.7v. The 1.5K resistor typically has 1 mA going through it, which means you would have 1.5v roughly across the 1.5K resistor. Regards Mark

Thanks for your reply, I appreciate that. Really, the amp has a presence control? Typically, I don't associate a 100 ohm tail resistor with a P. I. circuit having a presence control. What is the value of the presence pot? Typically Boogie’s have a 10K presence pot. The tweed P.I. circuits...

Here is an example of the Mark 1 P.I. stage using the 100 ohm tail resistor and the 820 ohm feedback resistor. I doubt there is a presence control on this amp.

Why are you looking for a Kingsnake, have you played one and been impressed? Why not open it up to various Mark 1 amps and the Rivera modified Deluxe amps sold through Sweetwater? 68 Deluxe w/ Rivera mods. Description of amp. Regards Mark

I thought Mesa tried to enforce one of their dodgy patents (the ones that were out of old mags that had no patent on them) on Marshall. I believe Marshall’s response was bring it on and Mesa did the ceasing and desisting. I think it foolish to consider the Mark 1 intellectual property when...

Parker Fly’s are a pretty interesting guitar. Mark

not to be too critical, but I’m a bit surprised that people here aren’t across the various factory mods to Mark series amps. My poison is the Mark 1 amps as I own an SOB Boogie. There have been a few incarnations of the Mark 1. One amp was the Kingsnake amp. I think they replaced the 10K...

Handy info Have a look at a few circuits, the reissue has a send and return jacks. Regards Mark

Handy circuits I understand Mesa wants to keep tight lipped about its IP. However in the case of the Mark 1 the cat is well and truly out of the bag. It amazed me that Mesa do amp mods to their amps. However, I have no idea what services they could offer. Those are my Mesa observations...

Where is the reverb tank mounted. I had a Mark 1 back in the day and the reverb tank was mounted on the back panel of the cab as opposed to being on the bottom of the cab in a bag. As a result the reverb tank interacted with the speaker and feed back. I did put the tank at right angles to the...

Hi Frederik The diodes are there for the fetron, if you still have the fetron in place stick with it as they sound good. If you have a 12AX7 then replace the diodes with 1.5K resistors. I would LOVE to know the values in the Phase Inverter stage of your amp. I have converted my Boogie SOB to...

I think the answer to that would be no. The model to look for is TR1009. I was able to find this link. https://el34world.com/Forum/index.php?topic=12710.0 Regards Mark

The link is to my efforts in rebuilding the SOB amp into something that sounds good and is similar to it's original form. I have pull pots to add the brightness switch that was in the Mark 1 and a mid switch. I will use the Dumble 2200pF value over the Mark 2 value of 750pF as I preferred the...

Thanks for your replies I appreciate your input. I liked the sound of the Fetron. It sounded better than a 12AX7. I was really annoyed when I loaned my amp to a friend's brother who returned it not working with the Fetron blown and without an apology. I bought a new Fetron but I couldn't get...

Hi There are various versions of the Mark 1, the earliest Mark 1 amp were quite bright whereas the later ones were quite mellow sounding. The S.O.B. amp was another version of the Mark 1 as was the Heartbreaker amp. The Mark 1 was also reissued some years ago too which differed from the...

The Mark 1 amps are a funny beast, I owned one but it never sounded like that, it had the Santana sound in spades. I knew people who bought the earlier amp and they were very bright. Not a lot is know why some Mark 1 amps are different to others. I wish there was more info available on them...

Hi Tiki, this isn't possible as the preamp is cascading one stage into the next. They aren't two seperate preamp stage. In the case of the Mark 1, a single triode is used to over drive the first stage of a Fender style circuit. Sorry, I couldn't give you good news.