Building a Rocket - Layout Check for group build

[txbluesboy]

I hate to complicate things but I wonder if I could get a walnut faceplate instead of cherry? I already have the cabinet I plan to put it in.

[Sven]

Greetings,

Strange project where the last and the least feature, front plate, is being discussed into a detail, while there is no schematics and layout.

Anyway, is the layout of the main board drawing of april 5, final? For example, are the two cathode capacitors 0.022uF or are they actually 22uF as in other schematics? What are the values of power supply resistors and other, smaller capacitors, and what are connections between pots and valves? There is a Mark Abbott layout, that is different than what is shown here, so far. Etc.

Not building, yet, but would like to see a solid schematics and layout. I can contribute good drawings if time is a problem, if some pointers are given.

Anyway, thanks for the effort so far, ... every little bit helps, but it is rather incoherent, IMO.

Sven

[Fischerman]

I think the lack of info on existing Rockets is why none of that has been totally nailed down Sven. My plan is to build mine 'in the spirit of' what we have already seen in Liverpools and Expresses but then making any changes I see fit. For example, I'm almost certain I'll build mine with 5.6k grid stoppers on the power tubes instead of 1.5k.

According to the Mark Abbott schemo the preamp power supply nodes are all in parallel and tap off of the screen node instead of the usual series string we see in an Express. So that's different.

Regarding the cathodes...I would probably use the same value Vox used so 22uF. I can't read the layouts posted earlier in this thread (I can see the layout but can't read values).

And FWIW, I've been thinking about the OT choice and I think I'm leaning towards an AC30-type OT. But you guys might want to do a search on 'Alwood Mod'. This is a mod that Valvetech had to do on a bunch of their AC30 clones that used Heyboer AC30 OTs (but not their clones that used other OTs). Apparently the Heyboer OT was too 'HiFi' and had too broad of a bandwidth and the mod is supposed to make the amp sound more midrangey and guitar friendly. But Valvetech also claimed that the amps with the Heyboer OT and the Alwood Mod sound better than the amps with other OTs and no mod. I don't know what the mod is...it is user adjustable with a pot though.

[RJ Guitars]

I think the lack of info on existing Rockets is why none of that has been totally nailed down Sven.

Exactly - A good set of drawings would be very much appreciated, although I'm inclined to believe it will be reverse engineered from an as built amp. I am creating the layout and such as I go from the archived material... Think "spirit" of Ken Fisher - lots of "sort it out by ear"... In the end it will all be posted and made available for future Rocket builders. Hopefully Ron will create one of his comprehensive build guides like he did for the Express - everything you ever needed to know in one package.

I would probably use the same value Vox used so 22uF. I can't read the layouts posted earlier in this thread (I can see the layout but can't read values).

I think you are right - Any values posted on my layout consider place holders until I make it back to finish that up - I plan to start with the Matt Taylor/Mark Abbott work and go from there.

And FWIW, I've been thinking about the OT choice and I think I'm leaning towards an AC30-type OT. But you guys might want to do a search on 'Alwood Mod'. This is a mod that Valvetech had to do on a bunch of their AC30 clones that used Heyboer AC30 OTs (but not their clones that used other OTs). Apparently the Heyboer OT was too 'HiFi' and had too broad of a bandwidth and the mod is supposed to make the amp sound more midrangey and guitar friendly. But Valvetech also claimed that the amps with the Heyboer OT and the Alwood Mod sound better than the amps with other OTs and no mod. I don't know what the mod is...it is user adjustable with a pot though.

This is a good find.... interesting. I searched it out and found Rob's (I think this is the Rob Alwood) post explaining what mods were. Simple but the cool thing was he didn't have to change the OPT to accomplish his sound... what do you think?

------

From Rob: Hi the alwood mod reduces the highs and lows in the power amp to give the amp that classic alboin high mid hump, with the nicer lows of the woden transformer, hence the name alwood mod. The heyboer woden clones I use in my amps have way too wide of frequency response,almost as much as a hammond HIFI OT.
With this simple kit the heyboer OT can exceed the tone of the mercury magnetics woden clone transformers in my opinion, and at the same time greatly reduce ghost noting without having the raise the filter cap values.
It took a while to get it right,but I knew it could be done eventually. The alwood mod is the result. Thats the best i can explain it. Rob

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There is a ton of expertise on the Dumble Discussion forum on midrange tinkering and boost - might have to tap them for info if we need it...


****Anyone wanting to add their name to the ROCKET Group Build list let me know ASAP - We are near a sellout on the first dozen chassis and board sets.****


cheers

rj

[Fischerman]

FWIW RJ, I think the term 'Alwood' comes from combining the names 'Albion' and 'Woden'...apparently the Heyboer equipped Hayseeds with the Alwood mod have the good qualities of each of those two OEM Vox OTs. Rob (I think his screen name is 'tralfax' or something) is the owner/builder of Valvetech. A friend of mine has an early Hayseed 30 and loves it.

At this point I'm thinking most about the trannies. FWIW, I just sent an e-mail to one of the more knowledgeable TGP posters on AC30s...mainly just asking for suggestions/experiences with different OTs and B+ voltages. I'll post what he suggests if he responds.

[dr. who]

Since the topic of rockets is ongoing, can some of this information be used to make a bom for rocket amps? Also is there a bom for liverpools?
Thanks,
Dr. Who

[Lonely Raven]

Rockit faceplates are done!

I'm bushed. With all the Trainwreck faceplates I've been doing, custom logos, and now this Rockit project...I'm just plum tired!

I do hope you guys enjoy them. I have two types per RJ's design.

The top is Option 1 the bottom is Option 2 - This is on cherry (sorry for the poor photo)

[img294]http://lonelyraven.zenfolio.com/img/v1/p988436124-5.jpg[/img]

Right now cherry is the only option. I do have a little AAA Birds Eye Maple and some lightly flamed Maple, but it's in short supply...so I don't want to make Rockit plates out of them if nobody wants them. The maple would come at a slight premium unfortunately.

Due to time constraints I can't do full customs on these, so I'm just going to mass produce the Rockit faceplates and get them to RJ to send along with the Rockit kits which sound like they are getting closer and closer to completion.

[RJ Guitars]

Rockit faceplates are done!

Awesome Dude!!! You will be an AmpGarage Legend...

I figured when i hadn't heard from you you in while you were busy with the high tech woodburner.... I hope the amps are as cool as the faceplates....

Thanks for your hard work!!!

----

The chassis are ordered and in production (2-3 weeks)

The transformers are ordered and in production (2-3 weeks)

The order goes in tomorrow for tube sockets and misc mounting hardware...

My wife cannot figure out why anybody would offer to run a zero profit build like this... I'm having a blast and I think I'll have one of the coolest amps in the universe when it's all done

The first option list has 11 names on it now... only one spot left!

rj

[RJ Guitars]

Since the topic of rockets is ongoing, can some of this information be used to make a bom for rocket amps? Also is there a bom for liverpools?
Thanks,
Dr. Who

Doc - I have a BOM that I've been working on for the ROCKET... my eyes are getting really computer weary and I think I'd like for someone else with fresh eyes to take a look and help polish it from a rough draft to "The List".

If you don't have a schematic to work with - PM me. Meanwhile, Sven is putting together a polished schematic for us as I write... Hopefully this will be a good document that comes out of this group build effort.

rj

[RJ Guitars]

Rocket Builders - there are a couple things that I have not found yet or I am not entirely happy with what I found.

Those vintage Dymo labels - does anyone have a label maker and enough tape to create 12 full sets of labels? Send me a PM

The choke - The AC-30 used a 15 Henry choke. There is not total agreement among the veterans as to whether this is even needed, but I want to offer it just the same. I can get Hammond no problem... AC-30 replacements are very high even for dealer pricing ($40.00). Heyboer is working on something for me, hopefully that will be the answer. Most vets agree that 10-20 Henrys would work just as well. Send me a PM if you have a product or a source.

rj

[Lonely Raven]

Make that 11 sets of Dymo labels. That stuff makes me cringe. I'd use a P-touch over the Dymo labels any day, but I'll probably figure something better out in the long run. But then, my goal is to make a nice looking modern rendition of the Rockit. Not clone it down to the screw.

So that's one set of labels you don't have to worry about.

[Fischerman]

10 sets...definitely won't be using Dymos.

[HeeBGB]

I have a vintage Dymo machine and some black embossing label tape.

Haven't used it in a while so I don't know if it's still good BUT you can buy more tape here

http://www.nextag.com/dymo-labeling-tape/search-html

[RJ Guitars]

... Dymo labels. That stuff makes me cringe....

That's great... when I saw my first Trainwreck I thought that was hilarious but had no idea that they were actually great amps... I thought it looked pretty cheesy at the time - I am wiser now.

I'm going for the added tonality that the Dymo label adhesive creates when it interacts with the aluminum, thus causing enhanced harmonic content in the 700-3300 Hz audio spectrum.

Phil at Heyboer has been excellent - he suggests going with a Hammond choke since they are off the shelf. He doesn't think there is a lot of winding magic to a choke.

HeeBGB, I'll send you a PM - thanks.

thanks

rj

[Fischerman]

I'm going for the added tonality that the Dymo label adhesive creates when it interacts with the aluminum, thus causing enhanced harmonic content in the 700-3300 Hz audio spectrum.

Phil at Heyboer has been excellent - he suggests going with a Hammond choke since they are off the shelf. He doesn't think there is a lot of winding magic to a choke.

Yes, Dymos for the enhanced harmonics @ 700-3300 Hz...but any ole choke will do.

Just messin' with ya RJ.