VJ Combo Cab

[sunvalleylaw]

Wow M29! The finished product is even better than I thought, and given your talents, I expected greatness. I LOVE that grill cloth!

 

[warren0728]

wow...what a beautiful looking amp! Where should i ship my valve jr. combo for a face lift?!! R

ww

 

[6STRINGS 9LIVES]

M29 , great job , nice design and choice of cosmetics , beautiful ..is it open back or sealed ?

 

[Tone2TheBone]

Oh wow! I just went back and looked at this thread. Dang that came out cool as hell! You're very creative!

 

[tot_Ou_tard]

Fantastic! If I ever need reconstructive surgery I think I'm going to talk to you first. I'll bet you can do a better job than almost any doctor.

So Spud, what color Naugahyde (er, I meen Tolex) ear do you want? Marshall green might clash with your tweed nose.

 

[ted s]

wow...what a beautiful looking amp! Where should i ship my valve jr. combo for a face lift?!! R
ww

Hey, now THAT sounds like a plan ! Good way to make some gas money ?!

 

[warren0728]

picturing m29 and dvm holding signs by the side of the road..."will build for GAS money"

ww

 

[duhvoodooman]

Hey, I never thought of that! Maybe I should take the ZYS "on the road"!

 

[ted s]

Maybe a little mobile pancake house as well ?

 

[M29]

Man...you guys are giving way more credit than I deserve . I am going to take some pics of the messups I did on this cab. Some of my corners have gaps, which are somewhat covered by the corner caps I have a large gap on the bottom where the tolex meets. I had to re drill a few holes that mount the speaker baffle on because I drilled into other screws that I used for bracing on the inside. Let me see... I had to redo the front face a few times because it did not line up right with the amp, bad planning and rushing the job. Now...do you really want me working on your stuff

Thank you all for the kind words I really appreciate it. It sure is fun though and I now have my Hammond transformer in (thank you oldguy for the help) and I have to say all VJ's should have come with a Hammond transformer, it is a huge improvement! I love it! I could not put the guitar down today while I had some time alone. I am now not lacking in bass. The whole sound has richend up like you would not believe. The best way I can describe the sound is to compare it to your computer monitor. You know how the 257 colors looks now compared to the richness of color of the new systems? That is what I think describes the sound of the tranny swap. I don't know what it is but there is a lot more sound throughout the spectrum than it had before and the sound is tighter. Maybe it is harmonics or whatever but it sounds so full and rich I just love it. I do think I could use a bit more top end sparkle but I think there are some mods that might address that.

6STRINGS 9LIVES, Here is a pic of where I am at with the rear panel.

I had a chance today to play loud with the back panel and see what sounds I could get. If I left the panel off completely, I got a pretty thin sound with a pronounced midrange. If I put the back totally on, I got a pretty flat response with good bass and a slight dip in the midrange. I messed with moving it around and around and I came up with this compromise, which I am pleased with although I would like a bit more bass response but I don't think I am going to get any heavy chunkin sounds with a 12 inch in this small of a cabinet. Overall I am please so far with the sound and that is with the Fender/Eminence Hot Rod Deluxe stock speaker. This made me wonder if a transformer swap on my Hot Rod would help out with the stock speaker. It sounds pretty good to me now.

I hope to get more pics up tonight of the tolex going on and maybe some of my messups

Thanks again guys, you are too kind:R
M29

 

[warren0728]

Maybe a little mobile pancake house as well ?

now you're talkin'!!

ww

 

[Spudman]

M29
What you need is a miniature folded horn design for the back panel. That would increase your bass.

 

[M29]

Hello Spudman,

Yeah that would work. I remember reading an audio magazine back in the 60's of my dads and seeing a guy that was trying to get the ultimate bass response from a 15 inch speaker. He mounted the speaker in a hole in the back yard and had a horn that he built from wood and what not that entered his stereo room from the back of the house. He had some awesome bass response but I bet he had a lot of neighbor response as well

M29

 

[6STRINGS 9LIVES]

Again beautiful job M29 .. If yo build a sealed back cabinet , ( one with no opening in it ) it would definitely improve the bottom end , you can use foam inside the enclosure to help dampen the reflected sound .. I've got some pics of a similar sealed back 1-12 combo that uses this design if you'd like .. 6S9L

 

[M29]

Hello 6STRINGS 9LIVES,

Yes I would like to see that cabinet. Do you know what kind of speaker it has in it?

Thank you for the help.

M29

 

[M29]

I have some images of the tolex going on this cab. First off I have not done this kind of stuff in quite a while and in this first step I drew a perpendicular line on the bottom short side to start my tolex install. I recommend that you do not do it this way and I would do it differently the next time I do it.

What I would do instead is start with a long side and work my way around to the last short side, (the bottom would be best). This way I could take both ends and overlap them and make a cut through both pieces. Then take out the cut off parts and then when I glue them together to make a perfect seam.

Now...lets say this image is a long side instead of the illustrated short side.

I try to get the wood and tolex perfectly clean so there will be nothing poking through when I glue it down. Also you want to get all the sanding dust off so the glue has good adhesion. I use a damp cloth and when that is dry I use a lint roller.
The best glue I have found for this is 3M's General Adhesive spray, which can be found in automotive supply stores. This withstands heat very well being made for automotive interiors, which helps when you play outside in the hot sun.

Here is a long side cleaned and glued, ready to apply the tolex. I did this alone because it was a small job but I could have used some help holding the tolex off the glue while I place it like I wanted too. Once this stuff is put together it is very very and I mean very tough to get back off. Actually impossible if left very long to dry. Sticking real good is what we want but if you misalign it, it is real bad.

I use a towel to run across the tolex to seat the glue. A rubber roller would probably be better.

Here is the top being glued up. The tolex fits nice and tight to the curves with this type of glue. Here you can see the mounting holes for the amp. These will be cut out later on and plugged with the plugs that come with the VJ head cab.

Well I hit the limit on images so I will continue this in another post.

M29

 

[M29]

I like to wrap the sides now. In this image I have cut a short angle at the end of each side, so I end up with a nice 45 degree seam at each corner. Then I cut a straight cut going in to the corner to the mounting strip. Next I put glue on both pieces and let it dry the appropriate time per the instructions on the can.

Here the same thing is done with the top. I put newspaper and masking tape where I don't want the glue this stuff is very sticky as you will find out on your hands.

You will have to make angle cuts to get a good fit in angles and corners like this.

Now it is time for the hardware. I used a rough grit disk grinder to hack off the ends so the steel caps will fit tight to the vinyl. I learned this trick when I took the corner caps off the Valve Junior head cab. Worked great!

I had bought some rubber feet for another cabinet a while ago and did not use them so they worked great here.

I wanted to place the pads out as far as I could because this cab is so narrow so I used one of the screws that held the steel corners on to mount the rubber pads. I did have to cut a section out of the pad so it set flat when mounted with the steel corner.

Then here again is the almost finished cabinet.

I hope this helps.

M29

 

[sunvalleylaw]

That is really cool! Great explanation. I love the combo look of the guitar and cab.

 

[ted s]

Nice tutorial M29 !

 

[oldguy]

M29, That combo amp looks great! You're now a boo-teak amp builder w/ a one of a kind custom amp in your collection... way to go, bro!
Thanks for posting the pics, that is good info you're sharing. Those little tricks and tips make projects like this go a lot smoother.

Thank you all for the kind words I really appreciate it. It sure is fun though and I now have my Hammond transformer in (thank you oldguy for the help) and I have to say all VJ's should have come with a Hammond transformer, it is a huge improvement! I love it! I could not put the guitar down today while I had some time alone. I am now not lacking in bass.

I do think I could use a bit more top end sparkle but I think there are some mods that might address that.

This made me wonder if a transformer swap on my Hot Rod would help out with the stock speaker. It sounds pretty good to me now.

M29

Glad you like the Hammond swap. I don't think an OT swap will change alot in the HRD, Fender didn't screw up the HRD design like Epi did on the VJr, AFAIK.
An EL84 tube "likes" to see around 5k impedance from the OT, Epi used an undersized OT, but with a whopping 7.5k imp. in the VJr, so changing it to a big, beefy Hammond w/ a 5k imp. is going to really improve that frequency response. Then you get that tighter, smoother tone throughout the sound spectrum.

 

[tot_Ou_tard]

Thanks for the pic's & description. I love to see how it was done & it'll be invaluable for anyone wanting to do something similar themselves.

 

[Big K]

thanks for the info, outstanding work....

 

[Tone2TheBone]

I never get tired of complimenting you on your detailed and comprehensive photo tutorials. Simply amazing. Huzzah!

 

[6STRINGS 9LIVES]

M29 heres a pic of my Traynor ygm-3 , you can see the foam used to surround the inside of the enclosure ..6S9L

View attachment 1120

 

[Robert]

M29, thanks so much for posting this - it is fantastic info for all of us, current and/or future fretters!

 

[r_a_smith3530]

Wow M29, I just came across this post. Beautiful job on the cabinet. Same goes for the strat/'51 leaning against it. You have a combo to really be proud of. While reading through your posts, a couple of ideas came to mind. I noticed that you used a lot of automotive supplies in your work. When it comes to cleaning the cabinet and tolex prior to spraying on the adhesive, wouldn't automotive tack cloth work better than the method you used? I know from doing a fair share of automotive painting over the years, that tack cloth picks up even the finest of sanding dust. Also, when laying out the Tolex, instead of using a towel, how about trying a rolling pin, like they use in a pizza parlor? Anyway, just a couple of thoughts to share.

 

[M29]

Hello,

Thanks all for the kind words, you are giving me way too much credit.

Thank you for the image 6STRINGS 9LIVES of the foam surround in your Traynor, I will add this to mine.

Yes, r_a_smith3530 I think autobody tack cloth would work good for taking the dust off the surface. Also vacuuming helps get the dust out of the pores and also a blow gun. It is actually best to use as many of these ways as you can because a small layer of dust can really cause trouble with adhesion.

I mustered up a couple images of my mistakes and maybe some solutions to them, this is what you get for rushing a job.

In this image you see my rather large gap on the bottom. This could have been avoided by lapping the two ends and cutting through them both and then removing the excess and gluing them both down at the same time for a perfect seam.

Here is one of my sloppy cab corner gaps. Rush rush rush...

This shows where I cut too short on my wrapping of the tolex around this curve. I actually saw this on a couple Fender amps as well but they put a layer of tolex under the gap on purpose to hide the wood underneath. You can see a fairly large gap between the amp and the front face. This was intentional as I was going to add piping here but now I don't know if I will or not, it might make it look too gaudy.

This image shows where I did not even up the gap around the back cover of the cab. There is a tight spot where the tolex gets pushed back when I put the back on. If I would have taken a plane or a sanding block with rough paper on it I could have avoided this. It is here to stay now that the tolex is on and glued down. This will probably tear in time if I have to remove the back very much. I think I will take it back off one more time to add some foam surround and then put it on for good. Or at least until I blow the speaker. But with 5 watts, I don't expect that to happen any time soon:R

I just wanted to mention that using solid board instead of plywood is not the best thing to do unless you are sure that the wood is very very dry. The reason is that when a solid board is used you run the risk of a crack, which will show up in your tolex and may also weaken your cabinet if it is in an area where there are no screws holding it together. I used poplar board from the local lumber yard against my own judgment but I wanted to get this done in a timely manner and I am now hoping that it will not crack. I spent a good deal of time looking for as dry and straight wood as I could to eliminate this problem but you never really know until you give it time. Actually it is a good idea to seal the inside with paint or something to help keep moisture from absorbing into the wood from the back side, the tolex will keep it sealed pretty good on the outside.
If you look at the end of a solid board you will see the grain pattern and if the board is cupping at all. It is sometimes rough to find a solid board that is not cupping and if it is not real dry it may end up cupping later on. What happens here is when you screw down the wood you put pressure on the ends of the board and if there is a cup in the middle is might crack on you. Here is an image that helps illustrate what I mean.

Because plywood has opposite layers of wood that are glued together, they all help keep the other layers from twisting and warping, which makes plywood a good material to use for a cabinet.
Now...There is also a lot of controversy, which I will try to avoid concerning the makeup of a speaker cabinet. Some like plywood and some like solid board. Some do not want the cabinet to add any sound at all to the speaker from resonates and some audio companies in the past have gone as far as adding a layer of sand between the wood layers of a cabinet to keep it from resonating. Some prefer baltic birch plywood specifically. I have heard that some of the guitar amp companies use solid board in their cabinetry in the past. This subject I do not know much about but have recently read on the web somewhere. Personally if I were to take my time, I would use a good stable plywood like baltic birch or fir or luan, Stay away, please stay away did I say please stay away from pine plywood? This plywood warps real bad and could cause problems later on. I would feel pretty secure with any of the other plywoods mentioned.

I hope this helps some. I am sorry if I have drug this out way too long and it was not my intention to do so but I thought some of this stuff should be mentioned and again, I really appreciate your kind words on my work.

M29

 

[WackyT]

How does MDF do in a speaker cabinet?