Re: [Harp-L] getting high gain... no feedback

[MARK BURNESS <markwjburness@xxxxxxxxxxxxxx>]

In some, unique circumstances, lower mu tubes can let you push the amp harder, 
but the idea that you are pushing the output harder is TOTAL BS, unless you are 
measuring a bigger output voltage at the speaker...even if you are, the 
softening of the sound can still mean that regular mu tubes kick out more sound. 
In most cases output will only be nominally different. Low mu tubes run lower 
plate voltages, which sound less harsh, they also bring down the SE distortion 
component (even order harmonics) which makes amps sound smoother...I'm not 
against their use, far from it, but they deliver a smaller signal to the power 
tubes, which in turn typically distort less at comparable power levels.




________________________________
From: Dane Paul <Monsterharp@xxxxxxxxxxx>
To: Rick Davis <bluesharpamps@xxxxxxxxx>; Harp- L <Harp-L@xxxxxxxxxx>
Sent: Saturday, 30 October, 2010 22:41:57
Subject: Re: [Harp-L] getting high gain... no feedback

To add to this disscussion Most of the amp techs I have disscussed this with say 
the sweeter tones come from the pushing the power amp not the pre hence 
re-tubing the pre with 12-AT 12-AU and so

on and allowing the power amp to overdrive. As well an amp tech that use to work 
with Clair Brothers suggested to run at least one of the Hi Mid or Lo controlls 
on 9 or 10 because most Amps use a cut

circut fo the EQ section. Doing this allows the amp to use all of it's 
potential, Mike you know who I'm talking about. He is our local tube amp 
guru.............Dane Paul


----- Original Message ----- From: "Rick Davis" <bluesharpamps@xxxxxxxxx>
To: "Harp- L" <Harp-L@xxxxxxxxxx>
Sent: Friday, October 29, 2010 12:00 PM
Subject: Re: [Harp-L] getting high gain... no feedback


> Yep, that's the secret:  Turn down your microphone!  A hot mic can send more
> than a volt of power to the amp on loud passages.  That is so much power
> that the amp does not even need its first gain stage... the signal could
> drive the second stage!
> 
> That big a signal overwhelms your input tube, beating it into square waves.
> What you hear is your input tube fighting for its life.
> 
> Turn your mic down, exactly as Michael suggests.  Your tone will be more
> musical and your feedback demons will retreat.
> 
> Custom harp amps such as the Mission Chicago and other fine amps are
> designed to handle the hot signal and there is no need to necessarily
> attenuate your mic.  But with most guitar amps it is a must.
> 
> -- -Rick Davis
> The Blues Harp Amps Blog
> http://www.bluesharpamps.blogspot.com/
> 
> On Fri, Oct 29, 2010 at 7:38 AM, Michael Easton <diachrome@xxxxxxxxxxx>wrote:
> 
>> I C/P'd  the message below from one I sent to the local harp players I
>> network with.
>> I played at our local blues jam last night using the house Deluxe Reverb
>> bought for harp use. (still set up with 12ax7's)  The amp is set on top of
>> the house Leslie speaker at ear level.
>> Read on.
>> 
>> "I tried something different with the Deluxe Reverb last night.  I don't
>> know if it will work for the rest of you because of the polar pattern of
>> your mics. Maybe with Bill's 545 and Daine's  Sennheiser.  I used the
>> Heumann volume pot on my SM57 and a line transformer on the xlr cable.  I
>> plugged into the 2nd input on the reverb channel and cranked the volume to
>> 6. This drives the amp output to play hotter. The 2nd input has a lower
>> gain, so while the amp was outputting hot the input was lowered so as not to
>> force the signal through the amp.
>> 
>> 
>