MESABOOGIE DC-3 HEAD WITH MODS?

[MESABOOGIE MAN]

I just bought a DC-3 Head a few weeks back. I think I am the fourth owner. Anyway, I was just wanting to know if anyone may know something about this amp. My friend bought it off of Ebay. It has had some modifications done to it. On the Clean channel it has a 3-way mini toggle between the gain and treble knob and one between the reverb and master control knob. On the lead channel it has a 3-way mini toggle between the gain and treble knob and one between the presence and reverb knob. On the back it has a 2 way mini toggle on the left side of the slave output jack and then another one a few more inches from that one. The best I can tell the first 2 on the clean and lead Channel have a deep, normal, and modern sound to them. The other 2 on the front I can't really tell if they do anything. I think one is a deep, normal, and modern for the presence. Could the other one be for the reverb? The one on the back by the slave output has a P label on it. Could it switch the effects loop from series to parallel? The other one has a 1/2 label by it. Is this a half power switch. When I flip the one by the slave output it sounds more like the half power. If you make an effects loop switchable does it make a huge difference in the volume. Anyway, if I get a chance I will post some pics. I hope someone can help me figure this amp out. It sounds awesome and it is light weight! It is a lot easier to carry to practice than my triaxis/2:90 rig!

 

[MasterTrax]

Cool, let me know when you decide to sell it.

 

[MESABOOGIE MAN]

I didn't know that the DC-3 were before 1991. Anyway, It is a good sounding amp. I don't think I will ever sell it.

 

[Hanslow]

I'd be interested to find out more about your mods. Can you post any pics (internal/external)? Anyone else know any more details, what they are, where they could be done, who might have done them, etc.?

Mines completely standard (from what I can tell)

The board on mine is dated 1993 so I'm still unsure about the production years of these!

 

[MESABOOGIE MAN]

I will try and take some pics and then post them.

 

[Hanslow]

Thanks!

 

[Monsta-Tone]

It sounds like (this is without pictures) someone put some Torres mods in the amp. He has a reputation for being a hack, but some of his mods are fairly cool.

The 3 position switch between the Gain & Treble knobs on both channels most likely changes the Cathode bypass capacitor on V1, the 1st gain stage of the clean channel. This will give you different gain characteristics and a completely different feel.

The ones between the Presence and Reverb knobs could affect the Negative Feedback circuit. A certain amount of Negative Feedback is sent from the Output Transformer to the Phase Inverter circuit. The more negative feedback you have, the cleaner the amp will sound. The less that you have, the more distortion you can squeeze out of it.


Since it's an EL-84 amp, I would say that one of the switches on the back changes the Power Tubes from Fixed Bias to Cathode Bias. It may be that the guy who did the mods made it so that you could have each pair of power tubes switched independantly of each other. Sort of like a poor-man's Simul-Class.

When an amp has cathode bias, it sounds a little smoother and will break up a little earlier on the clean channel. I have done a Cathode Bias mod to my DC-3, it made the amp sound a lot more Bluesy. It did affect the headroom, or overall volume before the clean channel breaks up, though. The amp had much more headroom before the mod.



That sounds like a very interesting amp. It would be great to see some pics.

 

[Hanslow]

MM, any pictures of your modded amp?

 

[MESABOOGIE MAN]

Well I have decided to sell this head. I see someone already posted it in the Boogie Classifieds. I was going to reply to the message but it says I am not authorized whatever that means. But anyway the amp does work and the reason it is cheap is because 1. The cost for a new cab is $250 and I do not feel right trying to sell it for more. 2. That is what I paid for it. The guy did not want to sell it for what it was really worth without getting a new cab for it. 3. I am really needing to sell it.

 

[Monsta-Tone]

I posted it for you! Just trying to help out.

I think that you have to have 10 posts before you can start a thread in the Classifieds section.



I can't believe it's still there. If I hadn't spent my Paypal money 3 hours before you put it up there, it would already be mine.

I have a bunch of stuff for sale if you are interested in a trade:
http://forum.grailtone.com/viewtopic.php?t=28738

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http://forum.grailtone.com/viewtopic.php?t=28739