Rockster Booster

[JazzGuitarGimp]

And it looks like a neat little trick!

Yeah it does! I was thinking that orphaned 5th stage in my Bruisemaker might have just found another research project.

You could even add a relay contact across the boost pot to make it foot-switchable.

[hans-jörg]

I was thinking about to switch it. The only reasonable way is via relay as you say.. Have to be switchable between coupling cap to ground / to boost pot. Right?

And: does a heater capacity with 4 Ampere be enough for the 9 noval tubes plus 1 relay.
Does a 12 V stabilizer work with 6,3 V rectified to around 9 VDC ? or better without stabilizer - the 12 V relay will work the simple way, I think

Best

Hans-Jörg

[dorrisant]

I talked with/emailed rj about his Rocket Booster about a year ago when I was trying it out. It works great!!! Adds a lot of fatness and seems to be out of the circuit at 0.

I did the Rocket Booster and a Watts control at the same time. Awesome versatility!!!

Tony

[M Fowler]

I should try this added gain stage in one of my Rockets.

I have the watts control in my reverb rocket which works very well.

[dorrisant]

Double Post

[dorrisant]

The Rocket I put it in has about 440 on the plates so it really liked the Watts control. The Rocket Booster goes all the way up to some sizzling hot preamp gain without any fizziness. I would strongly suggest it. It is like a "Fatness" control.

Tony

BTW... I personally don't see any need for a switch to remove the boost from the circuit, just turn it down to zero. It may make a difference but I'm just not sure it is worth the extra part(s) or effort. Try it though, you shouldn't be disappointed.

[JazzGuitarGimp]

I was thinking about to switch it. The only reasonable way is via relay as you say.. Have to be switchable between coupling cap to ground / to boost pot. Right?

That would likely be prone to popping when switched. I'd just use a SPST relay contact from the wiper of the Boost pot to the CCW terminal of the Boost pot (ground). When the contact is closed, no boost. When the contact is open, you'll get boost to wherever the boost pot is set.

[JazzGuitarGimp]

I was thinking about to switch it. The only reasonable way is via relay as you say.. Have to be switchable between coupling cap to ground / to boost pot. Right?

That would likely be prone to popping when switched. I'd just use a SPST relay contact from the wiper of the Boost pot to the CCW terminal of the Boost pot (ground). When the contact is closed, no boost. When the contact is open, you'll get boost to wherever the boost pot is set.

After re-reading your post, I think I misunderstood you - it looks like we're on the same page. My apologies....

[JazzGuitarGimp]

And: does a heater capacity with 4 Ampere be enough for the 9 noval tubes plus 1 relay.
Does a 12 V stabilizer work with 6,3 V rectified to around 9 VDC ? or better without stabilizer - the 12 V relay will work the simple way, I think :)Hans-Jörg

The Noval's are likely 0.3A apiece (if they are 12A_7 types). You need to consider the power tubes as well. If you have a standard pilot lamp, that's another 0.25A. The relay current will be negligible.

As for the relay power supply, let me first state that I have little experience with this. As well, I have read over on the Dunble side of the forum, that Dumble specifically used a separate power transformer for the relay supply to avoid popping in the audio path whenever the relay is closed / opened.

All that being said, here is my (untested as of yet) take on using the 6.3V filament winding for the relay supply (see attachment). I have drawn it with a center tap, but this will work equally as well with the 2x100R virtual tap. Note you'll need to use a 3V relay. Have a look at Mouser p/n 653-G6K-2P-Y-DC3. It draws 33mA and the 1N914 rectifier diodes are good for 100mA continuous (some are rated for 200mA) so you will easily be able to power two, if not three relays with this approach (as many as four or five if you use the 200mA-rated 914's).

HTH,
Lou

Need to retract part of what I said. After doing the math, the circuit in my example will not work with a 2x100R virtual ground. It will only work with a center tap. That's what I get for speaking before mathing!

[hans-jörg]

Thank you all.
I will give it a chance!

What I want to try is to rectify the 6,3 V to use the ~9VDC for my Finder Relay which I have at home. The working range is from 8,4VDC to 18VDC And no reason to stabilize with a 7812.
Or I put a small 9 V Trafo on top as I don with my 18 W Marshall for a 12V boost relay.
A third option is the 50 V tap which is there too. I can pull this down to~14VAC - recti - stab. - relay.
But I´m still on working out of the PT/OT constellation with my "head phone hum detector". The question w/wo relay is far enough. But RJ Boost + pot is fix.

Best

Hans-Jörg

[JazzGuitarGimp]

Thank you all.
I will give it a chance!

What I want to try is to rectify the 6,3 V to use the ~9VDC for my Finder Relay which I have at home. The working range is from 8,4VDC to 18VDC And no reason to stabilize with a 7812.
Or I put a small 9 V Trafo on top as I don with my 18 W Marshall for a 12V boost relay.
A third option is the 50 V tap which is there too. I can pull this down to~14VAC - recti - stab. - relay.
But I´m still on working out of the PT/OT constellation with my "head phone hum detector". The question w/wo relay is far enough. But RJ Boost + pot is fix.

Best

Hans-Jörg

I don't think you're going to be able to get enough voltage out of the 6.3V tap to run your relay reliably. Even if you use half-wave rectification with a diode having a 1V drop, you'll have 5.3 x 1.414 = 7.49VDC. The added detriment to this approach is that you'll be forced to ground one side of the transformer secondary for your DC reference ground. This will unbalance the 6.3VAC to the heaters, and will likely cause hum. I think your best bet is to use a separate tranny.

[hans-jörg]

Hm, you are damn right.
Thank you.

Hans-Jörg

[hans-jörg]

Hi,
I took Lous proposal with the 2x914 diodes and a cap. and have there now 4,3 VDC. Next the 3V relay (the 4007 Diode on it will drop another 0,7 V) so I´m quite right there.
https://tubeamparchive.com/download/file.php?id=25380

BTW the Bosster works perfect. With the pot you can diale in to where you want. On full its nice blast. Good Idea !
The relay is there to make a preposition and than to switch in.
I´m glad I saw RJs site with the Rocket Booster.

Best

Hans-Jörg

[dorrisant]

hans-jörg,

Glad to see the booster working well for you!

Tony