Rocket 4x6V6

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Doxie man
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Rocket 4x6V6

Post by Doxie man »

After being so happy with my Rocket build I just completed, I have decided to do another running 4x6V6 in the engine. They are my favorite tube to build with and I have a feeling they will sound KILLER with this circuit. I'll use the same Classic Tone PT, OT and choke but will tap the higher 300v HT and run a GZ34 rectifier. I'll probably bias the PI s little hotter as well to get those 6V6 valves singing. I'll try 820R/40 first then maybe 470R/20. We'll see when that time arrives. I have to admit that I never thought any circuit could pull me away from my beloved Tweeds and Marshalls but the Rocket has been quite the head turner for me 😍
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rp
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Re: Rocket 4x6V6

Post by rp »

Doxie man wrote: Mon Mar 27, 2017 11:54 pm I have to admit that I never thought any circuit could pull me away from my beloved Tweeds and Marshalls but the Rocket has been quite the head turner for me
You need to look over your schematics, compare the 5F6A/JTM to the AC30/Rocket topologies, the later is a Tweed, just a few small flavor changes in the pre, the LTP set up for the proper drive for little Brit pentodes, and the output w/ cathode bias and no NFB as was Denny’s choice.

Plenty others here have tried just about everything but 1000V transmitter tubes in the output section of the Rocket, unless someone chimes in that their 4X6V6 Rocket took then into orbit, I would think about pre-planning your board to have turrets for fixed bias and a NFB resistor, and the tone stack fix, so then easy-peasy to turn it in a 4x6V6 JTM45-ish amp - kind of like a stripped down low power Super-Lead, in case the 6V6 Rocket doesn’t meet expectations. Just a thought.
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Guy77
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Re: Rocket 4x6V6

Post by Guy77 »

Hi RP, your idea sounds very interesting.

" I would think about pre-planning your board to have turrets for fixed bias and a NFB resistor, and the tone stack fix, so then easy-peasy to turn it in a 4x6V6 JTM45-ish amp - kind of like a stripped down low power Super-Lead, in case the 6V6 Rocket doesn’t meet expectations."

I was trying to not find anymore reasons to build another amp and now I may have to try this one! Soon the wife will have me sleeping in the garage with my amps!!

Cheers

Guy
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RJ Guitars
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Re: Rocket 4x6V6

Post by RJ Guitars »

Looks interesting. I kinda think that either Normster or maybe David Root might have done a quad Rocket sometime in the past. I've done several Octal Rockets that were eventually dubbed as "Rockster" amps. I started out with 6V6's but as I tested out different tubes the KT-66 became my own favorite. IMHO, when a pair of KT66's enter the equation the Rocket takes one step closer to perfection. I suspect you'll find that a quad of 6V6's does very cool things to this circuit as well.
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Guy77
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Re: Rocket 4x6V6

Post by Guy77 »

Hi RJ.
I was curious about a KT-66 Rocket. The one thing I noticed with my new Rocket amp ( it was a Zwreck but i went with higher filtering and made it a rocket) is that it is not really suited to Lead playing ( not that there is anything wrong with that, the Rocket is an amazing amp!) . Do KT66's take it closer to that direction (Lead playing) ?

Cheers

Guy
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RJ Guitars
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Re: Rocket 4x6V6

Post by RJ Guitars »

Guy77 wrote: Wed Mar 29, 2017 10:23 pm Hi RJ.
I was curious about a KT-66 Rocket. The one thing I noticed with my new Rocket amp ( it was a Zwreck but i went with higher filtering and made it a rocket) is that it is not really suited to Lead playing ( not that there is anything wrong with that, the Rocket is an amazing amp!) . Do KT66's take it closer to that direction (Lead playing) ?

Cheers

Guy
What we found was that the really good sweet stuff was sweeter, the harmonics were a little richer, it was sorta like whatever was good in a Rocket was there plus a little more of it. This is hard to sort out because the amp is actually louder and that can fool us into thinking it sounds better because our hears hear things better when they are loud. Also, I've never had a pristine set of NOS EL84 tubes and I suspect they might bring a little more out of the average Rocket build.

So I think the ultimate Rocket sound is a little easier to get using the less expensive modern KT66 tubes. As a bonus you have half as many power tubes to wire up on the build. So I really like the KT66 tubes and my experience was that I got an amazing sound that was a little easier to obtain.

For lead playing some folks love Rocket amps. They do not have the blistering attack of an Express but are certainly more versatile. They also take pedals really well and that can make them into a very good lead amp. I would say I like the power chord tone of a Rocket above all others so I think they rank really high in that category. I don't think a Rockster is necessarily a better lead amp over a Rocket, but either can be made to do that job well.

Finally, an old Rockster sound clip. I ran ran the volume all the way up and used an attenuator but is was still a bit loud. The speaker cabinet & mic were in a closet together so there was no strong resonance back to the guitar from the sound. Not sure if you consider this lead tone or the kind of lead tone you ware looking for... ymmv
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Last edited by RJ Guitars on Wed Mar 29, 2017 11:47 pm, edited 2 times in total.
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RJ Guitars
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Re: Rocket 4x6V6

Post by RJ Guitars »

double post??
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Guy77
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Re: Rocket 4x6V6

Post by Guy77 »

Thank you for the clip! Great playing RJ. Love that song.

Yes the KT66 tubes give the Rocket amp some nice thickness. I like that tone.
And yes it can be hard to find good el84 tubes ! I went through several before I settled on some 7189 tubes.

The Rockster will have to be on my list of next builds!
Or maybe I get some yellow jackets to convert my 4 x el84 to octal tubes!

Cheers

Guy
Doxie man
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Re: Rocket 4x6V6

Post by Doxie man »

Nice clip and playing RJ but I have built a few circuits with 66's in the past and their tone is just not my thing. They are too "round" for my personal taste. I prefer a more cutting/on edge tone and 6V6 valves excel at that 👌 I've never built a circuit that did not sound less than terrific using 6V6 glass. I am betting 4 6V6 power tubes in a Rocket circuit will flat out do it for me 👍 Again....my preference and NOT an absolute for everybody 👍 I built a 5E3 with 4x6V6 tubes using Tweed Super Iron last year. Made it a 1x15 combo and it will stop you in your tracks when you hear it ! I build my Plexi circuits with those tubes as well.....never dissspointing.
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