Road King Series 1 Tube Question

[Pdmi]

Hi everyone. I'm hoping that someone can help me. I just got a used road king series 1 and it's killer I love it! The other day I switched it on and wasn't getting any output. I tried a few things and after shutting it off and turning it back on it worked. So I was playing it and I noticed that the reverb isn't working any more. I turned it on today and started to play and once I got it to give me volume the clean channel sounded like it had a lot more gain than normal, and the whole amp seems to have lost a bit of its definition and clarity... Long story even longer (sorry), I think I've got a preamp issue. I want to replace the preamp tubes and test my theory here but it's a series 1 combo, and well much to my embarrassment I can't figure out how to get access to the preamp tubes. Is there a way that I can seperate the sockets from the enclosure so that I can have room to work in there? And also, one more real stupid question. Should the amp be off or in standby when changing the preamp tubes? Sorry for all the questions but it's my first time with a Boogie and I don't want to screw this amp up, I'm already attached to it emotionally. Thanks!

 

[primal]

As far as standby or off, just set it off. It may not be necessary, but atleast you know it won't hurt it. Besides, unless your real good, you are going to have to remove the power tubes anyway to get to them.

As far as access, I do the following.

First I remove the power tubes. I then use a hand held mirror (I borrow my daughters), and just reach under there. The preamp covers come off real easy. Just twist them (THE METAL COVERS, NOT THE TUBES) and when they hit the keys just right they will pop off as they are spring loaded. The only hard one to get at is the one behind the output transformer.

Now, option two which is probably easier in the long run but can be a real ***** is to pull the electronics out.

You can just remove the four screws on the top , BEING EXTRA CAREFULL NOT TO LET THE ELECTRONICS FALL OUT.

This can be a big pain in the butt, but once you have it out, you can hook it back up to the speakers and easily have access to all the preamp tubes.

Putting it back in is even worse.

I usually use the mirror method.

The tube assignment for the preamps goes as follows.

Starting at the fan you have V5 and the numbers go down in order. When you get behind the transformer it is of course V1.

Here are there assignments (Got this from Marcus at Mesa since the Series 1 Roadking does not have a tube assingement chart in the manual even though it tells you to refere to it and the Series 2 has more tubes)
V1-A input stage for all channels
V1-B 2nd gain stage for channels 1 & 2
V2-A 1st gain stage for all channels
V2-B 1st gain stage for channels 3 & 4
V3-A 2nd gain stage for channels 3& 4
V3-B 3rd gain stage for channels 3 & 4
V4-A effects loop send stage
V4-B effects loop return stage
V5-A & B phase inverter/ driver tube

Good luck!

If you are new to tube amps and are unsure about something, ask first. It may save you loads of money in the long run! :wink:

I also have a good picture of the tube layout so PM me if you need it and I can email it to you since I am not able to attach it here.

 

[Pdmi]

Thank you so much! I really appreciate all your help. I actually got smart yesterday and called Mesa and spoke with Marcus as well. He provided me with a tube assignment chart for it. But thanks for the heads up on the removal process. I've got my new preamp tubes coming in tomorrow and as soon as I figure out which power amp tubes I want I'm going to order them. Thanks again!