66 Rockster Build
Moderators: pompeiisneaks, Colossal
Re: 66 Rockster Build
Excellent news. That is a great looking amp. 
Don't forget to run a voltage chart again and document where you are for future reference / comparison.
Regarding the raspiness.... don't be too hasty to judge. Amps tend to change a little with some time on them. The Sozo caps are reported to need extended time on them before they sound at their best.
Consider the whole picture also meaning speaker / guitar etc and put some time on it before you jump in.
If you have some other preamp tubes you can try I would do that before heating the iron up. Easy if you have tubes on hand and not intrusive.
What speaker / cab are you going through?
			
			
									
									
						Don't forget to run a voltage chart again and document where you are for future reference / comparison.
Regarding the raspiness.... don't be too hasty to judge. Amps tend to change a little with some time on them. The Sozo caps are reported to need extended time on them before they sound at their best.
Consider the whole picture also meaning speaker / guitar etc and put some time on it before you jump in.
If you have some other preamp tubes you can try I would do that before heating the iron up. Easy if you have tubes on hand and not intrusive.
What speaker / cab are you going through?
- RJ Guitars
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Re: 66 Rockster Build
Robert,
After you get comfortable that everything is in the right place and all is working well, take a look at some of the tweaks I did on my Rockster.
https://tubeamparchive.com/viewtopic.php?p=99275#99275
The values that I have here really softened up the amp a lot. If you look at how things deviate from the original schematic values that might help you with the tweaks. I really like having the trim pots because you can dial it in to taste pretty much in real time. In this case I went entirely for harmonics and fullness and the amp breaks up very early and very smoothly. In this configuration it's really acting like a much lower wattage amp.... this may not be for everybody or every occasion. I have to dial back the volume control on my guitar quite a bit to get clean sounds.
I need to run the next iteration to see how clean I can make the amp.
rj
			
			
									
									After you get comfortable that everything is in the right place and all is working well, take a look at some of the tweaks I did on my Rockster.
https://tubeamparchive.com/viewtopic.php?p=99275#99275
The values that I have here really softened up the amp a lot. If you look at how things deviate from the original schematic values that might help you with the tweaks. I really like having the trim pots because you can dial it in to taste pretty much in real time. In this case I went entirely for harmonics and fullness and the amp breaks up very early and very smoothly. In this configuration it's really acting like a much lower wattage amp.... this may not be for everybody or every occasion. I have to dial back the volume control on my guitar quite a bit to get clean sounds.
I need to run the next iteration to see how clean I can make the amp.
rj
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				bluesbreaker62
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 - Location: Netherlands
 
Re: 66 Rockster Build
Thanks for the feedback guys.
I'll leave the amp as it is for now.
I did try different tubes in V1, but the shrill top end didn't go away.
The trimpots seem like a clever idea, might give that a try.
The cab I'm using is a 2*12 open back with a Greenback/G12H30 combo.
			
			
									
									
						I'll leave the amp as it is for now.
I did try different tubes in V1, but the shrill top end didn't go away.
The trimpots seem like a clever idea, might give that a try.
The cab I'm using is a 2*12 open back with a Greenback/G12H30 combo.
- 
				bluesbreaker62
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 - Joined: Fri Apr 06, 2007 2:57 pm
 - Location: Netherlands
 
Re: 66 Rockster Build
At long last, an update on the 66 rockster...
The previous version was nice, but I wanted something else, more headroom etc, so I stripped the thing, down to the turrets and did a complete rebuild.
I installed a higher voltage PT, made it fixed bias ,added reverb and tweaked the circuit a little here and there.
This thing has been riding like this for well over a year now and its the best amp I've ever played, loving this thing. Bell like cleans, breaks up nicely when pushed, just perfect.
I've currently got it hooked up to a 1*12 openback loaded with a Celestion Gold, the first gold sucked, the second sounds great after break in. Weirdness, I expected more consistency with speakers like this.
Anyway, here she is..
			
			
						The previous version was nice, but I wanted something else, more headroom etc, so I stripped the thing, down to the turrets and did a complete rebuild.
I installed a higher voltage PT, made it fixed bias ,added reverb and tweaked the circuit a little here and there.
This thing has been riding like this for well over a year now and its the best amp I've ever played, loving this thing. Bell like cleans, breaks up nicely when pushed, just perfect.
I've currently got it hooked up to a 1*12 openback loaded with a Celestion Gold, the first gold sucked, the second sounds great after break in. Weirdness, I expected more consistency with speakers like this.
Anyway, here she is..
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				bluesbreaker62
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 - Location: Netherlands
 
Re: 66 Rockster Build
And another pic of the front..
			
			
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						Re: 66 Rockster Build
Question about your buss wire behind the pots: it appears in the photo that it's bent toward the circuit board and grounded to turrets at both ends. True? Or is it really only grounded at one end, and just soldered to turrets for stability?
Re: 66 Rockster Build
Nice job, these make great gigging amps.   
			
			
									
									
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				bluesbreaker62
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 - Location: Netherlands
 
Re: 66 Rockster Build
Thanks guys ,  the buss is grounded at the input, soldered it to the turrets for stability, didnt want it hanging off by the wires only, wire breaks and such.
Could imagine it wouldn't do any good knocking the amp around for a couple years with the buss flopping around inside the amp,.
			
			
									
									
						Could imagine it wouldn't do any good knocking the amp around for a couple years with the buss flopping around inside the amp,.
Re: 66 Rockster Build
I bet your house is really neat. 
 That is one the nicest builds I've seen. Superb craftsmanship! Glad you got it the way you want it. A Rocket amp of some type is on my radar for sure.
			
			
									
									
						- 
				bluesbreaker62
 - Posts: 70
 - Joined: Fri Apr 06, 2007 2:57 pm
 - Location: Netherlands
 
Re: 66 Rockster Build
Thanks for the kind words man, I think I went a little ocd on that one, but I’m very pleased with the outcome.
Still have to make a cab for it though.
			
			
									
									
						Still have to make a cab for it though.