60w Rocket Reverb EL34

Express, Liverpool, Rocket, Dirty Little Monster, etc.

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M Fowler
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Re: 60w Rocket Reverb EL34

Post by M Fowler »

Not sure I will even make a faceplate for this amp its a gigging amp and was an experiment.

1st switch 10uf cap to ground boost off V1b
2nd switch .001uf and 500pf caps on the board to volume this gives a bass boost.
3rd switch brite 500pf up - none - 100pf down
4th switch reverb pad when cranking I don't seem to use it much though.
Volume, Treble, Mid, Bass, Reverb, Cut, and Watts control.

All JJ tubes four 12ax7 and two EL34L

Celestion 4 ohm 12" G100-T
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rp
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Re: 60w Rocket Reverb EL34

Post by rp »

[quote="M Fowler"] custom 19" chassis/quote]

MF, who made the chassis for you? One off? Affordable?
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M Fowler
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Re: 60w Rocket Reverb EL34

Post by M Fowler »

PM Sound Technologies made me three chassis and he no longer is making them anymore, rats :)

Finding Fender style slant chassis is hard.
But they can be built by removing one inch on top and bend the front back and re-attach to chassis sides. That is the angle for a Fender slant chassis.
EDIT the above quote is wrong: it is 1/2 inch different to get the correct fender slant.
Last edited by M Fowler on Wed Aug 11, 2010 12:58 pm, edited 1 time in total.
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Structo
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Re: 60w Rocket Reverb EL34

Post by Structo »

I see AES is carrying some new boards.

http://www.tubesandmore.com/scripts/fox ... _TERMINALS

Those yellow tag boards with the flat terminals, weren't those $3 or $4 before?

Now they're $8.95?!
Tom

Don't let that smoke out!
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M Fowler
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Re: 60w Rocket Reverb EL34

Post by M Fowler »

Yeah when demand goes up so does supply costs. :)

I switched to the drilled 1/16 boards now rather than the tag type I attached.
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dorrisant
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Re: 60w Rocket Reverb EL34

Post by dorrisant »

Mark,
The amp looks great! I'm not surprised, your builds always look great. Ever get any sound clips together? Did you ever come up with a final schematic or layout for this amp? I have an old Elk Twin Amp 50 gutted and ready to rebuild. I would love to just reuse the two EL34s, PT, etc... Big chassis... lots of room. Could I use your plans for my project. This was what I was wanting to build with this old amp for quite some time now.

[IMG:1024:768]http://i946.photobucket.com/albums/ad30 ... hassis.jpg[/img]

PT - Labeled - 330V@180mA CT
6.3V@4.5A
5V@3A
Off Load Volts - 716VAC
Rectifier - GZ34
5 holes for 9-pin sockets
5 holes (1 not practical/usable) for Octal sockets or Cap Cans

Of course this is just what came with the amp, I don't know if I want to use the original OT as it is only 4 ohm output and I don't know what the primary impedance is.
Any help would be much appreciated. I would like to know what I can do to get the voltage down to a usable level more in line with a real rocket. I also want to know how to implement the PP EL34s. I'm thinking reverb later...
Would this really be worth the effort with a steel chassis?

Tony
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M Fowler
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Re: 60w Rocket Reverb EL34

Post by M Fowler »

Tony this amp was intended to have higher plate voltage.

The OT is Magnetic Components 40-18001 4k2 60w 4/8/16
PT is 40-18029 355-0-355 secondary 200mA
Choke is Hammond 158L 15h 75mA 411DCR

The amp is based off Normster's Rocket Reverb that I have posted many times :lol:

Your PT seems like it would well for the project the filament supply maybe cutting it close. That looks like a great chassis maybe a Dumble in that large chassis.

Getting the voltage down to the Rocket 250 or 260v range to me doesn't make sense when pushing EL34's but I like higher plate voltage.

If you haven't seen the Normster Layouts or Rawnster or rjguitars schematics and layouts let me know. They have been posted many times.

Otherwise you just build the amp with the same board as the normal Rocket and use your choice of caps, cap board or cans or cap stack.
You can go with either cathode bias power tubes or adjustable fixed bias.

Mark
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dorrisant
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Re: 60w Rocket Reverb EL34

Post by dorrisant »

Thanks Mark.
I'm not going to worry about dropping the B+. I would like to do an el34 Rockster, but I'm having trouble finding a schematic for it. I will proceed with a Rockster 6L6 instead of the KT66... I think. Depends on what I find in the next few days. Thanks again.

Tony
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M Fowler
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Re: 60w Rocket Reverb EL34

Post by M Fowler »

Tony,

There is no difference in Rockster using 6L6, EL34, KT66, KT77, KT88, or 6550. Remember to keep pins 1 and 8 wired for EL34's then you can use all tube types.

The only thing is increasing plate voltage for the various tube choice available. Go with adjustable fixed bias instead of cathode bias.

I have gone from EL34's to KT66 and no running 6550s in my other Rocket Reverb head. I am going to stick with 6550 and KT88's. It fits the aggressive blues/rock tone I like. The larger tubes produce more low end tone to my ears. The amp in this thread doesn't have any room to use anything larger then EL34's.

I know I have that schematic your looking for but I cannot get to my home computer right now. But rjguitar has posted that schematic and layout as well as the voltage chart in the past.

Mark
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dorrisant
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Re: 60w Rocket Reverb EL34

Post by dorrisant »

Thanks yet again... I think this will help me out:
http://ampgarage.com/forum/viewtopic.ph ... r&start=15

Tony
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M Fowler
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Re: 60w Rocket Reverb EL34

Post by M Fowler »

Tony,

Yeah that was the thread I was referring to, glad you found it.

rj and zippy can also answer your questions regarding this amp and probably a whole bunch more builders as well.

Mark
73GTV
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Re: 60w Rocket Reverb EL34

Post by 73GTV »

dorrisant wrote:Thanks yet again... I think this will help me out:
http://ampgarage.com/forum/viewtopic.ph ... r&start=15

Tony
You Gutted that Elk, Ahhhhhhhhhhhhhh!!!

What did you do with the parts? What ever happened to this project?
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M Fowler
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Re: 60w Rocket Reverb EL34

Post by M Fowler »

Fowler Hot Rod Tweed Bluesmaster.JPG
Had converted this Reverb Rocket to a Hot Rod Tweed Bluesmaster #2 a while ago.
IMG_0781.JPG
Sound Video: Try to figure out how to share non facebook.
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