Lil' dawg 5e3 D-Lux/ home-made combo cab build

[Dave_P]

As I mentioned the other day I have a new amp in the works. I was going to build a 5e3 from a kit but my electronics type projects never seem to come out quite right. So, after a lot of research, I went with Jim at Lil' Dawg amps. Great price, great service and I've read nothing but good things about his amps.

I went with the 5e3 D-lux build with 25watt OT, sozo blue molded coupling caps, and a switchable "Paul C mod" which is supposed to give you more headroom (I wanted the option of the regular 5e3 as well, hence the switchable)
I'll post pics up as they come in, should be done pretty quickly. I will also be building my own combo cab for the chassis, really want to do a 2x10 but I do have 2 12" alnicos without a home so maybe 2x12, we'll see.

Here's my amp so far







-Dave

[blargfromouterspace]

Sounds like it'll be a nice amp Dave. I'm very keen to hear about the head room with the bigger OT - that's the only problem I had with my old 5E3.

[Dave_P]

Sounds like it'll be a nice amp Dave. I'm very keen to hear about the head room with the bigger OT - that's the only problem I had with my old 5E3.

That's exactly why went with this build, the 5e3x2 seemed like it might be a bit much for my needs so this was an in-between option. The larger OT will let me run 6L6's more easily as well if I find I need more headroom than I can get with the 6V6's. Can't wait to try it out.

-Dave

[Michael-GnL-Michael]

.

Would someone define "OT" please?...................Nevermind "Output Transformer" I read on the Dawg webpage.

Thank you,

Michael

.

[Dave_P]

Pic Update!









Should be all wired up this afternoon, just waiting on the output transformer to arrive.

I've put the cab on hold because I can't decide on the speaker configuration I'd like to go with. I've always had a thing for 10's so my first thought was a 2x10 combo. The trouble is the 10's I have are 8ohms each (so I can only get 4 or 16 wired together). I do have 2 12" alnicos I pulled from an old organ that would work, not sure how they'll sound and it'd be a little more than I wanted to lug around, but I may have to go with it for now. The other thought was to get 2 more 10's and have a 4x10 but again with the weight/size issue.

-Dave

[blargfromouterspace]

There really isn't much inside these beauties, is there!?! I really, really want my old one back right now, they're such great amps!

[Dave_P]

Not much at all Jamie, can't wait to hear it in person.

Here she is all wired up


Warming up on the variac tonight, test drive tomorrow then I will be anxiously awaiting it's arrival

-Dave

[yowhatsshakin]

Neat job Dave!

- Jos

[Dave_P]

Thanks Jos, I wish it were my work Someday I'll get around to building my own chassis, for now I'm sticking to cabs.

A quick update, according to Fedex the amp should arrive next Tuesday. I just picked up a 15" Weber Blue Dog off of CL for less than the cost of their signature series 12" (+shipping). Wasn't planning on another 15" but it is almost brand new and if it's not my cup o' tea I'm pretty sure I'll at least break even on it.

Also bought a 12' x 12" x 3/4" #2 pine board from my local lumber yard. Slightly more expensive than a big box store but MUCH nicer wood and they cut it up to the lengths I wanted. Considering I'm going to cover the combo cab, the clear pine wasn't worth the extra expense.

Stay tuned for a speaker shootout and combo cab build pics!

-Dave

[Muleya]

Sounds like a cool project. At first I thought you were building the amp, too, and I was going to be impressed that you punched your own chassis! That's the part that intimidates me the most...much of the reason I've chosen to rewire my homebrew amp within the same chassis when I wanted something different!

I've built some of my own cabs, too, so I'm excited to see what you put together!

Sounds like you got a deal on that Weber...hope you end up liking it!

Looking forward to some clips and pics!!

[blargfromouterspace]

Very interested to hear how it sounds through that 15" speaker.

[Dave_P]

Muleya, I really wish I had built it myself, unfortunately, I'm pretty short on time these days. It's still on the list though, maybe when my daughter gets a little more self sufficient. At this age I keep take my eyes off her for a second

Jamie, I'm planning on posting a blind test with all the speakers I have available to me. The amp builder said it's ok to run at 4ohms, though I wouldn't want to run it that way all the time, so here's what I have to test out:
Weber 15a150b 4ohms alnico
Weber signature series 10 and 10s 4ohms ceramic
2 1960's Rola 12" 8ohms alnico (out of an organ)
Weber 15" Blue Dog 8ohms ceramic

should be interesting

-Dave

[louis cyfer]

hook up the 2 4ohm webers the 15 and the 10 and you will have the best of both worlds. put the 10 in one corner above the 15, it won't take much extra room. i don't think you can beat the combination of a 15 and a 10.

[darwinohm]

Louis, I was thinking the same thing. Hook them in series and you have 8 ohms. Should sound rich.-- Darwin

[Michael-GnL-Michael]

Muleya, I really wish I had built it myself, unfortunately, I'm pretty short on time these days. It's still on the list though, maybe when my daughter gets a little more self sufficient. At this age I keep take my eyes off her for a second

There are all sorts of indicators that seem to imply you are building this amp yourself, like this being the project section of the forum. Here and there you said something that sounded odd, the amp will be arriving or is being shipped by FedEx or something and the quoted post below. That is an impressive thingy that the amp-in-process is mounted to like rebuilding a car engine. So you are not building this amp with your own hands? Do you buy the kit and have it assembled somewhere and that is somehow less expensive than other amps?

Please answer A or B:
A. Dave is building this amp with his hands and some tools.
B. Dave is not building this amp with his hands and some tools.

Thanks,

Not much at all Jamie, can't wait to hear it in person.

Here she is all wired up


Warming up on the variac tonight, test drive tomorrow then I will be anxiously awaiting it's arrival

-Dave

[Dave_P]

I was going to build a 5e3 from a kit but my electronics type projects never seem to come out quite right. So, after a lot of research, I went with Jim at Lil' Dawg amps.

Sorry for the confusion Michael, the answer is B. I am not building the chassis I am building the combo cab. I put it in the project section because of that and included the build pics sent to me by the builder. I suppose I could have split it up and put the chassis pics in a separate thread under general music but I didn't see the point in two threads for one project.
Here is a link to the amp builder's site http://www.littledawgamps.com/

Louis/Darwin: I really like the idea of a 10 and 15 together. The 10's I have are 8 ohms each wired in parallel to 4 ohms, so it would have to be the 15 and 2 10's. I think it would sound great but I'm trying to downsize my rig for practice. I'll definitely give it a try, if it sounds significantly better I may just suck it up and build the bigger cab.

Just to be more clear the 12's I have are 16ohms each wired to 8ohms, though they are probably not a great choice judging by the magnet size and the amp that was in the organ they are probably only 15watts each.

-Dave

[Michael-GnL-Michael]

I really like the idea of a 10 and 15 together. The 10's I have are 8 ohms each wired in parallel to 4 ohms, so it would have to be the 15 and 2 10's. I think it would sound great but I'm trying to downsize my rig for practice. I'll definitely give it a try, if it sounds significantly better I may just suck it up and build the bigger cab.

Just to be more clear the 12's I have are 16ohms each wired to 8ohms, though they are probably not a great choice judging by the magnet size and the amp that was in the organ they are probably only 15watts each.

-Dave

Would it work out to build two smaller separate cabinets, one for the 10's and one for the 15, so you are not forced to carry all of it everywhere and have a choice to go the full 10/15route?

Dave thanks for clarifying the project.

All of this looks like a foreign language to me so I have missed the opportunity to understand exactly what you were doing on more than one level.

[louis cyfer]

I was going to build a 5e3 from a kit but my electronics type projects never seem to come out quite right. So, after a lot of research, I went with Jim at Lil' Dawg amps.

Sorry for the confusion Michael, the answer is B. I am not building the chassis I am building the combo cab. I put it in the project section because of that and included the build pics sent to me by the builder. I suppose I could have split it up and put the chassis pics in a separate thread under general music but I didn't see the point in two threads for one project.
Here is a link to the amp builder's site http://www.littledawgamps.com/

Louis/Darwin: I really like the idea of a 10 and 15 together. The 10's I have are 8 ohms each wired in parallel to 4 ohms, so it would have to be the 15 and 2 10's. I think it would sound great but I'm trying to downsize my rig for practice. I'll definitely give it a try, if it sounds significantly better I may just suck it up and build the bigger cab.

Just to be more clear the 12's I have are 16ohms each wired to 8ohms, though they are probably not a great choice judging by the magnet size and the amp that was in the organ they are probably only 15watts each.

-Dave

then go with the 2 10's. they are 4 ohms together, put a 100 watt 4 ohm resistor in series and you should get the 8 ohms. it is a pretty hefty looking resistor, but it should help your amp. or ask the builder to run an ot with a 4 ohm tap.

[Dave_P]

The 4ohm resistor is a good thought Louis, I may try it. I have read resistance and impedance are not quite the same and while you can do as you suggested it isn't really optimal.

Got the amp in last week but I had some rectifier tube problems, so I wasn't able to test it out until the weekend. The rectifier I ordered (NOS Bendix 5Y3) was arcing, I picked up another 5Y3 from a friend and the amp worked perfectly so I figured it was the tube. Turns out it was me, the tube I ordered takes at least 2 mins to fully warm up, once warmed up (I give it 4mins now to be safe) no signs of arcing at all. Quirky little tube but supposed to last a lifetime.

Anyway with the rectified I played a bit with the 15" weber blue dog and it sounds good, not quite what I was looking for but there are several factors I'd like to eliminate before I write that one off. Mainly, I need to fix up my current speaker cab, some of the mounting studs came loose when I was swapping speakers so I don't have a good seal and I never finished securing the back panel so it's got some rattles. Once that's fixed I'll set up those recordings I promised.

In the meantime.... on with the cab build. I opted for 20"x22" which was the tweed Pro's cab dimensions (1x15 combo). It is only slightly larger than the tweed super (2x10 combo) so I will be able to fit 2x10 , 1x15 or 1x12 easily.

Took a page out of Jamie's book and went with simple butt joints this time. I don't have the proper tools, or space for those tools, to make nice finger joints. I did them by hand last time, it took way too long and they didn't fit tightly so I ended up gluing and screwing anyway.
I rough cut the boards yesterday with a basic circular saw

Clamped up the sides and leveled them off with a belt sander, then did the same with the bottom

Here is how it looks so far, I have it all clamped up and ready to drill pilot holes etc tomorrow...hopefully

As it sits it is perfectly square, a pleasant surprise given my limited tools/experience and the fact that I'm doing this in my backyard. I guess miracles really can happen

Stay Tuned!
-Dave

[darwinohm]

Dave, this looks interesting. You are right on impedance/resistance. They are different. resistance is resistance to DC and impedance is resistance to AC and they are different so a 4 ohm resister may not be the right choice for impedance.-- Darwin

[blargfromouterspace]

put a 100 watt 4 ohm resistor in series and you should get the 8 ohms.

Try that on one of your own amplifiers before recommending it as a solution. Please film it when you do.

Took a page out of Jamie's book and went with simple butt joints this time...

I should mention at this point that the 115 cab I made is now functioning as a wine rack because it sucked as a speaker cabinet. Jamie's 'Book of DIY Home Joinery' sucks.

[louis cyfer]

put a 100 watt 4 ohm resistor in series and you should get the 8 ohms.

Try that on one of your own amplifiers before recommending it as a solution. Please film it when you do.

Took a page out of Jamie's book and went with simple butt joints this time...

I should mention at this point that the 115 cab I made is now functioning as a wine rack because it sucked as a speaker cabinet. Jamie's 'Book of DIY Home Joinery' sucks.

they use that on a lot of speaker attenuators. just a resistor.

[Muleya]

Good job getting that thing square!!

I used rabbet and dado joints on the last cab I made, and I REALLY liked that. Much easier than the half-blind dovetail joints I used on the two or three before that. I got the idea from the Cabinet Construction pics on the Zinky Amps website. If I ever do another, I think I'd go that route, since it can easily be done with a table saw and is a pretty strong joint. Of course, by the time you get your baffle in there, you've got a pretty strong cab regardless of the corner joints.

Did you say what your output jacks are rated at? I skimmed and didn't see it ever mentioned...other than you could run at 4 ohms, but not all the time. Is there only one output jack? If so I'm surmising it's an 8 ohm jack? If that's the case, I'd wire the 10s up in series for 16 ohms...you're always safe running the impedance HIGHER, it's when impedance is lower that you risk damage to your OT.

[louis cyfer]

Good job getting that thing square!!

I used rabbet and dado joints on the last cab I made, and I REALLY liked that. Much easier than the half-blind dovetail joints I used on the two or three before that. I got the idea from the Cabinet Construction pics on the Zinky Amps website. If I ever do another, I think I'd go that route, since it can easily be done with a table saw and is a pretty strong joint. Of course, by the time you get your baffle in there, you've got a pretty strong cab regardless of the corner joints.

Did you say what your output jacks are rated at? I skimmed and didn't see it ever mentioned...other than you could run at 4 ohms, but not all the time. Is there only one output jack? If so I'm surmising it's an 8 ohm jack? If that's the case, I'd wire the 10s up in series for 16 ohms...you're always safe running the impedance HIGHER, it's when impedance is lower that you risk damage to your OT.

that is true for solid state, for tubes not so much. i friend who designs output transformers for tube amps explained it, i couldn't repeat it, but it made sense.

[louis cyfer]

here it is, from and output transformer designer

"Not really, impedance is the sum of resistance and reactance. Reactance is the vectored sum inductance and capacitance. So he did create the correct load (4 ohm resistor plus 4 ohm speaker). Also with transformer coupled amps going down in load can only use up the output tubes a little faster. Going up is where you have a problem that can really damage an amp.

[Elwood]

i friend who designs output transformers for tube amps explained it, i couldn't repeat it, but it made sense.

I've heard/read the same ...with tube amps; a load that is (generally) higher than what the amp deigner calls for brings in the possibility of reflected voltages ,which may damage or shoerten the OT's lifespan.
Which must be why you never fire up a tube amp without the speaker connected (infinity ohms).

SS amps are the opposite . They are just fine being turned on without a speaker load (but usually don't like multiple pairs of speakers hooked up in parallel...I think I did that alot as a teen

[Dave_P]

Jamie, sorry to hear about your cab/wine rack, now you're giving me second thoughts
I won't be able to start assembling the cab today anyway so there is still time to make changes.

Everything I've read/been told by the builder is to go down in impedance on a tube amp. This amp has an 8 ohm output with another 8 ohm ext jack. I have been told it can handle a 100% mismatch down to 4 ohms. There is no 4 ohm tap on the OT, I wish I had pushed for that when I ordered it but it would have been a special order and I decided against it.

I am considering selling off the 2 10's I have(since I rarely use them) as well as the 15" and buying two 4 ohm 10's. Not sure I want to go through all that trouble/time though.

Thanks for the input (..that's what she said)
-Dave

[louis cyfer]

Jamie, sorry to hear about your cab/wine rack, now you're giving me second thoughts
I won't be able to start assembling the cab today anyway so there is still time to make changes.

Everything I've read/been told by the builder is to go down in impedance on a tube amp. This amp has an 8 ohm output with another 8 ohm ext jack. I have been told it can handle a 100% mismatch down to 4 ohms. There is no 4 ohm tap on the OT, I wish I had pushed for that when I ordered it but it would have been a special order and I decided against it.

I am considering selling off the 2 10's I have(since I rarely use them) as well as the 15" and buying two 4 ohm 10's. Not sure I want to go through all that trouble/time though.

Thanks for the input (..that's what she said)
-Dave

going down will shorten tube life somewhat but that is about it. that is why i suggested the resistor, it will extend tube life but lose 3db headroom.

[Muleya]

Hmmm...that's at odds with the standard info Randall Smith includes with every Mesa amp. He clearly states that you can go higher without damaging results, but too low will likely cause problems. I don't know if he means just for Mesa's amps, but he makes that pretty clear.

Personally, I'm not an expert, so I can't really argue one way or the other. However, when I've been in doubt, I've always erred on the cabinet being higher than the output and have yet to have any problems. However, that rarely happens.

I've also been told recently by an amp tech acquaintance of mine that modern OTs are pretty forgiving. I was worried about my home brew amp that had stopped working and I later realized I had the cab hooked up to the wrong output jack, though I don't recall the specifics (ended up being a burnt resistor by the power suppy). Anyway, he gave the impression that it wasn't all that easy to ruin one. I don't plan on testing that, but it's good to know there some room for making the occasional stupid mistake!

[Muleya]

Okay, found an article on Geofex that says as you all are saying. However, it also says that a high quality OT can easily withstand a cab impedance that is twice the output impedance.

[Dave_P]

The cab build has been slow going, my daughter has been sick and work has picked up but I did manage to get the box put together. I stuck with the butt joints despite Jamie's experience. I drilled pilot holes for the screws to prevent cracking and counter sunk them so they can be puttied over prior to covering the cab. Baffle board has been cut and t-nuts installed, baffle cleats are cut but not yet attached to the cab. I salvaged all the t-nuts and speaker bolts from one of the free organs I picked up a while back, as well as the grill cloth, and everyone knows vintage 60's speaker bolts sound better

Picture updates to come, work comp is blocking my access to them

-Dave

[Dave_P]

Here are some pics as promised, I had to work most of the day but I had some free time when I got home and just went for it.

Clamped and countersunk


Test fitting the baffle mounts,went with the narrow panel tweed style


Baffle test fit. In the interest of time I decided I was over thinking the speaker choice, decided to go with the 15" Blue Dog


Chassis cutout prep


Ready to load


Chassis in




Left off here for now, hoping to get the back panels made tomorrow


Obligatory G&L shot

It's far from perfect but I think it turned out pretty well so far and it only cost around $35 and some time. I still plan on making the sound clips when I get a chance. My question to you now is should I cover it or stain/paint it. Originally I had planned to cover it but the baffle was such a tight fit with the grill cloth on that I might ruin it trying to get it out.
Haven't had a chance to try it out yet, I just finished and my daughter is asleep, so that will have to wait until tomorrow.

-Dave

[Muleya]

Looks great, Dave! Nice job!!

I understand your issue with putting on tolex and dealing with fit issues. My 2x12 cab was stained for a while. Eventually I decided to tolex it and had trouble getting the grille in! I realized it was going to be a problem before I put on the tolex, and since my grille was attached from the front, I decided to chisel out an 1/8 of an inch or so all around the frame in front of the baffle. My cabinet was birch ply, which made it easier, but it still had its challenges! It's not perfect in the end, but you have to look pretty close and know what to look for to be able to tell, so I'm pleased with it.

[Michael-GnL-Michael]

Dave,

I think it looks good like it is. You should find a way to put a "Dave's Lil' Dawg" custom logo or something on it. It needs protection. It is also nice when people notice the amp because it sounds so good then they learn you built it. I would not know how I felt about dealing with the tight fitting piece unless I had gotten this far but I do think it would be better if it was covered in Tolex. What kind of wood did you use? A good staining requires a lot of preparation and then it becomes furniture. An amp will get banged up to some degree. Again I think the Tolex is the way to go. With the grill color you could use any color you want for the cabinet. Will you be adding casters or feet? What about a top handle or side handles?

BTW, when you buy a kit like this do they send you assembly pictures in process as part of the deal?

Michael

I love the look of that ASAT Classic.

[louis cyfer]

i hope those joints will work well for you, i know some people who didn't like the results in the long run. i like the cabs i have with dado joints, and of course the dovetails like my heritage and tweed.

[Dave_P]

I hope it works out too Louis, I would have much rather gone with finger or dovetail joints. Eventually I will invest in a nice table saw with a dado set, then I can make dado or finger joints properly. Unfortunately the low end table saws do not have a long enough arbor to use dado blades otherwise I would have gotten one already.

Michael, I like the logo idea I'll look into it. I agree with you on the covering as well, I think if I just mask off the grill cloth it shouldn't be too much of a problem. The tight fitting baffle was disappointing, I did account for the grill cloth but it was not quite enough and I would have had to take it off the baffle to trim/sand. Since the cloth was already trimmed I wouldn't have enough slack to pull it taut again. So I opted to bang it into place with a mallet The good news it the baffle does not rattle at all.
The handle is on it's way, I went with a "dogbone" style top handle and metal glides for the feet.
I'm not sure if the build pictures are common practice for all amp builders, but it seems to be for Jim (Lil Dawg Amps). He has great communication, talked on the phone a couple times and always kept me up to date with emails/pictures.

Thanks Muleya! Right before I banged the baffle in I knew it wasn't coming back out and would cause problems for covering the cab but I did it anyway. But the more I think about staining it the more I realize I should just cover it. Glad to hear your cab came out good.

Thanks for all the input!
-Dave

[louis cyfer]

brookwood leathers will make you a personalized handle, i got one for my ampeg. about 2 bucks for a very nice quality leather. comes complete.

[Michael-GnL-Michael]

i hope those joints will work well for you, i know some people who didn't like the results in the long run. i like the cabs i have with dado joints, and of course the dovetails like my heritage and tweed.

Is it a strength issue?

In the long run did they work loose?

[Muleya]

As for the joints, my very first cab I built I used mitre joints...while I don't know this for sure, I would guess their strength is comparable to butt joints??? Anyway, I figured by the time I got the baffle in, it would be adequate (and I actually dadoed the baffle into the cab...figured that would give me a little extra strength). Anyhow, that was probably 10 years ago or longer and it's still as strong as the day I built it, so hopefully those butt joints will do you well!

And here's some irony for you...that first cab I built is probably one of my best sounding cabs...just a 1x12 built out of cheap pine from Lowes. I did build it to the same sizing specs as a Mesa 1x12 Recto cab, so the extra depth likely has something to do with it. But any speaker I put in it sounds awesome...a surprising amount of low end. Unfortunately, my 1x12 combo cab somewhat pales in comparison...definitely has less bass response!!

[louis cyfer]

i hope those joints will work well for you, i know some people who didn't like the results in the long run. i like the cabs i have with dado joints, and of course the dovetails like my heritage and tweed.

Is it a strength issue?

In the long run did they work loose?

yeah, started to have some weird buzzy noises. a little creeky.

[Dave_P]

Thanks for the tip on Brookwood leathers, it looks like they make very high quality stuff. I wish their guitar straps weren't so expensive. I had already placed an order for a handle through Antique electronic supply, good to know for the future though.

Only time will tell on the the joints, they are very solid but I can see how they would be more prone to loosening up compared to dado or dovetails.

Covering is in the works, I have some tweed like material left over from my last cab build, hoping there is enough. Also, I may need to make a minor adjustment. I had planned on using the leftover pine as the back panels but this puts the chassis/tubes a bit closer to the speaker than I like. I may end up using plywood instead and remounting the chassis, it's only around a 1/4" difference so I'm not convinced it's worth the hassle yet.

-Dave