Comtemplating a wreck - couple of questions first

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statorvane
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Comtemplating a wreck - couple of questions first

Post by statorvane »

I have three amps under my belt, and have been contemplating a 6V6 PP amp build for some time now. I am really torn :? between a 6V6 plexi, JCM 800, or a 'wreck. The PT I have will probably get around 450 volts SS rectifier. I am thinking a 5U4GB rectifier to get down closer to 400 volts in a wreck. PT is 300-0-330 VAC @ 200 mA, 5 VAC @ 3 A, and 6.3 VAC @ 6A. The schematic I am interested is the A4 version here. I like something that responds well to the guitar volume and the A4 description sounds very appealing.

Which would be better - a SS rectifier at ~450 volts, or 5U4GB rectifier at ~ 400 volts? Or would it be more practical voltage-wise to build a 6V6 plexi / JCM 800? Way different amps I know. I really don't want to spring for another PT. I am hoping to build something my son will like - yes it will be his if he wants it.

I am also wondering if any of you have done anything useful with the extra triode in the 'wreck preamp -was thinking about incorporating a trem into a 6V6 'wreck.

Thanks,

Kelly
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Bob-I
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Re: Comtemplating a wreck - couple of questions first

Post by Bob-I »

The PT is a bit hot for a Wreck so I'd use the tube rectifier. I built a Wreck from a Bassman with about the same working voltage and it's fine but why not get it closer to the real thing.

As for that extra triode. I use it in parallel on the first gain stage. I wired the 2 input jacks so that #1 uses both triodes and #2 uses just V1b. Overall I like the parallel triodes better, a tad more overtones and grit and not really much more gain.
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dartanion
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Re: Comtemplating a wreck - couple of questions first

Post by dartanion »

That's about right for a Concorde. Give that a shot with your PT. Quite similar to an Express.

It take it that it's a 330-0-330 and not a 300-0-330 :wink:

Wrecks and Komets are not really a beginners build, but since you a few under your belt, go for it.
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John C
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Re: Comtemplating a wreck - couple of questions first

Post by John C »

Two inputs: one for single triode; the other for two triodes... How cool! I like your thinking. I too am using parallel triodes, and I like the tone more. Might be the overtones, as you said. Did you notice any improvement in noise reduction? Any other comments?

...Oops, I just noticed I hijacked somebody's thread - sorry. Bob-I, maybe a PM would be more polite. Sorry, sorry...
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Bob-I
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Re: Comtemplating a wreck - couple of questions first

Post by Bob-I »

John C wrote:Two inputs: one for single triode; the other for two triodes... How cool! I like your thinking. I too am using parallel triodes, and I like the tone more. Might be the overtones, as you said. Did you notice any improvement in noise reduction? Any other comments?
No change in the noise, but I ground out the unused triode when it's not in use. Honestly, I seldom plug into the other input.
...Oops, I just noticed I hijacked somebody's thread - sorry. Bob-I, maybe a PM would be more polite. Sorry, sorry...
Well, yes but I hope that Kelly can benefit from this into too.
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statorvane
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Re: Comtemplating a wreck - couple of questions first

Post by statorvane »

I built a Wreck from a Bassman with about the same working voltage and it's fine but why not get it closer to the real thing.
Pretty much what I am doing. The Bassman was cool, but far too loud to hit the sweet spot. I separated the cathodes on V1 and swapped in a 12AX7 which did give more gain, or edge over the 12AY7. Still a real house shaker though. Driving a 4 x 10" cab.
It take it that it's a 330-0-330 and not a 300-0-330
Yes, good catch.
That's about right for a Concorde. Give that a shot with your PT. Quite similar to an Express.
I am unfamiliar with the Concorde. Are there schematics and sound clips for this? I really like the wreck clips posted here, and Glen K's YouTube clips.
As far as the parallel input triodes, do you guys use shared cathode caps/bias like the 5F6-A or separate like the 1987? I seen to remember a wreck with a paralleled V2 - think it is a 12AU7.
...Oops, I just noticed I hijacked somebody's thread - sorry. Bob-I, maybe a PM would be more polite. Sorry, sorry...
Hey no problem - interesting discussion about extra triode uses. I am almost thinking that if I paralleled them this amp would begin to resemble a 1987 with an extra gain stage vs. the 1cathode follower. Superficial I know, but interesting discussion. Maybe not a wreck, but a.... Pileup?

Thanks again.
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Bob-I
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Re: Comtemplating a wreck - couple of questions first

Post by Bob-I »

statorvane wrote:Pretty much what I am doing. The Bassman was cool, but far too loud to hit the sweet spot. I separated the cathodes on V1 and swapped in a 12AX7 which did give more gain, or edge over the 12AY7. Still a real house shaker though. Driving a 4 x 10" cab.
We're talking about a different Bassman here. Mine is a Silver Face from the 70's, your sounds like a 5F6-A from 59.

If you think this is going to lower the volume, you're way off base. This thing is quite a bit louder than the stock Bassman.
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statorvane
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Re: Comtemplating a wreck - couple of questions first

Post by statorvane »

Well hey, thanks Bob. Looks like I will go with a 6V6 1987 then - hot wire mod. I know I can get a decent grind at a lower volume with this than a 5F6-A. I did not realize the wreck would be that loud. It is nevertheless, a most impressive amp.
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