A Phoenix is born (out of a Carvin amp)....

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by drgonzoguitar, Aug 10, 2008.

  1. drgonzoguitar

    drgonzoguitar Member

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    It is based off of the A035 Hammond Reverb Amp (and similar to a IIb Lite). [​IMG] I wanted to recycle my amp chassis, lamps, etc... to make a 18 watt, 2 EL84 Class AB amp. I realize I am a much better tech than builder---but it is a fun learning process regardless! I have included all of my mistakes so everyone can look and say to themselves, "...why the hell did he do that?"

    Here is the link to all of the schematics, layouts and actual build photos (including all of my mistakes)!

    http://s5.photobucket.com/albums/y199/CannonFodder187/phoenix/

    I have sound samples recorded with a Tascam DR-1:

    Sample 1: Phoenix through 112 Celestion Lead 80 in an undersized Carvin combo cab.

    http://soundclick.com/share?songid=6795675

    Sample 2: Phoenix through 212 closed back cab and a MXR Carbon Copy.

    http://soundclick.com/share?songid=6795683

    Sample 3: Phoenix through 212 closed back cab, modded BOSS SD-2 (both channels) & MXR Carbon Copy.

    http://soundclick.com/share?songid=6795691

    Things I am not real happy with:

    1) I wish the overall voltage was lower. Hammond transformers are rated at 110V, not the 123V AC coming from my bench outlets. My DC voltage is about 10-15 volts higher than I would like them to be on everything. I really need to get a Variac. Still, it is ok....

    2) The tone control sounds best around 5 o'clock. I wish there was more range from treble to bass response. Once you dial it in, you are fine. Check out Sample 3 when I sweep the tone knob (around 1:50). I might have to change that up. I am debating on a 5 position switch with an ES-345 RC tone matrix...I want to gig it a few times to determine what to change.

    3) It is 1:23AM and I want to crank it up...but my wife and kids might object. [​IMG] I guess I will have to wait until Friday to gig with it. I might need to make it "prettier" this week. [​IMG]
     
  2. Alvis

    Alvis Member

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    Very cool .I love this kinda stuff . I know what you mean about better tech than builder. I feel the same way . Practice ,right ?

    I cant wait to egt on with my next guerilla project
     
  3. drgonzoguitar

    drgonzoguitar Member

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    Thanks! This is my second amp I have built. I am already thinking about my next project too. I like the idea of recycling what I have laying around to make an amp come together. I figure this is a good way to work on some techniques. I do not ever plan on starting a company or building amps for others. There are way too many great builders out there! This is more for fun (that I can gig with).

    :BEER

    By the way Alvin, you kick musical a$$! I love the tune "Motivational Speaker."
     
  4. drgonzoguitar

    drgonzoguitar Member

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  5. jh45gun

    jh45gun Member

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    I do not know how to explain it but I had the same problem with my Hammond Chassis that I built my Super with and my tech put two large wire wound resistors in the circuit to cut the voltage. I do not have it here it is still being worked on because there were other issues I could not resolve so I gave it to my tech friend and let his shop fix it so I cannot see what he did since it is not here but he mentioned the same thing about the PT voltage being lower on the tranny on the wall side which makes it higher on the other side.
     
  6. hasserl

    hasserl Member

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    So you went from an amp with two discrete channels, reverb and four power tubes two a single channel amp, no reverb and only two power tubes. Seems like a step backwards to me. Those Carvin amps are pretty nice stock, but with a few simple mods can be made into great amps.

    I've built plenty of amps, (and have had plenty more on my bench) but I still have my Carvin and use it all the time, and would put it on a stage with any amp knowing it would hold it's own.

    Chassis are cheap, I don't think you saved anything in this deal.
     
  7. drgonzoguitar

    drgonzoguitar Member

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    I have modded the Carvin. Heck...some of the mods are yours! Mind you, not the ones you were trying to sell....Anyways, here are my mods to the Nomad.

    http://www.youtube.com/watch?v=UJPUSG0Tgc0&feature=related
    http://www.youtube.com/watch?v=HpGVs3VYowI

    I shelved the Carvin to gig with a Line 6 Spider Valve instead. I decided I wanted to do something different with the Carvin. So, I tried modding some more things and I broke the PC board. Nice big puff of smoke over V2. I could have repaired a few traces, but chose not to.

    I converted the combo cab into a head cab and I now gig with this amp. I dropped around $250 into building this. Our band has a decent PA with my own monitor mix (in-ear), so the size of the amp was not an issue. I wanted an amp that broke up a little more musical. I also enjoy a fun recycling project. I added a cut control to tame the HF. It has been an enjoyable process. I will post some pictures when I re-tolex it with

    Here is what it sounds like now.

    http://soundclick.com/share?songid=6823042

    The original Carvin power tranny and output transformer are still good. Who know...maybe I'll use them in another project. Thanks for commenting Richard.
     
  8. drgonzoguitar

    drgonzoguitar Member

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    This is what I did. I have a 12.6VCT with a switch, so I can cut either 6 or 12 volts off of my incoming AC.

    http://www.geofex.com/article_folders/vintvolt/vintvolt.htm
     
  9. hasserl

    hasserl Member

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    The point is, all you really gained is the reuse of a chassis, one that has a lot more holes in it than you need. You replaced everything else in it, including the transformers. Maybe a better idea would have been to start with a fresh chassis, one that fits the application. And as much as I like the Carvin amps it pains me to see one discarded like that.

    Your amp does sound very nice though, and I realize the joy of getting your own amp, that is your own creation, up and running and having it sound so good. Congrat's on that!
     
  10. drgonzoguitar

    drgonzoguitar Member

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    I know you dig the Carvin stuff. They make a decent amp for a reasonable price. The resale value was not worth the time of getting a new PCB. I don't want to sell something that isn't reliable. With the mods I was doing with the amp, I was learning a lot. I was also weakening the PCB every time I did something! It just made more sense to me to cannibalize it. And after some new faceplates, most of the holes will be gone.;)
     

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