TW Rocket Combo - What Do You Think About This Layout?

[Rocket Roll]

Hi! I have a friend, and he's a local amp builder here in Belgrade. I've shown him the documentation for the Rocket, and this is the layout he came up with (see attachment).

It's gonna be a 1x2'' combo w/ Celestion Vintage 30, Fender-type chassis (ie. tubes hanging upside down).

Since I'm a layman when it comes to amps (I dabble with guitar pedals, but I'm basically a solder jockey), I wanted to ask you about that layout - how does it look to you?

All I know is that he added another input and I believe he changed the grounding a bit.

I would be very grateful for your comments!

(Alternative link for Internet Explorer etc, containing a .pdf file of the layout hosted at box.net = http://www.box.net/shared/l5plzqyak5)

[breakfastbuddy]

its not showing

[Rocket Roll]

Right, here's an alternative link for Internet Explorer etc, containing a .pdf file of the layout hosted at box.net = http://www.box.net/shared/l5plzqyak5

The same layout in .pdf hosted on AmpGarage: https://tubeamparchive.com/files/pik_ro ... ut_879.pdf

[Rocket Roll]

A couple more explanations, if I may: he's building me one of Rocket combos (yey!) and therefore this thread - I'm looking for some advices from experienced Trainwreck builders so I could pass them to him.

Power and output transformers are his design and his work - I know they are nice since he's famous on the HiFi scene here for both his transformers and his work in tube amp building. Besides, I've heard a lot of amps he'd build and they all sound great.

OT has 4 and 8 ohms output, as noted on the layout - I didn't want 16 ohms output on my combo since it's going to be used as a combo and in studio/ home scenario only (pedal tests, occasional recording session).

Ron Worley has been kind enough to comment on a few things and he noted the B+5 20uF filter cap. I hope it's not going to cause excessive hum, since the layout is pretty much final (as far as my combo is concerned) and the vitroplast board is, as you can see on the added picture, finished and ready to be soldered on.

Added picture also shows powdercoated aluminum chassis with pre-mounted components, so you can get a better idea about the realization of the layout.

I believe the best description for this combo will be "a Rocket-inspired build". As far as the materials go, it's gonna sport a lot of Sprague caps (Orange Drops 716 and some silver micas for pF values), F+T (Fischer und Tausche) electrolytics, Illinois for 80uF cap, CTS pots, carbon-film 1W resistors pretty much everywhere and even a couple of tantalums (due to spacing issues, as I understand).

Of course, as soon as it's possible I'll make a couple photos of the finished amp and some sound samples.

[Structo]

Your layout did not make it through.

[doctord02]

You might wanna reconsider the 716 OD caps...

[Zippy]

Rocket Roll,

Does your builder know that you are second guessing his design? If I were him, I'd be a little annoyed after putting so much work into the project and then have a bunch of faceless internet folk critique my work.

Give it a chance and see what he can do. We could critique the layout but he may be doing some things for reasons that we don't know. You say he has considerable experience and success, have some faith in your selection of having him do your build!

I, for one, applaud builders taking some initiative in changing designs and perhaps developing new techniques that result in better amps.

Please show us the finished amp and let us know how it goes.

[Rocket Roll]

Does your builder know that you are second guessing his design?

Ah, I see - sorry if it came out like that... My concern was the possibility of some major difference or perhaps a flaw. Apart from that, my wish was to "give something back" - if it weren't for the AmpGarage there wouldn't be a TW Rocket project, so hopefully this layout (soon to be followed, I hope, with clips and pics) will be useful.

...layout did not make it through.

Does this link work: http://img56.imageshack.us/img56/2326/p ... outux2.jpg

[selloutrr]

dead link

[Ron Worley]

Ditch the Illinois 80uf too.... unless you want it sound like shit and then blow up....

If you must use an 80uf in stead of 2 40's, use a CDE Mallory or if you can't source that a Sprague Atom (but most don't like them for a TW, mostly Fenders).

The Illinois are cheap garbage....

[Zippy]

Ditch the Illinois 80uf too.... unless you want it sound like shit and then blow up....

If you must use an 80uf in stead of 2 40's, use a CDE Mallory or if you can't source that a Sprague Atom (but most don't like them for a TW, mostly Fenders).

The Illinois are cheap garbage....

Pretty strong words, Ron. Do you have some reason for expressing that sentiment? Have you had the experience of "sound like shit and then blow up"? I'm all for benefiting other people's experiences.

I've had the Illinois power caps show up in several amps and they work just fine. Any reason that the Spragues don't work in a TW? I've heard enough of the tone cap arguments but power caps??? If you hit the values right, why wouldn't they do their job? Where does the "sound like shit" aspect enter the equation?

[Zippy]

Breakfast Buddy, Structo, and Selloutrr: I'm using FireFox and can see all the posts and links that don't seem to be working for you.

[selloutrr]

I respect Ron's input he's been a huge help on this forum. Personally, I've had fine luck with the illinouis, the NTE, and the Sprague Atoms on plenty of builds / repairs as long as you form and test the cap pre installation. I've had a bad batch of sprague but it was quickly weeded out from testing and refunded / replaced free of charge. The mallory have a higher standard of testing before they are placed on the shelf or at least used to be. but you are paying for that extra step. As long as you don't abuse the cap you should be fine, to much current, exceed the temp, humidty, cold... I've found it's really just personal taste/budget. With that said I've only ever seen actual TW use mallory. If it was a tone cap we could go 1000 pages deep and still never have an answer we would all agree on but mallory are the OEM TW caps.

[Richie]

i use tech caps..made in USA.. they are a bit smaller than the mallory or sprague. Never had a problem with any of those.
I don't use any sprague caps anymore. I'm sure there are alot of different caps like f&t etc.. that weren't around when Ken was building the wrecks.

[rooster]

Richie - Tech caps of USA? Who sells these, this is a new brand to me. Are the prices better than Sprague? Thanks.