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Post subject: The Brown Box for vintage amps
Posted: Fri May 29, 2015 1:47 am
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The Brown Box ; to keep vintage amp in original specs for wall input voltage ?

http://www.amprx.net/about.html

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Post subject: Re: The Brown Box for vintage amps
Posted: Fri May 29, 2015 2:38 am
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Very intriguing......I'm interested!

8)

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Post subject: Re: The Brown Box for vintage amps
Posted: Fri May 29, 2015 3:03 am
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Seriously?


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Post subject: Re: The Brown Box for vintage amps
Posted: Fri May 29, 2015 11:00 am
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In looking at the adverts, it is an autotransformer with taps for lower voltages. It is designed around a 5f6 Bassman. So it will be accurate at the current draw of the Bassman. But if you overload it with a Twin or underload it with a Champ, it won't perform as designed.
I have seen B+ voltages on vintage amps exceed their capacitors ratings on power up, but I've never experienced a problem with 125VAC causing problems in a 110VAC amp.
This seems like a solution to a problem that doesn't exist.
But what does it do for tone? Anybody...


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Post subject: Re: The Brown Box for vintage amps
Posted: Fri May 29, 2015 11:09 am
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TimsAudio wrote:
I have seen B+ voltages on vintage amps exceed their capacitors ratings on power up, but I've never experienced a problem with 125VAC causing problems in a 110VAC amp.


I've had a few tube-rectified Fenders cross my bench where the GZ34, 5Y3, or 5U4GB failed prematurely (in each instance they were shoddily-made chicom bottles). After troubleshooting the entire P/S, the only possible cause I was able to proffer was extraordinarily-high wall-socket voltage. Once those marginal tubes were replaced the amp was returned to the customer without further incident.

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Post subject: Re: The Brown Box for vintage amps
Posted: Fri May 29, 2015 4:02 pm
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Post subject: Re: The Brown Box for vintage amps
Posted: Sat May 30, 2015 4:18 am
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All these informations came from my customer I installed zener diodes on its Deluxe Reverb to reduce voltage.

He think about buying this box


viewtopic.php?f=12&t=98981


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Post subject: Re: The Brown Box for vintage amps
Posted: Sat May 30, 2015 6:27 am
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Without a proper, controlled double-blind test I don't believe anything anymore.
The internet (and magazines before that, of course) is full of people waxing lyrical about the stupidest gear (think massive silver fuses, "oxygen-free" cables, refridgerated CDs...) making the sound more "sweet", "smooth", "transparent" and $@!& like that.
It's bad in other fields, too, but audio/music/sound seems to be the worst of them all. The human ear is not a good measurement device to start with, and the stereotypical audiophile character type makes it only worse. Especially if he just spent a lot of money on the gear in question.


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Post subject: Re: The Brown Box for vintage amps
Posted: Sat May 30, 2015 6:42 am
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About all gear and gadget , you can't put them in same basket , it is a case by case .

IMO you can't be wrong if using the right input voltage specialy on old amps which are desing to work at lower wall voltage .

I hear a very big difference with the Deluxe Reverb working at right wall voltage ; 30 volts more than Leo Fender original desing in modern wall voltage .
But fist it is because I want to save NOS 6V6 use in this amp



Read the post I give the like before


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Post subject: Re: The Brown Box for vintage amps
Posted: Sat May 30, 2015 10:21 am
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ChrisH1 wrote:
Without a proper, controlled double-blind test I don't believe anything anymore.
The internet (and magazines before that, of course) is full of people waxing lyrical about the stupidest gear (think massive silver fuses, "oxygen-free" cables, refridgerated CDs...) making the sound more "sweet", "smooth", "transparent" and $@!& like that.
It's bad in other fields, too, but audio/music/sound seems to be the worst of them all. The human ear is not a good measurement device to start with, and the stereotypical audiophile character type makes it only worse. Especially if he just spent a lot of money on the gear in question.


Your observation is noted and, more importantly, valid.

However, the fundamental fact of the matter is that Leo's amps were designed to operate with a primary AC input voltage of 117 volts. Period. And contemporary wall voltages are now 8% to 10% higher than that. The differential does impact the tone of these amps -- the degree of which can often be *perceived* by their owners. That sonic difference is quantifiable though it may be less significant than the assertions of those ad-copy writers who make their living via hype.

Arjay

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Post subject: Re: The Brown Box for vintage amps
Posted: Sat May 30, 2015 11:41 am
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Retroverbial wrote:
The differential does impact the tone of these amps -- the degree of which can often be *perceived* by their owners.

My point exactly. How many of these owners would recognize an active brown box in a double-blind test? And who says the amps sound worse on today's voltage (I'm not denying that it may make a difference)?
People futz around with bias and tubes and speakers anyway. I'm pretty sure anybody can get their dream sound by those convential means instead of blowing 400 bucks on snake oil.


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Post subject: Re: The Brown Box for vintage amps
Posted: Sat May 30, 2015 12:23 pm
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Why do you care?

If the product holds no interest for you then simply walk on by.

Even with my used-and-abused ears (small-arms fire, artillery, jet-turbine helicopter engines, un-muffled muscle car motors, mega-stack rock concerts, nagging SWOMBO, etc etc etc) I can discern the difference between vintage and contemporary wall-socket voltage as it applies to old Fender tube amps.

Arjay

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"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


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Post subject: Re: The Brown Box for vintage amps
Posted: Sat May 30, 2015 12:57 pm
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ChrisH1 wrote:
Retroverbial wrote:
The differential does impact the tone of these amps -- the degree of which can often be *perceived* by their owners.

My point exactly. How many of these owners would recognize an active brown box in a double-blind test? And who says the amps sound worse on today's voltage (I'm not denying that it may make a difference)?
People futz around with bias and tubes and speakers anyway. I'm pretty sure anybody can get their dream sound by those convential means instead of blowing 400 bucks on snake oil.


You may like better the sound with higher wall voltage , why not .
But if you never hear the amp with proper wall voltage , you must listen it before .

Other story ; I had often some customer bring me their amp for very light work like replace a broken power cord .
The amp play very well they said , just the cord .....

When I test the amp I heard it need some fine tuning to play better , just few dollars parts .
After I done that , customer said my amp play a lot better.


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Post subject: Re: The Brown Box for vintage amps
Posted: Sat May 30, 2015 2:39 pm
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UPDATE From this post ; How I fine tune Deluxe Reverb ;

viewtopic.php?f=12&t=98981&p=1120872#p1120872

I just receive a e-mail from my customer ,his Pro Reverb blackface was his favorite amp before he listen his Deluxe Reverb after I fine tune it .

Now he love so much his D R , he will bring me his Pro Reverb .

The greatest change in tone I do is to lowering power supply voltage with the zeners


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Post subject: Re: The Brown Box for vintage amps
Posted: Mon Jun 01, 2015 6:18 am
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Retroverbial wrote:
Why do you care?

I don't know. I guess snake oil is a pet peeve of mine, especially when targeted at audiophiles.


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