Thoughts on Master volume for my 5F6-A

Discussion in 'Shock Brother's DIY Amps' started by dunehunter, Jul 17, 2019.

  1. dunehunter

    dunehunter Tele-Holic Double Platinum Supporter

    Age:
    65
    Posts:
    580
    Joined:
    Jul 14, 2011
    Location:
    Larkspur, CO
    Just finished my 5E3 and it sounds great. I took one of several good pieces of advice from the @robrob website and added a Master volume to it. Used one of the input slots as was one of his recommendations. While the speaker still needs a break-in period, I love the amp!

    Now I'm taking on my last task for a while, which is to construct a 5F6-A and I'm starting to gather up all the stuff I'll need. But owing to my experience with the 5E3 and the master volume, I definitely want to do the same with this amp. So here are my questions for the gang.

    1. @robrob shows a couple of master volume setups that would only be easy if you were starting from scratch: the Type 2/Lar-Mar and the Frondelli. Does anyone have any experience with these and any comments before I get started? I think I'm trending toward the Type 2 but would welcome any comments.

    2. Placement will not be as easy. On the one hand, there's plenty of room on the bottom of the chassis but the problem with that is that it will only be accessible with a screwdriver to take off the back panel. It looks like I've got enough space to put it right in between the 4 input jacks. But I wonder about whether or not the position will have an impact on the input signal being in such close proximity.

    The other spot would be the hole for the "Ground" which is at the far end of the chassis, right in front of the transformer. The hole is a little big, but doable--and, I've got nothing else to put there. Question is, am I too close to the transformer even when using coax for leads? Am I asking for trouble here?

    Any comments are welcome, as usual.
     
  2. Vibrolux59

    Vibrolux59 TDPRI Member

    Age:
    68
    Posts:
    77
    Joined:
    May 30, 2019
    Location:
    PNW
    Have you considered an attenuator instead of a master volume? Might be something to consider. I have a Clarke Piedmont (5f6 clone) with one of his attenuators and to me, with these bigger amps, it's preferable for getting higher volume tone at a lower volume.
     
    voskarp, dunehunter and Wally like this.
  3. Wally

    Wally Telefied Ad Free Member

    Posts:
    32,541
    Joined:
    Mar 17, 2003
    Location:
    Lubbock, TX
    If you have to have a master volume, which pulls the output section back, why not do away with the number 2 input in one of the Normal channel as you did in the 5E3......simple.
    An attenuator lets the output tubes to be pushed so as to get that ‘whole circuit’ involvement. Get one thatis large enough, and you could use it on all of your amps...even that 5E3.
     
    King Fan, voskarp and dunehunter like this.
  4. Nickfl

    Nickfl Tele-Afflicted

    Posts:
    1,539
    Joined:
    May 24, 2016
    Location:
    Florida
    I've used type two and type three master volume controls in my builds and I definitely like the type two better. Type three seemed anemic sounding if you turned it down enough to actually matter, the type two is actually able to lower the volume a useful amount before it starts to drastically change the tone. However, neither of them is going to allow you to have the cranked bassman sound at anything approaching bedroom volume. An attenuator might get you closer to that, but even then it is probably going to start to change the tone well before you get it that quiet.

    I'd go with the type two in the ground switch hole. I wouldn't worry about being close to the transformer, especially with shielded cable. I'd be more concerned about the heater and mains power wires going to the pilot light and the power switch, but those shouldn't be a problem either as long as you twist them well.
     
    dunehunter likes this.
  5. dunehunter

    dunehunter Tele-Holic Double Platinum Supporter

    Age:
    65
    Posts:
    580
    Joined:
    Jul 14, 2011
    Location:
    Larkspur, CO
    I actually have an attenuater--used to use it with my SFDR. Problem? The attenuated tone was not the same as the full power tone. Just...different. I know, I know, I could go out and get another one but the doggone things are expensive too. Plus, without trying them out, you never really know.
     
    Vibrolux59 likes this.
  6. dunehunter

    dunehunter Tele-Holic Double Platinum Supporter

    Age:
    65
    Posts:
    580
    Joined:
    Jul 14, 2011
    Location:
    Larkspur, CO
    Never tried their attenuator. Mine is a Rivera.
     
    Vibrolux59 likes this.
  7. Wally

    Wally Telefied Ad Free Member

    Posts:
    32,541
    Joined:
    Mar 17, 2003
    Location:
    Lubbock, TX
    And a MV does not give you the same tone as a cranked amp, either. It does allow one to crank the preamp overdrive while castrating the output section, though. I have played one attenuator that did not emasculate an amp at sever cuts, but it was built into the amp....and the OT was specially designed for that attenuation in a manner which I have seen only in that amp. At whisper volumes it had good tone.....it sounded as much like the amp at full roar as it could with having the restriction of not moving much air.
     
    Vibrolux59, voskarp and dunehunter like this.
  8. dunehunter

    dunehunter Tele-Holic Double Platinum Supporter

    Age:
    65
    Posts:
    580
    Joined:
    Jul 14, 2011
    Location:
    Larkspur, CO
    Admittedly, it did (the master) seem to work well with the 5E3...:D
     
  9. King Fan

    King Fan Friend of Leo's Ad Free Member

    Posts:
    3,849
    Joined:
    Jan 1, 2013
    Location:
    Salt Lake City
    Heh, I don't have any experience, but Rob does. :) (Sorry, I know you know that, but he provides a ton of detail that sheds light on this question.)

    After a pretty thorough discussion of all the options including Lar-Mar and Type 3, Rob says, "If you are building a 5F6A then I recommend installing the Frondelli Post Phase Inverter Master Volume. This is my favorite master volume..." and he goes on to list four pretty compelling reasons.

    Also, I likely missed something, I'm a bit confused when you say "only be easy if you were starting from scratch." I thought this was a build you're currently planning.

    As far as location, same as the 5e3. Pull a #2 input, as Wally says (no real interference issues, I think) or (better from a function and looks viewpoint) put it in the ground switch hole. If you do that, use multi-conductor shielded mic cable -- Rob suggests this on this 5f6a page and I think shows an example on his 5e3 page.
     
    dunehunter likes this.
  10. dunehunter

    dunehunter Tele-Holic Double Platinum Supporter

    Age:
    65
    Posts:
    580
    Joined:
    Jul 14, 2011
    Location:
    Larkspur, CO
     
  11. dunehunter

    dunehunter Tele-Holic Double Platinum Supporter

    Age:
    65
    Posts:
    580
    Joined:
    Jul 14, 2011
    Location:
    Larkspur, CO
    Well, I certainly screwed up that reply. Wish there was a way to delete a post...

    I quoted the whole thing from @King Fan then split it up. Don't know why it kept the italics and collapsed it.
     
  12. King Fan

    King Fan Friend of Leo's Ad Free Member

    Posts:
    3,849
    Joined:
    Jan 1, 2013
    Location:
    Salt Lake City
    It's kind of a trap in the quote function -- it's all too easy to start typing your reply in the empty space above the closing *{QUOTE}* tag. I read it anyway and appreciate your clarity and insight.

    You mentioned that Rob praises the Lar-Mar Type 2 before later saying the Frondelli is his favorite. IIRC he had the Lar-Mar info in there before he added (and maybe before he tried) the Frondelli, so my guess is he liked the L-M a lot until he met the F...

    But you can read informed opinions by others saying they like the L-M better than the F, so your idea here to collect input is still a good one. :)
     
    dunehunter likes this.
  13. dunehunter

    dunehunter Tele-Holic Double Platinum Supporter

    Age:
    65
    Posts:
    580
    Joined:
    Jul 14, 2011
    Location:
    Larkspur, CO
    Thanks @King Fan . I'm always appreciative of your comments. I did go back and re-read that piece in Rob's website and, I think you may be right; he really seems quite supportive of the Frondelli over the Lar-Mar.

    I'm kind of hoping he'll chime in on this but I am also interested in the opinions of others who may have put one or both of these into use. So far, a good discussion, I think;)
     
  14. robrob

    robrob Poster Extraordinaire Ad Free Member

    Posts:
    7,533
    Joined:
    Dec 29, 2012
    Location:
    United States
    KingFan nailed it. I liked the Lar-Mar or Trainwreck Type-2 best until Mr Frondelli offered up his master volume. For an already built amp I like to suggest temporarily alligator clipping in a Type-3 master volume because it works surprisingly well, especially in amps with light or no negative feedback.

    A problem with the 5F6A is the power tubes are the first tubes to go into overdrive so a master volume that keeps the power tubes clean will fundamentally alter the overdrive tone. It's still good but not the pure sex of an overdriving 5F6A.
     
    dunehunter likes this.
  15. dunehunter

    dunehunter Tele-Holic Double Platinum Supporter

    Age:
    65
    Posts:
    580
    Joined:
    Jul 14, 2011
    Location:
    Larkspur, CO
    Thanks @robrob . I was hoping you would weigh in. I got a little preoccupied over the last couple of days with decisions regarding Medicare (yes, I'm THAT old) so didn't get back to this right away.

    I know that anything I do along these lines will change the tone of the dimed amp; I won't be listening to a quieter version of the amp at all--I'm not sure that's actually possible. But at full volume and the pot engaged to full resistance, even my little 5E3 is extremely loud; I am therefore grateful for the little pot that "tames" it so that I can continue to play this marvelous little beast. Ditto the Bassman. Always wanted one but, like the Twin, an amp that needs a large space to fill. Thanks again for your comment AND for your marvelous website that I continue to enjoy.
     
    robrob likes this.
  16. dunehunter

    dunehunter Tele-Holic Double Platinum Supporter

    Age:
    65
    Posts:
    580
    Joined:
    Jul 14, 2011
    Location:
    Larkspur, CO
    So, I think the jury is finally in. I'm going to go with the Frondelli and use one of the input openings like I did on the 5E3 (Thanks @Wally ). Also going to give the RockCrusher another shot too, just to compare the two.

    Might start a build thread. This one is much more complicated than my previous two and I may want to enlist the help of the gang here:).

    Thanks to all.
     
    robrob likes this.
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.


  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.