Epiphone Galaxie 10 Project

[stump]

I've got an Epi Galaxie 10 that I'd like to modify as a project. A Marshall style sound would be great or a killer Fender tone. I'd also like to have an effects loop in it. I'm open to any suggestions and hopefully someone will have a schematic of the mod. Thanks in advance for any help.

JT

[vibroverbus]

I've got an Epi Galaxie 10 that I'd like to modify as a project. A Marshall style sound would be great or a killer Fender tone. I'd also like to have an effects loop in it. I'm open to any suggestions and hopefully someone will have a schematic of the mod. Thanks in advance for any help.

JT
Well as long as you're not asking for much. I've got a 1984 Ford Fiesta that I'd like to handle like a Ferrari or have a Mercedes ride. :rolleyes:

First of all, for what these are they dont' sound bad out of the box, and people are doing a lot of mods to these, but there are limitations to what you're going to get. There are even some kits for transformers and circuit changes you can buy off the shelf, if you think it's worth it.

To your request - 'Fender' covers a lot of ground and most of it like 'Marshall' is beyond the realm of feasibitly for what ya werkin wit. What you can probably imitate is probably to do a Champ or Princeton imitation type of thing, which is - surprise - pretty much what this amp is in the first place, a baby-Fender-clone. If you're talking bigger amps you're talking different tube types and push-pull configurations with bigger transformers and more gain stages instead of single 12AX7 and single Class-A 6L6 which is what you got.

I've got an Electar 10 that I keep poking at from time to time (close to the exact same thing) and ultimately I cleaned it up a bit to convert some of the gain to touch and tone. Still sounds like a little amp with a teeny speaker though, and the best thing I can do for it is plug it into one of my 2x12 or 4x12 cabs, when it starts to sound pretty decent actually.

I'm guessing a speaker upgrade would be the biggest bang-for-buck first, then if you want a bit more grit and can put up with less volume you could use a 6V6 instead (re-bias of course). Stick a switch in to take out the negative feedback and you'll get more raunchy tweed tone (come to think of it that might be another good bang-for-buck - assuming it doesn't oscillate). You can fiddle with the pre-amp plate and cathode resistors to crank up the gain on both stages (I went down on the Electar) which will give you more pre-amp distortion, but with the master volume you can get a ton of that already. You can put in a Marshall 'treble-peaking' cap bypassing the coupling resistor between the pre-stages - I didn't like what that does to a small amp & speaker, but different strokes, so who knows...

[stump]

The biggest problem that I have with the amp is that the preamp gain sounds like crap... I'd like it to be smoother. I do agree that the speaker swap is probably be the best place to start as I've run it thru my 212 cab and it does sound better. Maybe the 6v6 will smooth out the gain characteristics. I don't recall if there is a bias pot in it. Maybe that would be a good thing to put in, if it doesn't have one, and external test points. Maybe part of the problem is the bias on the power tube. Maybe the Fiesta just needs tires:)

[vibroverbus]

The biggest problem that I have with the amp is that the preamp gain sounds like crap... I'd like it to be smoother. I do agree that the speaker swap is probably be the best place to start as I've run it thru my 212 cab and it does sound better. Maybe the 6v6 will smooth out the gain characteristics. I don't recall if there is a bias pot in it. Maybe that would be a good thing to put in, if it doesn't have one, and external test points. Maybe part of the problem is the bias on the power tube. Maybe the Fiesta just needs tires:)
Hey, a little economy tires with fat sticky tires can be fun to blast around in for yucks. Have we beaten that analogy to death yet?..

A lot of pre-amp gain with a turned down master volume into a little speaker isn't a great recipe for me either - that's exactly why I toned down my Electar.

A 6V6, IMHO, might tend to be brighter and raunchier, not quite as warm as the 6L6 which might go in the wrong direction for you, but might sound great. The benefit would be the lower power letting you crank the MV up more at any given volume level. In addition to the bias issue to convert, you'll also have the output resistance issue - if the 6L6 was driving 4ohms, the 6V6 will want 8ohms through the same transformer.

Hey - don't know what prompted me to do this, but these amps are virtually identical except for a few minor differences - guess Gibson just made a few minor changes when they rebranded it as the Epi...
http://www.musicyo.com/planet/tube10.pdf
http://www.freeinfosociety.com/electronics/schemview.php?id=2286

Single biggest diffs I can see are the screen resistor - "std" 470 for you but a 100k on the Electar, and the coupling cap value and attenuation voltage divider between the pre-stages on the Electar, and the cathode BP cap values. I'm on the road so can't ref: my notes on exactly what I did and was a while back so I don't recall exactly but there are some web pages with mods for the Electar that will be transferrable, although it seems a few of the common mods bring the Electar in line with the Epi. Here's a couple of them - I know I didn't do exactly as they did but I'm fairly certain I did trim the cathode resistor on the first stage down quite a bit - might have even been to 1k or 820, but don't quote me... I do remember finding that taking out all the attenuation between stages cranked up the overdrive too much again... I also had the NFB switch in place, and like these guys, found minimal effect from it so it's gone with no NFB now.

http://people.cornell.edu/pages/mt24/Amp/homebrews/electar/sound_better.html
http://www.geocities.com/rdiubaldi/electar.htm

[Mike9]

I have a Galaxie 10 and I built a new larger, resonant cab for it, installed vintage RCA 6L6GC and a Mullard 12ax7, and put a 12" Legend alnico speaker in it. People that play it really love the tone. I bought a Hammond 125ESE output tranny to install recently, but other than that there are no mods I've been able to find for them.

Some of the mods you see for the Electar 10 were incorporated into the Galaxie. I have an Electar as well and I'm going to do Riff Ron's mods to it and build it into a head.

Here's a pic of my Galaxie now:
http://www.deanguitars.com/userpics/lib5/gaxi1.JPG

[stump]

Thanks guys. I'm going to try running it thru my 112 cab and upgrading the tubes.

[Gaz Man]

I'm new here, but I've been using my Galaxie 10 for a couple of years as my bedroom/practice amp. I run the master wide open with a Weber Mini Mass to control the volume. I've installed a THD Yellow Jacket which converts it from a 6L6 to an EL83. Not only does this reduce the power and stress on the smallish OT, but it smoothes out the breakup and gives the amp a little different flavor. I've tried a 5751 in the preamp, but it didn't drive the power tube enough. I've gone back to a 12AX7 and been very happy with a Tung Sol tube.

I'm planning some mods for the future as follows:
Change R3 from 2.2K to 1.5K for a little more gain in the first stage.
Bridge C6 so the tone stack will work like it should.
Remove R15 to omit the NFB.

Any comments or suggestions to these mods are welcome!

[sumitagarwal]

Hi guys, I'm new to this forum. Interesting thread, and that's a beautiful enclosure you have for your Galaxie 10.

I've had mine for a while and I long ago changed out the tubes (including using a Yellow Jacket to get the EL84 in there) and I have a custom-made Weber alnico 'Blue Runt' speaker (not a lot of clearance in the cabinet). Sounds great, but I'm looking for a little more versatility. I do a lot of my 'amping' in my computer and like to keep the Galaxie around so I never lose sight of what a real amp sounds and feels like, but recently I've been wanting to try a hybrid approach.

Does anyone know how I would install a preamp bypass option in the amp (essentially an FX return)? My plan is to have a switch so that I can feed the output from my computer straight into the power amp in the Galaxie and then into the speaker. Any chance I might kill myself trying to do this? :crazyguy

[jumpchamp]

yep, bringing back an old thread :)

i updated my galaxie recently - had never built any sort of cabs before, so figured, what the heck. so i made a head and a slightly oversized 1x12 with a slant front. the vinyl i found for the covering was actually named 'galaxy' so i couldn't pass that up!

http://i11.photobucket.com/albums/a187/subjab/ampandcab.jpg

http://i11.photobucket.com/albums/a187/subjab/ampandcab2.jpg

speaker is a tone king with a hemp cone (made by eminence).

i want to try some different power tubes in here. definitely going to pick up a 6L6GC of some sort - any chance i could run a KT-66 in here? i'm guessing not. any other tube suggestions from anybody that has one of these?

[stump]

Pretty cool. Makes it look old(vintage). I really don't play mine at all anymore but I put in some old stock tubes and ran it thru a 112 cab. Definitely sounded better that way. You should be able to run a KT66 in it. I think I'll pull mine out and try it.

[jumpchamp]

thanks stump! i learned a lot building the cabs and putting the covering on. already know what to do differently for my next project like this. but i'm really satisfied with how it turned out. definitely sounds better through a 12 inch speaker and the bigger cab.

let me know if you give that KT66 a whirl and if you get any more volume out of it that way. i should probably replace the transformer too to really take it to the next level. we'll see...