1. avatar Leif Bodnarchuk
    After seeing a youtube video of a guy talking about his "bank-doubler" for his MM4, i thought 'oh, i can do that!' and i did.

    Instead of using an expression pedal, you use a footswitch. You can install it on the top of the unit, or you can make a separate pedal. i made a separate pedal with two switches that controls both my MM4 and DM4. i also added a pot control in case i feel like dialling in the difference by hand, but it's not necessary. You COULD use both or either latching & non-latching switches if you wanna get a little crazy.

    The guy also talks about the potential flimsiness of the stock switches; my own DM4 suffered due to one of these, so i 'upgraded' with a new switch and all is well.

    Thought someone might make use of this info is all.

  2. avatar dave_b
    Bank doubler?? Maybe this is why the pedal wasn't for me, if it's more than on-off my head hurts!
  3. avatar Leif Bodnarchuk
    Haha, know what you mean, however, with the doubler, you basically get 8 sounds instead of 4.

    Having said that, you can only 'bank' within one preset. IE, you can't stay on switch 1, and get (say) Overdrive AND Distortion. You can only change the controls within the confines of one 'virtual pedal.'

    But it's still very useful. On the DM4, i really like the Chandler OD setting, and with the doubler, i can increase the gain, EQ and volume with the extra switch, and still have room for three other types of 'pedals.'

    The sub-octave setting in the DM4 is to die for... classic rock awesomeness! i'll shut up now.
  4. avatar dave_b
    You do like your sub octive fuzz! And I get you now bout the bank thing, clever using a footswitch! Got a question for you actually, seeing as you're a techie :) you ever service a hot rod deluxe? I got an intermittent buzz on the clean channel I'd love rid of!
  5. avatar Leif Bodnarchuk
    Aye, gimme a shout.
  6. avatar Chuffola
    Ooooh. While we're on the subject of HRDs...

    I think I have a microphonic 6l6 (I'm a complete noob at this stuff but I think that's what it is). When the volumes up a bit (not that loud - around 2-2,5) theres a sound like a broken, vibrating lightbulb behind my sweet, sweet tones. Quietish but irritating.

    Is a swap of the output tubes with new ones something I can do myself? I've read that the amp will need biased, so I had a quick look and the blue adjusting wheel thingy seems to be at the lowest setting already so is there much chance of damage if I just buy a couple of new 6L6s and shove 'em in? Or do I need to borrow my dad's multimeter (he's bound to have one - he's a dad) and get all electrician?

    As long as I don't touch anything else I shouldn't die, should I?

    Appreciate any advice. I'm 43, have had a decent, fulfilling life but would like to continue on for a few years yet, if possible. At least until the fags get me.

    The amp's only a few weeks old but can't be arsed with the whole sending off to Fender and waiting for months for it to come back with the same problem and a service note stating "no fault found".
  7. avatar dave_b
    As far as I know, in a combo amp with the valves upside down they will all develop rattle eventually (at least all mine have!), never been a problem for me though. Changing the power valves is easy, although if I remember rightly, the valves arn't 6L6's, but 6L6GC's (or 5881's). At least that's what I got. If you get groove tubes of the same colour you won't need to rebias the amp, if you get different ones you will. Easy peasy to do, but you will need a multimeter. There's loads of guides online about it with pictures if you look.

    Leif, I'll shout you tomorrow bout mine.
  8. avatar Chuffola
    Yeah - appreciate rattle is an issue with combos but I'm pretty sure it's the tube itself. When the offending valve is held with an oven mit (!) and a looper playing almost magically, the vibration stops. I only play at home - never been above 2.5 on the volume (and that on the -6db input) so I would hope that wasn't enough to rattle the things.

    Thanks for the advice about the Groove Tubes though. Mine are the white ones - that's what I'll order!
  9. avatar dave_b
  10. avatar Chuffola
    Hehe - that stock amp is probably the one I bought. Well, if the rattle is just something to live with I'll not bother changing. I'll just sit further from the amp. ;)

    I'm happy enough with the stock sound, to be honest. But then, its just me on my own pretending to be in the Drive-By Truckers.

    Sorry for hijacking your thread Leif! Just getting you back for the pallet of greek water quip...
  11. avatar Leif Bodnarchuk
    Haha, no problem!

    6L6s can be mounted in any position, as stated in the old RCA manual...

    Upside-down, angled, inside-out.. not really, but you get the picture. Has nothing to do with the spatial positioning, it's more to do with being bombarded by vibrations from the speaker. You just get this in combos where the valves are exposed to the speaker.
    Now, there ARE things called 'tube rings' which as far as i can tell are like a cock ring for valves; i've never used one myself (my valves have 'staying power!:lol: ) so i can't say if they're any good. Perhaps they are, i dunno.

    As for biasing, it's usually a good idea to check it, unless as Dave says, you know you are getting exactly the same thing as you had. But all you have to go on is a promise; buyer beware.

    Just throwing it out there, but JJ MAKE their own valves (As far as i know) whereas Groove Tubes get tons of 'em in, and just match 'em. At least, that's what i've been told in the past, perhaps that's not the case anymore. (and it's an ignorant statement to say the least. i'd bet they have a rigourous process all the same.)

    i pretty much always suggest JJ valves mostly because they provide their own data for them. They seem to be a company that 'does their homework.'
    Electro Harmonix provide no data. Not sure Sovtek do either.

    Oh dear, this has become bigger than all of us!

    As a note - it's not always enough to check the bias voltage on the tube (pin 5 in a 6L6's case) it's best to check the current draw and voltage of the valves' plates, in order to determine the POWER dissipation. In a 3-way (ooh matron) equation (P=IV) you need the I and the V.

    Measuring for current can be a bit tricky; there's a really handy way of checking it... i should really put this on another thread!
  12. avatar dave_b
    Wow, thanks for dispelling internet myth! Look forward to having a chat about my hotrod when I get it up to you! I do love the techie stuff :)
  13. avatar SimonC