Key Points Learned From Build

[tweed5259]

I've just finished my year and a half long project of recreating the tone of an original tweed bassman I played in my own build. I'm just writing this down for everyone like me who had to use trial and error buying parts to find out which sounds like what. hope it helps, feel free to ask any questions, I'd be glad to offer my opinion.

This is just my opinion remember, it's what I've found from comparing parts one by one I don't claim to be an authority by any stretch of the word.

The pine cab is a HUGE difference between any other wood. Pine give the tweeds that boom and bark.

The caps are negotiable, I found the Mallory 150's were too warm, I like The Orange Drops, they add a nice sparkle to the high end in a very round way, not harsh at all, glassy and pleasing to the ear, but really it's so subtle if i was blindfolded I couldn't tell.

The resistors, for sure carbon comp. The metal oxide do sound stiff and cold.

Tubes - reissue Tung Sol 5881's sound as good as any NOS tubes I've heard when Biased to 30mmV - 38mmV, if you bias them colder or hotter, they kinda sound bland, I tried tons of different tubes. JJ's sound AWESOME too, just brighter.

Transformers - Here's where I say the goods lie. The reissue OT's sound good, but there's no vintage clarity, they're just ok. The Mercury Tone clones sound great but aren't as good as the Heyboer OT's on the paper bobbins. I don't care what anyone says, I tried to not believe it, but it does sound better on paper. This is where the real vintage amp tone comes in in my opinion. you can have mediocre caps, resistors, even speakers, but a good OT covers many sins.

Speakers - everybody's different. The Weber Sig10s are ok, not perfect. The Italian Jensen P10R's are awful too stiff and piercing. The Jensen P10Q's are awesome. I like two Eminence Legend 1028K's in the top and two Eminence Lil' Buddy's in the bottom. I think it's balanced and sound amazing in a 4x10 combo. I did find that there's no magic answer, it's all preference. There's no wrong answer either, with the OT in place even the Jensen P10R's sounded pretty great. The speakers never broke or made the amp, they just accent highs mids or lows, no night and day changes.

That's what I think, it's my two cents, but it's an unbiased two cents, nobody pays me to push their product, but I do have a basement FULL of different brands of parts now to know the difference.

I'd be happy to discuss any of the specifics between brands with anyone thinking of buying different ones. Again, I don't have much tech knowledge, I'm just one guy with an opinion. But hopefully I can save somebody some money.

[tweed5259]

oh yea, and watch those layouts... patience daniel san.

[cminor9]

Funny, I have put together a similar list of things and I have just had it sitting around for my next project. I'll dump it here too for everyone's benefit. Maybe my list and your list will save someone some trouble. Forgive the awkward formatting, it came from my text editor.

The number one failure was that I did not plan the chassis properly.
Oh, I thought I did. I read loads of material online, and everything I
read advised that you plan the chassis properly. I heeded the advice,
or so I thought.

I used a 12x8x2 aluminum chassis for my 5E3 head. Since the 5E3 was
originally meant to go into a chassis that was more along the lines of
15x5x4, I had to make some modifications. I would have been spared
some headache had I just bought a larger chassis.

Run wires for heaters first. After the chassis layout stuff, I
immediately went to the board and started laying out parts. I should
have started with mounting the tube sockets, switches, power
transformer, fuse, IEC plug, and pilot light. Then I should have wired
up the pilot light and tube sockets first. I just had to undo some
stuff. A pain and time wasted.

Panic ordering. Halfway through my project I realized that the chassis
(12x8x2) would be too small. So I ordered a larger one. 17x10x3 was
the most suitable size I could find on AES (I really wanted one that was
17x8x3) so I ordered it. It was late at night. The very next day,
after work, I started cutting the wood for the head. What did I do? I
cut it for a chassis that is 16" wide. DOH! Finally, I found and
ordered from Digi-Key a chassis that was the desired 16x8x3.

Too little tolex. I bought a piece of tolex that was 54" x 72". It was
a bit tight, since I made two 20X20X11 cabs and one 18x9x9 head. I made
it work with *very* little scrap (not just a little planning went into
that!). The downside was that I left myself just about an inch of tolex
to fold around on the inside. What this meant was that I didn't have
much room to spray tolex glue on the wood on the inside of the cabs.
This in turn pretty much guaranteed that my edges were a bit sketchy.
Some turned out beautifully, others turned out not so great with some
bubbling and so forth. Spending more time would have helped, but this
whole tolex bit was absolutely the least enjoyable part of the process
and I was trying to get it done with swiftly. Slightly more tolex would
have made it easier to work with, period. Next time...

Too many orders. I should have ordered everything the first time. Easier said than done, I suppose.

All of these planning failures cost me way too much time and money. The sad
part is that I was warned about some of these things from all of the reading I had done before taking the project on. Why do
some of us have to learn the hard way (through experience)?

Messy holes in chassis. My holes for the inputs, pots, jacks, etc
turned out beautifully. I drilled them, then deburred them with a file.
But the holes for the pilot light and tubes were a different story.
They take larger drill bits than I own. So, I drilled them with the
largest bit I had and used a file for the rest. Not only was this time
consuming and ear-splitting but it also made messy holes. Punches are expensive. But I found a unibit on Harbor Freight that was $15. My next chassis will be much neater and I will spent considerably less time.

[tyru007]

I thought I'd add a few lessons learned on a first build of a Fender Champ in a head. I was a little worried as I did not build this from a kit but designed and built my own turret board based on the AA764 layout with a TMB tone stack.

Using a diodes for a solid state rectifier instead of a tube rectifier really simplifies the power suuply circuit and allows you to use bigger filter caps for better filtering.

40uF/500V TVA filter caps very long and will not fit between turrets on a 3" wide board. Either get 40uF/450 TVA caps or go with a another cap. (i did not use a cap can for my build)

Bigger is better but heavier. I went with a Hammond 270EX PT (125 mA), 125ESE OT (15 watts) and a 225mA, 4H choke. All are overkill for this amp but I have/had visions of modifying the amp for a 6L6, parallel 6V6s ect. Each of these wieghs in a about 3-4 lbs and makes for a very heavy amp head.

I saw a 5 lug terminal strip when I ordered parts. thhis came is very handy as I wired all the terminal together and then ran each ground to this strip which I mounted near the tone stack.

I used the AX84 chassis layout as a go by for my chassis and I'm glad I did as it was set up for the transformer already. The 16x8x2 aluminum chassis was plenty big enough and a great size for a first build.

Turrets do not have a very big hole so don't even plan on soldering wires into the hole. It's was much easier to wrap the wires around the post and solder. The filter caps were about the only wires I soldered into the holes.

If you use cloth covered wire (which is great stuff) also get some heat shrink tubing and a heat gun. This really cleans up the ends of the wire one your done soldering.

Never guess. If you have a 50/50 chance of guessing wrong, you will guess wrong 100% of the time. If you don't know when building an amp, find out or ask teh question. I caught several mistakes later, when I had guessed. Luckily before I applied power.

Check you circuit over and over and then follow the startup sequency at the Ruby site.