Boothill 5E3 Kit - arrived and started

[pryde]

Originally Posted by blueshawk100

I removed the wire between 4&5 and did the neighboring socket.

Regarding the heaters. If I use all green wire it will be harder to keep them straight, especially when twisted. I could use the ohm meter I guess. The diagrams make it look like one twisted pair, but it really is a series of shorter jumps, right?

Any reason the green wire is heavier? It's only low voltage filaments right?

I twisted my runs of heater wire with my drill. works great for a nice, tight even twist. I started on V1 and just worked my way toward the power tubes. Only the preamp tubes are tricky as the you need to get the larger gage wire into single-hole lugs. When you get to the power tube sockets, the heater wiring is much easier as you have double-hole lugs. Good luck.

[Cruisin Home]

The picture quality is bad but it looks like your cap (blue electrolytic) is wired in backwards. Forgive my eyes if I am wrong.

[Cruisin Home]

Ignore if you know this already: the electrolytics (including the big power filter caps) are polarity sensitive (+ side has the groove). if installed backwards you may get a little "show".

[charisjapan]

Originally Posted by Cruisin Home

Ignore if you know this already: the electrolytics (including the big power filter caps) are polarity sensitive (+ side has the groove). if installed backwards you may get a little "show".

Cruisin,

I'm pretty sure those blue electrolytics are non-polarized. I went back and checked on my own build, and they are the same. Threw me for a loop for a while, then I found a match online. They have the indented 'ring' on both ends.

Probably best to ask Dave for confirmation... ?

charisjapan

[blueshawk100]

The black caps are polarized. The blue caps in this build are non polarized. I checked with Hackworth, and they do say NP on them. But thanks for 'keeping me honest'.

This is a nitty detail, regarding the twisted heater wires to the preamp tubes. I saw on the ceriatone diagram, which shows them pretty well, that the heater wires are run along the front side of the tube sockets (open side of the chassis), and it has an untwisted lead running around the tube socket to one of the pins. The wires are twisted up to the first pin and then the other lead wraps around from there. Is this OK?

Because another way to wire it, and I think I saw that in another person's build would be to essentially run the heater wires directly underneath the tube socket and, split one lead off to each pin. In that way more of the wires would be twisted together because the leads would be split off in the center between the two pins. This seems like it might be quieter, if this is a critical noise/hum source.

Hackworth, how do you feel about this?

[hackworth1]

Do it the way that makes sense to you and is the simplest way. A little bit of an untwisted run is not a major deal.

[Cruisin Home]

twisting the wires allows for a certain amount of common mode noise cancellation, but not completly eliminate all noise coupling. What is a more important factor is distance. distance is your friend. Certain types of noise will vary by the inverse square of the distance: meaning everytime you double the distance the field will decrease by 2squared ie 4. The opposite is true, as a wire gets closer to the source of noise the field will go up by the square as well. Make sure that you separtae the wires carrying your guitar signal, from the noise carrying power wires such as your filament by as much distance as possible. some people run filaments against chassis and have there signal wires run above chassis by some distance. Others do the opposite, both methods work.

Secondly the polarity(direction if you will) of the noise about a conductor is such that it will induce more of a a current on wires running parallel as opposed to perpendicular. where your power and signal wires cross have them do so at right anles if you can. The Ceriatone layout that Telenut has posted is fine and holds true to this principal.

i see your speaker will not be there for awhile, be careful of running up power without a load on the OT such as a speaker. You risk losing your OT without a load.

[Cruisin Home]

Ditto re Hackworth's comment. You are in good hands with him.

[blueshawk100]

Thanks everyone!

[blueshawk100]

Hoping to put the heater wires on tomorrow. How does it look?

[burninwordz]

NICE!!!!! good job

[Bentley]

How difficult would it be to build an amp like this!? That just looks like silly amounts of wiring. I need to try this out when I get the cash. Looks good though!

[motor_city_tele]

Originally Posted by Bentley

How difficult would it be to build an amp like this!? That just looks like silly amounts of wiring.

not too difficult. how good are you with a soldering gun/pencil?

it seems that this is where many builders find the process more challenging.

the troubleshooting piece is no picnic either.

[hackworth1]

If you go slowly...

With full attention to every detail...

Go slowly...

Never rushed, or tired

You don't have to get it done all at once. Do some and set it aside.

If you have practiced your soldering technique...

on this perhaps,

http://www.tdpri.com/forum/vendor-fo...nents-diy.html

Then, get the rest of the kit later.

You will have a good foundation.

If everything is correct - no bad joints, miswired connections or solder blobs to make shorts, there should be no troubleshooting to perform.

The only other thing is bad parts. I have not had any reports of bad parts, except one.
A bad Output Tranformer, which I replaced for the customer, of course.

Most often, a miswire and/or a bad solder joint is found to be the cause of malfunction.

[Cruisin Home]

looks good so far!

closeup pics would be better for us to check.

[blueshawk100]

I agree. It's not hard if you go slowly and take it in chunks. I have a rule that if I'm not enjoying it anymore or it feels like work, I stop for the day.

It also helps to not have all the parts (speaker, cabinet) here yet, because there is no possibility of completion yet. I got the chassis kit then ordered the rest in order of need.

Don't forget, this is 1950's technology. It's not that complicated.

[pryde]

The build is looking good blueshawk!

What rectifier tube are you going to use? If you don't already have one, I recommend a NOS 5Y3GT. I first had a Sovtek in mine but it made the B+ 405v which is pretty high. I swapped in a NOS GE-made 5y3GT rectifier and it dropped the B+ to 365v which seams to be preferred for this amp.

I scored a couple NOS rectifiers off of ebay dirt cheap so look around there if needed. Keep us updated with pics!

[blueshawk100]

As it turns out I bought a NOS Sylvania rectifier on eBay. I then had a change of mindset and ordered a 5E3 tube set from triode, thinking that getting new, known good tubes might be a safer route, and avoid debugging a bad tube issue. I figure I can pick up NOS preamp tubes later it I want.

After hearing your report, I guess I'll use the Sylvania. I wonder how their 12ax7's sound? They seem readily available.

[pryde]

Yah I bought the triode tub kit as well that came with the modern Sovtek rectifier. The rest of the tubes in the kit work great, (pair of JJ power tubes, 1 JJ 12ax7, and 1 EH 12ay7.)

At some point I may try a NOS 12ay7 for V1 but the EH tube seams ok for now.

[Telenut62]

You won't hear much difference with a NOS 12AY7 IMO You'll hear heaps more with a 12AX7...more gain of course which is handy for low volume...but try a 12AT7 in V2. That sweetens up the highs very nicely.