Rocket Build - done 10-27

[johnnyreece]

Hey, all. I've thrown together a layout for a Rocket I'm hoping to build into a gutted amp and using non-standard parts. One problem is that I don't have a center tapped PT, so I'm using a bridge rectifier with a simulated sag of a GZ34. This is one of those "I wonder if this will work" kind of projects. Definitely not for purists!

Any thoughts, other than, "Why did he us MS Paint to do a layout?"

[johnnyreece]

I've wired the board and started modifying the chassis. I'm guessing there are no glaring errors, or someone would have corrected me by now. No news is good news, right?

[johnnyreece]

Getting started. This has to be one of my slowest projects...lots of chassis mods on this one, and it sucks! Not sure on the placement of the filter caps yet, but I'll determine that after the rest of the wires are a bit more settled in. Got filaments run to the power tubes tonight, but no pics yet (camera battery died). Also got some of my VVR stuff on V1 added that isn't on my layout. We'll see how it goes!

By the way, how about that cramped rectifier/choke/tranny placement?

[M Fowler]

Johnny,

That layout should work but man it's hard to get an old chassis like that to work well and look good when your done. But it's a building experience.

Mark

[johnnyreece]

Johnny,

That layout should work but man it's hard to get an old chassis like that to work well and look good when your done. But it's a building experience.

Mark

Yeah, everything I've done so far (5e3, 5f2, JTM45, Two-Stroke) were all paint-by-numbers. I got this for almost nothing, and have less than $200 in it, so we'll see. I may learn to never "convert" anything again! I've given up on "look good", but am still hoping for "work well". The board is REALLY crammed in there, and is partially on top of the preamp/PI tubes. I'm hoping for functional, anyhow...

[M Fowler]

The Rocket is a very stable circuit so I don't think being close will create problems besides nice short leads are good.

Yeah price is right.

Mark

[johnnyreece]

Well, got some more done tonight. Finished the filaments and got a few odds and ends together. Boy, this is a Rocket's ugly second cousin...You know, the one everyone knows you're related to, but has the good sense not to talk about it?

[M Fowler]

I've used boards similar to those but mine had smaller eyelets

When it comes time to wire that VVR don't ask me because I know nothing about VVR's and still haven't installed mine yet. I'm waiting for the right amp to install everything known to amp mods, you know VVR, tube buffered effects loop, relay switching, two or three channels or maybe four.

Mark

[johnnyreece]

Yeah, this is my first VVR job. I think my wife will appreciate it!

[johnnyreece]

Okay, I'm getting to the nitty-gritty with wiring this up. Think I've got a pretty good handle on it, but updated my layout to reflect my switch type (they're lit switches) and add the VVR. Anyone spot any glaring errors (other than trying to put a Trainwreck into a Crate's clothing)?

[Colossal]

Yeah, this is my first VVR job. I think my wife will appreciate it!

Hey now, this is a public forum!

[johnnyreece]

Yeah, this is my first VVR job. I think my wife will appreciate it!

Hey now, this is a public forum!

BWHAHAHAHAH! Oh, how much inuendo there can be in this stuff.

[M Fowler]

Yeah I second the addition of the voluptuous woman

Mark

[johnnyreece]

Well, got the power rail and VVR set up. On my limiter, everything looks good. With the VVR all the way down, it gets down to 30V. All the way up is 360, which is what I expected with this recifier. The standard voltage Crate had the E-84's at was 391! Should be able to run it through the startup procedures this weekend, if I play my cards right.

[johnnyreece]

Okay, so trial run, everything seemed to be going well (as well as it can be at 12:30 at night). Realized I had very low volume, though. Got to checking voltages, and I had pins 6 and 7 mixed up on the PI. Straightened that out, and got more respectable volume (as respectable as it can be at 1:00). So, I crank down the VVR, everything seems to be doing its job. All of a sudden *POP*. I flip the switches, yank the plug, and start troubleshooting. Long story short, the insulator for the MOSFET was cracked when I got it, and was evidently cracked enough to let a short through. I'm assuming that's what it came from, as there's a teensy black burn mark at the MOSFET and a piece of the insulation's gone. I attached a pic so you can see. Kinda subtle, but it's easier to spot in person.

Here's my question: Where can one get another insulator? If the Rat Shack has them, I'd be glad to pick one up. Can't wait to crank this baby up for real!