Géraldine FINISHED!!! (6L6 Express)

camden_guitarist · Post by **camden_guitarist** » Wed Apr 01, 2009 8:56 pm

Hey there everybody,

Well, finally she's done! Fired her up last saturday with my pal (Soudoblack) and tested a few output solutions, we settled for the 6L6's which are giving me roughly 32 W I think, might go back to the EL34's if I need some more power.

My pal changed the second cathode cap to 1mF which I have put back for more extensive testing with the changing of the EQ settings.

I also put back in play the 3rd gain stage before the PI, my pal says it only amplifies noise from the input and adds nothing, I am gonna check all that out for myself, I didn't think she lost gain without it but we'll see, better to check with the stock Wreck.

All in all I'm quite satisfied with the result, taking into account that my soldering is hardly worth writing home about and I that I made a few mistakes wiring her up...it's my first project ever and she has absolutely no hum whatsoever and that was my biggest fear, that it would be a howling mess, I know, it's better to start off with something simpler for a first project, but there you go.

I'll record some samples this friday when I go into the studio for rehearsal with the band. http://camdenmusic.net

Cheers,

Paul.

ampdoc1 · Post by **ampdoc1** » Wed Apr 01, 2009 10:07 pm

My first TW (late 2004) started out stock, but I didn't like the amount of hiss. I finally ended up by changing my tubes for lower gain at the front end, and recovering gain before the PI with that "open" 12A*7 stage.
Much quieter, and it still had that ridiculous touch sensitivity and harmonic response. One afternoon a local guitar teacher was playing and let it feedback. As it took off, there were clearly 3 over/under tones besides the played note!

These are still my favorite amps.

Schematic attached. As you can see I added a few other features,..none of which degraded the sound.

ampdoc1

RevD · Post by **RevD** » Thu Apr 02, 2009 1:53 am

Wow that looks nice. What type of on/off, SB switches are those? Pretty heavy duty.

Regards,

Rev D.

M Fowler · Post by **M Fowler** » Thu Apr 02, 2009 2:10 am

camden_guitarist,

The amp looks good and this was your first build, nice.

I played around with using 6L6s as well, right now I am running the EL34s.

Mark

camden_guitarist · Post by **camden_guitarist** » Thu Apr 02, 2009 4:03 am

Thanks for the input guys. RevD, the switches were bought over here in France like most of the components except for the signal cap set which I got from Allyn. I bought them with the specs mentioned in the BOM so they are right on and switch really nicely without any effort but firmly if you get what I mean.

Just gotta do the cab now, I'm gonna try one in pine first since I also have never done any woodworking

If that one works out and I find that working wood is something I can handle I'll make one out of oak, I can't seem to get my hands on cherry in this country it seems

One more question, on the BOM it says 'self adhesive' cork for the bottom plate, would it really make a difference if I glued it, again, I can't find that stuff over here

Cheers and keep on rockin', I'll get up some clips ASAP.

Paul.

Mark · Post by **Mark** » Thu Apr 02, 2009 8:10 am

Nice build and it has your own touches which is always a good thing.

Just out of curiosity what wattage rating is the bias pot, it reminds me of the 1/8watt pots I saw years ago. The bias pot is the most important pot in the entire amplifier.

Just my two cents.

M Fowler · Post by **M Fowler** » Thu Apr 02, 2009 12:19 pm

You can use what ever wood you find and build it anyway you can. Find some local wood that has lots of figuring, the figuring will pop out when you stain it and clear coat the cab. You can use a butt joint if not able to do the mitered corners. If not satisfied at least you tried yourself.

The cork can be glued in a few spots rather than completely if you want, as long as it is there to help absorb vibration and stays inplace when you mount the chassis into your new self made cab.

Mark

camden_guitarist · Post by **camden_guitarist** » Thu Apr 02, 2009 2:23 pm

Hi Mark (Abbott),

The rating is 0.15W for a 22k lin pot. And the switches are rated 15A/250V. Thanks for all you guys' input and compliments, I appreciate it. I'll get working on the cab and I'll let get back with some pictures and clips soon.

Cheers,

Paul.

camden_guitarist · Post by **camden_guitarist** » Thu Apr 09, 2009 1:20 pm

Hi guys,

Well, the clips aren't up yet since the recording I made last weekend was SHIT. Small studio, and not a good setting to mic it up, I'll give it another try this saturday in a nice studio over here in Montrouge (southern suburb of Paris for those of you who wonder) It's a cool studio and all the big names who come though Paris on their tours and wanna jam one more time before their gigs come in this studio.

A nicer gutshot for the time being then:

Until very soon everybody,

Cheers,

Paul.

FYL · Post by **FYL** » Thu Apr 09, 2009 1:44 pm

What type of on/off, SB switches are those? Pretty heavy duty.

Apem 600 series. Some of the best available.

http://www.apem.fr/index.cfm?page=toggl ... langueID=2

camden_guitarist · Post by **camden_guitarist** » Thu Apr 09, 2009 2:37 pm

Hi FYL,

Sure thing, those are the ones, you're in France too? If so, where? I got most of the hardware and simple components at St. Quentin near Gare du Nord in Paris. You've build a Wreck as well?

Cheers,

Paul.

gahult · Post by **gahult** » Thu Apr 09, 2009 4:21 pm

Paul,

For the cork. I picked up a roll at our local Office Max, cut it to size and used contact adhesive (rubber cement for tire patches) painted on the cork and the metal bottom. I did the entire surface off both, 2 coats on the cork as it soaks in. Let it dry 10/15 min. and place and stick. Good to go. I trimmed the cork for the screw head, just kind of a slot from the outer edge. I'm no good cutting lil' circles.

Gary

M Fowler · Post by **M Fowler** » Thu Apr 09, 2009 5:32 pm

I found the adhesive cork roll in the cabinet section at Lowes. I did as Gary did and used an exacto blade to cut around things, but next time I am going to use my gasket hole punch set, forgot I even had one. I gave up on mechanics and street rods to build amps.

Mark

Ron Worley · Post by **Ron Worley** » Thu Apr 09, 2009 7:14 pm

BTW, The cork was not used by Ken Fischer, it was a mentioned idea here on the forum long ago to help with the mechanical vibration issue. I added it to the BOM as an option because it seemed like a very sensible thing to add.

camden_guitarist · Post by **camden_guitarist** » Fri Apr 10, 2009 2:25 pm

Hi there everybody,

Got some cork yesterday and some NeoPrene glue, in the store they told me it should work to stick it to the aluminium bottom plate. I've constructed a makeshift cab for the moment, not very nice looking but it'll do to transport the amp, buttjoint construction pine...oh well, I'll have to contact a woodworker over here to make me a real cab coz I just don't have the tools and I ain't gonna mass produce these things so to buy all the stuff myself does not really seem an option, neither do I own a workspace to do all this stuff, and I'm already driving my wife crazy with all this stuff

Cheers and thanks for all yer info/help

Paul.

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