How to mount components on a turret board?

[George61]

I have finally acquired all of the parts for a Rocket, including a cabinet that cost more than a perfectly good complete amp, and I am about to fire up the ol' Weller. This is only my second vacuum tube build. I do have a good bit of solid state experience.

My question is how to mount the resistors on the turret board. Should they be elevated or tight against the board? On a printed circuit board componenets are tight against the board for structual integrity. The excecption being resistors that run hot and then they are elevated for cooling.

Thanks in advance to anyone who replies. I have a lot of money in this project and I am trying hard to do a good job. I am not rushing into anything.

George

[surfsup]

The resistor will probably be hanging upside-down when you turn the chassis back over anyway? So I don't think it matters, personally.

[M Fowler]

If your using turrets you can decide if your going to wrap the leads around the turret or are you going to use the top holes.

I like to wrap my leads and keep the top holes for the wires. On Marshalls the guys use the bottom of the turrets for wire leads.

No need to have the resistors against the board material but I always wrap my larger caps at the base of the turret and the caps are on the board.

I really don't see a wrong or right way to any of this just good mechanical bond and then solder.

Mark

[rp]

When I do ptp I always worry about this, if the span is short floating caps and resistors will be pretty tight but if it's a long span they can boing like tuning fork, esp caps and I've put rubber grommets around them to try and dampen. Does it matter to the electrons, esp with modern impregnated molded parts, beats me? Modern parts don't seem very susceptible to microphonics. If it's a chunky cap I try and keep it hard to the chassis but with a felt pad or double stick tape under it. I hate the look of goop so no silicone or hot melt for me. Resistors are a little less boingy and and I worry about rattle to the chassis. Teflon wiring will definitely rattle and if necessary I'll clear tape it to the chassis here and there.

If I was using a board I'd put caps hard to the board but I have seen resistors burn the boards. Curious what others think about boingyness and electrons.

[Structo]

I haven't built a turret board yet.

I think I like eyelet boards better for a couple reasons.

On a turret board the components are usually elevated, while that is good for heat dissipation, it can put a lot of tension on the leads when wrapping them around the turret.
Add heating and cooling cycles and I'm not so sure it is such a good thing for the component.
I'm sure technique plays into that quite a bit.
I have seen builds where they put a slight Z bend into the leads to allow some expansion.

Another thing I like about eyelet boards is the ease of substituting different value resistors and caps.
Less heating and easy to sub in the part.

Plus you can fit about four leads into an eyelet.

Eyelets are cheaper, easier to install.

But, I will say this, a well built turret board is a beautiful thing.

[George61]

Thanks for the replies. If I didn't already have the turret board, which I didn't make, I believe I would build a board using eyelets. It would be much easier to assemble and to rework.

My only other build was a 36W Ceriatone kit and all of the leads where inserted into the holes in the turrets. Ceriatone uses the bigger turrets. Since this was my first tube amp I wanted to experiment with it. I decided to change all of capacitors on the board. That was a nightmare.

By the way, replacing the Mallory 150 capacitors with Sozo's didn't make any difference. Replacing the 'Holy Grail' electrolytics with BC Components tighten the amp up quite a bit, a definite improvement.

Solder on,
George

[gingertube]

A couple of things.
Caps can be microphonic so they need to be tight against the board or use silicon adhesive (or even a hot glue gun) after the build to stop them "wobbling in the breeze".
Resistors are generally not microphonic so mounting is less critcial. If the resistor in question is dissipating significant power (anode loads, etc.) then they are best spaced up off the board to allow airflow around the whole body.

I've done several MIL SPEC Solder courses over the years (day job). One thing which has changed is the recommendation for the component lead wrap around the turret. It always used to be 270 degrees wrap, more recently a 180 degrees wrap is recommended. Apparantly it has equivalent bond strength and is easier to rework.

Cheers,
Ian

[Gibsonman63]

Interesting thread, gents. I have been using the top holes for the componants and wrapping the wire around the turrents to make it easier to change componants. I haven't considered microphonics, but I haven't had any issues either.

[Structo]

Sorry for the commentary.

I do believe that it's best many times to follow the original type of build.

I guess since I'm on the Fender/ Dumble side of things I was first exposed to eyelets.

I'm sure your build will turn out great.

[Reeltarded]

I think microphonics and generally keeping an amp right at the edge of instability (within reason) is the key to a great tone. I am only as wary as I have to be, and only begining to really understand that concept in a way that is useful.

Everything lives in everything else's flux. I wish I could see it with my eyes instead of having to hear it with my mind.

[rp]

I think microphonics and generally keeping an amp right at the edge of instability (within reason) is the key to a great tone. I am only as wary as I have to be, and only begining to really understand that concept in a way that is useful.

Everything lives in everything else's flux. I wish I could see it with my eyes instead of having to hear it with my mind.

I fully agree. It's why I like old caps. The molded greenies in my 5f1 have some strange microphonic that sounds like a tiny touch of delay/reverb - Not sh*tt*ng yah. Ran it past friends and it's subtle but clearly there. Sounds amazing, totally in the flux. If I could replicate it I'd own the retro-repro cap market.

[Reeltarded]

I have swapped in many identical mustards, CDs and Sozos to the same place looking for magic and found it after 20 swaps. On my design that second stage needs a tiny ring when the amp is about to melt. That is where the sing and 1st order harmonic above all my unwound string notes hang out.

It all matters, but then it really all matters!

I love this place. You guys taught me stuff that was never spoken directly. Brilliant!