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Hot Rod Deluxe is too hot (accoustically)

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  • Hot Rod Deluxe is too hot (accoustically)

    I picked up a Fender Hot Rod Deluxe from a co-worker for repair. He said that it wasn't working at all. Funny, all I did was replace the jewel lamp and voila! Don't ask. However, something he said about the amp being really loud was true - he claimed that he couldn't play the thing with the volume set any hight than '1' because it was too damned loud (his words). I smirked to myself at the time that he probably hadn't adjusted the volume and master volume correctly. Well... he was right. In the 'normal' channel, only the volume control has any affect on the loudness - the master volume is used when the 'Drive' channel is selected. And I can't play without an ear-bleed on a volume setting above 2. Of course, ear-bleed volumes are relative, but nonetheless, it was louder than I expected it should be. For fun, I replaced V1 with a 12AY7 and now I can get to 5 before seismographs go off.

    In regards to the loudness of the stock amp, is this normal? Maybe this amp is just too much for a small room. Better on a stage or a family room, maybe?

    And I suspect there is nothing wrong with the tube substitution I made, right? Maybe a 12AT7 would give a little more headroom? I just don't have one lying around to try.

    Larry

  • #2
    Sounds like the Master Volume pot is bad.
    KB

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    • #3
      Aside from retarded naming conventions for the volume controls, the Hot Rod Deluxe/DeVille has an audio taper pot on the normal channel and a linear taper pot on the drive channel. As you said, the "master" volume controls the drive channel. Replace that pot with an audio taper pot and that should make a huge difference. As for it being labeled "master", well...you'll just have to live with that.

      I have a DeVille, been there done that. While you have it open, have your friend spring for some new switchcraft jacks for the inputs, effects loop, and footswitch. The ones with the metal nut on the plastic jack will strip and short out at the very worst time, trust me. Those jacks in theory isolate the signal from the chassis, but I have replaced them without any grounding issues (like hum).

      You can also put JJ 6v6s (and only use JJs, because no other 6V6s that I know of can take the B+ voltage) in the output section (with a rebias, obviously) and that will reduce the headroom quite a bit and give you a nice drive an reasonable volumes. I never even use the drive channel. Who needs it when you have real overdrive?

      Check out this site: http://studentweb.eku.edu/justin_holton/ You'll find loads of good info there for this amp. A good amp once you fix the moronic bits like the linear volume pot and the metal/plastic jacks. I have had mine for 12 years now, and it has been pretty solid.
      In the future I invented time travel.

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      • #4
        JJs in Blues Deluxe

        Couldn't AGREE more with the recommendation to switch out the GT 6L6 for JJ6V6 and rebias. Easy to do and you have a completely new amp.

        Have done it for a couple of friends with Hot Rods and did it to my BDRI.

        The comment about not needing the "drive" channel is right on the money.

        USE ONLY JJs they can handle the B+ [430 on the BDRI]

        Haven't changed out any jacks on mine but time may come.

        Mike

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        • #5
          ANd also, you could point out to the guy that there is a knob on the guitar itself that can be turned down some.
          Education is what you're left with after you have forgotten what you have learned.

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          • #6
            ROFL!

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            • #7
              There is one other issue that arises with the Hot Rod amps and that is the under rated plate resistors on the 12AX7s. They are only rated for 250 volts and run upwards of 350. Eventually they get noisy and need to be replaced with higher voltage resistors, I always replace the 1/2 watts with a 1 watt at the same time, they fit fine and don't get so hot.

              Part of the volume problem with them is that they were designed as a "hot rodded" amp and having a linear audio pot makes it seem like it is much louder at lower settings. Marketing hype at its worst.

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              • #8
                I've got a Hot Rod Deville 212 and it is definitely the volume pot. It's linear instead of audio taper. I heard that this is a gimmick to make the amp sound perceivably louder compared to other amps in the store when you're test driving it. I lived with mine for a while until I finally bit the bullet and replaced it with an audio taper. The hardest part about the mod was getting the circuit board out of the unit. I solder wicked the old part out and replaced it with a fender audio taper equivalent. It's now one of my favorite amps. What was once a setting of 1 is now a setting of 4.

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                • #9
                  Originally posted by stosostu View Post
                  There is one other issue that arises with the Hot Rod amps and that is the under rated plate resistors on the 12AX7s. They are only rated for 250 volts and run upwards of 350. Eventually they get noisy and need to be replaced with higher voltage resistors, I always replace the 1/2 watts with a 1 watt at the same time, they fit fine and don't get so hot.

                  Part of the volume problem with them is that they were designed as a "hot rodded" amp and having a linear audio pot makes it seem like it is much louder at lower settings. Marketing hype at its worst.
                  Hi,
                  good points,
                  talking 'bout HRDL there' s also another issue that maybe it's worth mentioning, they seem to have under-dimensioned two dropping resistors in the PS section ( R78 and R79 ) too, at least on the earlier models, I only have seen one of those and don't know if they fixed this in later issues of the same amp; anyway, these two resistors were prone to failure, so if you still have the amp on your bench it's a good idea to check 'em.

                  As to the "Marketing hype at its worst", we unfortunately live in an era where it's all about "appearance" and "make believe", not about "substance" and "being", and this virus seems to have affected some amp designers too.

                  Regards

                  Bob
                  Hoc unum scio: me nihil scire.

                  Comment


                  • #10
                    Well, what I ended up doing is replacing the first preamp 12AX7 with a 12AY7 and I could get to around 4 on the volume before it was too loud. He wasn't paying me anything to fool around with it, so I didn't want to do a complicated pot replacement. In fact, initially, all he wanted to know was why the pilot lamp didn't light (because it was burned out). He also said the amp wouldn't turn on at all. It actually worked fine. I think he thought since the light didn't come on that the fuse was blown. Anyway... I had already replaced the volume control on a Peavey Classic 20 with a nasty tri-folded circuit board, and I really didn't want to do it on this amp. And he hasn't played them amp since he got it back 6 weeks ago. Oh, well...

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                    • #11
                      And after you do all that, build yourself a volume box. Its cheap and helps control volume while pushing the tubes more. Heres the link I used to bulid mine.
                      http://www.fortunecity.com/marina/newland/2081/id3.htm

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