Master volumes.

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pinkphiloyd
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Joined: Mon Jun 13, 2011 1:01 pm

Master volumes.

Post by pinkphiloyd »

First, I'm drunk. I drank what was left of the Crown. Then drank what was left of the Dogfish head. And I've since moved on to some cheap, domestic swill that somebody left here after my Cotton Bowl watch party. (Pig Sooie, bitches!!!). So if this is incoherent...whatever.

I'm about to start another AC-15/Lightning/Spitfire-ish build. I'm still working out the details. I'm contemplating this master volume instead of the standard Matchless style. What's the difference, tonally? Anyone? Anyone? Bueller?

http://www.blueguitar.org/new/schem/mis ... -m-vol.pdf
d95err
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Re: Master volumes.

Post by d95err »

In my experience, the Matchless style MV only works for very small reductions in volume (a few decibels). Beyond that, it looses tone very fast. Bass is heavily reduced at lower settings since the PI outputs are loaded down. I also find it difficult to control, as the volume change happens very fast at lower settings, even with a logarithmic pot. I'd say it can be useful for minor adjustments of stage volume, but it is unusable for "home" levels.

The dual pot solution will give you a much more smooth volume change with less tone problems. Both solutions will of course reduce the amount of poweramp distortion.
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M Fowler
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Re: Master volumes.

Post by M Fowler »

I second what Erik just told you, go with the dual pot master volume.

Mark
Alexo
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Re: Master volumes.

Post by Alexo »

...plus, if this is an AC15-alike, or other cathode-biased design, you don't need those .1 uf caps after the MV. In fact, you don't need them even in a fixed bias amp if you just connect the "bottom" lugs of the pots to the bias supply instead of to ground - as the bias supply should already be at AC ground. Might get a little DC scratch on the pot though.
Life is a tale told by an idiot -- full of sound and fury, signifying nothing.

...in other words: rock and roll!
pinkphiloyd
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Re: Master volumes.

Post by pinkphiloyd »

Excellent! Thanks everybody.
Cliff Schecht
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Re: Master volumes.

Post by Cliff Schecht »

pinkphiloyd wrote:First, I'm drunk. I drank what was left of the Crown. Then drank what was left of the Dogfish head. And I've since moved on to some cheap, domestic swill that somebody left here after my Cotton Bowl watch party. (Pig Sooie, bitches!!!). So if this is incoherent...whatever.

I'm about to start another AC-15/Lightning/Spitfire-ish build. I'm still working out the details. I'm contemplating this master volume instead of the standard Matchless style. What's the difference, tonally? Anyone? Anyone? Bueller?

http://www.blueguitar.org/new/schem/mis ... -m-vol.pdf
You sound more coherent when drunk than many do sober. Cheers!

Definitely try the dual post PPIMV. I've used it with much success as have many others. I like to use a dual 1 Meg pot and parallel a 1.3 Meg resistors on the pot which helps keep some sort of current leakage path to ground for the grid in case the pot itself fails (don't remember which version of the MV this is).
Cliff Schecht - Circuit P.I.
Gaz
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Re: Master volumes.

Post by Gaz »

I'd say go with VVR to keep the EL84s distorting at low volume settings. It's cheap through Dana, and very simple to wire up. Fischer/Larmar master would be my next choice. Anything is better than the Matchless style cross-line master.
lenniepickit
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Location: Evanston

Re: Master volumes.

Post by lenniepickit »

Hey - just wanted to bump this to ask if I can do that dual gang pot mod to my bassman - not clear on if I need those extra resistor there or not?

Anyone care to weigh in on the vvr versus this mod...?

Thanks!
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Reeltarded
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Re: Master volumes.

Post by Reeltarded »

Extra resistors? On the pot? Yes. The resistors on the pot are for safe usage. If the pot fails the amp won't run away and fall down go boom.

You WILL be surprised, somewhat amazed, and very happy. I use them to knock a few db off the top. Turning a 50 into a 30, or a 100 into a 70, basically.
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
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Colossal
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Re:

Post by Colossal »

KyleAdam wrote:Paperback Writer and Rain came out prior to Revolver but were not included on the album.Things really started to change on amplifiers with the advent of the master volume control in the seventies.Then someone figured out that by adding a master volume control to the end of the amp circuitry, you could turn down the overall volume of the amp, but boost the individual channel volume to produce distortion.-
Bump for a moderator to delete this user and all posts. KyleAdam is a Spambot.

Thank you.
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M Fowler
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Re: Master volumes.

Post by M Fowler »

But Dave, he's such a good responder:)

A message needs to go to that guy or cut him off the TAG food chain.

Mark
lenniepickit
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Re: Master volumes.

Post by lenniepickit »

Looks pretty straight forward - So is this the standard PPIMV that I seem to remember stumbling into at time before I knew what that was lol?
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Structo
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Re:

Post by Structo »

Colossal wrote:
KyleAdam wrote:Paperback Writer and Rain came out prior to Revolver but were not included on the album.Things really started to change on amplifiers with the advent of the master volume control in the seventies.Then someone figured out that by adding a master volume control to the end of the amp circuitry, you could turn down the overall volume of the amp, but boost the individual channel volume to produce distortion.-
Bump for a moderator to delete this user and all posts. KyleAdam is a Spambot.

Thank you.
It's weird because he posted about building a #124 in another thread.

I don't have the ability to ban a user which kind of makes me a dog without teeth, I can however delete posts so I will do that.
Tom

Don't let that smoke out!
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Colossal
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Re:

Post by Colossal »

Structo wrote:I can however delete posts so I will do that.
Thanks! Yeah, "it" seems to be able to post semi-intelligently, but it's superfluous, non-value added garbage. Just trying to look legit while advertising for its parent company.
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Reeltarded
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Re: Master volumes.

Post by Reeltarded »

uhoh.. they are onto me..
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
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