Opened my Rocktron Silver Dragon...Pics inside!!

nebucanazza

nebucanazza

New member
I opened up my Rocktron Silver dragon to replace the Chinese 12AX7 tube with a lower gain 12AY7.Clicked a few pics while I was at it.Must say,this pedal is a real bitch to open up.

What do I find?The second IC under the slayer intensity control is a 4558P with 2 diodes in parallel(marked in red in image2) .Now where I have I seen that before??;)

Also, the IC on the left is a LF353P dual JFET.What are these used for, active EQ?

Here are the pics:
 
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Re: Opened my Rocktron Silver Dragon...Pics inside!!

Heres a pic of my Arion Tubulator opened up as well.
Notice the JRC4558DD chip(sorry for the poor pic quality)
 
Re: Opened my Rocktron Silver Dragon...Pics inside!!

The 4558 is a very common op-amp, used in spades in cheap poweramps for cars too:D
The LF353 is also an op-amp, a great deal more nice than the 4558, we use that one and its bigbrother LF347.
It is probally a cascading setup that is on the dragon.
 
Re: Opened my Rocktron Silver Dragon...Pics inside!!

I was a bit surprised to find the TubeScreamer circuit (4558 with 2 diodes in feedback)in the Dragon, as it doesnt have that TS sound at any setting.Looks like it uses a TS circuit with the additional gain stage provided by the LF353.

What exactly is the role of the tube running at low voltage if the gain stages are coming from those two opamps?I guess it is similar in design to other starved plate tube pedals like TubeDriver/Tonebone/H&K.Changing out the tube totally changes the sound and gain of this pedal.
 
Re: Opened my Rocktron Silver Dragon...Pics inside!!

Well for that matter, the Plexitone also uses a "tubescreamer" layout....but other than that, they have nothing in comon;)
The tube is probally used as a gainstage, they are probally cascading into each other!
 
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Re: Opened my Rocktron Silver Dragon...Pics inside!!

Interesting...so the 'TS' thingie is a pretty common feature in designs.

I wonder whether having the tube does improve the tone.There have been numerous low voltage preamp tube pedal designs over the years.My feeling is that if the underlying SS circuitry aint sounding good, that tube in the signal path wont be helpful.Its cool that at least Rocktron is not charging $300 for the supposed 'true tube' tone:laugh2:
 
Re: Opened my Rocktron Silver Dragon...Pics inside!!

Well it is like alot of other things, only a few ways to obtain overdrive from a solid state circuit.
The clip circuit is identical, the Plexi is assymetrical, uses three very special diodes, the op-amp is a LF347, in a very few it is a TL074, the latter OP-amp we use in the AC-Tone.
The tube gives a different feel, and like different diodes or Fet's, it gives a different sound.
 
Re: Opened my Rocktron Silver Dragon...Pics inside!!

I dont currently have any clips.But if do some, be warned that it will be thru a cheap 15W Marshall SS combo miced with a computer mic, with crappy playing further ruining it:laugh2:

It is touted as a metal pedal, but I find it good for the classic stuff.I have changed out the tube to a 12AY7(as with the 12AX7 it started distorting too soon), will test it tomorrow.Maybe I'll record a riff or two then.

So your 9V series is made in China?
 
Re: Opened my Rocktron Silver Dragon...Pics inside!!

I recently had my Rocktron Short Timers opened up for a little extra wiring prior to mounting them on my pedalboard. Yes, theyu are a bitch to open up, especially the first time before you figure out how they work.

Overall, I was really impressed with the physical design of the Rocktrons. As an engineer, I can see how they were designed to be mass-produced inexpensively, but still be durable. The pots are a bit cheezy, but the switch is good - which is OK with me since I stomp on the switch (and try not to stomp on the pots).

I haven't tried any of the other Rocktron pedals, so I can't speak about their tonal aspects but mechanically, I'm quite impressed. Great bang for the buck.
 
Re: Opened my Rocktron Silver Dragon...Pics inside!!

The pots are a bit cheezy
Click to expand...
I think that they use the same as ours, and then it is Alpha's...then they anything but cheesy!
:)
Yeah our new 9v series is made in China, they are handmade there, they make some serious good work with those!!
They even outdo our regular line in some details!!
Use the same parts as the more expensive 12v line, so it is all good!
 
Re: Opened my Rocktron Silver Dragon...Pics inside!!

I am happy coz the price is right and their stuff usually sounds so good.They are very durably made, are extra big, but that makes for a neat layout where you dont hit the pots while you are trying to hit the switch.Of course its difficult to fit on pedalboard made for Boss type pedals:laugh2:

The Silver Dragon, Short Timer, Tsunami chorus are all great sounding pedals.The Austin Gold is supposed to be a poor man's Klon.People should try them out and see for themselves.

Whoever has the Silver Dragon, please try the 12AY7 tube.Its just the PERFECT amount of gain!!
Now the first stage goes from slight compression to crunchy blues to hard rock.The second stage adds gain on top of it. Endless sustain and great feedback, and its is now usable all the way(previously it was useless past 11'oclock witht he 12AX7).The pedal sounds smoother and noise is greatly reduced.The Tubulatior adds another gain option.
Coupled with my cheapo Tubulator and Short Timer, I am quite happy:dance:
 
Re: Opened my Rocktron Silver Dragon...Pics inside!!

i've always wanted to try either the silver dragon or the zombie are these things alot better than say line 6 ubermetal and mt-2 etc.?
 
Re: Opened my Rocktron Silver Dragon...Pics inside!!

stangme01 said:
i've always wanted to try either the silver dragon or the zombie are these things alot better than say line 6 ubermetal and mt-2 etc.?
Click to expand...

I havent tried the uber metal or mt-2.The general opinion on mt-2 is not really a positive one, I must say;)

The Silver Dragon is touted as a metal pedal, but its much more.With the stock 12AX7 it can be noisy, and the knobs dont do much over their range.Some pieces have microphonic tubes too.But still its a great sounding pedal IMO.It feels natural and alive, with a huge but tight bottom end.Great for classic/hard rock and metal, 2 channels.Change out the tube for a lower gain one, and it goes from TS type boost to metal.It will not do nu-metal though,even with a 12AX7.

Havent tried the Zombie
 
Re: Opened my Rocktron Silver Dragon...Pics inside!!

Err..I think the lingering doubts about the tube not being wired etc etc have long been dispelled.I have seen the effect of a tube change first-hand, the tube is very much an integral part of the pedal's sound.
 
Re: Opened my Rocktron Silver Dragon...Pics inside!!

Hi!
Can you help singer? I received this pedal. The switches are connected. I linked back to. Written on it which cable goes to the switch? or good photos .. Thanks, sorry for my bad english :)
 
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