Building a Single Ended 5 watt amp - Can anyone help me install a Master Volume?

Discussion in 'The Workbench' started by Yamariv, Jul 28, 2020.

  1. Yamariv

    Yamariv Well-Known Member

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    Thanks Gene, good call on the Bay for the resistors! WAY cheaper there for sure, I'm gonna grab a bunch of spares for each value incase I want to build a few more attenuators down the road! :cheers:

    For the inductor coils, I'm not sure how to even search what I need..I have no idea how they work, are there different gauges of wire that I should look for? Sorry for the noob questions but I have never dealt with inductor coils.. :ohno:
     
  2. Gene Ballzz

    Gene Ballzz Well-Known Member

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    For the 50 watt unit, 19 gauge will be fine

    L1 > https://www.madisoundspeakerstore.com/air-core-19-awg/madisound-0.7-mh-19-awg-air-core-inductor/
    L2 > Either get the 1.25mH and unwrap a couple/few winds (JohnH can instruct you on this) https://www.madisoundspeakerstore.com/air-core-19-awg/madisound-1.25-mh-19-awg-air-core-inductor/
    OR get the 1.0mH and I think you should be fine > https://www.madisoundspeakerstore.com/air-core-19-awg/madisound-1.0-mh-19-awg-air-core-inductor/
    Again, reach ou to JohnH for the detailed specifics. He's a great guy!

    Then, you need to get into your housing and venting it. Here's a link to some pics of my first version in post #178/page #9. https://www.marshallforum.com/threads/simple-attenuators-design-and-testing.98285/page-9

    I've made some updates. If you scroll through all the pages of that attenuator thread you'll see pics of others' builds and some of them look absolutely stellar. Planning and layout is your best friend here!

    Have Fun,
    Gene
     
  3. Gene Ballzz

    Gene Ballzz Well-Known Member

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  4. Gene Ballzz

    Gene Ballzz Well-Known Member

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    @Yamariv
    I also suggest that you see posts #1116 & 1118 on page # 56:
    https://www.marshallforum.com/threa...design-and-testing.98285/page-56#post-2000746
    and if you have not placed any parts orders yet, you may want to consider the 16 ohm M2 that only uses one inductor coil. From JohnH's testing, any of the differences that may be able to be measured are nearly imperceptible to the ear. To get the real skinny, you gotta read the thread. And though the thread seems really long, it's pretty easy to figure out which posts you can skim past, where folks are talking about their goldifish having puppies, etc!

    With that said, all efforts here well worth it for the liberation this attenuator will provide. Imagine the thrill of being able to crank your AC30 into it's sweet spot, without vaporizing small pets and children at ten paces! I've been a gigging/jamming guitarist/singer for +50 years and this attenuator is the coolest piece of gear I've ever owned!

    Just Sayin'
    Gene
     
    Last edited: Jul 31, 2020
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  5. Yamariv

    Yamariv Well-Known Member

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    Hmmm, ok cool, so the M2 may be a better fit then!..I've found most of the resistors on the Bay but can't find the 39 & 47 Ohm 50 watters, looks like I'll have to do Digikey or Mouser for those unfortunately.

    Went through more of the thread this morning and it's all making sense. BTW, after your builds do you recommend a specific enclosure? I have a large double wide Aluminum Pedal case I was gonna try but it may be a little too thin to fit everything with the inductors in it

    Ok, back to reading!! :cheers:
     
  6. Gene Ballzz

    Gene Ballzz Well-Known Member

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    @Yamariv
    Here's the ones I've been using so far. They seem to be about the minimum you can get away with:

    https://www.ebay.com/itm/142615103868

    I need to find a flatter/longer one for my next build that I want to install in a head cabinet. The variety of sizes and shapes is mind boggling! Don't forget to drill cooling vents and use heat sink compound when mounting the resistors. Its also important that all the jacks are isolated from the chassis. HohnH says that he prefers to use Cliff UK "Stereo/TRS" jacks, even where "Mono/TS" would be sufficient, as they hold the plug more securely. I'm tending to agree and also see the ability to use that extra lug connection for some future switching mods I may have in mind. Make sure you find the genuine CLIFF UK units and not the crappy knockoffs that have recently been found flooding the market. I hear the REAN brand is also OK.

    Just Sayin'
    Gene
     
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  7. Yamariv

    Yamariv Well-Known Member

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    Good advice on the Stereo Cliff jacks, makes perfect sense, I'll order some of those!

    Double face palm for me living in Canada! :facepalm: I found the right Induction Coils at Madisound and went to order 4 to make some spare M2's and the shipping to Canada is more than the 4 coils combined. Cheapest shipping option is $39 US, that's going to be 60+CAD after exchange to ship, plus I'll probably get dinged brokerage etc.. Thats super disappointing! Are there any other sources that may have reasonable shipping rates that you know of? I checked Digikey but couldn't find the right Coils, maybe I'm searching them wrong though??..They willl ship to me overnight for $8 Canadian with no duties which is amazing!

    As for the cases on Ebay, they look nice but nope, seller doesn't ship to Canada :facepalm::io:
     
  8. Gene Ballzz

    Gene Ballzz Well-Known Member

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    How about Parts Express?
    Just Curious?
    Gene
     
  9. Gene Ballzz

    Gene Ballzz Well-Known Member

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    Maybe member @Freddy G knows a suitable source for those in Canada?

    Just Sayin'
    Gene
     
  10. Yamariv

    Yamariv Well-Known Member

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    Logged in and they want $30 US for shipping plus brokerage fees with that carrier..The other option is $44 US for $25 worth of coils..There's gotta be a place in Canada that sells these :run: The search continues..
     
  11. Micky

    Micky Well-Known Member VIP Member

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    Jeez for a 5W build just get a Bugera PS-1 and be done with it.
    $100 bucks and you can use it with other amps.

    If you already have a lot of parts on hand, THEN build one.
    Why spend all the time labor and shipping PLUS parts?
     
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  12. Gene Ballzz

    Gene Ballzz Well-Known Member

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    Micky,
    The PS-1 and even the Weber MiniMass sound like absolute doo-doo compared to the design I speak of, even though they certainly do a wonderful job of shedding volume. Not all attenuation designs are created equal! The JohnH design would easily cost nearly $500 if commercially packaged and available, while a bullet proof "home made" unit can be done for +/-$100.

    Just Sayin'
    Gene
     
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  13. Yamariv

    Yamariv Well-Known Member

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    This has now gone much further than an attenuator for just the 5 watt build :fever: I've always been interested in an attenuator but knew they were expensive and I had no idea there were plans for home built models at a fraction of the price until this thread :cheers: I LOVE building amps, pedals and anything else amp related so this is right up my alley!
     
  14. thetragichero

    thetragichero Well-Known Member

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    i get a chuckle at all this talk about an attenuator for a 5w amp. why not build an iso cab?
     
  15. Yamariv

    Yamariv Well-Known Member

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    Good to know Gene! Just gotta find me a Canadian coil supplier..worst case I'll just have to eat the crazy shipping cost. I'm guessing since @Freddy G is so close to the border, he must have just ran across to pick up the parts when he built his. I'm about an hour away from Ogdensburg and would just run down there normally but this Virus messed those plans up..:facepalm:
     
  16. Micky

    Micky Well-Known Member VIP Member

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    But Gene, have you ever tried a Weber or a PS-1?
    Do you believe everything you read on the Internet?

    I have built John's designs.
    I was in on it early, as I had parts.
    Most people have no idea what reactance and inductance even is.

    But yet, time after time I turn to the PS-1 because it is adjustable.
    By adjustable, I mean infinitely adjustable. 1 big knob does it.
    For ease of use it rates very high.
    I use John's design on my Fender amps. It works but is not enough.

    So please don't lecture me about what you 'read'.
     
  17. Gene Ballzz

    Gene Ballzz Well-Known Member

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    @Micky

    As a steadily gigging player/singer for +50 years, I've tried many if not most attenuators that have come down the pike since the early '70's (can you say ALTAIR?:rolleyes:) and have been thoroughly disappointed by all of them, some far more than others! My chosen core sounds are achieved by plugging my guitar straight into an amp and cranking the amp to it's tonal sweet spot and leaving it there. This is problematic if and when the amp is too powerful/loud.

    I have owned a Weber MiniMass (internet hype convinced me it was better than others that had come before and that hype was generally correct) for several years and will never sell it, as it has its place and convenience. I also owned (for 29 days of a trial period) a PS1, in hopes of a less expensive alternative to the Weber. The PS1 reacted quite similarly to the MiniMass, including the anomaly of there being only two or three "sweet spots" throughout the sweep of "The Knob!" Those "sweet spots" vary a little with each amp speaker combination, but generally end up at minimum attenuation, about 30% (according to "The Knob") and about 75% (again, according to "The Knob!"), with all settings in between exhibiting varying degrees of the sound, dynamics, response & subtle nuances being generally lackluster, dull, wimpy and lifeless! The JohnH designs do not exhibit these anomalies and allow great, uncompromised sound all the way down to bedroom levels.

    I realize that "stepped" attenuation levels do not allow for "fine tuning" of volume level, but those -3.5 db "steps" are fairly small and "in my considered opinion" are much easier to work around than losing the subtlties I want and having a sound I don't really like! And while I realize you tried John's design "early" in its development, the design has been tweaked and has evolved dramatically, along with John's testing. And while I also agree wholeheartedly with the "ease of use" of the PS1 and/or MiniMass, the JohnH is simply superior in every other way and just sounds better throughout its range! I "personally" rate the JohnH design as one of the best passive designs out here on the "Inner-Nest" and will continue to tout their benefits! You can "pooh-pooh" those benefits if you like and if those subtle losses of nuances don't bother you, bless you for not being afflicted with the curse of being as anally retentive as me! :rolleyes: And FWIW, this was NOT info read on the "Inner-Nest" but instead derived from years of my own personal experience!

    Please note also that I'm not comparing these "passive" units to items like the Fryette Power Station, BadCat Unleash, OX, etc, that are not actually attenuators at all, but should more accurately be called something like "re-amping" devices, as they are basically a load box that allows a signal to be derived from that load and "re-amplifies" it through its own internal power amp to power the speaker. There are varying levels of bells and whistles added that are somewhat comensurate with the pricing of each brand/model. Although the term "re-amping" can get a bit confusing, as it refers to a somewhat different process in studio recording!

    While I agree at face value, a cranked 5 watt amp can be quite loud in an "at home" environment. It should be noted that the OP also has an AC30 and a TSL60 that I'm guessing he'd enjoy using "at home" without driving family/housemates/neighbors crazy! Thus the benefits of a GOOD attenuator!

    Just My $.02!
    Gene
     
    Last edited: Aug 1, 2020
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  18. Micky

    Micky Well-Known Member VIP Member

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    I see you went back and edited your previous post
     
  19. Gene Ballzz

    Gene Ballzz Well-Known Member

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    ?????
     
  20. Marcell

    Marcell Active Member

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    Got something.
     

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