My new project

[kbp810]

So, from my prior post a short while back about the grogory mark v didn't pan out - thought it was a done deal but when I emailed the guy to arrange for pickup, I got no reply and haven't heard from him since... but I was still stuck in the new project mode so I decided to try my hand at a build. I've done some mods, repairs, restorations, and a few pedals, but this will be my first from amp scratch build (well not completely from scratch, I'm following the guide for the P1 Extreme from ax84.com).

 

I'm already well along in the build - have all the parts except the chassis I ordered hasn't arrived - and I haven't yet ordered the transformers.

 

Going to use 12ax7 preamp and 6v6 power - going to start with some GT's I have laying around first, then throw in a NOS mullard 12ax7 and a Marconi 6v6gt once I have confirmed the amp hasn't turned into one big fireball! (also going to make it adjustable bias, of course) The expected power should be around 10 watts.

 

...I had taken more pictures, but I took them with my cell phone so the majority came out blurry.

 

I will start the picture show with a lessons learned in how not to make your own chassis... I had a small piece of sheet metal available that was just about the right size. So without any proper metal bending tools, I took to task to make a terrible waste of my time and effort! (all while waiting for the first round of parts to arrive). I basically just used clamps and some wood for support to try and fold it into a box, didn't go as smoothly as I thought it would - and actually was quite a pain.

 

At first glance it almost looks like a chassis... but take note of the sharp edge sticking out bottom right, the wavy front, and the wavy top that came from not using a proper drill press for the holes - not to mention I demolished perfectly good 7/8" and a 1" hole saws cutting out for the tube sockets. Needless to say, I'm not going to use this one, and a real chassis was ordered shortly thereafter.

 

Note this is also my first attempt at inserting an image link from my gallery... hope it works!

 

Next up is the circuit board - fairly simple, and didn't take too long to solder it all together - here's where most of the pics didn't quite come out, so heres just a pic of the almost finished product (just missing the small diodes/rectifiers at the end in this pic)

 

[brentrocks]

WOW...and i just learned how to wire up a simple 2 humbucker Heritage....YOU GO MAN!!!!

 

good luck!!!

[kbp810]

Since there isn't much more I can do until the chassis arrives... this weekend I have been working on the cab for it

 

I'm going to make it a head, then build a seperate speaker cabinet (my own mini-stack )

 

I had a 1x8 poplar board that was exactly 48"'s long - which is what I figured I needed to make it 16"X8"X6.5"ish for a 16x8 chassis

 

Here was the rough cut formed together: (this was going much better then the chassis, I should learn to just stick with woodwork)

 

Once I had it together - I decided to re-check the dimensions; linear and height wise we were good; but I had made one critical error, the board wasn't actually 1x8, it was more like 3/4 x 7 1/2! So I decided I would look for an offsetting color wood to use as a trim to add the extra depth and with a little luck kind of look cool... I found a nice piece of bubinga at woodcraft that I went with...

 

Rough cut of the trim board added:

 

Sanded and shaped, and first coat of stain: I was trying to go bright, so I used a natural stain to just help bring out some of the color:

 

[Dick Seacup]

Good luck with the build; I did up a p1x several years ago and had an absolute blast learning all about electronics and whatnot. I picked up some great hole saws (or were they metal punches?) at the local Lowe's when I did my chassis. IIRC, I used a Hammond chassis that I purchased from Mouser when I bought all the electrical components. What are you planning on using for transformers?

 

EDIT: Nice enclosure. I was going to do mine in a head box, too, and even bought some beautiful flamed cherry to build it out of. I bet it's been five years and I still haven't done that.

[kbp810]

Good luck with the build; I did up a p1x several years ago and had an absolute blast learning all about electronics and whatnot. I picked up some great hole saws (or were they metal punches?) at the local Lowe's when I did my chassis. IIRC, I used a Hammond chassis that I purchased from Mouser when I bought all the electrical components. What are you planning on using for transformers?

 

This round I am going to use punches for the holes and head out to my dad's to use his drill press (also a Hammond chassis, from alied electric)

 

The build guide is set around a Hammond 125ese and 270ex, so that's likely what I will end up going with. I've been doing some poking around considering alternatives still though (including checking to see if I can find something cheap I might be able to harvest them from - though I don't want to intentionally skimp on them or throw in junk either)

 

It is a lot of fun - I keep reading through the forum post there soaking up tips and tricks, and contempating all the other mods out there for this amp

[kbp810]

Sorry to re-bump my own post - but I made the mistake of putting the images in my gallery here instead of externally and now can't figure out how to edit my earlier posts to fix the links (and my appologies to the HOC, rookie mistake on my part)

 

so here they are again in the order of earlier appearance..

 

Failed chassis:

 

Wired board:

 

Rough cut of cab:

 

Trim added:

 

Sanded and first stain:

[212Mavguy]

If you have not already done so, continue to read up on single ended output trannys...If the build were mine I'd not use any of the line of Hammonds you have chosen, even though it's the preferred build model. Instead, go for one out of the more top end OT line with the really big iron from Hammond at a similar input impedance as the one spec'ed, you will LOVE what pimping a build with over spec iron in the right places will do for the sound of the amp after it's done. Hammond iron is a great value. No problem with doing up the build with the original tranny, it's not expensive, then doing the upgrade...But after doing up my own single ended non ax84 project with a monster sized 5-7 pound SE output tranny, (mine was not a Hammond) the results loudly and eloquently in a detailed manner "speak" for going monster on the OT thang.

[kbp810]

If you have not already done so, continue to read up on single ended output trannys...If the build were mine I'd not use any of the line of Hammonds you have chosen, even though it's the preferred build model. Instead, go for one out of the more top end OT line with the really big iron from Hammond at a similar input impedance as the one spec'ed, you will LOVE what pimping a build with over spec iron in the right places will do for the sound of the amp after it's done. Hammond iron is a great value. No problem with doing up the build with the original tranny, it's not expensive, then doing the upgrade...But after doing up my own single ended non ax84 project with a monster sized 5-7 pound SE output tranny, (mine was not a Hammond) the results loudly and eloquently in a detailed manner "speak" for going monster on the OT thang.

Thanks for the input on the output! This is the sort of thing that has kept me from pulling the trigger on a tranny set as of yet... I know what to look for "spec" wise, but I haven't had much play in which ones might have a tone improvement over another for a given amp.

 

I think I am still going to roll with the Hammond for the PT (270dx)... I am considering a heyboer for the OT, I noticed the Doberman site has 20w that seems to have a good following... I'm probably still going to research more and waffle a short while longer though.

 

Meanwhile, I started working on the speaker cab... I was considering going with 4x8 for something a little different, but then decided to go a tad bit smaller and a little less ambitious and go with 2x10. I'm going to make it to match the head, with the exception of being 12" deep as opposed to the 9 1/2" head

 

[kbp810]

Okay, now I am seeking some quick advice on speakers...

I've had some local debate over whether to go with 2x10 or 1x15 (and one suggestion for 1x10 + 1x12, but I think that would be to much of a close call fit wise unless I want to start over on the box -it's 24" by 16" as is now)

 

And of course I realize this, like so many other things, is highly subjective; but just thought I'd pool some advice from the ever wise and humble amp guru members of the HOC.

 

Chassis should arrive today, I ordered the tranny's yesterday and should arrive tomorrow or Friday (I went with the hammond for power and the doberman/heyboer for the output)

 

So hopefully by the end of this weekend I should just about have this thing all wrapped up. Then I can stop bumbing my own thread and get back to the really exciting ones... like profile filling out bowling spambot's from Syracuse!

[Steiner]

I'm a big fan of variation! Mix it up as much as possible. I'm additionally a strong proponent of big iron trannies. I'd vote for the 2x10 where you can go with two different speakers.

 

By the by kbp810 - I like your popular choice of hardwoods...

[kbp810]

I'm going 2x10; ordered a fender blue frame alnico from angela.com, and then going to try one of those warehouse vet 30's (ceramic) to pair it with. I didn't like the way the first speaker box was turning out - there was a slight warp in part of the board that I though I had worked out when framing it, but all said and done I could still see it so I started again from scratch.

 

Chassis is now mostly wired up with the OT in place - didn't receive the PT yet...

I received a back order notice from Allied on the chassis... so feeling frustered and inpatient I just went ahead and ordered a prepunched one from doberman. A bit pricey, but it was nice to not have to endure all that drilling again! It was also nice to have it arrive and be able to get right to work on it so all in all no regrets. Also note on the wiring I got a little carried away and soldered in the standard cathode resistor on the octal socket, once the rest of the parts arrive for the adjustable bias mod that will be corrected.

 

The grill cloth and a few other random parts arrived so I was able to throw together a quick test fit to see how the head was coming together.

-Note that it was just all thrown in for a quick glance at what the finished product should look like, which is why there's only two knobs and it's all still slightly crooked. For the grill cloth here, I just used two sided tape to attach the fabric to a thin piece of board and then the strip of plastic trim at the bottom where it will meet the chassis, was a very simple solution andI think it worked out perfectly. I was going to also do a faceplate... but I have to admit in person I actually really like the way it looked "as is", so I might skip it (still undecided) - also pictured in the background is my wife who thankfully continues to support my crazy ideas to do stuff like this.

 

Speaker box take 2